80. Fishes, frogs and penguins

 

Tour to Neocene

 

80. Fishes, frogs and penguins

 

Previous chapter
Next chapter

 

This chapter is based on idea of Timothy Donald Morris.

Human epoch was a time of erasing of borders between phyto- and zoogeographical realms. Human activity allowed one or another species of live organisms to cross continents and oceans, overcoming natural obstacles to settling, and rendered thus enormous influence on fauna and flora of various areas of the Earth. In various places of the planets instantly to measures of evolution new species appeared, changing directly or indirectly conditions of life of kinds evolved in strictly different conditions for millions years. One of such kinds settled was the human species itself, and other kinds settled by people represented trade and commercially important species, pets or simply a tribute to whims and follies of intelligent species. After human disappearance not all species introduced by people have died out. Some of them have continued to prosper even without human protection, and their existence changed character of evolution of live organisms cooperated with them directly or indirectly. Results of the changes initiated by people are especially clearly appreciable many millions years after their extinction in places which nature has most strongly suffered from their activity. One of such places is New Zealand, the archipelago isolated from other land bodies by ocean spaces.
The geography of New Zealand has changed only a little from human epoch. Islands practically did not become closer to any continent, and no new islets which could serve as a “bridge” between archipelago and the nearest land appeared near to them.
Snow-covered mountain peaks are reflected in waters of the lake stretched in valley at the Southern Island. The landscape is very picturesque: the valley is surrounded by mountain ridges overgrown with forests, and the highest tops are covered with dazzling white snow. Lake shores are strewn with stones, among which there are some boulders of fair sizes covered with moss and overgrown with lichens of various color and texture. Lake shores are also grown with forest made mainly of coniferous trees. Here majestic kauris, representatives of native flora, still exist, however the significant part of forest is formed by pines, the descendants of the human-introduced plants. Kauri crones tower above the canopy of pine wood and grow lonely or in small groups. From time to time storms bring down centuries-old green giants, and they crush under themselves and break pines, giving open space for growth of bushes and deciduous trees. Deciduous trees also expand in places where ground is too moist for pines – near marshes and along the coast of water bodies. In underbrush ferns of various kinds prosper, undemanding to sunlight, and trunks of trees are covered with a carpet of mosses and lichens. Here and there on trunks the ferns expand also, seized with roots in their bark. Also in underbrush groups of treelike ferns grow – these are relicts of past times.
In the Southern hemisphere there comes spring, and changes are felt everywhere in nature of islands. In mountains snow begins thawing gradually, and the rivers running into lake become deeper, rough and wide. Change of length of light day and a chemical compound of water is felt by lake inhabitants – there comes the time to procreate and their behaviour changes gradually.
Forests of islands are full of life. Even if wood inhabitants cannot be seen, it is easy to guess their presence: from forest to lake shore many tracks lead, worn by large animals.
Terrestrial fauna of islands has strongly suffered from human activity in historical time. In the past its basis was made of various ground-dwelling flightless birds. People have exterminated birds and after that have introduced to the islands the set of various mammals, which make a basis of terrestrial fauna of large animals at the continents. And in Neocene in fauna of islands ungulates, lagomorphs, rodents, marsupials and carnivores dominate – all of them are descendants of the species introduced by people. The features of island fauna has changed forever and only in some places at coastal islets not numerous descendants of native fauna of islands still survive.
The introduced animals have found favorable conditions for life in New Zealand. The climate of islands never was too cold, even if glaciers at tops of mountains expanded and moved downwards the slopes. Influence of ocean strongly softened it in glacial epoch of the boundary of Holocene and Neocene, and in warm Neocene still makes climate more equal and humid, smoothing a difference of temperatures in various seasons. Snow in valleys and at coasts does not drop out even in the middle of winter, but the change of the season is felt all the same: in winter weather is a little bit damper and colder, and days are appreciably shorter.
But winter is already finished, and the sun stays in the sky for longer and longer and all rises higher for every new day. Spring gradually enters the rights though winter weather still makes the revenge at night. In the cool morning on leaves and grass there is plentiful dew. Slight breeze swings branches of trees, and dew falls from them on wool of large animal walking along the track to lake shore. The large deer – buck of New Zealand ultradama – comes to water. It is one of the most impressing kinds of New Zealand fauna of Neocene epoch – an animal of the size of large horse, but built more gracefully. Buck has reddish-brown wool without spots which it has left in due course of maturing, though its ancestor was a fallow deer introduced by people, which kept such colouring for all further life. One more attribute of buck maturity is a mane hanging down as tousle from its neck. But all the same this animal looks not so majestic, as in autumn. The main ornament of ultradama is huge horns with shovel-like expansions on the ends. Old horns had fallen off in the beginning of winter, upon the termination of courtship season, and new ones only have begun to grow – now these are simply small outgrowths covered by velvety skin. To an autumn horns will grow up to the full size, and this animal will become the true king of a local nature. But now it uses advantages of the condition – while horns are short enough, ultradama buck can come into rich wood and it is much easier to it to move now. To the summer, when horns will grow to considerable size, it will come to move in bushes and to put additional efforts to carry such heavy ornament proudly.
Deer buck walks to lake shore using one of numerous tracks. Its hooves tap on stones sticking out here and there from the ground, and this sound, transmitted through the ground and stones, is perfectly heard by underwater inhabitants. In lake there are no the animals capable to attack huge deer, but presence of large and heavy animal frightens inhabitants of lake. Tiny fishes in school have rushed away from the shore and have hided in floating thickets of aquatic fern. It is quite natural to them to be on the lookout and to be afraid of everything – in lake ones hunting them live also.
In shallow water thickets of water plants move, and from lake bottom clubs of silt and partially rotten fallen foliage have risen. From its ambush huge amphibian – neohanasaki – has crept out. This creature is similar to a huge salamander – length of its body is about one and a half meters. And because of it the more surprising is that as a matter of fact neohanasaki is a huge tadpole which will never become an adult one. One group of frogs descending from human-introduced Australian tree frog Litoria has simply evolved in a direction of occurrence of neotenic tadpole, only in part turning into adult individual. The appearing of four-legged caudate creatures capable to breed, not turning to a frog, became a result of this direction of evolution. And neohanasaki represents some kind of apotheosis of development of “adult tadpoles” group.
This predatory amphibian hunted, having dug in dust on lake bottom and waiting while any tiny creature will swim up close enough to its muzzle to be literally soaked up in a mouth, when predator sharply opens its jaws. But the appearing of huge deer has scared away all fishes from the coast, and now the monster has simply nothing to wait here. When deer has lowered its head to water and began drinking, neohanasaki has begun to move tail lazily and has swum away from the shore coast, from time to time pushing from the bottom by weak paws. This predator eats mainly fish, and in lake it still will find many tasty animals for itself.
Lake shores are overgrown with marsh plants giving a shelter to various kinds of birds. It is too early now for hatching the posterity, but birds prepare to forthcoming nesting season, occupying suitable territories and looking for breeding partners for them. After sunrise their muster becomes louder, and from thickets some more new inhabitants of lake appear – mainly ducks of various species. In thickets voices of rails and swamp hens behaving very secretively are heard. The lake has entered the time of its maturity: its shores are covered with diverse marsh and aquatic vegetation, but the features of bogging are not shown yet. This lake has some more thousand years of life ahead before it will turn to the circuit of marshes and finally will be overgrown with forest.
On surface of water, like green foam, small Azolla fern floats, almost unchanged from Holocene epoch. In fact, the presence of this plant in New Zealand flora is one of set of traces of human existence on the Earth. Some ducks include this plant in their diet, constraining its fast growth in the certain degree. In coastal zone, where water is warmed better, Azolla floats like large velvety islets surrounded by duckweed. Sometimes the surface of carpet of this tiny fern waves; it indicates an abundance of underwater life. Many fishes of various species live in lake, and their dark backs flash among floating plants in places where open water stays.
Floating plants represent a fine shelter for fishes: so they are more difficult for noticing from air. Besides on floating islets of Azolla various insects often alight to have a rest; the part of their life cycle passes in water of this lake. And in thickness of fern thickets mosquito larvae hide willingly. Small caddis flies, mosquitoes and midges hover above water, living their fussy short-term lives. And some of their neighbours aspire to make their life even shorter in every possible way.
When the sun rises above and begins to heat hotter, above the surface of lake dragonflies of various species appear. Dragonflies may be sizable frequently, and sparkle in air like brightly colored arrows with metal shine, and some of them in addition display black spots on wings. Their colouring is bright, but these dragonflies are not afraid to be eaten by any bird – their flight is so prompt, that only rare bird will manage to catch them. Damselflies are not so fast; they frequently simply hang in air above the chosen site of water, making short rush to chase any small insect flying nearby. At these predatory insects not only the body, but also wings can have bright colouring, that makes them some of the most beautiful inhabitants of lake.
The demoiselle damselfly, which body is colored blue with metal shine, hovered for a while above water, trembling its transparent blue wings and goggling with convex eyes. It looks for midges, hovering in swarms above Azolla thickets, but it hardly understands, that it became object of supervision itself. Convex eyes watch it from under water, and fins move slightly, moving slowly a streamline predator’s body forward, closer to its prey. Through a small hole in Azolla carpet demoiselle is perfectly visible from under water and it is enough to make one exact rush only.
The carpet of floating fern as if had blown up: in fountain of splashes from water the fish has jumped out, being little bit similar to small pike, with large eyes and lengthened peaked jaws. Jaws have swung open, extended forward as a wide tube and have sharply slammed immediately, but ineffectually: insect managed to fly off at last instant. Fish plopped down in water, and green carpet of floating fern closed above it.
Moving its transparent fins, fish has slowly swum under fern carpet, trying to swim as fast as possible across the sites where through thickets beams of sunlight penetrate in water. Maybe, the sunlight involves other creatures, but this fish at an opportunity of choice prefers to remain in shadow and to expose itself to eyes of the possible prey less often. The fish is named ‘ika-kaihopu, and it is a local species of viviparous fishes, a product of last 25 million years of evolution of the species appeared at the islands according the human will: it is a descendant of the introduced species, of mosquitofish. In human epoch the uniqueness of nature of New Zealand was substantially broken by people, and in Neocene numerous species of fishes inhabiting fresh waters of archipelago are descendants of the human-introduced forms. Evolution has transformed this descendant of tiny and ordinary-looking fish to dexterous and specialized predator. Large convex eyes of ‘ika-kaihopu help it tracking down wriggling mosquito larva in plant thickets, and in this case its lengthened snout with pointed jaw tips works as tweezers. The body of ‘ika-kaihopu is a body of sprinter, capable to make a lightning jump to chase prey. Larvae of mosquitoes and other insects, and also fry of various fishes, settling among floating plants, make only small part of a diet of this kind. The most delicious prey for ‘ika-kaihopu includes flying insects. The dragonfly spending the night carelessly on stalk of plant low above water, or sluggish butterfly brought to the lake by wind represents the desired prey for ‘ika-kaihopu. One jump – and fish overtakes its winged victim. Widely opened mouth of fish turns to a tube at this moment. Body colouring of ‘ika-kaihopu helps this fish to mask among plants – the spotty back is indiscernible on the background of carpet of floating Azolla fern, and greenish colouring of sides helps fish to remain imperceptible for eyes of underwater predators.
‘Ika-kaihopu is only one of many species of fishes inhabiting this lake. And abundance of fish is a basis for successful existence of other inhabitants of fresh waters of New Zealand.
Under water the body of streamline outlines flashes. This is a creature of small size, but it is difficult to descry it against the background of bottom because of dark back. In beams of sun silvery sides of tiny fishes trying to escape it sparkle. Pursuing them, the creature makes sharp turns at the great speed, and then for few moments its snow-white stomach is appreciable. Speed of its movement is great, and its lunges frequently finish successfully: in thickness of water here and there silvery scales turn, falling on bottom – it is the only thing remained from fishes seized by this one. From time to time the creature rises to the lake surface and jumps from water, looking thus like a tiny dolphin, but then dives again.
But soon hunting is finished, and the creature swims to the shore. At the shoaliness covered by the sun its body with peaked mobile head and fins flapping like wings become distinct. Or are they really the true wings? The creature comes up to shallow water, straightens its body and moves to the shore, ridiculously rolling over on short legs. Now the picture is full: it is a very small penguin. Following it from lake some more birds appear. They leave water and hobble along the narrow track to the forest. Some tracks leading from forest to water are made by them and are used by some generations of these birds in succession.
Birds walk on the track to the forest and move now into the fern thickets. For people it would be strange to see these birds in forest, because in memory of people penguins were always associated with the sea. But here these birds obviously feel like very much confidently. They move so dexterously, that only casual moving of fern fronds and hardly heard rustle of leaves under their paws give out their presence. Besides colouring of backs of these birds is grayish-brown, and even spotty at some individuals. It makes birds poorly distinct among thickets, especially for those ones, which like to search for prey from above, from tree crones.
Penguins have gone already approximately one hundred meters deep into the forest, and one of birds has uttered short call. Reciprocal call is heard immediately, and then one more follows. Other birds also began calling, and new voices began answering them. It turns out, many penguins live in forest; they simply became somewhat similar to other forest inhabitants, having learned to be imperceptible when it is necessary.
These birds are New Zealand mountain penguins. Resettlement of their ancestors to these places has taken place in quite natural way – during the global “plankton accident”, directly or indirectly destroyed a significant part of sea inhabitants. Escaping themselves from food shortage caused by “plankton accident”, ancestors of these birds have adapted to life in fresh water, and their survival, as it is paradoxical, had been provided by human activity: the main fodder resource for these birds represents the descendants of fishes introduced to the islands by people. New Zealand mountain penguins settle near the rivers and lakes of both islands and live in small colonies between which there is a certain contact – from time to time by virtue of various reasons birds one by one or in breeding pairs move to the next colonies.
New Zealand of Neocene epoch is a place where it is rather difficult to live to flightless birds and ones nesting on the ground. Islands are inhabited by numerous mammalian predators, descendants of the kinds introduced by people. Some birds, living in this island world changed up to unrecognizability, also have turned to dangerous predators capable to compete in forces with mammals of comparable size. Therefore the skills of shelter building and becoming imperceptible are very important, if somebody wants to survive in such environment. New Zealand mountain penguins have succeeded in art of shelter construction. The colony of birds in forest near the lake numbers approximately twenty pairs and several birds temporarily remaining without partner. At the order of these birds there are about thirty holes dug out among stones and under roots of trees. It is made intentionally to prevent predators to dig out holes – stones and roots complicate this work.
Penguins come back from the lake with stomachs full of tiny fish. One of them even managed to catch rare prey – in its stomach the young individual of neohanasaki curtailed as a ring lays. While these creatures are small, it is not necessary to be afraid of them and even it is possible to eat them unpunishably. And the adult individual of this “tadpole” can easily swallow the small penguin entirely – it is enough only to open mouth in right moment. While penguins gorge on for themselves – the time to brood chicks had not come yet, but already just about to come. Before the nesting both birds of pair need to be fattened well. The care of chicks is the self-denying occupation is taking away lots of energy. Taking care to chicks, adult birds grow thin strongly and live half-starving. Therefore, while there is an opportunity, they try to live for themselves.
When successful fishers return to the colony, from holes their nesting partners appear. Pairs at New Zealand mountain penguins are kept all life long or until one of birds will perish. Breeding partners care about each other gently: they clean each other’s plumage on head and around of eyes, share prey and in common defend the territory against neighbours – it is the ground approximately one meter in radius from an entrance of the hole. Therefore the bird coming back to the hole is compelled to enter the conflict with the several individuals perceiving its occurrence as an encroachment to their possession.
One of penguins, having filled its stomach with fish to the full, walks clumsily to the hole under roots of large tree. But this way is accompanied day-to-day by small skirmishes with at least three pairs of neighbours, and one hole is dug out almost on the way of this penguin. Having reached up to the edge of colony, it has uttered the salutatory call addressed to its female, and it immediately has got out of their hole and has answered to it. Rolling over and having spread wings wide, penguin has bustled to the hole. Jumping over tree roots and falling, it has crossed the territory of one of its congeners while that one has not returned. It also prefers not to stay for long on the territory of amicable breeding pair, because it may be nibbled fairly. And when it passed the territory of the third pair of congeners, its tail appeared in dangerous affinity from an entrance to other’s hole and the female waiting for its male patiently has jumped out and has seized its scanty tail by beak. The penguin has screamed and has pulled, has fallen down the ground, has jumped again and has run, trying to reach its own hole as fast, as it can. Its female, seeing, that her spouse has undergone to an attack, has cried and has begun to clap flipper-like wings, hoping to impress an aggressor. Having reached her, male turned around and they began to cry to neighbour’s female together. It has receded at once, seeing that it appeared in minority, and the conflict has died away as quickly as it has inflamed.
When no more occasions for scandal with neighbours remain, the pair of penguins has exchanged overdue greetings, having touched beaks of each other. After that female, having sat down in front of male, began to stick suppliantly with its beak to male’s beak from below. This action is clear to any penguin busy with chick rearing and means only the wish to be fed. Having pulled its neck for some times, male penguin has opened its mouth, giving the partner an opportunity to pull out prey from its gullet on its own.
Fishing is connected to danger sometimes – large fishes, able to swallow the adult penguin entirely, are found in lake. But on land the number of dangers is not less, therefore penguins should to be on the lookout constantly. Their alarm signal sounds more silently, than a usual voice, but it is distinguished well by the whole colony.
Among the New Zealand forest predators the special place is taken by feathery murderer named ruacapangi. This bird, as against to carnivorous mammals of archipelago, is the descendant of a native kind, and, probably, the presence of small carnivorous mammals had forced its ancestors to join the “arms race”, that had resulted in appearing of this predator. Being a bird, ruacapangi has quite good competitiveness on the background of local fauna of carnivorous mammals, and local herbivore beasts frequently become its prey. It has keen hearing, fine sight, fast feet and strong beak making fatal wounds to small animals.
Ruacapangi, large adult female, wanders in forest. When spring days will become even warmer, it will meet the male and will begin nesting. But now it hunts only for itself. Morning hunting appeared not too successful – ruacapangi tried to prey any rodents, but no one attacks had been crowned with success, and it had to peck up several beetles and one small frog to satisfy its famine for any degree. Sense organs help this bird in search of prey, and it receives enough information to understand who is around of it in forest. Somewhere in branches above the head of bird rustle of feathers is heard – its constant satellite of the last autumn and winter, eagle kea keeps it up. This carnivorous parrot managed well, eating up the rests of ruacapangi’s prey, but it was the true helper of this bird, more than once guided it right to possible prey. The connection of these two birds is still strong, and the parrot does not miss an opportunity to feast on the rests of prey of its strong patron. In spring the vegetation becomes denser, and the number of insects and other smaller animals grows. Therefore life of many medium-sized inhabitants of New Zealandian forests becomes easier, and there is a great probability that somebody of them will simply lose care, having been carried away with search of food. And then the predator will not miss the chance.
It is very simply to find a colony of New Zealand mountain penguins: it is enough to stand silently in forest and to listen. Being not frightened, these birds call very loudly, establishing their relations, or simply communicating with each other. Ruacapangi female already tried to hunt these birds. It does not like taste of their fish-smelling meat, but it is an easy prey, if penguins are taken unawares. And each individual ruacapangi perfects such skill during all its life.
Ruacapangi has easily distinguished among forest noise voices of penguin colony. Having slightly inclined its head to one side, the bird has listened, and then directed to the colony by silent step. Eagle kea watching it from trees has guessed upon the bird’s behaviour that it has found out possible prey, and has simply stayed where it was, expecting in case of ruacapangi’s success to join its meal later. But now its presence itself may be alarmed for possible bird’s prey and break up the hunt.
Ruacapangi puts feet on the ground very cautiously, and the wood litter almost does not rustle under its toes. The bird steals cautiously to the colony of penguins, having bent down and having extended head and neck forward. After each step it listens and freezes on the spot if voices in penguin colony suddenly began to sound a little bit silently, than up to this moment. Ruacapangi moves forward very cautiously, but it can not take into account all circumstances which can prevent its hunting. And thin twig, having crackled foully under its foot, discontinued all spent efforts instantly.
The crunch of twig is too sharply distinguished from the background of forest noises, and an alarm signal in penguin colony became an answer to it. Voices of penguins at once have ceased and ruacapangi has heard only footfall of small legs on the ground, and then at the place, where some seconds ago birds cried loudly, the silence fell. All insignificant conflicts appeared forgotten at once, and strictly protected borders of territories as if disappeared. All birds have instantly hided in holes and have broken off. While penguins do not nest, some individuals have simply got into another’s holes, but in the face of the common danger hole owners have not paid attention to it. Birds keep silence and even have instinctively dropped to the ground to hide their presence. And in silence they have heard sounds of steps – of long steps of very large creature. And also the noise of wings of another creature is heard.
In penguin settlement ruacapangi walks and at the edge of colony of penguins on the ground eagle kea stands and observes of its actions. Penguins behave so silently, that from the side it seems, as if their colony has died out. While it is difficult for bird to make a choice – both empty holes and holes in which birds are hidden differ from each other in nothing in its opinion, while penguins sit still. Therefore ruacapangi simply wanders randomly from one hole to another, listening and scratching the ground by claws from time to time.
In one hole at the edge of the colony at once three penguins wait through dangerous time – breeding pair which possesses the hole and male appeared in this hole by the will of fate, because this one lives at the other side of the colony. In usual life these birds met each other a little, but now they appeared in immediate proximity from each other. And two males have not found anything better than to begin to establish their relations. Newly arrived male has simply seized by beak feathers of the male owned the hole in order to force it to move aside. From unexpectedness attacked male had cackled shortly, and this sound was heard.
Ruacapangi has instantly defined, from what hole this short silent sound was heard, and has reached it in two long jumps. But it was only the easiest part of its task. Penguins are masters of construction of fortifications, and the predatory bird has learned it to the full. The hole is dug out intentionally near the big stone and is directed right under it. Ruacapangi has listened for a while, and then has tried to dig out a hole, scratching the ground by claws. But it had not succeeded to reach the success even a little bit: stones are placed deep in the ground and are too heavy for this bird to shift them from their place. Eagle kea, having seen than its patroness has become interested in something, also has approached to the hole and has glanced into it, but has run off aside when ruacapangi began digging out the ground again. The only thing that it was possible to it to lay after approximately ten minutes of persistent work was to turn out a small stone from the ground. Larger stones are too heavy to be removed; therefore dwelling of penguins is almost not touched as a whole. Ruacapangi is tired fairly while attacking an underground fortress of penguins, and it would not like to continue unsuccessful attempts to reach the hidden birds. Therefore it simply walks here and there on territory of the colony, turning head to any noise and hoping to profit by any casual prey. Penguins have stood in holes. Only due to alternation of light and shadow and due to quiet sounds from the surface they can guess what takes place near the entrances of their holes.
Eagle kea did not begin to recede so quickly. Its size allows it pushing head into the hole, and it does not miss an opportunity to check up a hole of penguins left by ruacapangi. Having stolen up to the hole cautiously, it has pushed head inside and has clicked its beak in darkness. The hole appeared much deeper, than parrot expected, and its beak has not reached any aim. The stranger penguin has nestled against earthen floor of hole: the beak has not touched it, but has clicked in dangerous affinity from its tail. Eagle kea has obviously decided to stay here for long: it has pulled head out from hole, has darted a glance at ruacapangi wandering at the opposite edge of the colony, and then clambered into the hole again. And at this moment the penguin appeared in another’s hole has decided to act: it turned around in hole, crept along the wall of hole and has seized plumage on eagle kea’s head by beak, right near its eye. Crying loudly, the predatory parrot has pulled its head out from a hole. Fair flock of plumage appeared ripped out at it, and from the wounded skin blood leaked.
Ruacapangi has hardly paid attention to problems which its hunting partner has faced. It lives for itself, and this parrot is only a part of world around, not better and not worse than all the rest. Therefore ruacapangi simply is not going to react to its problems.
The attention of ruacapangi was involved with rustle in ferns. The bird has raised head and has looked round, trying to detect a source of noise. It noticed how in fern thickets among trees some fronds shudder and move. And noise is heard therefrom. Ruacapangi has made some fast steps aside a source of noise, and began to peer into thickets. One penguin simply has not had time to hide in hole and has hidden on the ground. Due to colouring of back it is invisible among wood dust when stands motionless. It has noticed in proper time that ruacapangi moves towards it, therefore has simply lain on the ground, hiding its white belly, and freeze. The endurance of the penguin can be envied: ruacapangi, huge in comparison with it, passes almost near to it, having almost touched the penguin with its claw. Despite of it, the penguin keeps immovability up to last moment. Having looked round, ruacapangi made some more some steps and has returned to the colony. The penguin can not remain motionless for long: it is the great probability of being found out and seized nevertheless. It also will be not possible to hide in colony for the bird: the voice of eagle kea, which also will not miss an opportunity to attack it, is heard there. Therefore the penguin makes the desperate decision: it stands and rushes to water at full speed.
Ruacapangi has turned back in direction of rustle and has seen fern fronds shuddering: someone small will get away from it, being hidden among plants. The intelligence of this bird is not so high; therefore its response is predicted: ruacapangi has rushed to chase it not trying to understand at all, what creature is pursued. Prey is hardly visible under ferns, but it is obvious that it is someone small for ruacapangi to cope with it easily. The penguin has advantage: it has low growth, therefore ferns hide it, and from height of ruacapangi growth it is poorly visible. The large predatory bird should stop to understand, where the penguin pursued by it runs. Penguin easily changes the direction of run, forcing long-legged bird to reduce speed of run on turns. Besides the penguin perfectly sees road on which it is running, and ruacapangi does not notice roots of trees, coiling on the ground. And during one lunge ruacapangi has simply stumbled over the root and had broken claw tip. Not wasting time, penguin crossed the zone of thin forest, where ferns do not grow any more, and has directed to lake shore. It is tired strongly and runs with what is left of its forces. Rates are not equal in this struggle of predator and prey: the predator loses only some food, but prey in case of loss will lose its own life. Therefore the penguin has directed right to the water. Behind its back footfall is heard: ruacapangi runs closer and closer to it. Some seconds will decide everything, and the penguin is going to win the time. It has rushed to water and has dived. Having jumped out to the lake shore, ruacapangi has seen only thin chain of air bubbles marking its way under water. Having come up, the penguin has looked round and has seen ruacapangi running along the shore forth and back, obviously trying to guess where the pursued penguin will appear. Having seen it, the predatory bird has bravely come in water and has made some steps on the bottom. But here it is not in its element, but the penguin feels like very much confidently. Having seen that ruacapangi comes nearer, the penguin has simply dived and in some seconds was put out from water already in deeper place, farther from the shore. Ruacapangi has made some more steps, and water has already wetted feathers on its stomach. Having pecked the thickets of Azolla fern floating on water surface, ruacapangi turned around and dragged itself to the land. Having got out on land, bird has shaked feathers and has walked back into the forest. And among branches the silhouette of large bird has appeared – eagle kea has decided not to lag behind the predator yet, even if now it was unlucky.
The penguin has cautiously swum up to the shore, has emerged among floating plants and began to look around, trying to estimate the degree of the danger. Having convinced that ruacapangi went off, it has got out to the shore, sinking in stalks of coastal plants, and has rushed to the colony at full speed. Now it just got lucky, but nobody can know, as far as successfully there will be even a next day of its life.
Penguin is lucky now, but it also happens, that predator is onto a good thing. Nevertheless, penguin colonies near the rivers and lakes of New Zealand exist stably enough, and sometimes even prosper. This is promoted in great degree by abundance of fish in fresh waters of islands, which became possible also due to human activity in historical epoch. Various kinds of fishes, descended mostly from the species introduced by people, are found in lake. Among fishes of New Zealand there are also descendants of native fishes and the species settled in the rivers and lakes of islands already after the end of human epoch. But the number of such species of fishes is insignificant.
New Zealand mountain penguins have good appetite, despite of their size, and go to fishing one or two times per day, depending on their luck in previous case and the degree of hunger of the other bird of their pair. They obviously prefer to hunt in group of congeners – this way it is easier to chase small fish, which they eat, and to cut off the ways to escape.
The group of five small penguins has left colony and has gone to lake. Walking in forest, these birds prefer to keep secretively, trying to hide from eyes of possible predators. They choose a way among fern thickets, hiding under lacy plant fronds. Plants feel the beginning of spring, and in the middles of last year’s rosettes of ferns clusters of young fronds, turned to sappy hard green spirals have already appeared. But every day the sun will heat stronger and shine longer a little bit, and thickets of ferns will be decorated with fresh greens, providing penguins with good shelter from extraneous eyes. At the forest edge thickets of ferns thin appreciably, therefore penguins should behave more cautiously. They run in group from one tree to another, looking round for a long before making the following dash. And at the lake shore they run, not stopping, and at once dive into water.
Under water penguins swim and flap wings, as if in flight. They gather speed quickly, swim under thickets of floating plants and jump out of water already far from the shore, like tiny dolphins, and their wet backs shine in sunlight.
Having caught their breath and having made a deep inhalation, penguins almost simultaneously dive and begin their hunt. They prefer to swim at the depth of about two meters that is rather deep for such tiny creatures, but allows coming nearer to prey, being almost unnoticed – brownish backs of birds are almost invisible on the background of lake bottom.
Penguins perfectly distinguish their prey – school of small fishes feeding on tiny planktonic crustaceans at the surface of water. These fishes are New Zealand eversmolts, descendants of the human-introduced trout. As a matter of fact, this species is dwarfish trout migrating for spawning to mountain streams. It has kept the adherence to clean water rich in oxygen, characteristic for its ancestors, and prefers to keep in mouths of the rivers flowing into lake. Here water is cooler and also richer in oxygen. Here spring changes in nature are felt especially clearly: when snow thaws in mountains, eversmolts feel changes in chemical compound of water, and it serves as a signal for them for the beginning of preparation to spawning.
The mouth of the river has become overgrown with rich thickets of pondweed. Due to creeping rhizomes and long roots this plant firmly keeps for the bottom and can maintain a current of river running into lake. Long stalks of pondweed, covered with numerous leaves with a pinkish underside, wave in current, serving as fine shelter for New Zealand eversmolts. Colouring of this small fish helps it to remain imperceptible in the world full of predators. Out of courtship season males and females of New Zealand eversmolt are colored in similar way: they are silvery with black marble pattern on sides. If such fish hides in plant thickets, it cannot be noticed.
The school of eversmolts keeps near to pondweed thickets. From time to time fishes dart into thicket of plants in searches of insect larvae and others small invertebrates, but then come back in open water. Some fishes swim near water surface, and among leaves floating on surface their spotty backs flash. When certain tiny moth has flown by above the surface of water, from thickets some eversmolts have jumped out one by one, following it, but no one of them manage to catch it. In the beginning of spring the number of flying insects is low, therefore those few individuals that fly above water serve as an object of steadfast attention of underwater hunters. But eversmolts obviously do not suspect that hunters for them are already close.
The group of New Zealand mountain penguins has simultaneously emerged to inhale, has synchronously dived and has swam to pondweed thickets along the lake shore, hiding in shadow of floating plants. They already have well fulfilled strategy for hunting of cautious eversmolt. The fish is quick; therefore, if it would disappear in thickets, it would be impossible to be caught. Penguins have inhaled air once again, have dived and have rushed to thickets. Birds do not try to attack fishes, even if they see how the lengthened bodies of eversmolts flash near them and their scales shine. Penguins simply drive fishes from their shelters, not giving them any opportunity to return there. The round-up of penguins has gone right: from thickets some young ‘ika-kaihopu fishes darted, and they were followed by the whole school of eversmolts. All fishes are frightened and instinctively gather to the common school. Even ‘ika-kaihopus nestle close to eversmolts, trying to hide in their flight. In few seconds from thickets their pursuers have appeared and hunting has proceeded. Penguins drive fishes away from saving thickets, cutting off the way to escape. From time to time any birds rises to water surface, inhales fresh air and rushes to the center of fish school. If the rush finishes successfully, bird swallows prey right on the move and continues hunting, but now as drover and its place is occupied by another individual.
One ‘ika-kaihopu fish has tried to avoid the fate prepared for it. It has escaped from the congestion of eversmolts surrounded it, and has jumped out of water, having disappeared from the field of view of penguins. Maneuver has gone right: it has plopped in water far behind the pursuers and has rushed immediately to thickets, moving by zigzags. In beams of sunlight the scales on its sides flashes, and these short-term flashes only confuse possible chasers. But penguins do not pay attention to one fish managed to escape: the main prey is here. Penguins continue hunting, preventing the spread of eversmolt school. They eat small fishes one by one, not giving them any opportunity to escape.
Saving thickets have remained far behind, and the bottom is far in depth now. Eversmolt school keeps right under the surface of water, and each fish tries to hide behind the bodies of congeners. Some fishes jump from water, but it does not help them – they inevitably return to the water, where they are attacked by penguins.
The birds keen on hunting have not noticed, that splashing of eversmolt school has drawn attention of one more lake inhabitant. In thickness of water the silhouette of large fish – monster of about one meter long – appears gradually. This lake inhabitant has large head, and body rises behind its nape like high hump. This fish tries to not give out its presence: having noticed eversmolts and penguins hunting them, it has only dived deeper and began coming closer cautiously to the place of a drama. One penguin, having caught and having swallowed one eversmolt, has dived to help its relatives to keep school of eversmolts captive. But during the dive it has noticed absolutely casually, how weak sunlight has flashed in the eye of large fish. The penguin has rushed to the surface, breaking the hunting formation of congeners, has made a long jump above water, having inhaled air, and has rushed away. Its panic has disturbed other birds; they began looking around, and one bird has noticed under itself cross-striped back of huge fish. Not waiting while the fish will start an attack, penguins have rushed away. Keen on hunting, they have swum too far from lake shore, and now their lives are threatened with real danger.
The monster has waved its tail and has rushed from depths to water surface, right in the middle of eversmolt school. The wide mouth with pointed teeth has swept open, and one eversmolt has disappeared, being sucked into the mouth of fish with a stream of water. Eversmolts have rushed every which way, and at the place where their school rushed some moments ago, under the water surface the large striped fish swims. It is the largest species of fishes in this lake – ‘ika-taikaha. Vertical stripes on body, spiny fins, humped back and predatory habit of life are the features inherited by this giant from its ancestor – European perch introduced to New Zealand from Europe in historical epoch. The creature formed in conditions of struggle for existence in rivers of its native land has got accustomed well in new place, and in the subsequent millions years has undergone very few changes. Actually, ‘ika-taikaha is simply a perch of huge size. It has “twin brother” in far Venedian Lake at the north of Europe: both species independently from each other have got out on top of food pyramid in their habitats.
‘Ika-taikaha is a gluttonous predator not disdaining any prey – it is enough for it only to squeeze into its gullet. And small eversmolt does not satisfy famine, and only works up an appetite. The penguins scared by appearing of this monster, try to move off its way as quickly, as they can. Desperately flapping their wings, they are swimming away, keeping near the surface of water. By their size these birds are just suitable for a role of dinner for ‘ika-taikaha, and it seems, fish is going to catch for dinner something larger than small fish. Moving tail and having lowered its back fin, ‘ika-taikaha rushes to chase penguins seeking safety in flight. It has chosen one of birds lagged behind others for its attack, and now its attention is concentrated on this prey.
To escape, penguins need to reach the shore – while depth is enough for swimming for ‘ika-taikaha, they can not feel like in safety. It seems, the pursued penguin has guessed, what may be its fate, and tries to escape desperately. It jumps from water like a dolphin, inhaling air and simultaneously gathering speed of the movement. This tactics brings the result: the huge fish lags behind, as it is not adapted to a long pursuit. And saving thickets of pondweed in mouth of the river, flowing to the lake from mountains, are closer and closer. Desperately flapping its wings, the penguin, as if a bullet, ran into thickets of underwater plants and has disappeared from the view. Making the way through thickets to the land, penguin has not noticed a striped fish side next to itself. It has hastened to the shore, but its movements have frightened away one more fish – young ‘ika-taikaha, longer a little bit than the penguin.
As against the adult individuals patrolling open water at some distance from the shore, young ‘ika-taikaha fishes prefer to live in shelters. To hide better, young individual of this species has more contrast cross strips and expressed greenish background colouring of body. Scared by sudden occurrence of the penguin, young ‘ika-taikaha has rushed away from thickets, and faced nearly face to face the adult relative pursuing that bird. The mouth of the giant has opened almost automatically, and the next second pointed teeth stuck into flesh of young fish. The tail of prey pulled some time in spasms, and then the adult ‘ika-taikaha has opened its mouth a little bit wider and has accurately pushed prey into the gullet. The feeling of satiety has brought peace to the huge fish. Moving its fins lazily, the adult ‘ika-taikaha turned around and has swam away into the depth. Fish even has not paid attention to young neohanasaki rushed away from the bottom in cloud of silt at its approach. The fish returns to its territory in order to have a rest on the bottom in favourite hole and to devote some days to digestion of its prey. It is too cold now to search for the breeding partner, and it is still possible to lead the same slow and measured life, as in winter.
Spring inevitably wins from winter the positions in nature, and the change of the seasons is more and more appreciable every new day. Spring days become longer, the sun rises higher and heats hotter. Snow at mountain tops thaws and the rivers running into lake turn to rough streams. Chemical characteristics of water change – it becomes fresher, more transparent and richer in oxygen. Plants react to increase of light exposure by intense growth; therefore stones in mountain streams exposed to bright sunlight are overgrown by greenish film of microalgae. And the abundance of food stimulates breeding of small animals, which turn prey to larger inhabitants of mountain streams and rivers. Larvae of mayflies, midges and mosquitoes scrape algal film and eat microscopic worms and protozoans settling among microalgae cells.
Largest ones among permanent residents of mountain rivers after the beginning of spring also became more active and they may be frequently noticed on stones overgrown with algae. Large creatures of brown color with black longitudinal strips stretched along each side of this animal attach to stones among whirlpools. Their lengthened bodies wriggle in current, and the sucker mouth on the bottom side of flattened head allows keeping firmly on smooth surface of stone and to resist to current. They resemble fishes very much, but at close look one strange feature of their shape is found out: they do not have paired fins – pectoral and abdominal – and in fin plica bordering body and tail fin rays characteristic for fishes are not present. These creatures are not fishes at all, but tadpoles of local rangitahi frog. It is one more masterpiece of evolution of tailless amphibians in the rivers of archipelago. Rangitahi frogs spend some years in condition of a tadpole. It allows them to use the food resource inaccessible to adult individuals – microscopic aquatic animals and unicellular algae. The low temperature of water in rangitahi tadpoles’ habitat slows down the metabolism and allows them to be content with a small amount of food; therefore in every mountain stream rangitahi tadpoles are rather numerous. Among them there are individuals of various ages – from tiny creatures hatched in previous spring up to large individuals about 25 cm long. These are the five years old creatures ready to transformation to adult frogs in the nearest future.
Tadpoles are among the largest inhabitants of mountain streams. They cling to stones by oral sucker and leave behind only clear paths in algal films. Each tadpole protects the territory zealously, not permitting relatives to swim to it. If it is necessary, it will drive strangers away from the territory by impacts of sides and tail.
The most plentiful algal epibioses are formed on the top side of stones, which is only slightly covered with water. In addition the current is not such strong here, and the spring sun warms well. Therefore, when water in streams rises and covers the stones, which usually stick out from water, tadpoles move to such places for feeding. But it is the great risk, and they should be cautious: nearby there can be predators, and the meeting with them does not promise anything good to any creature not able to be protect itself actively.
Large tadpole about four years old crawls on the surface of stone. Here algae form moss-like layer which it eats with pleasure. If the skin dries up in wind, the tadpole reaches a deepening on the surface of stone with sharp movements of tail and pours sparks over itself, and then continues scraping algae. Its small unblinking eyes look indifferently upwards and in sides. Its way of life is primitive and simple, and it does not need to express the feelings and emotions for survival. It simply eats, simultaneously keeping up the occurrence of possible danger.
It is no need to wait for it for a long: danger has found it itself. When the shadow swooped above the surface of stone, and the sight of tadpole has distinguished quickly moving black spot on light background of sky, reaction of animal was predicted and automatic: having waved tail here and there, the tadpole has scrambled along the stone, has fallen down in water and has immediately stuck to lateral face of stone in a shadow.
The black wings flashed in the sky belong to New Zealand false raven, one of widespread birds of New Zealand. Like many species living at these islands in Neocene epoch, this bird is the descendant of the introduced species, of rook. And in shape of bird its relationship is guessed: the adult bird has white beak clearly visible on background of black plumage. It is the large adult male, its wingspan reaches 160 cm. Near to it the female keeps, not making a concession to it in size – it is a breeding pair united for nesting some years ago and not leaving each other since that time. Success in a survival of New Zealand false ravens is provided by family features of corvids – by high intelligence and ability to learning and storing of the information. Both these birds keep in minds great life experience and skillfully apply it in search of food and protection against enemies. They know many receptions of hunting for various small animals living in New Zealand, and remain hungry for night seldom. And these birds had been involved to the stream with an opportunity to catch small invertebrates and even fish in case of luck. Rangitahi tadpoles also represent quite good prey; both birds of this pair are able to catch them and taste of soft meat of these creatures is well familiar to them.
Female perched on stone sticking from water and began peering steadfastly into the stream. Among the puzzle- work of gleam and shadow at the bottom and flashes of sunlight on water surface it managed to distinguish body of one tadpole extended motionlessly. It has attached by sucker to the stone and keeps an immovability, hoping thus to wait danger. But the hunter nevertheless is more artful, than its prey: having convinced by that prey is recognized correctly, female of New Zealand false raven by single fast movement has dipped head into the water, has seized tadpole’s tail by one exact movement, has pulled out it from water and has strongly struck against the stone. When prey has stopped pulling, the bird has pressed it by paw against the surface of stone and began pecking it.
Other rangitahi tadpoles were hid quickly. Some of them have simply rushed to middle of stream channel, where it is deeper and it is more difficult to get them. Some more tadpoles have swum away under the edge of stone and have stuck to it from below, having squeezed into narrow cracks. Male of New Zealand false raven was late a little and it would hardly catch prey as easily as female has made it. Of course, it has tried to take away prey at female, but she stopped his attempt by loud cries and menacing display. After that she has seized the rest of prey and has swallowed it entirely, knowing, that her partner in life, probably, would try to force her to share prey once again. When after the caught tadpole only some spots of blood on stone remained, male had an opportunity only to flutter to the next stone and once again to try to catch dinner for it independently. It has seen how one tadpole darted away under the stone on which it stands. Male raven walked to the edge of stone and took a look in water by one eye. It managed to discern the tip of tail of rangitahi tadpole which has begun to move and has passed out of sight immediately. Male raven decided to try to seize this tadpole. It has quickly put its head under water, has run slightly opened beak over the bottom edge of stone and at once has pulled out its head from water. The first attempt has not gone right, but it obviously has not stopped the raven. It has an experience in getting various small animals from their shelters – it is possible simply to stick into such shelter something long and thin to force prey to leave its shelter. It has flied up and was landed on the ground. Strolling in growing grass, the raven has seen some dry last year’s stalks of the grasses, just of the necessary length, straight and strong enough. Having seized one stalk by beak, the raven has loosened it and has pulled out from the ground. Its female has expressed clear interest in manipulations it makes. The raven has returned on stone under which rangitahi tadpoles are hidden, has put the found stalk on stone, and then has taken its tip by the beak, has put its opposite end under stone and began to move it there. Female has fluttered on the male’s stone, has approached to it and began peering into the water steadfastly. The scared tadpoles, escaping from the enemy never seen before, have rushed out from under stone. Male has not had time to let out a stalk used to frighten prey, and female has already seized rangitahi tadpole and has stunned it by impact against stone. But this time, however, it was not possible for her to take advantage of fruits of her own success: male let off a stalk, has pushed her away inconsiderately and began pecking prey itself.
The pair of ravens is too keen on hunting for tadpoles, therefore birds have not noticed, that they became an object of steadfast attention of one more predator. And not birds, but their hunting successes interest it so much. Having seen, that birds have begun eating something, the predator has left its shelter and was directed to them. It is not large in size, but thickset and has strong constitution. Moreover, only one animal can have such characteristic black “mask” on white muzzle – it is New Zealand unbadger. This furious predator is the descendant of ferret introduced by people in historical epoch. Because of such animals and their relatives at the islands of New Zealand there are no flightless birds in Neocene, with the exception of ruacapangi, and New Zealand mountain penguins had to transform their holes into fortresses.
New Zealand unbadger does not try to hide from ravens’ view at all. It began skipping from stone to stone, coming closer to birds and their prey with each skip. Thus it behaves deliberately defiantly: opens mouth and shows its teeth, lifts up tail to back, making the tuft of white hair growing on it especially appreciable, and growls loudly. Seeing its approach, the couple of ravens has displayed protective pose: they have slightly stretched wings, have slightly bent down heads and have fluffed up feathers. On background of black plumage their white beaks look especially impressively. Threat is supplemented with loud croak of both birds. Unbadger has stopped on the next stone, at the distance of one jump from birds and their prey. Ravens have obvious tactical advantage: they can fly up and simply push this predator in water, having forced it to take a cold bath. But unbadger wins in using of brute force, because it weighs much more, than both birds taken together. Its chances to make use of prey of ravens are rather great, and it is not going to recede. Seeing it, birds have flied up and began to attack it in common, trying to peck the contender in head or back. The beast should defend itself, opening mouth wide and growling threateningly. It has managed to snap tip of wing of one raven, but the bird was escaped, having left just two feathers in its teeth. Having received strong impact of beak in back, unbadger has risen on hind legs, balancing on stone, and has prepared for fight its clawed forepaws. But ravens also know some tactical tricks, and silly beast is easy to deceive. Male raven began simply to fly above the muzzle of predator, observing, however, a safe distance and distracting the unbadger’s attention to it. And female has flown behind the beast at this time and at the most improper moment has rushed on unbadger with the whole weight of its body, having simultaneously put strong impact of beak in predator’s hindhead. Having lost balance, unbadger plopped in cold spring water and fast current has carried it away. Beast is wounded: on its head skin is slashed by impact of bird’s beak, and from the wound blood exudes. Another’s prey appeared too expensive for it: beast managed to get out on the ground only in several tens meters downstream. It had shaked the wool, had smelt air and moved into bushes, stepping clumsily.
When predator had been carried away by the river, ravens have lost any interest to it. Male has returned to the interrupted meal, having given the female the right to catch prey independently while it is sated.
With the coming of spring in the colony of New Zealand mountain penguins preparations for nesting begin. These birds, like New Zealand false raven, are monodins, though their behaviour, certainly, is much simpler, than at ravens. The finally formed pairs of birds keep amicably, trying not to separate. These are the partners which have finally made the choice for the benefit of each other. At such birds, got used to each other and showing some kind of “psychological compatibility”, nesting and rearing of posterity passes much more successfully, than at the birds formed breeding pair for the first time and not too suitable to each other in temperament. But sometimes external circumstances interfere with family life of penguins and then the settled pair ceases to exist. Such small birds have too many enemies, and sometimes some penguins do not return to native colony.
Adult penguin female wanders alone in colony, looking around and from time to time uttering loud advertisement call. During two previous years it has a breeding partner; birds enjoyed life together, shared food, built and repair hole, took care on posterity and defended chicks against enemies. Now life has turned another side to this bird: female is a widow, though, probably, it does not realize it yet. Yesterday her male had not returned from fishing: chasing for fish, it has swum away too far from the shore and large ‘ika-taikaha has successfully taken advantage of the hunting opportunity occurred. Female does not know it and does not lose hope yet to meet him – wandering in colony, she looks in another’s holes, calls and listens attentively to voices of neighbours, aspiring to hear the answer to the appeal. But, unfortunately, in chorus of voices of her congeners there is no that voice she wants to hear.
Within several next days this female calls her male less often, and is gradually restrained with the status of the single bird. In her present status of widowed female there is one more important circumstance determining her relations with other birds of the colony. This female is “a wealthy widow”: she still owns a good hole close to the protected center of the colony. While she made a pair with her male, both birds could confirm the rights to the hole, giving the coordinated repulse to neighbours. But now she is alone, and neighbours understand it not worse than she does. When widowed female leaves for fishing, neighbours already gradually begun inspect her hole. In their idea if nobody protects an entrance to the hole, this hole is free to settle there. Two pairs of neighbours come freely to the territory of lonely female and look into her hole. They do it cautiously, as if expecting, that the second bird will jump out suddenly from the hole and will rush on them. But nothing happens, and neighbours gradually turn brave. However, one pair has quickly left from the number of applicants for new dwelling: the second pair of penguins appeared both more amicable and stronger. When lonely female comes back, they still move aside, but do not miss an opportunity of breaking borders of territory around of her hole in a pointed manner. The closer the nesting season, the more critical is “a housing problem”, and more actively neighbours of widowed bird try to solve it. Next day male from neighbour's pair simply got to her hole and began pinch the hole owning female by beak. She has managed to defend against him and to expel the impudent aggressor from her hole, but soon she had to leave a hole just to catch some fish for herself.
Having returned about midday, female has found out that on her territory neighbour male perambulates, meeting her with aggressive scream and obviously not going to return to his territory. But one more occasion for anxiety became the head of neighbor female appeared from her hole after male’s call; nobody knows how much time she managed there. When lonely female has tried to get into her hole, being her property even in the morning, she has met furious repulse from the side of impudent usurper. Having find shelter in hole, her former neighbor female began crying and pecking her, not letting the former owner of hole to come inside. But, maybe, the hole usurper understands, that while her rights in property are too illusive, and at approximately equal forces she shows features of uncertainty: her voice sounds more silently, and she tries to avoid fight and recedes deep into the hole. But male comes to help her: he gets involved in conflict and begins pecking lonely female, and then simply pulls her by the tail from hole entrance. Encouraged by such support, his female also has gone over to the offensive. Together they have easily driven away lonely female from her hole. The taking of her habitation is completed and now her troubles were increased in addition – she does not have a shelter anymore, therefore, if now any predator like ruacapangi or unbadger would attack the colony, she is doomed. Certainly, she can hide in another’s hole for any time, but she would be expelled at once, when danger would pass. In her present situation not only success in nesting in this season, but also her own life appears under threat.
And life of other creatures proceeds. Snow in mountains of archipelago thaws actively, and the river running into lake, has overflown banks, and the chemical compound of it is changed a little in comparison with the condition in winter. Changes in chemical composition of water determine life of aquatic animals in many respects – using them underwater inhabitants feel change of seasons in the greater degree, than using the temperature of water. The flow of fresh and rich in oxygen water is the powerful initiator of courtship behaviour of eversmolts. Cautious fishes begin preparing for arduous travel, which culmination will be spawning in mountain streams. Maybe, for some of them this travel will be the last one in their life – many difficulties wait for these small travelers at their way to spawning areas. Like their ancestors, eversmolts remember a smell of native stream and will aspire to spawn eggs in the same place where they hatched.
Before the forthcoming travel eversmolt males have already started to change, as if trying on the courtship dress. Their shape varies not as considerably, as at salmons of human epoch: at them hump does not grow and jaws do not bend, but the colouring changes only. Within several days males differ from females appreciably: background colouring darkens at them, and on this background pinkish spots appear. But these are only weak signs on the further magnificence which will be shown to the full only at the spawning area.
Eversmolts gradually cease to hide and gather to schools in mouth of the river. They prepare for spawning and at this time do not pay attention even to predators. New Zealand mountain penguins use short-term availability of the favourite prey to the full. They pierce through schools of eversmolts as if bullets, but fishes do not rush to the shelters even if the congeners next to them appear in beaks of birds. The loss is compensated by arrival of new schools from other parts of lake during several next days. Schools of fishes unite gradually, and penguins already are rather afraid to come nearer to this huge live mass: they cautiously swim near to many thousands congestion of fishes, seizing only the individuals strayed from a main bulk of relatives.
At last, according the invisible signal understandable only to fishes themselves, eversmolts at once leave a river mouth and move to spawning areas. The school of eversmolts enters the river, as if a rain cloud. New Zealand false ravens, herons and other feathery lovers of fresh fish hover above the river and have an opportunity to observe with their own eyes this magnificent show. Birds do not miss an opportunity to fish: they land on stones along the riverbanks and at the shallows, and almost at random peck fish swimming in dense school. Eversmolts rush away and try to swim to the depth, but the density of school is those, that one fish is immediately replaced by another, and the beak of the successful fisher all the same overtakes the prey – if not this, so the next fish. But what such destruction of tens and hundreds fishes means compared to tens of thousands of survived ones moving for spawning?
Travelling in the river, eversmolts meet other representatives of freshwater fauna of New Zealand. In the lower reaches of the river benthonic layers of water are occupied by other fishes – by native thick-lipped carps, large and rather peaceful herbivorous fishes. Like eversmolts, they lead their origin from the nonnative fishes introduced to New Zealand in historical epoch: they are descendants of a carp. But in due course of evolution these fishes have changed strongly enough in comparison with the ancestor and lead absolutely different way of life. These fishes do not love life in lake with stagnant or slowly flowing water and prefer to live in fast current. Body of thick-lipped carp has streamline shape; it is completely different from its sluggish deep-bodied ancestor. Flattened head reduces the resistance to stream of water, and sucker-like mouth shifted downwards helps to attach to stones. Mobile fleecy lips allow fish scraping from stones algal films – the basic food of this species.
Living in different parts of the world, algae-eating fishes display similar features of behaviour. The more fish depends on algae as a food source, the more furiously it behaves relatively to congeners and the more extensive is its individual territory. Thick-lipped carps are closer to the end of such impromptu scale: these are selfish individualists changing anger for favour relatively to their congeners only in courtship season.
The upper lip of this fish is divided in the middle to two halves which can move both in coordination and independently from each other, when fish scrapes algae from substratum. Thick-lipped carps prefer coastal parts of river channel, where the bottom is well lit by sunlight and on stones microscopic green algae grow – it their basic food. If nothing breaks rest of these fishes, they simply cling to stones, turning heads against current. Thus fishes keep against substratum not only by mouth, but also by pectoral and abdominal fins, in which tips of several forward rays jut out from membrane, forming something like tiny claws. Each fish watches closely behaviour and movement of the relatives, ready to rush in any minute for protection of borders of the territory. The owning of “an observant point” on stone sticking out above the bottom or on snag is the important requirement to territory which is occupied by fish. Such place serves for submission of visual signals to relatives. The fish looks especially favourably at such place when it is well lighted.
Some individuals of thick-lipped carp differ from other ones: on the top blade of their tail fin long thread with well appreciable cross strips of black color grows. Fishes with threads on tails are males, and each of them supervises the territory especially zealously. Long threads of tail fins wave in current, submitting warning signal to other males. But female is willingly admitted to the male’s territory: in spring at these fishes the spawning season begins.
When female of thick-lipped carp lack of long thread tail, appeared in male’s territory, he has turned to the gallant groom: having gone down from stone, male has swum up to the female and has stopped in current near to her, having stretched fins and displaying to her thread on tail. It seems female likes him: she folds back fin slightly, expressing the submission. Male continues courtship: keeping side by side with female, he began cracking and clicking with the help of pharyngeal teeth, which have turned at this species to the sound-reproducing device exclusively. Female behaves modestly – if she will not express submission to the male, it will be recognized as an encroachment to the territory and then instead of courtship games she would get impact by strong snout in her side. She holds fins pressed against the body and replies only with rare clicks to male’s courtship song. It is obvious, that female accepts male’s courtship, and he begins the following element of courtship display: male creeps on the stone, moving pectoral and abdominal fins one by one. He has crept forward a little and has stopped in front of the female, turning by side and showing to her his bright and widely stretched fins. It seems he managed to find suitable female for this breeding season. But external circumstances rush into measured and constrained life of thick-lipped carps in the most unexpected way.
At first eyes of native thick-lipped carps turned in sides and upwards a little notice separate small fishes, swimming quickly above them. But within several minutes conditions in the river change completely: eversmolts swim upstream like a continuous flow, and their shoal is stretched across the whole width of a channel. In addition the shoal of fishes becomes denser every next minute. Each thick-lipped carp busy with courtship games receives some appreciable impacts in sides and fins – eversmolts moving to spawning in continuous mass run into them. Everything is changed – now there is no trace left from peace and quiet conditions having to courtship games. Fishes constantly feel waves from movements of numerous eversmolts, and motley sides of these fishes flashing before their eyes completely close the field of view and transform world around into mad dancing of colors and flashes. Thick-lipped carps having got in school of eversmolts can hardly make a way for themselves in live mass of these fishes. They simply slip from stones downwards, on the bottom, and wait the end of pass of this shoal.
Gradually the main number of eversmolts has swum past, and sun rays reach river bottom where thick-lipped carps hide again. Only separate small groups of fishes remained behind the main shoal are swimming by them now. But thick-lipped carps do not hurry up to leave their shelters: they see how highly above water silhouettes of birds following the eversmolt shoal sweep over. This danger passes gradually – birds fly off further, or simply return to their territories, having taken advantage of benefit of short-term easy fishing. Approximately half an hour after a leaving of eversmolt shoal is passed, and life of thick-lipped carps completely returns to accustomed train and fishes swim away to their places, but not all do it. The female so actively courted by male, has moved away somewhere, and now he needs to make new efforts to involve new female ready for spawning. Therefore thick-lipped carp male continues courtship display with the double eagerness. Now he has dark green colouring with bronze shining. To display itself at its finest, he keeps at top of stone as on a throne, and around of him the carpet of filamentous green algae waves. Having stretched red fins, it is clanged against the stone with their help. His back fin is widely stretched and in sunlight its red colouring is appreciable, and the long thread of tail fin waves in stream.
Male displays itself not only to females. For other males its colouring and pose represent a challenge to a duel or the warning of probable repulse which it can give the contender which is not commensurating force and ambitions. And it is not necessary to wait for the answer to this challenge for a long: in provoking affinity from this male the competitor appears, being also in fine physical shape. Small and weak males prefer to steer clear of such handsome male, but this competitor is a large and strong fish which would like to take for itself a part of possession of this male. But fight is usually preceded with an estimation of physical opportunities of the contender – it is a ritual which allows avoiding putting injuries to each other by battling contenders. Noticing the contender which has broken borders of his territory, male has gone down from the stone and has swum towards to it. Having turned muzzles against each other, fishes have begun “negotiations” – both males began uttering series of clicks, simultaneously frightening each other by stretched fins. The owner of territory turned its side to the contender, continuing uttering “trills” with pharyngeal teeth, and has sharply waved tail, producing a wave to contender’s side and enabling it to estimate his force. But the contender has answered it absolutely unusual way: breaking “the code of honour”, it did not begin waving tail, but at once has emerged and “sat” on the next stone. It tries to take at once a place indicating its superiority. The answer to it from the side of the territory owner appears simple and predicted: he has overtaken the impudent contender, pushed it from its place with ramming impact of a snout and has forced to swim down to the bottom, pressing it by own body from above. Accompanying its movement with the series of clicks, he has driven the contender to the border of territory, pushing it from time to time by snout in sides and tail. At the border of his territory he has not missed an opportunity of displaying itself, having stretched fins and making sharp movements by tail aside the contender, and then turned around and has majestically swum to his stone “throne”, expecting for the attention from the side of females.
In colony of penguins life takes its normal course. In life of many members of colony there was nothing new, and among young birds one more breeding couple has appeared, which should nest for the first time. Also there is one more good event: it seems widowed female expelled from her own dwelling has found a new husband for herself. She has expressed the great interest to young single male which was just busy with digging of new hole under flat stone, which edge now hangs above an entrance like a roof. Work is not completed yet, but it is already visible, that he will make a good dwelling. It will take only two days of work – he will turn to enviable groom with a fine apartment. Lonely female was frequently late near his hole, and this male did not drive her away. Maybe, at first he was too busy with the work to pay attention to his associates, but later the presence of female became an additional stimulus for him for continuation of the building. He related neutrally to the female, but did not beat and did not drive her away – and it is already a good sigh as itself. And the female gradually began to behave as if he already became her nesting partner: when male left for fishing, female remained near his hole and displayed aggression to neighbours, protecting the space around of the hole. Having returned, male continued digging a hole, and female simply walked beside and cried loudly at relatives appeared nearby.
In human epoch forests of New Zealand have ceased to be safe for ground-dwelling birds, especially if they lost their ability to fly. And Neocene fauna of islands bears on itself heavy burden of human activity – it includes numerous descendants of terrestrial mammals, and among them there are also predators.
Vanity of penguin colony was broken by alarm signal, and penguins have habitually run up to their holes. Lonely female has got into the hole unfinished yet – male has left to feed, and nothing prevents her to hide in his hole. The wood litter and dry fern fronds rustle under paws of sluggish and clumsy creature. Nevertheless, threat is quite real and not illusory – towards the colony of penguins New Zealand unbadger hobbles. It is sluggish, but strong and ruthless predator capable to be very quick if necessary. It is smaller compared to ruacapangi, but it does not make it less dangerous opponent: maybe, it loses to ruacapangi in speed, but wins in force. Using strong paws, it can turn out the stones protecting an entrance to a hole, dig it out and eat the penguin cornered. The passive defense saving from ruacapangi is disastrous here, and a pledge of success in confrontation to this animal becomes active defense which penguins are able to make to some extent.
The behaviour of New Zealand mountain penguins living in places, inhabited plentifully by predators, has appreciably changed in comparison with behaviour of their ancestors living in rather safe world of islands and ocean coasts.
New Zealand unbadger wanders in colony of penguins. It sniffs at holes and tries to pick off by claws stones near which they are dug out. It succeeds to scratch some little stones from the ground when it has felt as someone has strongly pinched its tail. Having screamed, the beast turned around and has seen near to itself a small group of penguins. They are obviously not going to hide. One of them has called loudly and belched semidigested fish, having spat it in muzzle of predator. The others have caught up its cry and unbadger has shaken its head – so loud was the cacophony of voices of penguins. Then in its wool some more some pieces of semidigested fishes hit. Now cries sound from everywhere: penguins leave holes and call loudly, surrounding the predator. Unbadger has grinned and has clicked teeth – hunting is obviously broken, and these strange creatures behave somehow unusually. And at this time it has felt sharp pain in hip – one of penguins has rushed to it and has bitten it, having squeezed beak strongly. In beak at this kind of birds there are two tooth-like outgrowths, and it makes its bite even more painful. The beast turned around and its teeth chattered, having tried to get the offender, but from this movement the penguin has flown aside and has rolled on the ground, holding in its beak flock of beast’s wool. One more penguin has rushed to the enemy from behind and has seized its skin. Bird’s beak has broken through the beast’s skin, and on its wool the spot of blood has appeared. The animal is surrounded with those ones which it expected to catch and to eat, and it is obvious, that good luck is not on its side now. Penguins pinch its sides and tail by beaks, jumping aside when it is turning to them by muzzle. In wool on its hip the spot of blood flows and unbadger feels acute pain in wounded place. The male penguin, to which lonely female pays attention, has had time to return to the colony just in heat of battle and at once has joined in struggle against the enemy. He managed to pinch a predator strongly for some times, and his voice has joined the common cacophony.
Shaking its head, unbadger recedes. The moment of suddenness is lost, and now it had to lick its wound somewhere in shelter, instead of feasting. In due course of its distance from the penguin colony their battle cries become more silent: the colony gradually returns to habitual life. Such incidents, besides minuses, have also small pluses: joint defense against unbadger has even more rallied a couple of penguins. Female has cautiously approached to male, has sat down in front of him and has touched his beak from below by her beak. The answer was immediate and predictable: male has opened his beak and has bent head downwards, allowing female pulling out fish from his gullet. After that it is already impossible to name female as lonely one – the pair of penguins has contracted the conjugal unit. As a sign of trust male has cautiously touched feathers around of female’s eye and has cleaned them. Then he has inclined head on one side, and female has cleaned a mote from his plumage. Now work on a hole will go much faster, and it will be possible to begin nesting soon. And nesting and rearing of chicks will show, as far as successful there is this married couple.
Changes in a nature stimulate courtship behaviour of animals even if it demands the application of significant efforts. It takes place so at eversmolts – small fishes which continue travel to the upper course with amazing persistence. During the travel in colouring of males changes take place: they become velvety-black, and on their backs now irregular-shaped spots redden. The great shoal entered the river from lake has gradually thinned: feeling a smell of native inflows, a part of eversmolts has already left the common school. Ones still remained and continuing the travel to upper courses need to overcome many obstacles. More often these are river rapids which should be stormed for a long while. Maybe, any large salmon would easily overcome such rapids in single jump, but from small eversmolts significant efforts are required for the decision of this problem. The school of fishes stops below the rapids, and with each minute their number becomes larger due to the individuals running after the main school. In breakers of water under rapids spotty and black backs flash, and some fishes jump out of water vertically, as if trying to estimate the situation. When the number of fishes becomes too great, storm of rapids begins. Eversmolts begin jumping in groups over rapids. They squeeze between stones, where current is weaker, or try to make two-three strong jumps in succession to overcome rapids quicker. Some fishes try to swim upwards in jets of water against current, but such ones, as a rule, are carried away downwards, and they had to begin anew. Some fishes succeed to overpass rapids, but, having grown weak, they can not keep speed in current and the river carries them downwards. The jump of one fish may serve as stimulus for other fishes, and sometimes one jumping eversmolt is followed by some more ones and after them up to fifty fishes jump in total. Such live wave as if is broken against water, but some fishes all the same succeed to overpass rapids. Above rapids, in the places behind large stones protected from fast current tens tired fishes managed to overcome this obstacle gradually accumulate. When to them other lucky ones swim up for rest, in places convenient for rest small conflicts flash, but even they may be enough to push some individuals out back in stream. Then they should spend the rests of forces to break back. And some especially unlucky fishes are washed downwards, and they had to spend forces again, overpassing river rapids.
Storm of thresholds gradually comes to an end. Current carries away losers – the stunned, weak and dead fishes. Some of them have spent all forces for jumps; current has simply broken head or backbone to other ones by impacts against stones. And some fishes had never overpassed the rapids at all. Such fishes cannot have any progeny and will be, most likely, simply eaten by predators.
Above river rapids the fish school continues its movement. Tired fishes keep at the shoaliness along the riverbank, where current is not such strong. Silhouettes of birds on the background of the sky force them to hide in depth, but do not stop their movement to upper courses.
At last, travel of eversmolts comes to an end: they swim into the streams which smell of water was embodied in their memory as soon as they hatched from eggs. They are not alone in these streams: when these active fishes appear, small tadpoles of rangitahi frog swim away in all directions and hide under stones. Eversmolts are predators, and rangitahi tadpoles of suitable size become their prey. But now everything in behaviour of eversmolts is subdued by the only purpose: to have a progeny. At the stream shoalinesses males display their impressive courtship dress: velvety-black with red spots on sides. Silvery eyes as if shine on black background of colouring of male heads. Females, on the contrary, turn even paler. The marble pattern on their sides vanishes almost completely, from it only separate black spots remain. The number of fish increases, and it serves as a push for the beginning of spawning.
In fact, it is all the same for eversmolt female, what male will make courting to her. At these fishes breeding pairs do not form and spawning passes very quickly. In the main, every male managed to reach up to spawning areas has proved the suitability for propagation of the species, and any of them can be considered as the best one from the female’s point of view.
Eversmolt males spread in regular intervals along the sites of a channel where the bottom is covered with straight layer of pebble of small size. Each of them signals to neighbours with its colouring, that the place is already occupied, and banishes late males by impacts of snout into their sides. But, as soon as near to male the female appears, it begins making court to her gallantly. Having stretched fins, he stands side by side to female and begins shuddering with its whole body, enabling her to estimate his force. If the female does not swim away, male falls on bottom and begins scattering ground in sides with sharp lateral movements of body and tail, digging a shallow groove in the bottom. Female follows the male, laying eggs in this groove, and male at once impregnates them and both fishes in common fill up a portion of eggs with pebbles. The only element of parental care at eversmolts is a choice of pebble ground of the proper size for the arranging of the nest. If the pebble grains would be too small, the water carrying the oxygen will reach hardly to developing eggs. If they would appears too large, it will be more difficult for digging out, and current would simply wash up outside a part of eggs through intervals between pebbles.
Travel to nesting areas may be too expensive for eversmolts. As against the majority of salmon fishes of human epoch, eversmolts can spawn for some times in succession. But all the same the part of eversmolts perishes – from wounds and simply because of irreversible changes in an organism connected with spawning. Mature fishes, as a rule, are strong enough to recover from stress which they endure during the spawning and the organisms of old and weaker fishes do not sustain such test for durability and its degradation begins.
Having grown weak after spawning, eversmolts cannot resist to current any more. They hide behind stones to defend themselves from the current washing them away, and in such places tens small fishes gather. Males at this time already start to turn pale. Red color vanishes at them especially quickly, and black colouring gradually changes to grey. Females, on the contrary, restore spotty colouring and become less appreciable on the background of stony bottom. It is important for them, because after spawning eversmolts appear very vulnerable for some time.
The run and spawning of eversmolts involve to mountain streams some local animals. Almost the same took place at the salmon rivers of Eurasia and North America, where bears, seagulls and ravens gathered to have a feast. At the rivers of New Zealand this picture repeats, but with local colour: here “salmons” are much smaller, and instead of bear New Zealand unbadger goes fishing. New Zealand false raven, on the contrary, is much larger, than its continental analogue of human epoch, and a role of seagull in some rivers is performed by New Zealand mountain penguin.
Massive New Zealand unbadger is a rather sluggish beast, but even its quickness is enough to hunt eversmolts restoring forces after spawning. Beast obviously avoids bathing in cold water of mountain stream; therefore it prefers to hunt from stones. It dexterously leaps from stone to stone, getting rather far from the bank, almost to the middle of stream. Having leaped on large stone, unbadger cautiously steps on it by soft paws, trying not to make superfluous noise. Having walked to the edge of stone, beast has lain on stomach and began observing of the fishes keeping under the covering of stone in small school, and has held one paw ready for impact. Expectation was short: in one minute unbadger has made one fast movement by paw and has snatched out an eversmolt from water. Having pressed struggling fish against the stone, beast has seized its head with teeth and has bitten its scull through. Having eaten meat from the backbone quickly, it has thrown out the rests of prey in water and stands again with paw ready to attack. During a half an hour it managed to catch one by one five fishes and to eat them. And its success in fishing has drawn attention of feathery lovers of easy prey.
Fishes have rushed in all directions and were hid, when on a surface of water the shadow of winged creature flashed. Then loud wing flapping followed, and on stream bank New Zealand false raven landed. Unbadger has looked back on it, being obviously angry, because the appearing of this bird has scared away fish which it hunted, and in two leaps has got over to one of the next stones, almost at an opposite bank. Large black bird walks forth and back on land, glancing to unbadger with its shining black eye. Having seen that the bird does not represent any threat for it, unbadger has concentrated on fishing. Some minutes of waiting have been crowned with success – it has snatched eversmolt out from water. When the fish was fluttered, being pressed against the by beast’s claws, the raven has quickened. It has flied up, in two strokes of wings has flown over the stream and has attacked unbadger, trying to take away the fish caught by it. Attacked unbadger, not letting out prey from under paw, has begun roaring, having forced raven to fly up above stone and to land on next one. Hardly keeping on slippery stone, the raven has cried loudly and has begun to flap wings, and unbadger has fluffed up in return the white wool growing on its cheekbones, and has raised tail, which trembled in air. Birds have too weak sense of smell; because of it raven simply has not felt a disgusting protective smell which unbadger has let out from special glands at the root of tail. To attempts of taking away its prey from the part of raven it invariably answers by growl and demonstration of grinned teeth. The warning is very obvious, and raven prefers to recede. In itself the New Zealand false raven is rather successful hunter, but for the clear reasons it likes to live by robbery of weaker predators. Nevertheless, care prevails, and the bird makes reasonable decision to leave unbadger free. The raven has simply flown to the next stone, landed on it and after several minutes of waiting has dexterously snatched itself one eversmolt from stream and began pecking it immediately.
Small eversmolts are creatures having many enemies. Frequently these fishes are saved from extinction only with the considerable fertility. At this kind of fish enemies are present at any stage of development, even when posterity is not hatched from eggs yet. And the paradox is that eversmolts come for spawning right into the home of their enemy. Grown up tadpoles of rangitahi frog are large creatures representing danger to eggs of eversmolts and for their larvae, at which yolk sac has not resolved yet.
In streams spawning of eversmolts still proceeds. But now the fishes that have been late to spawning, ones that for any reasons were late during the migration are breeding. Nevertheless, even they have chance to have a progeny.
Couple of eversmolts spawns at the bottom covered with small pebble. Some days prior to them here rough spawning games took place, and this territory was divided into set of the individual sites protected by males waiting for females. Now the hullabaloo declined, and success in spawning depends only on the ability of potential breeding partners to find each other. A competition to others males is absent and male displays itself to the female. By powerful movements of tail male scatters ground in sides, making a small groove for eggs, and female rushes following it, laying eggs. Male fertilizes them, and fishes immediately bury their clutch in pebbles. But they are not alone here. Involved with their movements, the large rangitahi tadpole is swimming behind them. It is careful and keeps aloof from fishes, trying to not come nearer to them before the proper time. But when it hears characteristic silent knocking of pebbles stones under tail of male burying the clutch, it rushes to fishes. Male just finished the burying of eggs under pebbles, and the tadpole is already swimming after it, ready to dig out the clutch. When eggs are spawned, female abandons male, and when the last movement of tail to dig the clutch is made, male also loses interest to its own posterity. Fishes do not protect eggs – their parental instinct is silent, they have made everything provided by their behaviour for propagation of the species. They swim off, being completely indifferent, gradually acquiring the colouring characteristic for this species out of spawning time. And the rangitahi tadpole began ravaging just dug nest, scattering smaller pebbles by snout and dragging larger stones in mouth transformed to sucker. After several minutes of its work at the bottom small hole was formed, in the middle of which orange eggs wave. These fishes cannot hatch: the tadpole absorbs eggs, swallowing some pieces at once, soaking them up by eternally opened mouth. Involved with its activity, some more relatives swim to join its feast. Having finished with one clutch, tadpoles dig out other nests of eversmolts and eat eggs. Sucker mouths help them to take away the large stones, preventing to ravage fish nests. Only the rests of eggs are carried by current from the dug out nests. But nevertheless the part of eversmolt eggs will escape, having fallen deeper between stones, and the new generation of these fishes will appear in stream to join the constant flow of life.
After spawning eversmolts go through very difficult time. It seems, as if all weariness which it has gone through during the travel to upper course of the river at once falls upon every small fish, and at once all wounds received during the travel begin to ache. Bodies of some individuals are covered with wounds and the grazes received at the making of nest. At the moment of spawning nobody had paid attention to these wounds – fishes had more important task. But now all wounds have an effect. At some fishes wounds gradually heal, and ones are less lucky – in wounds parasitic microscopic fungi have settled, covering the wound with cotton-wool coating. Some fishes will not cope with infection and will not survive even after the first spawning in their life. But the most durable members of population can return to native places five, and even six times per life. Eversmolts gradually leave spawning areas and move down to lower reaches of the river. But it occurs not in huge shoals, but in small schools which are not noticed at all by other inhabitants of the river.
Penguins also prepare for nesting. Pairs of birds spend more time in holes, deepening them or making some repair of walls. In some days the first eggs will be laid, and members of a colony will accept parental duties which they will fulfill within approximately three months – while the brooding proceeds and while chicks will learn to search for food independently. For now life in a colony of penguins proceeds in former rhythm, under accompaniment of loud voices of these small birds. But life in a colony is not insured from accidents which can result in the most unexpected consequences.
The ground hoots from impacts of hooves: some adult ultradama deer run in forest, being frightened by a predator pursuing them – by marsupial pardus. Rattle of hooves comes nearer, and in colony of penguins panic occurs. Short-legged birds run up in all directions, hide among roots of trees or near stones. Some of them try to hide among ferns. Impacts of hooves against the ground become louder with each second, and, at last, there comes an outcome: one of huge deer runs directly across a colony of penguins. Probably, it has not noticed it at all – for it the penguin settlement differs only a little from the forest around it, and it has crossed a colony in some leaps. But for penguins the consequences of this accident are too well appreciable: hooves of the beast have destroyed some holes. And at the pair occupying a site in the center of a colony, the hole is destroyed completely – it cannot be dug out any more. In ovary of the female the first egg already began to ripen, but now it could not be laid. To say more exactly, this amicable and strong pair of penguins knows, how it is possible to become owners of new convenient hole very quickly – it is necessary simply to look for themselves a good hole which weaker pair owns and to expel them. Or it is possible simply to seize the moment when the hole is empty and to occupy it.
The pair formed by widowed female and young male becomes an object of an attack. Their hole is well fortificated and represents a tempting prize for aggressors. And this pair does not behave yet so harmoniously, as pairs keeping together already for some nesting seasons. Therefore they frequently make the mistake, due to which usurpers of their house have taken advantage: they went for feeding approximately in the same time, and also separately from each other. And the hole staying empty for about two hours became easy trophy of the pair which has lost their house.
Male has returned from fishing the first. Having approached to the hole, he has found out near it a couple of birds which he saw very far from his dwelling before. And this pair was obviously engaged in establishing of relations with neighbours. Having not paid attention to it, he was directed to the hole which he has dug out itself. Screams behind his back have interrupted immediately, then he has heard sound of steps coming nearer, and finally impacts of two beaks at once have fallen upon his back. These two birds rushed simultaneously to him with loud screams and began pecking him, driving away from the hole. He has tried to protected himself, but he had been tumbled down on the ground and both birds began pinch him painfully, and then the usurper male has driven him away, screaming and pecking him. Fight appeared crueler than daily conflicts happening between neighbours. If in those cases everything is limited only to cries and displaying of the body size, ritualized in addition, but now there is a real fight, and the main prize in it is an opportunity to rear the posterity in this season.
When female has returned, she has seen how the extraneous pair of birds absolutely freely plays the masters in the hole which she only recently began to accept as her own one, and her male wanders beside, and on his side traces of blood are appreciable. When female has tried to enter her hole being her property even the morning, aggressors attacked her, screaming loudly. Male has tried to help her, but one of aggressors has simply pushed him aside from the female and has continued to beat her. Two large adult birds operate as a team against owners of the hole. They beat each of birds by turns, not giving another bird to come to help each other. The neighbouring pairs do not pay attention to this conflict: while borders of their territories are not crossed, they are simply indifferent spectators. Only when fight proceeds at the border of the territory of the neighbouring pair, birds go to protect their possessions. But neighbours are not helped by anybody – they remain face to face with aggressors. For other birds there is actually all the same, which pair would be their neighbour on results of the conflict – the already familiar pair, or any another one. While borders of private territory of pair are not broken, they would not begin to interfere with another’s conflict.
The result of struggle for vital space is predictable – aggressors supersede a pair of penguins from their own hole. But it is not enough of it for fastening the success: aggressors simply expel the homeless birds from the colony. Hackneyed birds with traces of blood on their plumage cannot show worthy resistance to aggressors, and from the side of neighbours, in whose territories they appeared, birds are waited only with an additional portion of beak impacts. As a result they appear at the edge of the colony, hackneyed and grown weak. The world around has suddenly changed for this pair: they have lost a habitual society of neighbours, safe dwelling and fishing areas. Now their survival is under the question in addition to the opportunity of nesting in this season.
The pair of penguins has abandoned the colony. It is a very risky step for birds which have got used to live being surrounded by their congeners. But the even worse circumstance is the absence of neither shelter, nor the society of relatives capable to render protection and support to them in case of need. Lack of neighbourhood of relatives, runaway penguins are afraid of literally everything – easy rustle from the lizard creeping among ferns or flapping of bird wings among branches of trees forces them to rush to roots or to dense fern thickets in searches of protection. The penguins expelled from a colony walked to the lake shore and now walk along the bank of river flowing from it. They do not leave far from water to have an opportunity to feed when they will feel famine. They have chance to survive – along the riverbanks small colonies of New Zealand mountain penguins frequently exist, and sometimes there are same “tramps” – lonely individuals or breeding couples. But usually the destiny of such birds is unenviable: too many predators live in forests and near the coast of reservoirs, for which lonely penguins represent easy prey.
Looking back against each other, penguins lag along the riverbank overgrown with ferns, bushes and low trees. They are good walkers, but walk clumsily, jogging from side to side on short legs, and frequently stumble against tree roots. From time to time birds listen, hoping to hear somewhere in the distance voices of congeners. But they did not manage yet to find out the signs of their presence. And their own presence is revealed and they are watched already by local predators. In rich branches of one tree the pair of New Zealand false ravens is hidden. These birds are able to hunt small ground-dwelling animals, and penguins, lagging along the riverbank, represent easy prey. These ravens form a breeding pair which has perfectly fulfilled tactics of a joint attack to small animals, and now they are ready to attack penguins. Penguins do not look in crones of trees, and therefore do not notice yet the threat from above.
Female perfectly knows habits of penguins, therefore she has left a role of drover to her male, and has flied up, has flown behind the penguins and, having overtaken them, landed on the ground between them and the riverbank. Having seen her, penguins have rushed away, but their way had been blocked by male raven which has terribly clicked its white beak. Pair of penguins against pair of ravens – their position is not so hopeless: the lonely penguin would be killed at once and here the certain opportunity to escape still exists. It is more difficult to pursue two penguins, rather than one. But another thing is much worse: female raven has cut off the escape way to the river, and now penguins should save their lives on land, where they feel like not as confidently and easily as in water. But they have two advantages compared to ravens – low growth and skill of hiding. Therefore penguins, having seen that the way to water is cut off, have tried to hide in ferns. Using this dexterous move they have deprived ravens of advantages of an attack from air. Ravens cannot fly up – ferns prevent them to see penguins. Only casually rocked fern fronds allow predators to guess, where penguins hide. Having bent down, ravens wander among ferns, trying to find out penguins. And penguins are skilled in hide-and-seek play. They simply lie among plant dust and stay motionless. From time to time one raven or another raises head above thickets and looks around, trying to find out penguins. But it is uneasy to find them: camouflage colouring has reliably hidden them from predators. Penguin female lies on the ground, having nestled against large fern and does not move, even when the raven walks near her. Only slightly opened eye of bird watches how the raven walks very close. Penguin female has not moved even when the claw of feathery predator has scratched the ground fast beside her wing. Her male is somewhere nearby, but he also has hidden. Shadows from trees crones and fern fronds help penguins to disappear from the sight of predators. Due to skill of hiding penguins succeed to deceive ravens – having not noticed them, feathery predators have passed by, and now penguins appear behind them. Now at them the opportunity to escape has appeared, and both penguins have almost simultaneously rose and have run to water. Thus they certainly have given themselves out, and ravens, having heard them, have rushed to chase prey. Two huge black birds have flied up above ferns and have begun hovering in air. While penguins run among ferns, ravens have fewer opportunities to find them. Small birds intentionally foul the trail, changing direction of run. Ravens win in speed at the direct distance, but now they should constantly change the direction of flight, therefore they are in equal conditions. A small part of the way between forest and riverbank appears critical for penguins. Here ferns have receded to the forest shadow, and penguins should make the way through thickets of high coastal grasses. For flightless birds of small growth this is a very difficult task, but also for ravens it will be impossible to catch them from air. Black birds are compelled to land in grass and to continue chase for penguins at a run, but good luck has already smiled to penguins. Having made the way through thickets, they have felt under paws fenny ground – it means water is already close to them, and in water there is an escape from ravens for them. Some more steps, and feet of penguins slosh in water. Having rushed forward, they have crumpled marsh grasses and have got out in water. Feathery predators have missed prey. The pair of ravens hovers above the river, and birds see, how two silhouettes of penguins slide in water. New Zealand false ravens are able to hunt on land successfully, are able even to catch fish from stones, but they feel like not so confidently in water and are not ready to continue the chase for penguins in place where they feel so easily and freely.
Male penguin has emerged the first. He was put out from water, has inhaled fresh air and has cautiously looked round. He has seen two black silhouettes of large birds above the forest in heavenly blue, but whether these ones were the same ravens or any other ones – it doesn’t matter anymore. Near him the female has emerged. They are still together and vital circumstances did not manage yet to separate them, despite of loss of house and company of congeners. Right now they managed to avoid danger of death. It is already good, but it is not enough yet for them to look confidently in the future. It is too indistinct now at this pair.
Male penguin has dived, and in some seconds in sunlight silvery sides of small fishes, which he has pursued, have flashed. Female has taken a deep inhale and has dived, joining the hunting. They are too silly to reflect on the future, and live only by present moment, accepting everything happened to them as is.
The pair of penguins expelled from their colony wanders along the bank of the river flowing from lake. And at the other edge of lake the river flowing down from mountains turned to the migration way for live creatures again, but they already move in opposite side. Tens long-bodied creatures with muscled tails gather to schools and swim downstream. These are rangitahi tadpoles which have spent some years in cold mountain streams, feeding on algae and small invertebrates. They prefer traveling at night when they are threatened by lesser number of predators. Small groups of rangitahi tadpoles reached the maximal size gather in river channel to numerous schools and in common swim down to the lake to finish there their life cycle. For them it is a one way road: no one individual will return to the stream where almost the whole its life had passed.
Rangitahi tadpoles are in the best position compared to eversmolts which shortly before it swam upstream for spawning to mountain streams. For eversmolts the watercourse was one of numerous obstacles, but it only helps tadpoles to migrate, therefore they can reach the lake, expending only few efforts. Tadpoles begin migration at night, and in the morning in the river large schools numbering hundreds individuals already swim.
In lower reaches of the river migrants swim through possessions of native thick-lipped carps. But the relation to them on the part of these fishes is absolutely different, than to eversmolts. For these fishes eversmolts were only a certain incident, an annoying obstacle for fishes busy with courtship games or spawning. And tadpoles with their sucker mouths cause aggression in these fishes: native thick-lipped carps perceive them as food competitors though during the migration tadpoles already stop feeding.
The school of tadpoles migrating to lake is swimming near the bottom. It numbers some tens individuals of absolutely identical age of five years. They differ only a little from each other in size, that reflects just a difference in conditions of life in different streams and rivers. Suddenly tadpoles have felt sharp abrupt sounds with their whole bodies – these are the series of clicks uttered by thick-lipped carp. Large male of native thick-lipped carp has stretched back fin and has rushed towards to them, chirring threateningly by pharyngeal teeth. It shudders with the whole body, uttering warning sounds, and some tadpoles appeared close to the fish, have swam away, but their place was on the spot occupied by other ones. Thick-lipped carp has rushed to the congestion of tadpoles and began to strike them by chaotic impacts of its sides and tail. But the stream of the tadpoles, swimming towards it, does not decrease, and many of them are large enough to repulse it. But they do not care at all of self-defense, and impacts which native thick-lipped carp puts to them, remain without any response. They have a purpose in their life, and they are too strongly subjected to it to distract to such casual meetings.
Riverbanks extend and then completely vanish in bluish-green haze. Cool river water gradually becomes warmer – rangitahi tadpoles have reached the lake. Having felt changes of temperature of water, tadpoles begin to “yawing”, searching for places with the warmest water. Having got into the lake, schools of tadpoles stay for some time in thickets of plants in river mouth, and then begin to move along the shore, searching for shallow gulfs where water gets well warmed by rays of spring sun. It is vital for them – they have very short time of further life, and they should fulfill the parental duty and only after that their life cycle will be finished.
In some sense rangitahi tadpoles are similar to mayflies. In absolutely the same way, as these insects, rangitahi frogs spend the most part of life in a stage of aquatic larva. The adult stage both at mayflies and at rangitahi frogs is ephemeric and serves only for breeding, which is followed by the inevitable death. But before eggs will be spawned, rangitahi tadpoles should undergo metamorphosis. The stay in well warmed water accelerates this process, therefore in gulfs numerous schools of these creatures gather. Large tadpoles, more similar in size to fishes, swims in warm water at the surface. They literally on the spot undergo the metamorphosis. The buds of extremities formed during the life in mountain streams, have started to increase, and at tadpoles already in the first days of life in lake rear legs, and after them, with small backlog, front ones develop.
In due course of metamorphosis bodies of these creatures undergo further changes – the slight trace of neck appears, head extends, eyes become convex. At the future frogs legs grow larger and now outlines of their bodies are more similar to typical for frog. The only thing that is still differing young rangitahi frogs from frogs of other kinds is a tail. It serves as a stock of the nutrients necessary for metamorphosis and breeding. In literally noticeable way tails of rangitahi frogs grow thin – muscles degrade and bones literally dissolve. Muscled tail becomes similar to wrinkled sac of skin, quickly decreasing in size. But at females stomachs are increased simultaneously – eggs quickly mature.
Having left the mountain rivers, rangitahi tadpoles have got into the dangerous world. In cold water of mountain rivers only few dangers waited for them – they could freeze, if the rivers became covered by ice, but predators in mountains were rather rare. And here, in warmer lake water, they should meet other dangers.
Long body slides under water near to the surface. It is covered with small scales, with a simple pattern of narrow white cross strips on dark grey background. The small flattened head moves from side to side, putting out the thin doubled tongue, and small eyes look, but not blink. It is a marshland aotearophis, the New Zealand endemic kind of snakes. As against many other species, this creature is the descendant of natural settlers of archipelago. It descends from sea snakes which began to develop fresh waters, and then also wetland habitats of the islands already after the ending of human epoch. As well as it is necessary to the descendant of sea snakes, marshland aotearophis is poisonous. Its poison is an adaptation for hunting cool-blooded prey; therefore it has great killing power. But the snake, having such weapon, prefers not to enter conflicts to other inhabitants of lake. Also the reptile prefers to keep near to the shore and at a surface of water where is warmer.
Some New Zealand mountain penguins are swimming under water, quickly flapping wings. Having seen the snake, birds simultaneously dive and try to swim out far away. Aotearophis does not attack penguins – adult birds are too large for this snake, and additionally marshland aotearophis is a specialized herpethophagus, obviously preferring catching false salamanders and lizards of suitable size. Penguins are not a prey for this reptile, but all the same they are afraid of it and prefer to keep the safe distance.
Jutting out its tongue, snake gathers with its epithelium the molecules of the odorous substances dissolved of water. It feels that somewhere nearby it is possible to find a lot of prey: the reptile smells rangitahi tadpoles. They a little than differ from false salamanders, therefore marshland aotearophis snakes hunt them in regular way, when tadpoles go down to the lake for metamorphosis. The snake heads for shallow water and soon swims into the shallow gulf where the numerous group of rangitahi tadpoles has gathered. Warm water in gulf has forced snake’s heart to beat faster, and the reptile has felt famine much clearer. It feels a distinct smell of prey: the great school of rangitahi tadpoles swims at the surface. Pleasant heat has spread in the body of snake and the reptile began hunting. It has cautiously emerged aside, in thickets of marsh plants. Having inhaled air, the snake has dived and has swum above the bottom, wriggling smoothly. Its eyes slightly turned upwards distinguish the school of large fish-like creatures swimming at the surface of water. They are obviously not frightened yet.
As if a miniature fantastic water dragon aotearophis has come up from the bottom, and its head has risen directly in the middle of school of tadpoles, rushed in panic in all directions. One tadpole, however, did not manage to escape, and now it is struggling in teeth of the snake. Its movements weaken with each second, and soon only tip of its tail quivers in last spasms. The teeth of aotearophis stuck into its body have injected into the body of prey strong poison which has almost instantly killed prey of the snake. Hunting is completed, and the reptile, wriggling its body, is swimming to the shore, frightening tadpoles swimming in panic in all sides and squeezing into the thickets of aquatic plants. But now just nothing threatens to them: the predator has received the prey and is not going to attack yet. Aotearophis has crept into shallow water, has turned its body in several rings, and began swallowing a tadpole, having raised head above water. It had taken at the reptile no more than ten minutes; then the snake has got out to the land and has crept to search for place in coastal thickets well heated up by sunlight.
Some more days passed. Rangitahi tadpoles have already almost finished metamorphosis and have turned to small black-and-white frogs with the reduced tails, swimming at the surface of water. Due to their behaviour and shape it is possible to think, that they literally hasten to live: rudimentary larval tail has not disappeared yet completely, and rangitahi males already began to share a surface of water into set of small territories. Having chosen for itself the place on the surface among thickets of aquatic plants, male begins to drive other males away from it, distinguishing them by smell. Some males also start to give sound signals – squeaky croaking similar to whistling. At first these are abrupt and dissonant calls, but gradually the concert of frogs becomes much louder. It is enough for one male to start calling, and its neighbours join it, and their calls sound all more harmoniously at every new attempt. Hearing these calls, individuals at which for any reasons metamorphosis is late, accelerate their transformation. Females gradually start settling at the possessions of males, being evenly distributed on the surface of gulf – so there will be more likely to meet male and to avoid a competition to relatives. Everyone prepare for the magnificent denouement in which life and death will interlace in single dance.
In the early morning of one spring day the culmination of this performance begins. When the sun appears above the edge of a mountain ridge, rangitahi begin singing. At first separate rangitahi males begin its song. They start uttering sharp abrupt calls similar to whistling, but their concert is dissonant and gradually calms down. After the first wave of voices rangitahi males as if synchronize the voices: they utter the muted sounds similar to ticking. Males try to fit into the rhythm set by relatives. If in water there are two “synchronized” males, the third male will join them much more willingly and will fit to their rhythm. And when some males “tick” synchronously, the rhythm set by them is adopted quickly by the other males around them.
The excitation of males grows gradually. Ticking becomes louder and louder until one or two males begin uttering the courtship song characteristic for this species and similar to acute whistle. And then the silence is literally blown up with simultaneous calls of hundreds males. They call synchronously, keeping a rhythm given in time of “ticking” phase of courtship songs. At this time lake shores literally shiver from their voices.
The noise created by singing rangitahi is simply deafening. During the courtship concerts of rangitahi even beasts are afraid to come to the lake, being frightened of their voices, and the birds living at the sites of lake shore chosen by rangitahi, simply stop their songs – their voices are all the same not audible against the background of frog concert. The expenditure of energy for this performance is simply enormous. At this time rangitahi frogs eat of nothing, and they cannot do it at all – the digestive system of adult frog is strongly reduced and gradually degrades. Their existence is a single ticket, and the whole short adult life of rangitahi is dedicated to the only purpose – to leave a progeny. Males sing in unison, and between females there is a competition for the best groom: they gather around the most vociferous males, pushing away each other. If the competing females do not hurry up to leave, jaws are used and due to aggressive behaviour the strongest female literally clears away a place to herself near the male. Gradually rangitahi females spread in more or less regular intervals near males. Bellies of females are full of eggs: if males spend energy exclusively for courtship display, at females the resorption of tail provides mainly the development of eggs. Rangitahi female, having chosen suitable male, literally creeps under him, and male automatically clasps her by forepaws across the body. At this moment he stops croaking, and only utters acute squeak when any of neighbouring males tries to attempt on female already chosen by him. Having reached the culmination to approximately three or four hours p.m., the courtship concert of rangitahi gradually stops to the sunset.
When the pair of frogs has found each other, the most important stage of all this action begins: it is the egg spawning. Rangitahi female lays a lot of small eggs which are at once impregnated by the male. Within several hours after the appearing in water eggs inflate strongly; because of it the surface of water in places of rangitahi spawning resembles kissel. However, rangitahi frogs attenuate and exhausted by courtship ritual do not abandon their clutch. Their further life will proceed not for long, and their last efforts are directed to protecting the future posterity.
The next morning the sun shines numerous clutches of rangitahi frogs floating in water in large slimy lumps. Adult rangitahi frogs, having turned paler appreciably, stay motionlessly atop of their clutches, coming to life only at the approach to their future posterity of any animal which can threaten something to the future tadpoles.
The young New Zealand mountain penguin swims along the lake shore. This one hatched the last year only and until the present days had never heard voices of rangitahi frogs. Therefore yesterday it had stayed till the whole day on land, suffering from famine and being afraid to come nearer to lake because of calls of these frogs. But closer to night voices become silent, and the morning has met the inhabitants of lake with saving silence. The penguin has managed to catch some fish and was sated, and when he has swum along the shore, its attention had been drawn by lumps of rangitahi eggs waving in water near the shore. The penguin has swum up closer to rangitahi spawning area, has inhaled air and has dived. For some wing flaps it appeared near one of egg lumps, and has noticed from under water silhouettes of two frogs inside the mass of developing eggs. While it was at the some distance from clutch, frogs remained motionless. But it has swum up closer and has tried to peck up some eggs. Both silhouettes of frogs came in movement immediately and were directed to it, making the way through the mass of eggs. One frog has got out the first. It wasn’t stopped by the expressed superiority of penguin in size. With fanatical purposefulness the rangitahi frog has rushed on it and has seized bird’s leg by its own paws. The penguin has felt, as its leg as if appeared squeezed in vice: so strong was the grip of this frog. Having been frightened from unexpectedness, the penguin began jerking its leg, trying to throw out frog from itself, and it succeeded to do it not at once. The frog dumped from its leg turned to it again and has swam, having extended front legs forward. The penguin has swum aside, and the frog instantly turned around, has swum up to its clutch and had got into the middle of egg mass.
The penguin didn’t like the taste of frog eggs, and it has simply begun teasing frogs which sat in their clutches. It swam up, touched eggs by beak and waited until the frog will get out of clutch and then swam away, not giving the amphibian any chance to seize it. It succeeded to do it for some times, but one frog has managed to cling strongly to its wing and did not let it off for long, though the penguin shaken its wing and even tried to peck the frog. But, as soon as it has left from the protected clutch, the frog has let it off. Soon game has bored the penguin, and it has returned to the colony.
This penguin has place which it may regard as its home, but some of its relatives are not so successful. The expelled penguins wander in thickets, still not finding a society of relatives. They keep near the riverbank where it is easier to find food and to hide from the enemy, and spend nights in any casual shelters. Time of nesting has already come: in the colony left by birds the first eggs already have appeared. And at this pair the opportunity of nesting in this season is very questionable now. If birds will not find the suitable place for habitation and the making of nest, they will have to refuse nesting. And then it is possible, that family of these birds will simply break off. But the intelligence of penguins is not so high to reflect on the future. They simply live in the today’s afternoon, realizing their vital needs. Simply now, lack of the society of the congeners, both birds of this pair keep much closer to each other and try to do everything together.
The pair of penguins in common dives for food in the river flowing out from lake. In water they feel like easily and freely, but they should struggle against current which was almost not felt when birds lived in colony near the lake. Penguins are swimming under water together, flapping wings, and look for prey. They swim above the coastal shoaliness overgrown with bushes of eel grass. Long narrow leaves wave in current, casting moving shadows on bottom. And among shadows at the bottom one of penguins has casually noticed creatures move in silt. It has turned aside and has swum along the edge of thickets. Its movements scare away small long-bodied fishes having pattern of black spots. At the approach of penguins fishes dig themselves in silt by the only fast movement, and bird simply cannot notice them. Fish hides from view instantly, leaving after itself only the little cloud of silt. It is rahirahi galaxia, one of the river inhabitants. It also lives in lake, but penguins, preferring to hunt in thickness of water, could simply did not notice them. But here, in the river, conditions are different a little bit: many fishes prefer to hide in thickets, and it is necessary to hunt in shallow water much more often, than earlier, and habitual tactics of hunting are not applicable here. Birds should be content with casual prey.
The penguin swims through thickets of aquatic plants. It was one of elements of hunting during the former life in lake, and also works here. But in lake the whole group of drovers swam through the thickets, and here, when the penguin acts alone, is very easy to avoid its chase: it is enough for fish to swim aside. But for this purpose it should start to move, and then inevitably will give out its presence. Some small fishes rush away, being scared by movements of the penguin. The penguin does not feel movement of water so subtly, as it is done by fishes by means of lateral line, and is compelled to be guided with the help of sight, suitable for hunting in thickets only a little. Nevertheless, it managed to see, how in thickets certain cross-striped body has flashed. The penguin has precisely noticed a direction of movement, but has rushed at random and has clicked its beak. It has felt something moving and slippery, struggling in its beak, and has emerged, having seized jaws strongly. It managed to catch small fish with prickly fins and contrast vertical black strips on the body. The penguin has shaken up its prey, has dexterously turned it head to itself and has swallowed with the only movement. It managed to catch young ‘ika-taikaha – adult individuals of this species are enemies of penguins in lake. Probably, in some years a ratio of forces between predator and prey would change to opposite condition, but now this creature is a food. Having inhaled a portion of air, penguin has dived and has continued hunting. It has noticed its female flashed among thickets, and has joined her. Hunting goes on.
In searches of prey penguins have swum away to the coastal shoaliness. Here among plant thickets there are sites of sandy bottom where in sunlight small schools of little fishes and tadpoles and also false salamander larvae swarm. It is a lot of prey there, but it is rather unfamiliar to hunters from the lake got used to hunting in thickness of water and at the surface. But the most important circumstance is that penguins are completely unfamiliar to larger inhabitants of underwater thickets. Who are more numerous here – friends or enemies?
The penguin female surveys thickets of aquatic plants in depth. Suddenly she has noticed somewhere from the edge of field of view certain fussy movement in thickets. Female has instinctively frozen and began peering into thickets. Having noticed its excitement, male searching for prey nearby has cautiously swum up to her and began to look in the same direction. Birds have seen how a certain creature of approximately their own size digs sandy bottom. Its movements are fast and fussy. The creature quickly emerges to the surface of water to inhale fresh air and also quickly dives to the bottom, continuing search of food. It is not a penguin – its colouring in fact is one-colour: white spots characteristic for penguins are not present in it. In addition at swimming this creature paddles by hind legs, which long toes are connected by palama. It has tail, but it is not peaked, as at the penguin, but wide and covered with naked dark skin. It is not a bird at all, but small beast swimming near the bottom in searches of snails and insect larvae.
When penguins have emerged to the surface, following them from the bottom this creature has risen also. Having emerged, small beast has exhaled air squeaky and has looked at penguins by small black eyes. It has cautiously moved nearer to them and has cautiously smelt air. Not knowing what to expect from it, penguins have swam away from this mammal and have cautiously looked at it. Small beast has simply inhaled a new portion of air and has dived, having plopped on water surface by its flat tail. And literally in the same second, but from another side from birds, one more beast of the same kind has emerged.
The pair of penguins has got out on the riverbank. Here birds have found out that river and forest are connected by the whole circuit of paths well appreciable among marsh vegetation and wood litter. It is very similar to the colony of penguins; therefore the pair of birds has walked on one path, feeling some anxiety. Birds have quickly crossed riverbank and have stepped under tree shadow. There are some footpaths leading to the forest, but all of them stretch in approximately the same direction, therefore it is almost impossible to get off in a way. In their way penguins have met one more animal similar to those ones which they saw in the river. The animal hastened to the river, pattering its paws and holding its wide tail stretched above the ground. Having seen penguins, it has chosen another track and has run past them. Birds have hardly looked at it and have continued the way on the track. One more mammal of the same kind with brownish wool emerged from sickly grass of underbrush and has glanced at them curiously.
The track leads penguins towards the thickets of bush, to the place where many years ago the big tree has fallen. After some tens steps birds have seen the thing they wanted to see for a long time: in the ground under branches of one of bushes the aperture blackens – it is an entrance to the hole. Having gone deeper in bushes, penguins noticed some more holes in the ground. It is a good sign from the point of view of birds: it seems to them, that they have got into the colony of congeners. But this feeling stays incomplete: if there is no danger, in colony of penguins loud voices are audible. Birds constantly quarrel because of territory, communicate with each other and declare their presence to neighbours. And here holes are present, but it is unusually silent. Bending down under bush branches, penguins move farther in thickets and look around. They do not notice anybody’s presence, but some tens eyes look at them attentively: owners of holes hide, because they do not know what may be expected from these strange creatures. Maybe, someone of them sees these strange flightless birds with white-and-brown plumage for the first time. Tens noses smell air, trying to feel how do these strangers smell. And their noses do not feel frightening or hostile smells. Movements of these creatures also do not seem suspicious to inhabitants of holes, and some animals have begun to get out of holes gradually to get acquainted closer with strangers. From some holes small mammals with whiskered muzzles have appeared. Penguins are the only birds appeared in this colony: not their relatives, but waitorekes, local aquatic mammals, live here.
The colony of waitorekes is something similar to the colony of New Zealand mountain penguins. These animals also love a society of relatives and live in forest, but feed in water. Because of too plenty of concurrences in habit of life of absolutely different animals, instincts of penguins have some kind of failure, and birds do not feel like aliens in the colony of these rodents. Waitoreke is a descendant of the rats introduced to New Zealand by people in historical epoch. Waitoreke resembles externally a tiny beaver with whiskered muzzle, rich fur and wide paddle-like tail. But in character of feeding this animal is more similar to desman: waitorekes feed on aquatic invertebrates and small fish, and if necessary they can attack together any large fish or false salamander and bite it to death. Penguins are not similar to their habitual prey; therefore waitorekes do not attack them. In turn, holes made by waitorekes cause obvious interest in penguins. But the occurrence of penguins in colony has not done without the certain misunderstanding: when birds have glanced into one hole, towards them a whiskered muzzle of waitoreke appeared, and birds had to recede. Near some next holes there was the same. At last, one hole appeared empty and male courageously moved inside while female waited him near the entrance. A bit later he has got out to the ground surface and has shaken off: in depth the hole was crumbled, as it was empty for a long time. Nevertheless, initially it will be bearable shelter. Not having met the discontent from the side of waitorekes, male penguin has crept inside the hole again and soon therefrom lumps of the ground had been thrown out. He started to expand a tunnel to be possible to move inside the hole freely.
Similarity in way of life has turned the balance to the settling of penguins in waitoreke colony. Besides the beasts preferring to hunt aquatic animals do not represent any danger to penguins on land, and birds actually receive an opportunity to nest, maybe, even in such unusual neighbourhood. And there is just a proper time to nest – biological rhythms hurry birds, and in colony which they have abandoned many females have already laid eggs and have started brooding. Within several days the pair of penguins has examined all empty holes in waitoreke colony, and finally has found suitable ones for them. They have chosen for life one of holes at the edge of the colony, under branches of bush hiding an entrance to it. The hole is abandoned for a long time and has strongly crumbled, but it is dug out near the stone, and it is favourable for penguins, because it corresponds to their hereditarily programmed representations about good dwelling. Having found out this hole, male penguin at once has begun to dig it out – penguin is somewhat larger than waitoreke is, and the hole seems a little bit narrow to birds. He started to work very actively: from under bush the ground, which has been thrown out from the hole, has fallen to various sides. Female, on the contrary, spends a significant part of time searching for food. Many kinds of fishes are found in the river, but not all of them she met in lake. Also in river lack some kinds of fishes which were favourite prey of birds during the life in lake. The supply of male with food depends completely from the female: he almost does not interrupt the working, digging out hole and making it suitable for nesting. Male hastens very much, therefore in brief minutes of rest the female replaces him and herself adjusts the newly found dwelling. Male is very tired, and the fish brought to him by female hardly covers his needs for energy. But due to coordination of actions of both birds work goes very quickly. The result of their works is a perfectly fortificated hole. The part of the main gallery adjoins to the surface of stone and is bent under it; therefore the hole is well protected from predators. At the entrance of the hole the small wall of mellow and wet a little ground has grown, but paws of birds quickly trample down and throw it about, therefore soon nothing reminds that somewhere beside the digging of hole proceeds. And in two days of hard works penguins came to a final step in arrangement of hole: they made the nesting chamber, spacious enough to allow the adult bird to stand in it in full growth. Now they can devote themselves to parental cares.
While some inhabitants of lake only prepare to become parents, at others parental cares are already finished. Rangitahi frogs have made everything for their posterity that they could for the brief adult life. Embryos in eggs are developed enough, and now are seen through transparent jelly-like shell: creatures turned to lump and slightly moving from time to time. They must wait only few days to hatch, and then they will be given to the mercy of fate, and their survival will be exclusively their own care. Until they will hatch, parents will protect them, maybe, at the cost of their own lives. This price, however, is not so expensive: adult individuals of rangitahi frog are strongly exhausted and will die in some days. But, while they are alive, eggs will be under their protection.
In lake there are lots of lovers of frog eggs. More often these are fishes remarkable in their omnivory and illegibility in meal. One of such fishes is ‘ika-kaihopu, the predatory viviparous fish little bit similar to a pike because of the lengthened snout and protruding eyes. Large female of ‘ika-kaihopu swims along the lake shore, searching for clutches of eggs of rangitahi frogs. It also likes tadpoles of this kind though it is rather difficult to search for them in the bottom layers of water for a creature got used to hunt at the surface. But the clutch of frog eggs represents fine nutritious food which is as tasty as tadpoles are, unless of being slimy a little. Having reached shallow waters, where clutches of rangitahi frogs develop, ‘ika-kaihopu swims to the nearest lump of eggs. But parents do not leave the posterity in danger, therefore towards the fish from egg lump two frogs creep. They are strongly exhausted, and joints of their legs are clearly seen under flabby wrinkled skin. ‘Ika-kaihopu does not pay any attention to them: slow movements of frogs do not guard it. Having slightly opened its mouth, ‘ika-kaihopu has soaked up some eggs and has swallowed them. And one of frogs has on the spot seized its head by paws. Its paws have clasped long jaws of ‘ika-kaihopu, preventing fish to breathe normally. The fish began making sharp movements by the whole body, trying to be exempted from the unexpected and importunate opponent, but the frog has squeezed its paws using power that remains, not giving it to open the mouth. The fish began to choke and has tried to free, shaking the whole body. At last, it has made a high vertical jump and plopped in water with loud splash. After impact against the water frog has unclenched its paws and ‘ika-kaihopu has rushed away from its clutch. Having convinced that the enemy has moved out, the frog has slowly creeped on aquatic plants, returning to the posterity.
Two days has passed, and it seems like eternity for dying rangitahi frogs. Tadpoles are developed completely under protection of slimy cocoon and egg shells. Now they are completely ready to independent life and begin hatching. Egg shells turned thinner so, that it is just enough to tadpole to straight its body, and shell bursts. Tadpoles begin leaving the clutch one by one, dumping from themselves egg shells and making the way through slimy mass in which the clutch was enclosed. Rangitahi tadpoles have lengthened thin bodies, and tails make the significant part of their length. Having got out from the rests of clutch, they at once rush to lake bottom, searching for shelter among underwater plants and silt.
It sounds paradoxical, but the hatching of rangitahi tadpoles initiates a final stage of a drama – the inevitable death of adult individuals. Frogs have physically made for posterity everything they could, and now the chemicals appearing in water at the hatching of tadpoles accelerate their death. Rangitahi frogs are strongly exhausted after egg spawning and protection, and now are literally decomposed alive. Full of life even some days ago, now they are covered with necrotic spots and thin coating of parasitic fungi expanding on wounds and grazes. There are only few hunters for them at this time – nutrients in their exhausted bodies are almost absent.
Large neohanasaki moved to shallow gulf serving as the last haven for dying rangitahi frogs. The large amphibian easily moves in water, wriggling with the whole body and pushing from the bottom by toe and finger tips. Predator’s nostrils feel a smell of death which is dissolved in water around. Neohanasaki has bad eyesight; therefore it hardly can distinguish rangitahi frogs among plants. Any of them are still alive, but the majority of rangitahi frogs is already dead, and they do not drag attention of predator. Having felt weak movement of water in front of itself, the large amphibian has waved tail, rushing forward, and has simultaneously opened its jaws, having soaked up in mouth the half-dead rangitahi frog appeared in front of its muzzle. Having taken it in mouth, neohanasaki has opened jaws and has spat out such unalluring prey with disgust. Having emerged to the surface, the predator has inhaled air and has dived again. It seems, here it is nothing to do for it: the gulf became a communal grave for hundreds of rangitahi frogs, and the smell of decomposition frightens off other animals.
Somewhere the death inevitably takes away its share, and somewhere life overcomes barriers build on its way by circumstances. The pair of penguins expelled from the society of relatives has settled down successfully in waitoreke colony. Birds feel like in safety among these beasts which do not seem to be their food competitors and do not encroach on their new dwelling. In colony there are some empty holes and there is no competition for dwelling; therefore nobody prevents penguins to live privately. And soon the event happened, that should happen, though a little bit earlier if events would have developed differently a little: the penguin female has laid the first egg. It lies in small pit in the bottom of hole, without any litter, and from the moment of it’s appearing it represents the subject of gentle care of female. In completed clutch it should be two or three eggs; therefore female does not begin brooding yet. She feels rotundity and weight of egg, touching it with feet and stomach, and these sensations start the program of parental behaviour. Now she is ready to protect clutch and her relation to world around began to change. Having caught rustle and steps outside, she at once crept into the gallery and has uttered warning signal. But the familiar male’s voice has responded her, and female has calmed down at once. There is no danger now, therefore she has returned to the nest chamber, has passed her male inside and has enabled him to see (though, to be more exact, only to feel by touches of feet and body) the first egg in their family.
In two days the female has laid the second egg and after that began to brood the clutch. Now she depends entirely from the male supplying her with food, and appears on ground surface for very short time. After successful fishing male feeds her and leaves again, but if he was unlucky in fishing and his catch is not enough to feed the female, he simply replaces her on nest, having a rest and enabling her to hunt herself. Such moments give female an opportunity to take care of herself. She hobbles to water, stretching the legs which have become numb from the immovability and dives with pleasure. Female starts to fish not at once: for any time she simply enjoys an opportunity to swim quickly. Sometimes she crosses the river up to the opposite bank and even gets out of water there, and sometimes dives up to the bottom or swims at the surface of water, jumping out like a dolphin. At such moments the fish caught casually or intentionally represents, maybe, just an addition to the main feeling, to the pleasure of freedom of movements. After limbering up the bird catches some fish, satisfying her famine, and returns to the land. Here the parental behaviour prevails above other again, and she hastens to the hole to replace her male.
The first week of brooding had passed so – some days similar to each other. Female and male replaced each other on nest and moved by turns for the food; their neighbours were not interested in life of penguins, and birds managed to avoid the predators living in the river. Maybe, if this pair would nest in the society of congeners, the habitual order of things would be kept further, but in this case penguins nest in completely unusual conditions, and they will come to get used to the future changes.
Approximately at the eighth day of brooding female penguin, having returned to the hole after daily exercise, has noticed, that near the entrance of the hole the pair of adult waitorekes stays. Beasts do not express any aggression, but look into the hole and sniff by turns. And from the depth of nesting chamber the muted hissing is heard – the male has also noticed their presence and is trying to frighten them off from the dwelling. Having come nearer to the hole entrance female penguin had also hissed, opening wide its red beak and expressing by its posture the determination of protecting the house. The waitoreke pair did not begin to get involved in the conflict – small mammals have simply run off aside and have disappeared in the nearby bushes. Self-satisfied female has got into the hole and has replaced on nest her male which has gone for fishing immediately.
Next day, while brooding eggs, female has heard rustle again, but this time already much more clearly than earlier. The bird has hissed and has opened beak, but rustle has not stopped. It guarded the female; she has left from nest and has moved to protection of precious clutch. Having bent down, she has walked along the gallery and has seen near the entrance silhouettes of two waitorekes are clearly visible against the sunlight penetrating inside from the entrance of the hole. Beasts have hesitated for one second, but nevertheless have jumped out from hole. Penguin female has not noticed that one wall of gallery was dug slightly by these beasts, and at the floor of the gallery small hip of mellow ground lays. Beasts have left, danger to the future posterity is not present – therefore the bird has returned to the nest and has continued brooding. Monotonous conditions are soothing, therefore her eyes closed soon, the head lowered and the tip of beak has touched the ground. Female has dozed off and did not hear any more that in gallery rustle was heard again: the pair of waitorekes has returned. Silently and cautiously, trying not to disturb the owner of the hole, waitorekes have continued their work in gallery – beasts gnaw the ground by incisors, having biting off bush roots by the way, and throw it to the exit from the hole by webby hind legs.
Penguin female had been woken by shrill squeak of waitoreke. It happened that pair of these small beasts, not feeling any resistance from her side, has managed to dig rather deep side gallery before the male penguin has returned. For him the occurrence of these strange neighbours appeared a surprise, and he has taken them as unwelcome guests. Male has loudly hissed and clicked beak, and then has pinched wool of one beast. Its squeak was just a reason of female’s awakening, and she crept through the gallery outside to expel the extraneous visitors from hole. Waitoreke scared by female appeared literally squeezed between two birds in the underground gallery. To avoid punishment, it has literally stopped at nothing, having rushed under male penguin. Waitoreke has squeezed literally under his stomach, having pressed male penguin against wall and ceiling of the gallery, and having nearly squeezed out the fresh catch from his stomach. It has got out of the hole quickly and has rushed to bushes where the second animal of pair had already waited it. Despite of this incident, they are not going to leave far and are obviously going to continue what they’d started.
The pair of waitorekes expresses direct interest not so much to penguins, but mainly to their dwelling. The hole dug out by penguins seems very attractive for the pair of waitorekes, and they would like to settle there also, despite of resistance on the part of penguins. At first penguins related to this pair of waitorekes aggressively enough, because these beasts came too close to their nest. But gradually penguins have got used to the presence of waitorekes near the entrance of the hole – these animals do not do anything bad and do not disturb the brooding female. At the appearance of penguins waitorekes simply give them way to the nest, avoiding the conflicts. This pair of rodents has acted rather originally: they did not show claims for the whole hole occupied by penguins, and have only attached at some depth the side entrance from the main gallery and have engaged in their own building. Rodents dig a hole together, throwing out the ground outside, and in the gallery leading to the penguin nest heaps of the mellow ground accumulate. Waitorekes throw out a part of ground, and penguins involuntarily help them while get out of the hole – birds push out by breast in front of themselves some ground left by their new neighbours. But this is an only inconvenience which waitoreke have caused them. When the hole was ready, and the rests of the ground had been thrown out from it, penguins have almost ceased to notice the presence of waitorekes. Only sometimes penguins meet their neighbours at the entrance of the hole, but waitorekes let them pass, preferring to solve small life problems without conflicts.
From time to time waitorekes try to squeeze into penguin nest chamber, but female drives them away, hissing and clicking beak. She is still busy with brooding, and the incubation proceeds successfully. While waitorekes add their tunnel to the hole of penguins, almost two thirds of incubation term has passed. Less than one week remained before the hatching of posterity at birds. Till the whole time male regularly moves to fishing and supplies female with food, and also replaces her on nest.
To reach the river, male penguin prefers to use convenient pathway worn by waitorekes and animals do not pay attention to him when he waddles on the track. Some generations of waitorekes laid this track, and now it is convenient for movement: the track bends around obstacles and is smooth enough. But near the water the track runs through rich thickets of coastal plants, therefore the penguin has to slide on dirt on stomach, pushing by wings and legs. The penguin moves to feeding not alone: some waitoreke beasts of various sizes and ages hasten to the river side by side with him, mincing paws and having raised flat leathery tails above the ground. When the penguin has reached the edge of thickets, water became deep already; therefore the penguin has simply pushed by wings and paws against the bottom and plants, and has swam. Following the bird, his shaggy companions have almost silently dived into water.
Under water the penguin at once tries to leave thickets. It has already studied places of feeding and has remembered some escape ways in a case of predator’s attack. He also remembers the predators living in the river. Sometimes the penguin had to see large neohanasaki swimming through underwater thickets, and once only speed of swimming and responsiveness have saved him from an attack of one of such giants (maybe even, from the same one which he saw – penguins do not distinguish such predators “personally”, it is simply not necessary for them). And more recently the sunlight flash on scales betrayed the presence of huge ‘ika-taikaha – a monstrous fish with wide and toothed mouth and eternally insatiable famine. The penguin saw this fish only from apart, but it was a terrible reminder on presence of dangerous animals in water. Therefore the penguin began to behave much more cautiously, than at first.
While the penguin should leave from the riverbank for hunting, waitorekes do not make distant sorties, preferring to search for food in coastal thickets. Waitorekes dive not too deep, but it does not cause them any inconveniences. They eat mainly invertebrates – snails and insect larvae. And such forage can be found also in shallow water. Moreover, such animals usually do not differ in great speed of movement; therefore for waitoreke the skill of diving for a longer time has much greater value, than depth of diving.
Keeping in shallow water during the feeding, waitorekes avoid a set of troubles. Usually river predators live in deep water, and only neohanasaki can threaten these beasts when lies down on the bottom for a long time, mimicking the piece of driftwood and waiting while careless waitoreke will swim up closer, not noticing danger.
Male penguin has gone fishing once again. He managed to catch several small fishes, and had a rest, swimming on the surface of water. The sky above him is clean, and only voices of New Zealand false ravens and hoarse call of eagle kea somewhere in the distance are heard. Having inhaled full lungs of air, the penguin has dived. The school of small fishes has rushed in all directions when he has swum along the thickets, searching for the pass leading to the land. Waitorekes used it for many generations, and plants expand worse in this place – they are in regular way pulled out or simply beat by paws and tails. Some more minutes, and he will get out on land. The penguin has very good underwater vision, and he notices how here and there above thickets air bubbles raise – waitorekes are searching for food. The usual picture, which he has already got used to observe, has a little bit dulled perception of the bird, therefore the penguin not at once has noticed something else – also well familiar, but for absolutely different reason.
Among plants the scaly back of large creature with tall fin has flashed, and from movements of tail thickets waved as if in strong current, and on surface some plants has emerged, being pulled out by tail of this creature. Cross-striped colouring of sides does not leave any doubts: it is the adult ‘ika-taikaha. The huge fish usually hunts in deep water, but, possibly, it had been involved by waitorekes swimming among plants. Presence of the monster has forced the penguin to rush to land. Forcing the way through thickets and dropping from itself long leaves of the plants twisting wings and paws, the penguin has got out on land somewhere aside from the track and has rushed away from water. His panic was seen only by one waitoreke which had uttered loud whistle – warning signal which penguins have learnt well, living near to waitorekes. Some animals, having heard this signal, have got out of water and began looking around and trying to find a reason of danger; but some animals being under water at this time, have continued search of food. Animals did not see danger and did not know where to look, and warning signal was single and was supported with nothing. Therefore, not having felt a smell of predator and not having seen a silhouette of predatory bird on trees, some waitorekes have made the great mistake: they returned in water again. And only one of the beasts, appeared, probably, more cautious than the others, has remained on land. And it had become an eyewitness of awful scene.
Among thickets the scaly back has appeared, shining in sunlight. A certain creature many times larger compared to waitoreke has made a rush, moving plant thickets apart by head. Strong tail splashed water, and the creature turned around in thickets, showing its cross-striped side. For one second the head of the underwater giant appeared, large yellow eye has flashed in sunlight and struggling body of waitoreke caught by fish has flashed. Some more impacts of tail followed, and the monster have got out of thickets. Only its back fin has struck the surface of water, and from river bed the cloud of silt has risen, marking the way of fish. Everything had last for some seconds only, but waitorekes scared by appearing of huge fish have not soon dared enter water. Adult ‘ika-taikaha fishes seldom appear in shallow water thickets, but their juveniles frequently appear objects of hunting from the side of waitorekes. Maybe, the beasts pursuing and devouring small striped fishes in underwater thickets, do not guess, that these creatures and the giant fear installing in them belong to the same kind, and, probably, represent its progeny. But laws of a nature are those, that for the sake of occurrence of one adult ‘ika-taikaha hundreds of its relatives should perish, especially at early age.
Spring is most favorable time to bear the progeny, and almost at all water inhabitants there comes breeding season in spring – at some ones it takes place earlier, at others later. Light day becomes longer, and fresh water rich in oxygen entering the lake from the mountain rivers stimulates changes in appearance and behaviour of neohanasaki males. One male of this species has chosen for courtship games a site of the lake shore overgrown with aquatic plants, near the place of confluence of small wood stream. Neohanasaki does not mark borders of its territory with specific smell or visual marks – it simply patrols borders of individual territory, furiously driving away possible competitors. Within several days its appearance gradually changes: the stomach turns bright yellow color with dark spots scattered on it, and on skin plica bordering tail fin peaked jags appear. The outlines of the male swimming near the surface of water in sunlight look very much recognizably and represent thus the warning for others males which would decide to intrude to its spawning area. Attracting the female, male is not hidden, as it behaves during the hunting, but swims at the place covered by the sun, from time to time plopping by tail on water surface. If on his site the female would come, as a sign of submission she would keep in depth, and would appreciate the colouring of male’s belly. And male will make everything for her to be impressed by his magnificence and force. But frequently the magnificent display involves another male instead of female, and his intentions appear rather aggressive.
Neohanasaki male swims in circles above thickets of pondweed with long stems. From time to time he dives to bottom and with the help of flat head pulls out any bush of plant, which seems to him as superfluous in his territory. Some bunches of grass already float on the surface of water, and male moves them away by head, because it prevents him to display himself. Occupied with cares of the territory, it does not notice, how above the bottom the oblong brown creature with flat head and short paws – its congener – is moving. Having driven away the bush floating at the surface of water by muzzle, male has begun its courtship display – it turned around and has swum along borders of its territory, rising to the surface and churning the water with movements of its tail. He has swum some meters when has felt, that his tail as if has got in a vice: the competitor which has made a way secretively to his territory and hidden for any time at the bottom has seized his tail from below and has hung down on it. The moment for attack was chosen very successfully – impressive display of the owner of territory was interrupted at the most improper moment. The owner has made an effort, having dodged sharply, and his tail escaped from competitor’s jaws. Now they appeared face to face on equal terms. Stranger male is almost equal in size to the owner of territory, is obviously full of ambitions and is not going to recede. Therefore the owner of territory has made the only true decision – he has immediately attacked this stranger. He has seized skin on one side of stranger male and at the same moment turned its body in parallel to contender’s body, to avoid its bite. The attacked competitor has swum to the surface of water, and the owner of territory has hung on its skin, seizing its jaws. The skin of neohanasaki hangs from each side of its body in soft plicae; therefore it hardly can be injured. But the might of jaws at neohanasaki is great, and the bitten male all the same feels an acute pain. Trying to dump from itself the furious owner of territory, it began rolling as if a spindle, at the surface of water, plopping by tail. But the owner of territory does not hurry up to unclench its jaws at all: the stranger has not taken to flight yet. Continuing keeping the attacked contender, he scratches by short paws its skin and beats the contender’s tail by its one. Fight proceeds about twenty minutes; from time to time both amphibians lay motionless at the surface of water, twisting their bodies around each other’s, but then fight proceeds with renewed vigour, being accompanied by splashes and tail plops. At last, there comes an outcome: stranger male gets away, having dived to the bottom. The owner of territory pursues it only formally: blood and the killing of the contender are not the purposes of the combat; therefore the flight of the contender is quite enough for him.
Wounds at the winner male are minimal, and he continues the interrupted courtship display, swimming forth and back above the thickets brightly covered by the sun. At last, there comes the moment for the sake of which it works so hard: near the border of his territory the female appears. She behaves peacefully, displaying humility in all features of behaviour: she moves above the bottom, stopping when male appears near her. She swims ahead closer and closer to the center of male’s territory where he continues displaying himself. His stomach is brightly coloured, and this colouring as if fascinates the female when male swims right above her. Male touches the female by its stomach for some times, swimming above her, and then cautiously bites her skin on back. Female endures the pain, showing her humility, but male bites her skin only slightly and not for long – it is not a combat, and he has no desire to banish the female.
Female has remained at the male’s territory for night, and in the morning right after the sunrise courtship games of huge amphibians have begun. Neohanasakis spawn far away from the coastal zone covered with decomposed corpses of rangitahi frogs. They prefer spawning eggs in clean water among plants. At the sunrise male began to show its force to the female: he began closing the way to her, turning the side to her and shuddering with the whole body. When female turns away from him, male again swims forward and stops, crossing her way by his tail. At last, female has ceased avoiding him and has remained where she was. It became the stimulus for the second part of courtship games. Male has emerged to the surface of water and began to swim above the female in circles, loudly plopping by tail on water and displaying its bright belly. Having dived, male has gathered speed, rising to the surface, has jumped up, having put out from water almost half of his body, and then has plopped in water sideways. His activity became the stimulus for female which has also joined the race. Neohanasaki male and female began swimming in circles together, touching each other by sides. After several circles in thickness of water male has suddenly replaced a direction of movement and has rushed to the bottom. He was lowered into the thickets of aquatic plants, has cautiously crept among stalks, moving them apart by body, and then has crept out and has emerged above plants. The nest for posterity is ready. Having swam some times above the nest, neohanasaki male began pushing female to it, hooking her under stomach by wide head. He has cautiously brought female to thickets, has pushed her inside of thickets, has swam after her and has clasped her body with short legs, seizing by fingers skin plicae on her sides. Female has felt his touches and trembled by the whole body. She has strained and has spawned among plants the large portion of the eggs capsuled in slime cords like at frogs, their ancestors. Male has slipped to one side of female and has immediately fertilized eggs, and then female has spawned one more portion. While she spawned eggs, male did not let her off, but as soon as she has stopped it, male began pushing her aside from the clutch, driving out from thickets. When it seemed to him, that female leaves the nest insufficiently quickly, male has strongly pushed her by side, and then has bitten tip of her tail, having forced to retire. Female has played her role in breeding and now should move away. And male’s parental duties have just begun.
Male has remained to guard the clutch which gradually absorbs water and turns to the inflated slimy mass laying among stalks of pondweed bush chosen by parents. At this time male eats of nothing, having devoted itself entirely to protection of the future posterity. The fishes swimming nearby now become not prey, but enemies: if neohanasaki male will lose vigilance, the clutch would be destroyed by them less than in one hour. Therefore male has no right to leave from the nest within several days to come, and even for longer time. However, having slow metabolism characteristic for amphibians, neohanasaki male will not suffer at all: the age of this individual is over forty years, and he protected the progeny many times in succession.
Some days represent very short time for long-living neohanasaki, which age may reach 90 years. In fact, the large individual, since the certain size, has no enemies, and the animal can live as much time, as its organism is able to function, fading away from natural old age. But for those ones which only prepare to get in this world, such time may appear crucial. The small creature already from the entering the world has numerous enemies; therefore the parental care is a quite good help even for the future large predator. At the entering the world its length is hardly more than length of finger of its own father. It is just a real size of newly emerged neohanasaki tadpoles – they are small and helpless creatures which can be eaten by almost any fish in this lake. The slimy mass shrouding eggs is gradually dissolving, and the developed tadpoles get out of it and hang on leaves and stalks in pondweed bush in which eggs had been spawned. Near to this bush male is on duty. It has felt by smell that there is an important event for which he waited during all last few days, and in reply to smell of hatched tadpoles in his organism the important changes have started to proceed. Tadpoles will spend the first day, hanging motionlessly on the plant and absorbing stocks of yolk from resolving yolk sac, but then they become to move actively and for them another food is required. And neohanasaki male has engaged in manufacture of baby food in literal sense.
In the evening neohanasaki male had cautiously got into the bush of pondweed and has felt easy touches to his skin. And in the next morning the whole brood of tadpoles is already moved on his back and sides. And it has served as stimulus for the next phase of parental behaviour at this huge amphibian. The skin on back and sides of neohanasaki male began swell, and its top layer began to exfoliate, being mixed with plentifully secreting slime. But while earlier slime served only for greasing at movement in water and as protection against parasites and infections, now when hundreds small mouths pinch skin, it has got temporarily some nutritious properties. The male’s organism spends its own nutrients for manufacturing of food for posterity, and this is a quite favourable adaptation allowing lowering of the dependence of survival of neohanasaki tadpoles from presence and abundance of food in the most difficult first days of their life.
Tadpoles attach to father’s skin by sucker-like mouths and scrape off the top layer of skin. They do not leave from the male and surround him like bee swarm. If there will be a necessity, male will protect them against almost any danger.
Spring is the time of occurrence of new life. Birds in forest are occupied with brooding eggs or bringing up of nestlings, and in waitoreke colony some females have already given birth. In life of the penguins settled in waitoreke colony important changes also take place. A little more than one month has passed in total from the moment when the pair of penguins had been expelled from the colony of congeners. Maybe, the breeding instinct has forced this pair to settle in waitoreke colony, and there comes a new stage of coexistence of two kinds of animals simultaneously similar to and different from each other. At last, the most important day in life of this pair has come. Even yesterday female had heard how from eggs thin voices of the chicks ready to hatch sound. And now she feels that changes come to the nearest minutes. Tiny beak began to punch shell from within. After the first blows on shell little crack has appeared, which becomes longer and longer with each new pecking. At last, from one egg the triangular piece of shell breaks away, and in the aperture formed in twilight of nest female sees a beak of the chick punching for itself the road to the wide world. The second egg also rocks, and inside it the second chick tries to peck through the shell. Female does not interfere with a natural course of chicks hatching, and only rows up eggs under her sides by wings. She feels how chicks became more active in heat and have started to hollow shell stronger. At last, approximately in three hours after occurrence of the first opening in shell, female has felt, as the egg-shell has broken in two parts, and something has nestled against her side – something soft, warm and wet. Now it has healthy and strong penguin chick, which cannot stand on legs yet and requires heat. Female has cautiously taken from under her side broken egg shells and has split them by impacts of beak, and then began to eat the pieces. Small stones in her stomach will pound shell to powder. She feels how the second chick also tries to get out from shell: the second egg moves under her side. Approximately in half an hour its efforts also hade crowned with success, and female has felt touches of both of her chicks.
When male has returned, he has felt at once, that something has changed in nest. Even while moving in gallery he has heard absolutely new sound which female utters – a silent guttural cackle. And the most important is that he has heard also two squeaky voices answered her. And when female has risen from the ground at his approach, male has seen even in darkness of nest against the background of white plumage of female’s stomach two chicks having dark down.
Somewhere in gallery rustle was heard. Changes in home life have drawn attention of neighbours of penguins – of waitoreke pair. One of beasts has cautiously gone down to penguins, but it was met not with the hearty welcome – both adult birds have hissed and clicked beaks. Fairly being afraid of the annoyed birds, waitoreke has rushed up the gallery and has disappeared in their part of a common hole.
The parental care is an important advantage which is received by neohanasaki tadpoles compared to larvae of many other kinds of New Zealand amphibians. The survival rate of posterity at this kind is very low – too much time passes up to the sexual maturity, but even at this time full safety is not guaranteed to young animal. And young tadpoles of the first days of life are very vulnerable in general – not only almost any fish, but even the water beetle can eat them. And father gives them both food and protection.
Protection never happens absolute: despite of presence of the adult neohanasaki male, predators do not miss an opportunity to attack his posterity. The huge amphibian is strong, but too sluggish, therefore having a certain measure of dexterity it is possible to try to attack its posterity and to leave unpunished. And one of lake predators tries to attack neohanasaki tadpoles – it is large live-bearing fish ‘ika-kaihopu, a sort of “pike” of the New Zealand rivers. It is able to mask dexterously and to attack quickly. And the help in masking to it is rendered, strangely enough, by neohanasaki male. Preparing the place for spawning, the amphibian has torn out from the bottom some bushes of pondweed, and now one of them floats at a surface of the water, being carried by wind. But this bush is floating not alone – near to it adult ‘ika-kaihopu slowly moves. The wind drives pondweed bush at the some distance from neohanasaki male looking after posterity, and fish would have an occasion to leave shelter for an attack. But now it is coming nearer to the male under covering of the plant. Danger for neohanasaki juveniles is quite real – this fish feeds on animals of just their size and is capable to swallow a tadpole easily. But the wind gradually drives drifting pondweed bush aside, and the fish is compelled to leave it. It simply stays where it was when the plant floats away. ‘Ika-kaihopu moves very cautiously, trying to not give out its presence. Its colouring has turned much paler, and the body is almost completely motionless: one pectoral fin on the side turned to opposite side from neohanasaki male with posterity works only. The fish even breathes very cautiously, having slightly opened its mouth and slightly moving with branchiate covers. It comes nearer to neohanasaki brood very slowly, keeping its eyes on tadpoles scurrying carelessly above the male’s back. The distance between predator and prey is gradually reduced.
Movement of tail of neohanasaki has lifted a cloud of sand and silt from the bottom, having pulled out thus one more bush of aquatic plant, and frightened tadpoles have rushed in all directions and have disappeared among plants. Neohanasaki male has noticed the danger coming nearer right in proper time and has made the true decision – to attack first. Maybe, he could not catch ‘ika-kaihopu at the moment of its attack, but now the predator has made for his posterity much more. When clubs of silt began to dissipate, and sand fallen down to the bottom, the tadpoles scared by sharp movement of neohanasaki male, began to come back to his safe back. Their father lies among pondweed thickets as before, but now there is one essential difference: he holds convulsively moving fish in its mouth. This time speed has lost to brute force, and life abandons a body ‘ika-kaihopu in clouds of its blood. Involved with a smell of blood of prey, neohanasaki tadpoles swim right near the father’s jaws, forcing him to wait with dinner swallowing. At last, male is bothered with it. He shakes his head, frightening tadpoles away, and squeezes jaws. The bite smashes head of predatory fish, and under water weak crash is heard. Having slightly opened jaws, neohanasaki male turns prey head to him and swallows it entirely.
The predator is defeated, and this time the posterity is saved. In some days the male’s parental instinct will fade and posterity will be given to itself. But now, while male protects posterity, any animal in which he would see any threat for tadpoles will not come nearer to them. On the other hand, if to find the correct approach, it is possible not to be afraid even of such monster.
Neohanasaki male does not see anything suspicious in rotten leaflet with strongly destroyed edges floating closer to him. He has bad sight, and he simply does not distinguish this leaflet from some more ones floating on the surface of water. The lake is surrounded with forests, and there are lots of fallen leaves in water. But the giant does not suspect at all, that it has become a victim of the dexterous deceit. The rotten leaflet to which he has not paid any attention, is actually not floating at will of current, but is swimming actively and its final aim is back or side of this neohanasaki. Tadpoles also do not differ neither in visual acuity, nor in ingenuity; therefore they are not noticing that the stranger, even harmless, is swimming to them. The edges of leaf begun to rot represent only the illusion, a pattern of dark brown spots on bright green background of body of small fish with deep body strongly compressed from sides. It is a tiny viviparous fish ‘ika-‘iti, or leaf-mimic live-bearer. Masking is its only protection against enemies, and at this kind it is brought to perfection. Transparent fins do not break the accuracy of leaf imitation, allowing fish to move cautiously to smaller prey, and if necessary to imitate plausibly the rotten leaf of tree. Neohanasaki tadpoles are too large for it to be its prey, and ‘ika-‘iti is not going to attack them. It is interested with food of other kind: of skin secretions of neohanasaki male. ‘Ika-‘iti is an omnivorous fish, and it willingly uses a gratuitous entertainment in case of opportunity. The thing impossible to make to large predator is easily succeeded by small peaceful fish: it cautiously swims up to the huge amphibian lying among plants, and moves into the school of neohanasaki tadpoles. Tadpoles creep on skin of their father, scratching out nutritious skin secretions, and cautious ‘ika-‘iti shares their meal. Its mouth is capable to extend like a tube: the distant relative of this kind is predatory ‘ika-kaihopu. But, using its tiny size and masking, makes things inaccessible for ‘ika-kaihopu: having “standing on head”, it pinches accurately flakes of nutritious slime from skin of the amphibian. The predator does not notice a stranger among its own posterity and cannot distinguish its own progeny from strangers. And if he would manage to distinguish them, how would he separate the own progeny from strangers? For him ‘ika-‘iti feasting among tadpoles is only a small leaf. It is good that ‘ika-‘iti does not represent any direct danger to neohanasaki tadpoles. And they will be protected by father from the other troubles.
Not all tadpoles have the same luck with parental care. Rangitahi tadpoles initially lack of parental care – features of biology of this species are those. The only things that parents could make for them are to protect, as far as possible, developing eggs and… to fertilize shoalinesses with their own bodies. And they have fertilized water with organic substances so strongly, that in some gulfs it even became yellowish and muddy. Decomposed bodies of rangitahi frogs have caused plentiful development of microorganisms, and after them also of microscopic crustaceans and worms turning to food for larger inhabitants of lake including rangitahi tadpoles. Tiny, almost threadlike tadpoles hide in great numbers among plants. They scrape stalks and leaves of underwater plants, and also bones of, maybe, their own parents. Sometimes tadpoles rush to thickness of water, seize infusorians, crustaceans or worms floating by, and then hide in shelters again. They are numerous, but too vulnerable for predators – many inhabitants of lake would like to diversify their diet with these soft and defenseless creatures. Therefore their escape is in being careful. But there are predators which succeed to lull the vigilance of rangitahi tadpoles.
‘Ika-‘iti is an expert in masking. One fish of this kind has hidden under thickets of floating Azolla fern which is driven by the wind on the surface of water. Having masked, is swimming above shoaliness which has served both as nuptial bed and a tomb for rangitahi frogs during some weeks passed. Among plants numerous thin translucent tadpoles swim, being hardly distinct in thickness of water. They quickly hide, when near them small fishes or water beetles swim by. Care saved their lives more than once, and still will save many more times. But all the same some of them will lose the life to any predator which would appear more successful, quicker, more cautious, or… more imperceptible. Azolla thickets involve tadpoles. This plant gives shadow which helps them to hide from enemies, and on the bottom surface of plants it is possible to find many edible microscopic animals. Tadpoles at lightning speed cross the distance of some centimeters between thickets of plants at the bottom and floating islet of Azolla fern. They at once attach by mouths to roots of fern and begin scraping the cover of microscopic animals, not paying attention to the thing looking simply like the leaf begun to rot from sides. They obviously do not notice a danger which is quite real. ‘Ika-‘iti stays motionless among roots of plant hanging down in water, slightly moving its fins. Its masking is perfect enough to deceive even sharp-sighted predators. And rangitahi tadpoles with their bad sight are easy to deceit.
One small tadpole has swum up to the head of the hidden fish. ‘Ika-‘iti lays in pose unnatural for fish, on one side, head turned downwards. The tadpole has cautiously touched its skin by lips and gathered from it the stuck particles of vegetative dust. ‘Ika-‘iti is motionless; only its eye slightly turns, watching the tadpole. When nothing suspecting rangitahi tadpole appeared near to its head, ‘ika-‘iti has opened its mouth, having extended its like a tube, and has soaked it up in single fast movement. Other tadpoles scurrying among Azolla roots have not noticed disappearance of their relative, and have continued so careless feeding… disappearing imperceptibly in ‘ika-‘iti’s mouth. The fish has had time to be sated before tadpoles have felt the threat emanating from it. And when it was moved carelessly, the scared tadpoles have rushed downwards and have disappeared in silt and among plants.
But protection which plants and silt give is not also absolute. The rivers and lakes of archipelago are inhabited by various species of fishes adapted to different ways of food getting. Therefore, having disappeared from ‘ika-‘iti, tadpoles of rangitahi frog appear vulnerable for another inhabitant of lake. Small fish with narrow and lengthened body comes up from shelter representing small hole which walls are stuck by slime. It is not able to swim quickly, but slides and wriggles among plants dexterously. It has small eyes, and in sides of its mouth the pair of short wattles grows. It keeps very cautiously, disappearing in silt and vegetative dust at the slightest signs of danger. It is rahirahi galaxia, one of few truly New Zealand kinds of fishes. The significant part of rahirahi galaxia population inhabits the rivers, and in lake this species lives mainly near the shore, avoiding its deep-water areas.
Due to the sensitive cells concentrated in short wattles rahirahi galaxia feels the presence of the tadpoles dug in silt even if it does not see them directly. But rangitahi tadpoles are so numerous, that to a fish is enough to stick its head into silt in any casual place to find out a tadpole. Rahirahi galaxia swims above the bottom, shaking head in sides, and its wattles at this time strike on the top layer of silt. Suddenly fish rushes violently headfirst into the silt in a little cloud of silt. Its long spotty body wriggles in silt and one second later its head flashes; the struggling tail of rangitahi tadpole sticks out from its mouth. Galaxia quickly swallows it and then continues search for prey.
Some tadpoles did not feel any parental care from the moment of coming into the world, and others will lose it very soon and will be compelled to struggle for the existence alone. Parental cares of neohanasaki male come to an end. For some times he drove away from the posterity certain predatory fishes, and once even too curious penguin. His tadpoles have appreciably grown up, feeding on plentiful food the male had gave them during all these days, and their number has almost not changed, but for the death of several individuals weak from birth and casual victims of small predators like water beetles from which the male cannot protect the posterity. The giant lies among plants, resembling externally a mossy log. His skin has turned pale, and in some places its top layer exfoliates like rags from under which the new smooth skin is visible. Male lies motionlessly, from time to time scratching body by short paws. One hind leg has seized skin plica on one side and has pulled it. The peeled layer of epidermis has easily slipped off, exposing bright brown skin. Neohanasaki male has bad vision now – the skin on its head also flakes off and exfoliates, closing its naturally small eyes. Having jerked, male has scared away tadpoles which still surround him looking like a bee swarm. The skin on his jaws exfoliated, and he has waggled the forward part of its body, trying to free from rags of skin. At last male has simply crept forward through rich thickets of pondweed. Tatters of skin were hooked against the plant, and the large amphibian has continued movement, feeling as old epidermis peels off from him as an entire layer. Tadpoles follow the father as they always did in their life so short yet, but now he does not pay attention to them anymore. Male jerks some more time, and then waves its tail and swims forward. His old skin has remained among thickets, and after the moulting his parental cares come to an end. Now he can live his own life till the next spring. Moving its tail, neohanasaki male has disappeared in greenish depth of lake, and only among pondweed thickets his old skin sways as white translucent tatter. As if trying to take everything that father can give them, tadpoles scrape his peeled off skin, gathering the rests of “baby food” produced by the organism of male protected them. When this food will be over, they must come to live independently, relying only to their own abilities.
In colony of New Zealand mountain penguins located in forest at the lake shore numerous chicks had hatched: almost at each pair of adults two chicks have appeared. At some birds one of chicks has already had time to dies, and they bring up the only offspring. However, if the pair of birds not amicable or has insufficient experience in chick rearing, the death of one chick lets them bringing up the second one successfully. But the experienced pair of birds easily copes with bringing up of two chicks at once. But now it is too early to talk about success or failure of any pair in bringing up the posterity – their chicks have just got out of holes. And now, maybe, only absolutely deaf predator would not find a colony of penguins. Demanding their portion of food, chicks cry loudly. Having seen their parent coming back from fishing, they run towards it and inevitably get on another’s territory, causing displeasure of its owners. Borders of territories at this time are broken at least every some minutes, and to calls of chicks craving for food voices of displeased neighbours, banishing strangers from their territory, join also. Some chicks living at the edge of the colony and closer to the paths leading to the lake prefer to wait for parents and other colony members right at the path, under fronds of ferns grown up appreciably from the beginning of spring. Noticing any congener hurrying up to get home after successful fishing, chicks one by one or in pairs rush to it, scrounging food actively. Sometimes the effect of suddenness works: the penguin belches the caught fish before it understands that not its own chicks are fed now. Frequently chicks get pokes and pecks, but sometimes they succeed to profit by gratuitous food. In addition it is possible to have a sleep in shadow under ferns in relative rest from other members of colony.
The location of penguin colony is well familiar to ruacapangi – large predatory bird controlling this part of forest. In second half of spring eagle kea, the assistant and the informer of this feathery predator, is busy with its own private life, and ruacapangi hunts alone. However, even without the assistant ruacapangi hunts successfully enough. In spring in forest it is possible to find lots of young animals of various species, and ruacapangi does not miss an opportunity to attack the inexperienced animals not capable to repulse.
Wet rotten foliage, soft moss and sappy shoots of grass muffle steps of ruacapangi. The bird has heard voices of penguins from apart and has decided to push its luck. Ruacapangi creeps to penguin colony cautiously, bending down and standing motionless for a long time. It is able to be patient and chooses the proper moment for an attack. Ruacapangi steps very cautiously, trying to not make superfluous noise: bird has a wide experience of hunting, and it is able to prey even cautious animals. Low-sized penguins do not notice ruacapangi, and it allows this bird to come close enough to their colony. And when one of birds has noticed this predator nevertheless, it was too late.
Ruacapangi has rushed to penguin colony and in some strides appeared almost in its center. Warning signal was late hopelessly, and not all penguins managed to hide in their holes. Some of them, saving their lives, have rushed to another’s holes, but at this time they have not met repulse from the part of owners which also have preferred to squeeze deeper and to keep silence, hoping, that the predator will pass by. The worst of all was the situation of several chicks lived at the edge of the colony: they simply had not time to reach holes, and now are compelled to hide from bird’s sight among ferns surrounding them. And it is rather risky occupation – to deceive ruacapangi, it is necessary to have considerable self-restrain. Not any forest inhabitant can keep an absolute immovability and hold its breath when this ruthless predator, having also acute hearing, passes by. Penguin chicks are simply not able to hide from the enemy in forest; therefore they are threatened with real danger.
Ruacapangi walks in colony of penguins, listening and looking in sides. Birds were squeezed deep in holes; therefore ruacapangi hardly can get them, even if it will push head into the hole. And this bird also has not enough forces to dig out a hole – stones near to which penguins arrange entrances to the holes prevent this predator to do it. Nevertheless, the bird does not hurry up to leave a colony of penguins – it walks across it, listening carefully. And then it walks along the edge of a colony turned to lake, where tracks, on which birds return home, come to an end.
Penguin chicks look in horror at huge bird wandering across the colony. At the instinctive level they understand, that it is a dangerous creature: in general, every animal larger, than the penguin, may represent any danger for it. And this bird expresses obvious interest to holes of penguins, and its appearing had been connected to an alarm signal. Chicks have remembered this lesson, but they do not know the most important thing – how to avoid danger which this monster represents. The best way to protect against ruacapangi would be a complete immovability: having nestled against the fern or even having slightly dug in wood litter, penguin chick would be imperceptible for this bird. The black down of chicks would help them literally to dissolve among forest shadows. But they still have not enough experience to play such games with fatally dangerous predator.
One chick has not sustained a tension: when ruacapangi has gone along the edge of colony, it has rushed ahead, hoping to escape from the predator in forest. Predator’s reaction had been instant: ruacapangi has turned around, has made long jump, has picked up an escaping chick, has thrown it up, has caught and has swallowed entirely. But this tragic event has helped several another penguin chicks to escape: when ruacapangi has run for that chick, they managed to reach the nearest holes and to hide there. Of course, these were another’s holes, but in the face of real danger, all members of colony are equal and it frequently saves their lives in the dangerous world these islands turned to after the ending of human epoch.
Waitoreke colony, in which penguins left from a colony of relatives have settled, is also not a quiet place. Waitoreke themselves behave peacefully enough relatively to each other and between them the conflicts connected to quarrels for territory or food flash much less often. But in waitoreke colony there are specific problems. These small mammals have a lot of enemies from which it is necessary to defend themselves.
Predators observe of waitoreke colony from the tree. The pair of New Zealand false ravens is going to hunt these animals. Birds, usually noisy and appreciable, behave silently and cautiously, trying to hide in branches. This tactics paid back for many times: usually waitorekes trust smells and sounds, and their sight is insufficiently keen to distinguish a raven among branches, and additionally at the great height. But now there are not only waitorekes in colony and the pair of ravens did not consider this important circumstance. While the penguin female is fishing at the river, male keeps in touch with the situation. His attention was not escaped by small black down feather whirling in air. Having raised head upwards, the penguin has seen how among branches the large black bird cautiously moves, and on next branch one more bird perches. The shape of these birds is very recognizable, and the penguin, having uttered a short alarm signal, has rushed to the hole. He has pushed two curious chicks deeper inside the nest chamber, and turned around head to the entrance, ready to give fight to any enemy which would want to enter the hole.
The alarm of the penguin was noticed by his neighbours in proper time. Having seen how the penguin has absolutely unexpectedly rushed to the hole, one waitoreke beast has uttered warning whistle and has disappeared in hole. Some more animals repeated its signal, and from the river, as if an echo, congeners have responded. The waitoreke colony, full of life even few seconds ago, as if became deserted. Beasts, not having understood at all, from where the danger comes, have warned about it their relatives and have hidden.
New Zealand false ravens have flied down from tree to waitoreke colony. They had been noticed, therefore now birds have no sense to hide. Vigilance of the penguin has complicated their hunting, but has not made it completely impossible: ravens have in reserve many ways of food getting. But at first birds want to look round and to define what tactics can be used. Two ravens wander on the ground, look around and poke beaks into holes. Some holes are empty, and other ones are too deep to make possible for them to discern something inside. It does not stop ravens: they compensate absence of any opportunities with the ability of using of objects of world around for their purposes. Birds of this kind have skills of use of simple tools – various objects found in nature. The experience of tool using is transferring from parents to posterity, and individual skills of tool use are improved within the all further life. New Zealand false raven female has looked round, and then has walked to the edge of waitoreke colony. She has found out in bush a dry stick fallen from the tree growing beside. The bird has pulled out this stick from bush, having broken thus a twig on its side. It is easy for making – stick is dry and fragile. Moving back, bird had dragged the stick to the place between holes free from bushes. Having taken it for thicker end, raven female has clumsily approached to one hole and has put it into the hole by sharp movement. The answer was a squeak from depths of hole – this waitoreke was at home. Raven female has put stick even deeper, and squeak has repeated. The bird has dragged stick from the hole and has glanced inside with one eye again. Having discerned of nothing, she has used the stick again, but this time the silence was an answer to her actions. Raven female has moved stick in hole, and then has put it inside of hole so deep, that her head and neck appeared in hole up to shoulders level. But it appeared ineffectual. Waitorekes also have some tricks in reserve. If the hole would have only one exit, it would become a trap for its owner; therefore some neighbouring holes of waitorekes are necessarily connected by tunnels. When raven female has taken stick out from the hole, she has made a mistake: she has simply allowed the beast to escape in the next hole. While the pair of ravens walks in waitoreke colony, beasts prefer to stay in holes. They only cautiously observe of birds, having put out from holes only noses, and instantly hide when ravens only take a look in their side. The penguin, staying in the hole, also does not hurry up to get out outside. Maybe, if these ravens would have decided to engage in robbery in colony of penguins instead of waitorekes, the population of the colony would render them worthy repulse. But local inhabitants obviously prefer the different tactics of protection; therefore the penguin left alone to protection of the dwelling, would look rather strange and would subject itself to real danger, not having any support from among waitorekes. Therefore he also has preferred to hide in hole while enemies wander in the colony.
Penguin chicks hatched in waitoreke colony gradually grow up. Waitorekes perceive them as members of the colony, therefore penguin chicks are in safety though waitorekes frequently rob, eating chicks of ducks and other waterfowl. Penguin chicks are already bored to stay in dark hole, and they wish to get acquainted of the world around. Curiosity takes top above care, and every next day chicks move closer to an exit from the hole. Light and the sounds getting into the gallery from an entrance draw their attention.
The first members of colony which penguin chicks have got acquainted closer are their neighbours – breeding pair of waitoreke attached their hole to the hole of penguins. When penguin chicks impelled by curiosity began creeping up the gallery, they had found on their way the entrance to waitoreke hole. One of penguin chicks has cautiously glanced into the hole and has immediately recoiled back. From the hole the whiskered muzzle of waitoreke female appeared. Chicks had been frightened a lot – they had never seen these animals so close before. But waitoreke female has only sniffed at them, showing its large incisors with yellowish enamel. Chicks smell the same as adult penguins to which smell waitorekes have got used. Therefore after the short acquaintance with penguin chicks waitoreke female has moved back, turned around and disappeared in depth of its hole. And there, above, literally in ten penguin steps, the huge world is stretched, attracting by its novelty. Penguin chicks make some more steps towards to this new world, but… The acquaintance of it is delayed for any time: waitoreke male has returned home. It was also interested with two creatures that seem to be covered with black wool, which stand in gallery right at its way. Waitoreke male has taken a view, and then has smelt them. Its caution is evident: they are the first chicks of New Zealand mountain penguin which it happens to see in the life and so closely in addition. But the familiar smell coming from them has calmed it and has removed the mistrust. Having looked at chicks once again, waitoreke male has made some steps towards them. Chicks have delayed, and it had to stick nearest of them with head in order to force it to recede back. Pushing them step by step, waitoreke male has reached an entrance to its hole and has disappeared there. And chicks have cautiously hobbled to meet the world around.
Not having got out from the hole yet, chicks have already felt a diversity of the world in which they should live. Sun beams penetrate tree crones, the foliage rustles in wind, and somewhere in height strange and unfamiliar sounds – calls of local birds – are heard. Branches of bush under which the hole is dug out, partly close their field of view, but even the small part of things seen by chicks from the hole impressed them a lot. They cautiously move to the exit, looking around and listening to sounds of world around. Some more steps – and chicks already stand at the edge of the hole. They extend necks and take a look from the hole for the first time. The world around strongly differs from the nest chamber which seems now so close to them. Above their heads branches of bush stretch, hiding an entrance to the hole from curious sights of some forest inhabitants. Chicks inhale the fresh air strongly differing from air in their hole smelling as ammonia. Their eyes gradually get used to the variety of colours of world around, but chicks still behave very cautiously and do not dare to depart even to a single step from the hole.
Behind backs of chicks footfall of small paws was heard followed by dissatisfied puffing. Waitoreke pair has left their hole and has decided to go to the river to have a meal. And penguin chicks standing at an entrance of the hole obviously prevent them to pass. Waitoreke female wants to get out from the hole the first. She cautiously pushes penguin chicks by head, but they do not hurry up to let her pass. Not seeing what is happening, waitoreke male has simply bitten female’s hip in order to stimulate her to move quicker, and the female, having screamed, has pushed penguin chicks away and has got outside. After her male has got out from the hole and both beasts have run on the track leading to the river. And chicks have quickly returned to the entrance of hole. Now the world around seems to them too obscure and frightening. But one sound has forced them to quicken: from the side of track the voice of their mother coming back with full stomach of small fine fish and tadpoles was heard. Chicks began to look around and to cry loudly, calling the mother to them. In reply to their calls the voice of mother is heard all closer and closer. At last, chicks have seen how mother squeezes to them under branches of bush and have rushed to her together, loudly asking for food.
Due to plentiful feed penguin chicks grow quickly. In waitoreke colony they do not have competitors, because penguins and waitorekes eat different animals and hunt in different places of the river. Besides young waitorekes have no habit to take away each other’s food, therefore nobody of them encroaches on food which brought to chicks by parents. Only occasionally young waitorekes watch how penguin chicks get food from mouths of their parents, but do not make attempts to take it away as it would happen by all means in the colony of penguins. Gradually young penguins turn brave and begin to walk off from the hole, being interested in life of waitorekes. They do not see relatives around of themselves, therefore prefer to keep side by side and frequently even nestle against each other by sides. Now their age is about one month, and they have considerably grown in comparison with the moment when they just hatched. Life of penguin chicks without coevals would be boring, but young waitorekes add some diversity in it. Waitoreke cubs constantly scurry beside, busy with games and learning the world around. They caper, having raised flattened tails, run one after another or struggle, scratching and slightly biting the contender. Sometimes in struggle some cubs take part at once; they form a live fluffy heap, pushing and biting their game partners. And then from under heap thin squeak of the cub appeared at the very bottom and pressed down by the others is heard. Chicks do not get involved in waitoreke cub games, but sometimes they should take part in them without their will. Waitoreke cubs like to creep behind very much silently, then to attack and to seize penguin chick’s tail, causing it to shrill loudly. Nothing threatens to chicks – waitoreke cubs like to play so with each other. If near them any adult penguin appears, waitoreke cub prefers not to continue this game – some most courageous ones of them have already received from birds strong impacts of beaks. But if parents are not present nearby, penguin chicks are compelled to protect themselves by their own means.
One young waitoreke has decided to enter the game with penguin chicks. Two penguin chicks stand on the ground, being heated in rays of sunlight penetrating through forest canopy. Their dark down allows them to get warm quickly, and they sunbath with pleasure. Warm and rest incline to dream, and eyes of chicks begin to close gradually. One of chicks still tries to struggle with dream, moving head up and forcing to open eyes, and the second one has already fallen asleep, having placed its beak in down on chest. At this moment young waitoreke has crept to them from behind and has seized tail of one penguin chick. Having squeaked with pain, penguin chick has rushed forward and has fallen down the ground, and young waitoreke has continued to pull and to slabber down on its tail. And then the second penguin chick has made an unexpected step: it has seized young waitoreke’s tail and has pulled it with effort to itself. Its beak has strongly seized tail of small waitoreke, and hind legs of tiny beast have come off the ground and have jerked in air: its forepaws keep for the ground, and teeth still bite a tail of another penguin chick. Having seized the moment, seized penguin chick has torn its tail out from teeth of waitoreke and has run off to some steps. And the second penguin chick has continued to keep young waitoreke by the tail. Feeling pain, seized beast has begun to squeak desperately, and others waitoreke cubs, having heard its voice, have stopped the games and have looked in its side. Seized cub has pulled out its tail from the beak of penguin chick with some efforts and has rushed to the hole, cheeping resentfully. The others cubs have gradually returned to their games and penguin chick have found again the place on the ground covered by sunlight and began to bask, waiting for parents with food. Now their life became little bit quieter: they have found a way to repulse too importunate neighbours, and they, in turn, became less importunate relatively to their feathery neighbours.
Waitorekes are not the unique mammals inhabiting forest, and are far from being the largest ones there. The waitoreke colony should frequently face with larger inhabitants of New Zealand forests. More often these are peaceful herbivorous beasts, but even from them it is possible for small beasts to wait for troubles, at least casual.
In spring at ultradama does fawns are born. Almost right after birth they are capable to follow mother, but all the same are vulnerable for such predators, as marsupial pardus and ruacapangi. Therefore does with fawns prefer to gather in small herd to protect them in common. Due to large size it succeeds for them easily to drive away small predators or to hold them at the safe distance from posterity.
In the forest a group of ultradamas moves slowly – it includes five adult does with fawns born approximately one month ago. The wool both at does and at fawns is covered with white spots on reddish-brown background. When different does and their posterity meet each other, individual distinctions in colour of wool of these animals become appreciable: at one doe wool is light brown with yellowish shade, and such color was inherited by both of her fawns. And at another doe, on the contrary, background colouring of wool has darker shade. Ultradama doe usually gives birth to two fawns, and only one young doe in this group takes care to the only fawn – it’s first-born one. The next year, having got stronger, it can give birth to twins, as usually takes place at this species.
Ultradama doe behave thoughtlessly and carelessly, arranging games and chasing each other among ferns and sickly bushes in underbrush. Adult does behave much more cautiously: there is an important reason to do so. Away from herd, observing a safe distance, ruacapangi follows – an adult bird, male in the prime of life. It has recently left its female and chicks of last year’s brood, and now, being not burdened with cares of posterity, presumes to itself to “shepherd” the herd of herbivorous beasts, waiting for an opportunity for an attack. Ultradama does smell it and sometimes see its brown plumage flashing among bushes. Therefore adult ultradama does try to keep between this bird and fawns to repulse in proper time a probable attack. Ruacapangi male is not going to attack them – of course, ultradama fawn has good taste, but now it cannot be preyed without meeting its mother ready to protect it. And crushing blows of hooves of its front legs can kill adult ruacapangi on the spot. The predatory bird is involved with another circumstance: at their movement in forest large animals disturb and frighten small animals which usually hide well, especially if they notice a predator. And such prey draws attention of ruacapangi.
Ultradamas go down to the river, and their way passes directly across waitoreke colony. Massive animals do not pay attention to smaller forest inhabitants and their occurrence in waitoreke colony is comparable in destructive power to act of nature. Some waitoreke holes appear caved in by hooves of these deer. The only thing that waitorekes can make is to run away from under hooves of large beasts, uttering loud alarm signals. Penguin hicks had never seen yet such large beasts so close, and they were very much frightened by ultradamas in spite of the fact that these animals are herbivores. They had time to disappear in hole and are only listening as hard blows of hooves of these animals sound through the ground. Many waitorekes also have preferred to hide in holes, but several animals in a colony simply have no place to hide in – their holes are destroyed, and they will need to dig out an entrance and to throw out from holes the crumbled ground.
Ultradamas had stopped for a while in waitoreke colony, feeding on bushes. Fawns half-heartedly taste food of adult animals, and then begin to play, chasing one another in the thickets of ferns surrounding the colony. But things, which seem to only a game to them, bring lots of inconveniences to inhabitants of the colony. Waitorekes are compelled to seek safety in flight from under legs of these unbidden visitors.
Occurrence of ruacapangi was fast and unexpected. The bird has rushed directly to playing ultradama fawns. They did not interest ruacapangi male by themselves, but their game has frightened away several young waitorekes noticed by feathery predator. Scared by the appearing of ruacapangi, ultradama fawns have rushed away with plaintive low, and their voices have forced adult does to take alarm. Large ultradama doe has rushed across the way to ruacapangi, forcing the bird to do sharp turn and jump. Ruacapangi managed to avoid a meeting with ultradama doe, but it has reared up and has made a leap in its side, ready if necessary to bring down killing hooves of front legs on it. Ruacapangi male had to recede – hit of hooves of ultradama would easily break its backbone or flatten out its skull. And this female is followed two more ultradamas also attacking ruacapangi. Forces are obviously unequal; therefore ruacapangi male has preferred to disappear in bush.
While giants are at war, small creatures are compelled to seek safety in flight. The majority of waitorekes managed to hide in holes, and some individuals are compelled to hide among ferns and under roots of trees. One waitoreke has rushed to the bush where the hole of penguins is located. Having seen an entrance of penguin holes, it crept inside and freeze. Penguin chicks see how unfamiliar waitoreke had shielded weak light penetrating into the nest chamber. They have got into the most distant corner of the hole and have calmed down. In fact, they have nothing to be afraid of – the stone under which the hole is made is also a ceiling of the hole and protects their dwelling reliably from caving-in. And even ruacapangi can’t dig out their hole.
Ultradamas have herded fawns together and have continued the descent to water. Waitorekes fed in the river, and also adult penguins have seen, how these majestic animals were left from the forest. Adult ultradamas have lowered heads to water and began to drink by long gulps, from time to time raising heads, looking around and smelling air. Fawns have finished drinking much faster and began to race at the shoaliness, raising legs high at each jump. Scared by their occurrence, one waitoreke has emerged and has uttered loud disturbing whistle. Ultradama fawns have shuddered with unexpectedness when near to them its loud voice was resounded, but have calmed down, when tiny beast has swam away and has dived. One adult doe has stepped in water and has moved through thickets, lifting sand and silt from the bottom. Long leaves of water plants represent the favourite food for these herbivores, and they frequently come to small rivers to regale themselves with sappy greens. Adult doe has grasped by lips and has pulled out from water the whole bunch of plants. Having shaken it up, deer began to chew soft greens. Fawns, seeing what it does, also have wanted to taste this delicacy. But they hadn’t manage yet to get these plants as dexterously, as adults do it: one fawn has lowered head in water too deep and began to sneeze, when water has got into its nose, and the second one managed to pinch off some leaflets. But their taste appeared good for it, and fawn began browse the leaves waving on surface of water.
Ruacapangi male also has gone down to the river at the distance from ultradama herd. It sees large adult ultradamas and is not going to attack on fawns. Nevertheless, at its presence one doe has walked along the riverbank, keeping between the bird and fawns, and the doe walked in the river stopped feeding and has made some jumps in water in its direction, making a cloud of splashes. Both females show the intention to protect juveniles: they utter loud low and stamp front legs. Ruacapangi male has stepped back from water and has disappeared in bush, and deer have continued feeding in shallow water. It seems their appetite may destroy fodder areas of waitorekes, but in fact it does not occur: deer thin thickets of aquatic plants, enabling fresh greens to appear and interfering with accumulation of silt near the riverbank. Therefore their presence is only an annoying obstacle for waitorekes’ normal life, but nothing more. Consequences of their stay will only improve conditions of life for these beasts.
Spring gradually finishes. Every next day becomes hotter, and soon there will come humid New Zealand summer. Life of underwater inhabitants takes its normal course, and there are important changes in it. Neohanasaki juveniles hatched this year gradually grow up. Many neohanasaki tadpoles were lost after males have ceased to care of them, but it is quite natural loss of posterity. And neohanasaki adults also have contributed in extermination of their own posterity. Survived tadpoles of this kind do not remain in lake – for the period of growth they migrate to the small forest rivers where there are no adult relatives representing considerable danger for them. These creatures already differ from tadpoles of frogs in larger sizes and the lengthened body. Small neohanasaki at this age already differs considerably from the creature just released from fatherly trusteeship. At this one legs already develop gradually; at first hind legs develop, and it gives out the relationship of New Zealand false salamanders with tailless amphibians. Front legs represent now only lumps covered with thin skin. But already in such early age neohanasaki tadpoles are predators, and due to the diet they grow quickly. Their task is as soon as possible to pass a dimensional category in which they are vulnerable for the majority of predators of fresh waters of New Zealand.
The small tadpole neohanasaki arranged an ambush in shallow water under roots of the tree fallen across the forest stream. The roots sticking out in water are partly ground off by snails and crustaceans, but form good shelter for this animal: alternation of light and shadow completely hides this tadpole. Having clung by hinder legs to one root, it simply waits while prey of suitable size will swim up close enough to be seized. Small eyes of neohanasaki tadpole look upwards and partly in sides – from shadow it watches a site of surface of the water covered by sunlight penetrating through forest canopy. Here microscopic crustaceans swim like smallest dots, and fish fry hunt them. The tadpole should not emerge to surface of water for air – while it breathes using internal gills which completely provide its requirements for oxygen. It needs to wait only.
Small fish fry form large shoals. Most likely, this is posterity of any kind of galaxias or cyprinoid fishes descended from any species introduced by people. They rush near the surface of water, from time to time sparkling by silvery sides. Fry eat, among others, small insects falling in water, therefore everything that the river carries causes interest in them. But some insects can hunt fishes. The neohanasaki tadpole sees how sparkling shoal of fry suddenly rushes in all directions, and on their place the oval silhouette of the clumsy water beetle appears. When the insect swims away, fry shoal gathers again – at first separate individuals, but then shoal gathers again approximately in the same number. When fry have continued search of food, small neohanasaki has cautiously let off a root, for which it kept, and slides smoothly to fry shoal. Its movements are slow and cautious, therefore fry have suspected of nothing. Colouring hides neohanasaki tadpole on the background of the flooded tree, therefore its attack on fry was unexpected, and therefore successful. The neohanasaki tadpole managed to seize one fish juvenile, and the small predator has immediately swallowed it entirely. While it should be content with small prey, but in due course of growth prey will become larger also. Though now the tadpole neohanasaki is so small, that it may become easily anybody’s prey itself. At early age the tadpole neohanasaki has more chances to be lost than to survive: up to an adult condition only separate individuals from many tens of them survive.
Having swallowed fry, neohanasaki tadpole has returned to an ambush. It has hooked by rear paw against root to have a rest and to digest prey… but near it the wide mouth opened wide, current of water has torn off a tadpole from the root and young neohanasaki from last year’s hatch had literally soaked up its smaller relative entirely and has closed mouth. Tip of prey’s tail sticking out of its mouth still twitched, but then has disappeared. This creature already resembles adult individuals in greater degree: both pairs of its legs are advanced, and the body gradually gets the shape characteristic for adult individuals of this kind, though its stomach is still convex, as at a tadpole. Length of this young neohanasaki is only about 15 centimeters. Such creature has much more opportunities for survival, though it is also necessary for it to be cautious and to keep in depth not to fall casual prey for any predator.
Young neohanasaki has swum down under tree trunk, and has simply lain on bottom in shadow. Now it is difficult for making out from surface of water, and other inhabitants of the river are perfectly visible to it. If it will be lucky enough, in some years it will return in lake and will can take part in courtship games. But for this purpose it needs not to leave a safe channel of the river for some years.
Rangitahi tadpoles have considerably grown up and have got a recognizable appearance characteristic for this species. They have slightly lengthened cylindrical body, very big tail bordered by fin plica and strong sucker-like mouth. They eat algal films and sedentary animals, and during the rest hang on stalks and floating leaves of plants. In case of danger they are able to seek safety in flight and dexterously bury themselves in silt. But their behaviour begins to change gradually: if earlier they were hidden in warm gulfs and did not avoid water stagnant and poor in oxygen, now rangitahi tadpoles leave their native places and keep in sites of lake with cool and clean water. They gradually have “reassessment of values” in relation to choice of habitats: they have grown up and prepare for the first migration in their life, therefore previous forms of behaviour fade, and the next ones are expressed clearer. Now they are involved with a smell of river water and current. At this age rangitahi tadpoles already prefer to keep in parts of lake where current of the rivers running into it is felt. Some tadpoles by mistake swim in forest rivers and cannot get out of them, following instincts blindly, and soon perish, becoming prey of river predators. But the most part of rangitahi tadpoles finds the aim correctly: shoals of these creatures gather in thickets of underwater plants in mouth of the river flowing from mountains. It has returned into the channel a long time ago, and its current became smooth again. Now the river became convenient way for travel, and tadpoles move in mountains – in place where they will spend almost all further life to return for the short time to native lake to give life to new generation and to die.
The smell of water of the mountain rivers involves tadpoles, and positive rheotaxis forces them to move against current. Primitive reactions to conditions of an environment help them to make long and difficult travel. At the whole extent of the way they will come to overcome current and to avoid meetings with predators. Rangitahi tadpoles are very fine; therefore they have a lot of enemies. They are saved in part only by their large number and skill to disappear in narrow cracks, from where the predator will not get them.
For a way to upper course of the rivers small rangitahi tadpoles should swim through places where native thick-lipped carps live. By the end of spring these fishes already spawned eggs and new generation of thick-lipped carps grows up in secluded places among stones where adult individuals will not reach. Young thick-lipped carps also win to themselves fodder territories from relatives and express aggression to everyone leading a way of life similar to them.
Rangitahi tadpoles migrate upstream, keeping coastal shallow sites. Here current is not such strong, and it is easier for them to swim. But here young thick-lipped carps gather and between them and tadpoles conflicts for territory flash. Tadpoles are only temporary visitors of these places, and fishes do not understand it; therefore they defend the tiny fodder sites as actively, as adult individuals. But rangitahi tadpoles move above the bottom in numerous shoals. The distance between separate individuals sometimes happens shorter than the length of the tadpole. Along the column of tadpoles as if run waves: forward lines of tadpoles almost synchronously come off the bottom and make a forward rush, and then fall on the bottom again and attach to stones by sucker to have a rest and to scrape off anything edible. The individuals staying in back lines repeat their movements with some delay, and it creates an effect of the wave running along the column. While the individuals moving in rear-guard of the shoal finish their movement, the avant guarde of shoal already prepares for a new forward rush.
Young thick-lipped carps break the coordinated movement of the column, attacking on tadpoles. They behave like adult individuals, exposing to tadpoles the stretched fins though they have not got adult colouring. Signals of fishes mean of nothing to tadpoles, therefore they continue the movement, indifferently swimming past. Some of young thick-lipped carps scare them away with impacts of heads, but the live stream of rangitahi tadpoles only parts on safe distance from aggressors and continues movement.
Rapids in upper courses of mountain rivers appear more serious obstacle for small travelers. Rangitahi tadpoles feel smell of water of the mountain rivers attractive to them and also strong current, and it serves for them as powerful stimulus for moving ahead. In the beginning of spring the same rapids became an obstacle for shoals of eversmolts moving to spawning areas, but fishes have overcome them though have wasted many efforts for it and have left behind the rapids some weakened, wounded and perished individuals. For rangitahi tadpoles thresholds represent the even greater obstacle: they are too small and weak to overcome such obstacle with jumps. But the kin of rangitahi frogs does not interrupt, as tadpoles use different tactics for overcoming river rapids. The thing which in other cases becomes a source of troubles helps them in this hard work: it is the small size. Eversmolts overcome rapids by moving in places where the fish of their size can swim. But in these places, as a rule, the current is strongest. Rangitahi tadpoles act differently: they squeeze into narrow cracks between stones where current can be not such strong, and sometimes simply bypass rapids at the edge, moving on wet stones and having exposed backs from water. The big advantage at this stage of travel is strongly extended body shape lowering the resistance to stream of water in which it is necessary to move, and allowing squeezing in the narrowest cracks between stones. In some places tadpoles slowly creep on surface of stone, attaching by oral sucker and moving ahead by short lunges alternating to the long periods of rest. Not all of them succeed to resist the current: the stream of water tears off some tadpoles and carries them downstream, forcing to overcome an obstacle from the very beginning. Some tadpoles are floating downstream, helplessly tumbling in water: they were stunned by impact against stones and cannot resist to the stream of water. Some of them cannot rise over rapids anymore and, most likely, will become victims of river predators. Others, however, quickly “come to the senses”, rush on bottom, hide between stones and have a rest. Sometimes they succeed even have to have some meal. But then they swim again to rapids and desperately attack this obstacle. Rise over rapids is a serious test for small tadpoles, but sooner or later the obstacle appears behind, and there comes the final stage of travel.
Not all rangitahi tadpoles can reach places where will spend almost all their further life. The part of them perishes at rise over rapids; another part receives wounds and further dies from infectious diseases. And someone becomes simply a victim of predators. Too small rangitahi tadpoles will hardly become prey of New Zealand false raven or other carnivorous bird. But they may be easily eaten by dragonfly larvae or water beetles, let alone fishes.
In the mountain rivers of New Zealand there are not so many species of fishes, but the most typical representatives of local ichthyophauna are eversmolts. River forms of eversmolts differ from lake ones in features of colouring and in smaller size, but frequently in their schools separate representatives of the lake form stay. These fishes for various reasons are late in the river after spawning. Usually these are individuals which have received wounds during the migration to spawning areas and have simply remained in cleaner river water, waiting while wounds will be healed. On sides of such fishes there are visible healed scars or the places covered with deformed scales – these are consequences of rough spawning or unsuccessful attempts to overcome river rapids. Now fishes restore forces, and feeding on tadpoles promotes it very much. Large rangitahi tadpoles, that are ready to a metamorphosis, can be larger, than adult eversmolt is, but each of such lucky beggars managed to survive and to bring up is paid by tens individuals becoming victims of predators.
In upper courses of rivers rangitahi tadpoles travel not in numerous shoals as in the beginning of the travel, but in small groups. Different schools of tadpoles choose for life the different rivers and streams, and from the numerous congestions gradually the groups numbering only of some tens or hundreds of individuals rest. Having reached the streams, they settle in a channel, choosing for themselves suitable shelters and fodder territories. They should be afraid of larger relatives who can easily swallow them, therefore, when the large rangitahi tadpole is swimming in stream, smaller individuals are ready to vanish literally: they are hidden at the bottom and squeeze into cracks between stones, where they are difficult for getting.
Spring comes to an end. Days are already warm as in summer – as far as the winds blowing from ocean allow it. And one more creature, obeying its instincts, aspires to give life to new generation of the kind.
The flat scaly head has seemed from under water among thickets of water plants. It has only touched a surface of water with a tip of snout as skin valves above nostrils were slightly opened, letting air out with silent hissing. Having made a breath, the animal has dived and among plants its body of grey color with thin white cross strips slides. Female of marshland aotearophis has felt that there comes time to lay eggs. Now its task is to choose a place for nest where eggs would be protected from casual predators and would successfully pass the incubation.
The reptile easily slides in thickets of water plants. It does not hunt, therefore does not pay attention to waitoreke body flashed among plants. But for these beasts such creatures represent obvious danger – it happens, that some local reptiles visit waitoreke colonies for hunting for their juveniles. One more waitoreke has noticed the snake swimming to the riverbank. It was put out from water and has whistled sharply. Its voice had been listening by some more individuals, which at once have disappeared in coastal thickets.
Female of marshland aotearophis does not hear voices of waitorekes, but feels waves which spread in water at the movement of these animals, and also feels their smell. It is not going to hunt them – waitorekes are not included into its diet. In addition now the feeding behaviour of this reptile is suppressed – it searches for a place for egg laying. The snake, wriggling its body, slides at the shoaliness near the surface of water. It has weak sight; therefore it cannot notice in time the predators attacking from above. On land, and also at the distance from a reservoir, female of marshland aotearophis would become easy prey for such birds, as eagle kea, ruacapangi or New Zealand false raven. It can protect itself from them with the help of poison, but speed of reaction of bird frequently predetermines the success in such duel. Now its problem is to be imperceptible. Dim colouring helps this reptile to hide, and the snake creeps out on land among thickets of coastal plants to remain for shorter time at the open place. Having got warm at the shoaliness, the reptile has cautiously got out on the firm ground and has crept to the nearest thickets which it vaguely distinguishes in front of head. Now it does not feel yet the vibrations of the ground indicating the presence of large animals, and continues creeping farther from water.
Having gone deep in forest, the reptile prefers to hide under the cover of fern fronds and among bushes. It creeps cautiously, frequently raising head and putting out the doubled tongue to catch a smell of the probable enemy. But it does not notice how it comes nearer to waitoreke colony. The smell of waitoreke is familiar to this reptile – it more than once met these beasts at the river, and waitorekes preferred to let it pass, being afraid of aggression on the part of the snake. Therefore the smell of waitoreke colony does not seem dangerous for snake, and it safely creeps to the territory populated with these small beasts. It has crept near one of holes, and receptors have informed it that the smell emitting therefrom is not similar to usual smell of waitoreke. The snake stopped for a moment, testing the smells emanating from this hole; it has caught a strange smell of an unfamiliar creature to which the strong smell of fish of different degrees of freshness is added. Not having felt anything dangerous to it, the reptile has crept forward – in direction from where the distinct smell of waitoreke was felt.
Penguin chicks already have almost reached the size of adult birds. New Zealand mountain penguins are birds of the small size, therefore development of chicks at them is much faster, than at the kinds lived on the Earth in human epoch. Juveniles behave very actively – they will become adults soon, and it is a proper time to them to get acquainted with world around much closer. While parents fish at the river, juveniles wander over waitoreke colony, looking into the holes of their neighbours. If grown up waitoreke cubs try to seize their tails, continuing the games, young penguins repulse them: they chase for young waitorekes, having stretched wings wide and screaming loudly, and have not always time to stop, if their way is crossed by adult waitoreke not going to enter their game at all. Waitorekes got acquainted to penguins for a long time and do not perceive them as enemies: they simply relate neutrally to their presence. But the playful young penguins risk receiving repulse from an adult animal: the adult waitoreke dissatisfied with too rough games displays its incisors, and this expression of displeasure forces penguins and young waitorekes to stop their noisy games.
Female of marshland aotearophis has crept to the territory of waitoreke colony, and its occurrence was noticed at once by one of adult beasts. It has uttered shrill whistle, warning its relatives about danger, and all animals remaining on the ground surface have disappeared in holes. It was far from being best tactics of protection somewhere at the continent where snakes can eat rodents. But aotearophis is a herpethophagous species and it may represent any danger for waitoreke only when it would not possible for two animals to miss each other.
The alarm signal has found young penguins too far from a native hole. They well know what does such sound mean, therefore, having heard it, they have rushed to the hole in which were always hidden in case of danger. But on their way there was a strange creature which they are seeing for the first time in their lives – it is long, coloured grey with white cross strips. It is absolutely legless, but thus can move on the ground and can bend. Having noticed young penguins, this creature has raised head and has opened mouth in which the set of the thin recurved teeth sticks out. It has hissed and began making fast jerks by head aside birds, having forced them to move back.
Aotearophis female has unexpectedly faced a new obstacle. These two creatures which so suddenly appeared at its way are unfamiliar to the reptile – it seldom faced with New Zealand mountain penguins, and even less often with their juveniles which have not replaced yet the down dress to adult plumage. But their smell is very similar to what the reptile has felt while crawling by one of holes. These creatures are not going to attack it and make way to it, but make it too slowly. The reptile crawled into ball, continuing to display its opened mouth to them, and then has made a rush and has poked with its muzzle into one of these creatures.
After the poke the young penguin was tumbled down on the ground, and the second chick has rushed to run. The fallen chick has loudly shrilled and began pulling legs and wings, trying to turn over and to stand again. And the snake, seeing jerky movements, has apprehended them as aggression and has hissed. It was ready to put the second impact when has felt an acute pain in body.
Mother of juveniles appeared there just in time. It has run up to snake from behind and has strongly pinched it by beak. When the reptile was turned around to her, the penguin female has run off aside, and at this time the fallen chick has stood up, has run off aside and has hidden behind the root of tree. Penguin female has remained face to face with the large reptile, which haves deadly poison in addition. The snake is too sluggish now, and is not going to hunt. Therefore the penguin female at certain dexterity can escape even during the conflict to such dangerous enemy. But she does not know about it and is not going to estimate its own opportunities: it comes to her posterity, and the parental instinct stimulates her to protect her chicks from the reptile. Therefore she has simply run off aside and has rushed to the snake again, putting it the impacts by beak. Attacking the snake, the penguin female shrills loudly – she acts the same way as her relatives act during the joint attack on any predator like New Zealand unbadger. But now she does it alone and can expect only for herself. However, her force so is strong, that the reptile has to recede. The snake does not hear bird’s calls, but feels pain in body from impact of her beak, and it forces reptile to pull after each impact.
Penguin female is obviously tired – she breathes deeply and reels. But the enemy is still here, and she is obliged to continue to drive it away, even being alone. Her voice loudly sounds in waitoreke colony became silent of fear, and soon she has heard well familiar answer to her voice – male had returned from fishing. His occurrence appeared very appositely – female’s forces are already close to exhaustion, and the snake creeps away too slowly. When the reptile has once again turned head to penguin female, it has suddenly felt a pain with fresh force – male had literally seized its scaly skin by beak and has sharply pulled it. Having turned to the new opponent, the reptile appeared vulnerable for penguin female, and she at once has pecked it in turn. Advantage appears on the side of penguins. Birds are adjusted resolutely, and it pays off: the pair of penguins in common banishes the snake from territory of the colony.
Birds have won. They stand among waitoreke holes, panting and looking around. And somewhere at the distant edge of the colony the snake’s tail disappears among ferns. When it was gone from the field of view, female has uttered short inviting signal, and two young penguins, pushing each other and waddling, has run up to parents. The enemy has left, peace life proceeds, and now it is just a proper time for chicks to have a meal. They shrill impatiently, and both parents widely open beaks, enabling juveniles to regale themselves on the fish brought for them.
At this time from holes waitorekes begin to appear. First they only look out and smell air cautiously. But gradually waitorekes turn brave and get out of holes. Some young animals smell the ground on which the snake crawled – they remember a smell of the enemy to distinguish and to avoid it in the future. Danger was passed and waitoreke colony comes to life again. It seems that penguins are not so bad neighbours though they are not similar to waitorekes.
Marshland aotearophis female is wounded – in one place its skin is broken off by beak of male penguin. This wound hurts, but it seems it is the only one. In other places the pain of beak impacts gradually fades. The parental instinct has prevailed again, and the snake began to search for a place for the future clutch. It captiously tastes air with tongue, trying to find the best place for the future progeny. The reptile creeps by the stony sites of the ground, preventing to dig out the nest, and by the big stones which only cool ground with their mass. After long searches it has found out such place – it is under roots of the large tree. The ground at its bottom is covered with a layer of fallen foliage and is mellow – it is ideal for the nest arranging. It is difficult for legless reptile to dig out a hole, and aotearophis female should work hard to make it. By movements of front part of body it began to rake off the layer of foliage and the ground, and soon wide hole of suitable depth was formed. During its work female stops some times to have a rest, and then continues the work. From time to time it crawls back and tries the smell of the dug out ground by tongue. When it seemed to it that everything is ready, it turned to the ball at the bottom of hole and began to lay eggs. One by one in the ground six eggs with soft leathery shell have fallen. Having got free of them, the snake has felt much more freely. It began to creep around of the clutch, raking up the ground and foliage atop of the clutch with lateral movements of its body. This work had taken from it about half an hour. Having finished it, the reptile has simply crept away in bushes and began to search for a way back to the river. The destiny of the laid eggs does not interest it any more. Maybe, one more female will lay eggs in the same place, even having dug out another’s clutch, and it is possible, that any predator would simply find a clutch and would destroy it in hour, day or week. It does not interest the snake any more: it has made everything that the parental instinct needed from it.
After the meeting of penguins with the snake about one week passed. Young penguins have matured enough to leave for the first time a colony which represented the whole world familiar to them before. In addition some days ago they have started to shed down, and now became more similar to parents. At them black juvenile down had already moulted almost completely, and instead of it they have smooth plumage now, white on stomach and brown on back. Only on shoulders and neck of young birds there are appreciable fragments black down, and their beaks are not such bright yet, as at adult birds. In the rest young birds are completely similar to parents. Waitorekes are not confused at all with such change in shape of young birds: their smell has remained the same, and waitorekes trust the sense of smell more, than sight.
When adult penguins have gone to the river at that significant day, one of young penguins has simply followed them. The second chick wanted to remain in the colony, but, having seen, that the first young bird leaves, it has cried, has waved wings and has rushed after it. Parents have not paid attention to actions of their posterity: they always returned to the colony, and chicks always waited for them there. But now, having casually turned back halfway to the river, female has seen that both young penguins follow her, waddling and keeping balance by means of wings. Female has only waited for them a little, and when young birds have overtaken her, she has continued a way to the river.
Young penguins look around curiously: the world appeared much larger than one to which they have got used, constantly staying in a colony. They curiously look at tops of trees, try to peck small beetles creeping in grass, or pluck off small white flowers blossoming in shadow under fern fronds. Keen on knowledge of world around, they have not noticed, how have left to the riverbank, and have understood it only then when the track turned downwards sharply and they have slid on it, not having kept balance, almost to the edge of sandy beach.
Parents have waited while young birds stand, and then have come in water and have confidently swum along the pass in the thickets made by waitoreke. Young birds do not hurry up to follow them. One chick has cautiously stepped into the water, but almost at once has run back and began to shake off. The second juvenile has also tried to enter the river and has returned to land, and then has put beak in water and has sneezed, when water has got to its nostrils. They are not ready yet to follow parents, and they still need to learn not to be afraid of water and to feel like confidently in this element new to them. While young birds wander on the land, forcing their way through thickets of marsh plants.
While some inhabitants of the river make the first shy steps in water, others, on the contrary, leave it and master for a short time the elements which will never be subdued to penguins. Day when young penguins have seen the river for the first time is absolutely special – it happens once a year only. Tens of thousands of tiny six-legged creatures have left the former habitats at the bottom of the river and have gathered in thickets of coastal plants. These are mayfly larvae preparing for the first and last air dance in their life. Waitorekes which has had the luck to appear at the riverbank at this time, snatch greedily easy and defenseless prey which, it seems, creeps in their mouths itself. And under water from the river bed silt rises – fishes swim up to the coast, gathering mayfly larvae creeping on the bottom. Sometimes the silvery side of the fish, which have swum up almost to the edge of water in attempt to overtake prey creeping away, sparkles in muddy water. But all the same larvae are numerous. Their number is too great to be exterminated by all predators taken together. In addition they appear from their shelters simultaneously, and predators will not manage to exterminate all of them.
Brownish creatures creep out on leaves and stalks of plants, and hang there, keeping for a support only with tips of legs. They undergo a magic transformation: brownish skin bursts on back, and bright green translucent creature with two pairs of wrinkled appendages on back gets out of crack. It hardly makes some steps, leaving its old shell, and hangs on plant, undergoing new transformations. The wrinkled appendages on its back get smoothed back and turn to wings – back ones are short and rounded, and front ones are much larger and lengthened, with rounded tips. At the tip of abdomen three thin threads, which length appears approximately equal to the length of body of an insect, fall out at this time. The first moult is followed at once by the second one: it is a tribute to an ancient origin of mayflies, which has remained also in Neocene epoch. And only after that winged creatures rise in air to meet each other and to die up to a sunset.
Mayfly flight at the river is the almost fantastic show showing the actual scale of productivity of such ecosystem. At first in air only tens insects flit, and some wood birds fly by above the river, seizing them right in flight. But with each hour there are more and more mayflies: simultaneously above riverbanks hundreds of thousands and millions of insects fly up. The blizzard of insects literally storms in air, despite of birds piercing it like arrows. At each mayfly only tips of wings touch each other slightly, but insects are so numerous, that a rustle of millions of wings softly, but reliably muffles all other sounds around. After pairing mayfly males literally fall down: they have executed their duty to the species, and now they are waited with old age and death promptly coming nearer. And females scatter above water incalculable set of eggs, giving life to new generation of insects which in two-three years will also perform an air dance of love and death above the native river.
The feast of predators takes place not only in air, but also on the ground and in water. Dying mayflies cover with their bodies land and surface of water. Young penguins walk on the riverbank and peck greedy the fallen insects. Near to them on land waitorekes run and small birds of various species hop, and somewhere in the distance the pair of New Zealand false ravens fills stomachs hasty with a gratuitous entertainment.
Everywhere at the surface of the river under the live cloud of mayflies hovering in air water splashes: fishes also take part in feast. Schools of small fishes seize the insects fallen in water and drag them in various sides, gradually tearing them off, and larger fishes swallow mayflies entirely. The striped or spotty back flashes, a small whirlpool appears on the surface of water, and the insect disappears without any trace. And other fishes show their acrobatic abilities: adult ‘ika-kaihopu live-bearers jump out from water to the height of one meter, dexterously seizing mayflies right at flight. And among thickets of water plants long spotty bodies of small fishes from time to time flash: rahirahi galaxias also eat mayflies. They do not come up in open water, but dexterously move among leaves and stalks of plants, turning upside down and seizing from below the insects floating on the surface of water.
Young penguins approach to edge of waters and gather dead mayflies. One of them has pecked up several insects too hasty and has had a fit of coughing, having choked with their thin dry wings. It may not hurry up: the amount of entertainments would be obviously enough for everybody. But even being at such feast it is better not to forget about care: the nature always reminds, that the enemy may hide somewhere beside. On surface of water the big fin has struck, and then from under water the huge head with the big yellow eyes and widely opened mouth has put out – the adult ‘ika-taikaha also has taken part in eating of gratuitous entertainment. As soon as this creature has marked its presence, some waitorekes from the riverbank uttered alarm whistles, and some more beasts appeared in water, have immediately got out on firm land. Young penguins see this underwater monster for the first time, but disturbing voices of waitorekes are well familiar to them, therefore birds also run off the edge of water and cautiously look at the surface of water.
Adult penguins come back from fishing, having filled stomachs with small fish. They emerged on the surface of water for some times and had seen how above the river the huge cloud of mayflies hovers. They also met the fishes swimming near the surface of water and engulfing the insects fallen in water with loud smack. But they have found out the presence of huge ‘ika-taikaha even earlier, than waitorekes swimming near the riverbank. Penguins saw how this fish directed to coastal thickets and have decided to get out on land in the other place. The huge fish swimming at the shoaliness represents a real danger to such small penguins.
Not all inhabitants of the river have apprehended the appearing of ‘ika-taikaha as a threat. Dexterous and mobile ‘ika-kaihopu live-bearer continues to catch insects, jumping out for them from water. Almost each jump of fish appears remunerated by prey, and sometimes it succeeds to seize even two insects in one jump. Successful hunting has dulled care of this fish: it is not known, what can take place while the fish is in jump. And during the next jump of ‘ika-kaihopu for prey below it from water the huge head of ‘ika-taikaha has appeared. The predator has only opened mouth wide, and ‘ika-kaihopu has fallen down into its teeth. Jaws closed immediately and very strongly, the striped back of predator has flashed among water plants and the strong tail has splashed on water. The huge fish left on the depth, pacified by temporary feeling of satiety.
The live cloud of mayflies still hovers above the river, but the culmination of breeding flight of insects has already passed. On surface of water thousands of dying insects float, and the river bed and underwater plants are covered with a cover of the smallest eggs of these insects. Lots of eggs and larvae of mayflies will be lost during the next days and months, but in two-three years survived larvae will turn to imago and will also perform their last dance above the river.
Hobbling clumsily, adult penguins come back to their chicks which have stayed on the riverbank. Would these birds have more emotions, they could be surprised to that young penguins do not run to them and do not ask for food. Juveniles are glad to returning of parents, but only one of them has languidly asked for fish at female. The second one has not taken a look at this fish at all: its stomach is filled with mayflies which they managed to peck up at the riverbank. Perhaps, it is the first day from the moment of their hatching when adult birds could be full.
The last mayflies have finished their flight shortly before a sunset.
Rainy New Zealand summer has come. Young penguins have gradually lost fear of the water and have begun to master this element new to them actively. They have completely left their juvenile down and only dimmer colouring of beaks shows that they are not adults yet. They are not afraid of water any more, as earlier, but now still prefer to swim along the riverbank to have an opportunity to leave water at once in case of danger. They are already familiar with local species of fishes and try to gather from bottom insect larvae, looking at waitorekes. From time to time young penguins follow adult birds and swim to the middle of the river channel, but nevertheless feel like not so confidently yet and quickly turn to land. The first hunting successes of young penguins are still modest, but these birds already succeed to catch young ‘ika-taikaha fishes hiding in thickets and even to chase small fishes in thickness of water. Parents already feed them less, and soon they will come to rely on themselves only.
Famine is a good teacher; therefore in two weeks after the young penguins appeared for the first time at the river, they began to provide themselves with food independently. Their connection with parents turned weaker considerably – now they perceive their parents exclusively as congeners to which society it is necessary to adhere. Young penguins did not begin to leave from waitoreke colony, but one by one they have left parental hole and have dug out their own dwellings nearby.
Many inhabitants of the rivers and lakes of New Zealand breed in spring. Incentives for this purpose are the increase of length of light day and thawing of snow in the mountains, and also changing of chemical compound of water. But some inhabitants of New Zealand rivers submit to other stimulus: the rhythm of their life is set by the Moon. Shortly before the beginning of syzygial tide the migration of rahirahi galaxias to spawning areas begins. These fishes live in many rivers of islands, but they live in fresh water not the whole life: the first months of their life pass in the seas washing the coast of archipelago.
If migrations of eversmolts or rangitahi tadpoles are difficult for not seeing, rahirahi galaxias migrate for spawning very silently and imperceptibly. These fishes do not like to remain visible for long – many predators apply for prey of just such size. And their migrations take place at night. Small schools of fishes move in the river channel, choosing deep and dark places where they are more difficult for noticing. In case of danger fishes instantly hide in sand and silt, or squeeze in cracks between stones. The rivers of New Zealand are short; therefore they reach the sea only for one or two nights. There these fishes will wait for high syzygial tide, when the wave will cover sandy shallows in rivers mouths. In these places hardly covered with a tidal wave, rahirahi galaxias will dig in sand by tails vertically and will spawn eggs, leaving them in safety up to the next inflow. And the posterity of these fishes will appear in the rivers only in the beginning of winter, if they will survive for some months in the sea.
In waitoreke colony young penguins have perfectly accustomed with all difficulties of adult life. While they do not have occasion to leave this colony and to search for new places for life – the river provides their needs for food, and here it is less number of large predators compared to lake upstream. Young penguins are acquainted with ‘ika-taikaha monsters and prefer to swim far away from places where these fishes hide. Now they succeed to avoid meetings with these predators, but it is not known what may happen the next day, therefore the survival of this group of penguins without contact to the main colony hangs by a thread. It is enough to perish even to single birds, and the survival of this population of penguins would appear in doubt, and unexpected natural experiment with formation of a colony of two species of animals would be interrupted. But penguins, as well as waitorekes, live only by the present moment, not thinking about the future.
Every day young penguins swim downstream farther and farther. They have learned to use a watercourse to reach places of fishing, and have learned to choose places to swim against current, spending as small additional efforts as possible. They have obviously accustomed in the river better than their parents, and hunt more successfully. Distant excursions bring one more benefit: fishing areas are not exhausted and penguins always have food. But there are days when stay at the distant fishing areas brings something greater than simply full stomach of fish.
Young penguins dive for fish together. Using current and force of their own wings, they gather the great speed under water, pursuing school of silvery fishes. It is not so convenient to drive schooling fishes and to keep them far from shelters when there are only two hunters. Birds should pursue each fish which they want to eat. But it is costs of their small number which should be taken for granted. Penguins, however, get out of this difficulty, compensating the small number in the speed and dexterity. They do not give fish school to come nearer to the riverbank where they can hide among plants, and seize fishes one by one. Their tactics bears the fruits, but suddenly fish school swims off in all directions and many fishes managed to escape from the chasers. The panic of fishes has forced penguins to interrupt hunting and to look round. They at once have seen the originator of a fright of fishes. It does not hide, but also does not attack: it is not a predator, but the congener. But it is not anyone of parents of these birds, but absolutely unfamiliar bird, the male. The stranger does not try to swim away and does not show any aggression – it obviously wants to remain with young penguins. Its beak already gradually began to get red colouring characteristic for beaks of adult individuals. This single is a “tramp” moved from the colony living in other mountain valley. It has simply abandoned the valley and has gone down the river and then spent a long time in wanderings in searches of congeners. When two young penguins have swum to the colony, it has followed them, trying to keep abreast and not to lose track of them. When birds have come nearer to the colony, the first ones they have met were some waitorekes searching for food at the shoaliness overgrown with plants. Old residents of a colony have not paid any attention to them: they have got used to the society of these beasts from their hatching. And the newcomer, being older compared to them, has cautiously related to these beasts. But it has seen how its congeners have got out on land and after small hesitation has followed them and also has left water. Birds have walked three together on one of the footpaths leading to the colony. When they met one waitoreke, young birds have simply passed by it, and the newcomer has slightly bent down forward, has extended neck, has spread wings and has opened its beak wide. Waitoreke has shuddered and has made way for unusually aggressive creature. When the penguin has passed by, it has smelt its traces and was directed further to the river. It has already got used to strange biped neighbours and knows that these display acts usually have no continuation.
Penguins have reached a colony. Young birds have at once disappeared in the holes, having left the newcomer alone. It has looked round and has seen numerous holes, as in the colony of congeners which it has abandoned once. But it has shuddered with unexpectedness when from the nearest hole waitoreke has got out and has safely approached to it to smell. This penguin had never met waitorekes so close, and their presence here, and moreover in a plenty, disturbs it. But from one hole at the edge of the colony the voice of one more penguin suddenly was heard, and two its relatives have got one by one out of the hole under bush – they are a pair from which this strange union of penguins and waitorekes began. These old residents waddle to get acquainted with a new member of the colony. Their presence has reconciled a little the new male to waitoreke neighbourhood: if there are congeners here, it means that it is possible to live in this colony, even if the majority of it is made with the strange shaggy beasts looking unlike penguins. This male will learn to coexist with waitorekes in the future, but the main event for it is a meeting of congeners. If it will be possible for birds to coexist further with waitorekes successfully, it will give rise not only to new colony, but also to new relations with neighbours in common habitat. And it is quite possible, that it will be a new step in evolution of not only one, but of two species of animals at once.

Bestiary

New Zealand mountain penguin (Microsphenicius pusillus)
Order: Penguins (Spheniciformes)
Family: Penguins (Sphenicidae)

Habitat: New Zealand, rivers and mountain lakes.

Picture by Alexander Smyslov

Change of epoch is negatively reflected in sea fauna and species of large animals connected to it. The plankton – the basis of food chains of ocean, and also community where various sea inhabitants spend a part of life – is very sensitive to natural accidents. During changes in climate and geography of planet its amount reduces sharply, that results in mass extinction of sea fauna. Such situation had taken place at the boundary of Holocene and Neocene when the rigorous and long ice age had changed shape and climate of planet for a long time. Numerous species of sea animals had died out, but some ones managed to survive, having “hidden” in fresh waters.
Among freshwater “fugitives” from plankton accident there were basically various species of fishes and at islands of New Zealand the relic species of penguins had lodged – it is one of last species in varied and ancient by origin order. The New Zealand mountain penguin had kept in fresh waters of New Zealand, isolated from typical oceanic fauna. It had adapted to life in cool lakes and rapid rivers of islands, eating the various animals living in them. Less productive, but more stable ecosystems had permitted to these birds to survive.
Island isolation and scarcity of food resources had an effect at appearance of the mountain penguin: it has strongly decreased in size, having turned to the bird about 20 cm tall. Instead of the strict black-and-white attire this bird had got spotty gray-brown coloring of back – it is easier to the mountain penguin to mask among a non-uniform landscape of the new native land. Stomach is white with black cross strip on throat. Strong and muscled fin-like wings now help not only at swimming, but also at movement on land. On the edge of wing feathers had turned to flat corneous spikes similar to nails. They help mobile and dexterous bird to climb on stones and to rake pebble in searches of invertebrates. Sometimes New Zealand mountain penguin even escapes from predators, climbing on trees with inclined enough trunk. Thus it clings against bark by paws and wings.
Shining red beak arrests attention like bright spot on dim background of this penguin feathering. Besides for it the bird has narrow rings of naked skin around of eyes. In their colouring the sexual dimorphism is shown: at males “glasses” are pink, at females – grey. Beak of the mountain penguin is short and thick. In maxilla two short sharp tooth-like outgrowths jut out. They are using for killing of small vertebrates containing the food of this bird.
New Zealand mountain penguin catch fish in lakes and rivers of islands, and besides it eats water invertebrates – crayfishes and snails. As against sea congeners of Holocene epoch, this bird had expanded a diet and eats also ground animals – on land mountain penguin pecks insects, snails and small vertebrates (lizards, rodents).
Similarly to all representatives of the family, New Zealand mountain penguin nests in colonies. The size of colony depends on efficiency of habitats: near big lakes number of colony can reach hundreds of individuals, near big rivers up to several tens, and near small wood streams this bird nests in settlements numbering only few breeding pairs. If fodder resources of habitats are exhausted, birds having no nests can abandon the colony and search for new places for life. They are able to survive in wood or to overcome watersheds in searches of new place for life.
This penguin arranges nests in holes which it digs independently in river coast, under protection of large stones and roots of trees. In each hole with long common “corridor” some pairs of adult birds occupying separate nesting chambers nest. Pairs at this species keep till all life. Nesting partners pay attention to each other, in common equip the nesting hole and protect it from competitors.
New Zealand mountain penguins nest once a year, in spring. In clutch there are 2 – 3 large white eggs, both parents hatch them alternately within 18 days. Eggs are laid in small hole serving as the nest, without any litter. Nestlings hatch rather advanced, with opened eyes, covered with rich black down. Beak at them is also black: it will gradually change color when the bird becomes adult. Till first weeks of life nestlings sit in the nesting chamber; growing up, they leave it and wait for parents on ground surface. At danger nestlings and adult birds hide in hole and actively protect themselves from enemies, biting.
Young birds become able to breeding at four-year-old age, and general life expectancy makes till 25 years.

The idea of existence of this species had been supposed by Simon, the forum member.

New Zealand false raven (Notocorax novaezealandiae)
Order: Passerine birds (Passeriformes)
Family: Corvids (Corvidae)

Habitat: New Zealand, various landscapes.

Picture by Alexey Tatarinov

The avifauna of New Zealand in human epoch was extremely diverse, but some families, being widespread in other parts of the world, did not live there. One of them was corvid family. Two species of this family, Corvus antipodum and Corvus moriorum, inhabited the main islands of New Zealand and Chatham Islands accordingly, but have died out before the arrival of European colonists there. However Europeans “have filled this blank”, having acclimatized rook (Corvus frugilegus) in New Zealand. Rooks survived in epoch of ecological crisis between Holocene and Neocene, and in Neocene the descendants of this bird, representing the corvid family in New Zealand, occupy various ecological niches at the islands. The largest descendants of rooks are the species of genus Notocorax, or southern ravens.
New Zealand false raven reaches weight 2-2,5 kg at wingspan up to 170 cm. Such size makes this kind larger than any passerine bird of human epoch, but at the background of such Neocene giants as eagleravens it looks almost dwarf one. At first sight New Zealand false raven resembles slightly enlarged copy of Euroasian raven of Holocene, but there are certain differences in its appearance. Rather long beak of this bird has conic shape without small hump above and at adult individuals it is colored white. Birds of the first and second years of life have beaks of black color. “Family feature” inherited from rooks is a site of featherless skin at the basis of beak – at false ravens it is colored black and is almost not distinguished on the background of plumage. Plumage of these birds is black with violet shine, legs are also black. False ravens use various sounds, but more often it is hoarse croak.
New Zealand false raven inhabits various types of landscapes – mountains, light forests, sea coasts; it cannot be met only in dense forests. The food of these birds is rather diverse: menu of false ravens includes carrion, invertebrates, smaller vertebrates and vegetative food. Being mainly gatherers, false ravens spend a lot of time, looking out for food in soaring flight or wandering on the ground, though sometimes they purposefully hunt smaller animals. In searches of food these birds show a high degree of ingenuity: for example, to break mollusks shells, they can drop them on stones.
New Zealand false ravens nest on old trees. They live in rookeries numbering no more than ten nests. Rookeries may exist for decades, but birds not always return there in nesting season. Social life allows false ravens to protect themselves against predators successfully, but also bears the certain inconveniences: neighbours frequently quarrel and steal nest materials at each other.
These birds are monodins, but pairs are formed more often only to one breeding season. Pairs are formed at the end of winter (in August or in the beginning of September); in September rookeries are already occupied by tenants. First of all birds renew old nests, and then begin egg laying. In clutch it may be up to 7 eggs, 5 ones are more often. Only female is hatching, but male feeds her. After young birds become independent (it takes place 1,5-2 months after egg laying), rookeries quickly become empty. In non-nesting time false ravens live solitarily or migrate in small flocks.
New Zealand false raven belongs to the number of long-livers: this bird can live up to 40-45 years.
At Chatham Islands the close species lives – Chatham false raven (Notocorax chathamensis). It is a little bit larger than its New Zealand relative (weight up to 3 kg), and in its meal seafood prevails. Some individuals of this species fly far to the south, to subantarctic islands. They can nest there, but have not formed a constant steady population. More often these birds fly back to Chatham before the beginning of winter.

These species of birds were discovered by Simon, the forum member.

 

Waitoreke (Waitoreke potamophilus)
Order: Rodents (Rodentia)
Family: Mice and Rats (Muridae)

Habitat: various reservoirs of New Zealand – lakes, streams and rivers.

Picture by Alexey Tatarinov

Waitoreke is a creature equal to black rat in size, but much more graceful. This rodent is the descendant of black rat introduced to New Zealand by ancestors of Maori – aboriginals of archipelago. Waitoreke is named after certain river animal (“otter”) of local legends. In many respects it resembles this animal which remained a mystery for official science.
The wool of waitoreke is colored grey tone: back and head are dark grey, and the bottom part of body is ash-grey. The tail of waitoreke is black, flattened, covered with hairless skin, resembling beaver tail in outlines. Forepaws are shorter then rear legs and have well advanced fingers. Around of eyes of mammal there are white “glasses”. Its muzzle resembles muzzle of rat, with well advanced vibrissa. With the help of vibrissa touches this animal can search for food even in muddy water. Eyes of waitoreke are large, and ears are small, rounded and almost unnoticeable in wool.
Waitoreke is skillful fisher, and this fact has leaved a mark on its appearance: this little mammal has small ears, strong webby hind legs and waterproof fur like an otter. Secretions of special glands give to waitoreke’s fur necessary water-repellent properties. Due to greasing the animal gets out of water almost dry – it needs only to shake some drops of water from itself. Such adaptation helps this animal to keep heat even at life in cold mountain lakes and streams. The special valve closes an acoustic duct when animal dives.
This little mammal lives in coastal zone of rivers, streams, lakes of both islands of New Zealand. Waitoreke prefers to live in woody area, but also settles in plain areas. It eats various aquatic animals: snails, frogs, aquatic insects and fishes. Sometimes waitoreke catches nestlings of waterfowl, snatching them from under water or stealing from nests. Animal catches prey by forepaws and kills by bite of strong incisors. Waitoreke hunts large fishes in packs.
Waitorekes live in rallied colonies resembling a colony of meerkats. The colony represents some tens of holes dug near to water edge of reservoir. In each hole one couple of adult beasts lives. One couple is dominant – their hole is located in the center of colony, and at lack of forage dominants can take food away at other animals of a colony. But at danger the dominants attack enemy the first. When in the morning all animals go to the search of food, some “sentinels” stay in colony. They notify relatives on danger by loud whistle, and if necessary, protect cubs actively. The enemy of waitoreke is antipods’ unotter (Xenolutra antipodorum) which lives in a lower reaches of New Zealand rivers. Herons and large predatory fishes, and also neohanasaki (Neohanasaki aotearoae), large species of amphibians, may eat adult animals and cubs.
These animals form pairs to all further life. Courtship period at waitoreke takes place in spring (October in Southern Hemisphere), and posterity is born in the beginning of summer. The second litter is born at the end of summer. In spring litter of this animal numbers up to five cubs though usually it is less, in summer – no more than three ones. Cubs are born at all couples capable to breed, and not just at the dominant couple. However in dominant’s litter cubs are larger, and on the average, the litter numbers one cub more, than at other couples. Young animals become sexually mature at the age of 6 – 7 months. At this time young animals leave parental colony and form their own colony, or join one of existing waitoreke colonies.

This species of mammals was discovered by Simon, the forum member.

Marshland aotearophis (Aotearophis paludicola)
Order: Squamates (Squamata), suborder Snakes (Serpentes)
Family: New Zealand snakes (Aotearophidae)

Habitat: New Zealand, coasts of freshwater reservoirs.
New Zealand, being separated from the continents many millions years ago, had unique fauna before human colonization. At the great variety of endemic birds there was a minute quantity of species of amphibians and mammals here. The specific variety of reptiles was also low – this class was represented at the islands only by lizards and tuataras. Crocodiles, tortoises and snakes had never lived in New Zealand. But in Neocene the situation has cardinally changed. Mammals and frogs introduced by people have occupied the archipelago, and during millions years of evolution they changed into new species. Also snakes had occupied New Zealand. However, as against many other species, these reptiles colonized this area independently, without the help of people and later after human extinction.
Neocene New Zealand snakes descend from sea kraits (Laticauda), the most primitive ones among sea snakes that had kept strong connection to land areas. Low specialization and absence of competitors have permitted them to settle at the islands lack of snakes earlier. Possible, the colonization of New Zealand by snakes had taken place after the end of the ice age bordering Holocene and Neocene. Three species of New Zealand snakes represent two genera of family Aotearophidae close to elapids. The name of these reptiles is formed as a sum of words “Ao-Tea-Roa” (Maori name of New Zealand) and “Ophis” (snake).
Evolution of these reptiles is directed to occurrence of land forms having a diet differing from each other. More primitive forms are closer connected to aquatic habitats and are ichthyo- and herpethophags to what their high degree of poisonness is connected. More advanced forms eat warm-blooded animals, and activity of their poison is much less: in bodies of mammals and birds having faster metabolism poison has faster effect. In anatomy of even the most specialized species ancestral features are traced – these are tail slightly compressed from sides and nostrils shifted to the top part of head.
All aotearophids are egg-laying reptiles. They lay a small number of eggs (usually less than ten ones) in heaps of vegetative dust or in wet ground. In the convenient and protected places collective clutches are possible. Parents do not care of posterity in any way. The first time newly hatched young snakes eat invertebrates, and then pass to hunt for small vertebrates. The young snakes of aquatic species eat fish fry and tadpoles.
Large birds and mammals are enemies of New Zealand snakes. Despite of presence of strong poison, aotearophids almost do not use it for self-defense. They had inherited peaceful behaviour of ancestors and in case of danger seek safety in flight, trying to hide in grass or in water.
Marshland aotearophis represents the transitive form between primitive and more advanced species of family. It is still attached to damp habitats, preferring to settle near water – in marshes and at the riverbanks. This snake swims perfectly, however it hunts almost always on land. Marshland aotearophis is specialized herpetophagus. Lizards and amphibians from among false salamanders, local group of neotenic tree frog larvae, become its prey more often. At this species cases of cannibalism are possible. Poison of this snake is still strong enough, as it hunts cold-blooded animals. The body length of marshland aotearophis reaches 1.5 meters. Colouring of this animal is dark grey; on body thin white cross strips stretch.
Two close species of New Zealand snakes display other stages of evolution of this group.
Forest aotearophis (Aotearophis sylvestris) is the most evolutionally advanced New Zealand snake. This reptile inhabits forests of New Zealand. It is almost not connected to water, but prefers wet places. Representatives of the present species swim not so good; also they are not capable to climb up trees. In anatomy of forest aotearophis only few ancestral features are kept: these are tail slightly compressed from sides and the nostrils located in the top part of head. The largest individuals reach the length of 2 meters; usual length is about 1.75 meters. This snake has olive color with which numerous thin rings of black color contrast. Food of forest aotearophis includes small mammals and birds. Poison of this snake is weakest of all New Zealand snakes, but is strong enough to kill fast small warm-blooded animal.
Aquatic aotearophis (Preaotearophis ichthyophagus) is the most primitive species of family. It keeps many features characteristic for sea snakes – for example, it is capable to absorb the oxygen dissolved in water by mucous membrane of mouth. However it already lacks salt-secreting glands characteristic for sea snakes. Representatives of the present species inhabit the rivers and lakes at the plains of both large islands of archipelago. Sometimes they may be met in sea near rivers mouths – these snakes frequently settle along the coast of islands, therefore islands are inhabited by only one species without subspecies. Aquatic aotearophises eat mainly fishes, occasionally hunting also larvae of amphibians and aquatic invertebrates. Egg laying takes place on land. This snake is about 1 meter long; its tail is strongly compressed from sides and serves as body of movement in water. Colouring of this reptile is contrast: the whole body is covered with alternating cross strips of silver-gray and dark brown colors.

These species of reptiles were discovered by Simon, the forum member.

Rangitahi (Rangitahi ephemera)
Order: Tailless amphibians (Anura)
Family: Tree frogs (Hylidae)

Habitat: New Zealand, mountain rivers and lakes. Breeding in reservoirs in lower reaches of the rivers.

Picture by Alexey Tatarinov

In human epoch Australian green tree frog Litoria caerulea was introduced to New Zealand. It survived during the mass extinction at the boundary of Holocene and Neocene, and its descendants in due course of evolution have occupied set of island habitats. One direction of evolution of Litoria descendants was the prolongation of larval stage of development down to occurrence of the separate group of neotenic amphibians – New Zealand false salamanders. It was promoted by poverty if island ichthyofauna. Also among New Zealand species of tailless amphibians there are some species displaying various stages of transition to complete neoteny. One of such species is rangitahi – a special kind of frogs which had a complete redistribution of roles of larval and adult stages of development.
At this species larval stage lasts up to 4-5 years. Rangitahi tadpole lives in cool mountain streams where feeds on algal films and sedentary larvae of insects. Its shape is adapted to life in current – rangitahi tadpole has strongly lengthened body about 30 cm long, scraping mouth looking like a sucker, elastic lips covered with set of corneous fibers. Tail of tadpole is very large and muscled – it makes more than 2/3 of the general size of tadpole and is bordered by skinny fin plica. It not only swimming structure, but also a stock of nutrients for metamorphosis. Body of tadpole of this frog is brownish with lighter belly and black longitudinal strip stretching from muzzle across the eye up to the tip of tail.
Tadpoles grown up to maximal size gather to schools and migrate downstream to lakes where water is warmed better. Here they undergo very fast metamorphosis and turn to adult individuals. During the time of metamorphosis rangitahi tadpoles gather in schools numbering up to several hundreds of individuals. In school metamorphosis proceeds more speedily due to pheromones secreting in water and synchronizing this process.
Rangitahi frog has contrast black-and-white color – the bottom part of body, fingers, toes and spots on sides are white, and back, sides and the top side of extremities are coal-black. During the metamorphosis at rangitahi frog tail is resorbing, therefore the adult individual of this kind has length about 10-12 cm. At the same time the rough ripening of reproductive products takes place. The adult stage at these amphibians serves only for breeding and is simply not adapted to long existence. It has the reduced tail without the bones, remained from the stage of tadpole. The intestines at rangitahi frog are reduced in great degree and nonfunctional, and frequently the cavity of intestines is filled with connecting tissue. The adult individual of rangitahi lives exclusively due to stocks of the nutrients saved up during the larval stage. Ephemerity of adult stage of this species is shown in the name of the species: the word “rangitahi” in Maori language means something instant, short-term, and existing not for long.
Courtship ritual at this species is very rough. It begins synchronously and involves all individuals gathered at the certain area of the coast – it provides guaranteed success in breeding. Loud calls of this frog resemble sharp abrupt whistling. When males call in unison, the sound turns out painful for hearing.
In clutch of rangitahi there is up to 300 small eggs surrounded by individual capsules of slime. The whole clutch is friable and spherical, floating at the surface of water. Adult individuals do not leave clutch and eggs up to hatching of tadpoles, and actually to their own death. Frogs protecting eggs are easily excitable and ready to seize death grip any enemy which has encroached on eggs, and even their own relative appeared nearby casually.
Incubation lasts for about one week. Hatching of tadpoles is followed by fast degradation of the organism of adult animal. Stocks of nutrients are already exhausted to this moment, then fast tissue necrosis follows, and frog perishes within several days. Tadpoles hatched from eggs hide at the bottom and among aquatic plants. They gradually migrate to the rivers and reach up to cold streams in upper reaches, where their feeding and maturing proceed. At the tadpole stage the settling of this species takes place.

New Zealand eversmolt (Salmini novazealandiae)
Order: Salmons (Salmoniformes)
Family: Salmons (Salmonidae)

Habitat: mountain rivers of New Zealand.
In human epoch the ichthyofauna of New Zealand differed in certain poverty and high degree of endemism. This archipelago had separated from continents in Mesozoic era when typical groups of freshwater fishes had not evolved yet. In Holocene freshwater fishes of New Zealand were presented by descendants of sea and euryhaline species. But later the situation had sharply changed. People had introduced to New Zealand various freshwater fishes descended from other continents, and had caused irreparable damage to local fauna by this action. After extinction of mankind newcomer species had quickly developed new habitats, having superseded the majority of survived native species, and development of ecosystems of archipelago had proceeded in absolutely another direction.
Climate of New Zealand in Neocene is typical subtropical, and in the south it is warm-temperate. But the significant part of archipelago is presented by mountain areas where the cool climate dominates. And at high tops of mountains the most part of year snow and ice lays. Short cool rivers of islands originate here. In upper courses of rivers, in crystal-clear and ice-cold water the small fish keeping by large schools on current is found. From time to time these fishes jump from water, trying to seize any insect flying above water. It is one of fishes appeared due to activity of human had missed for millions of years before epoch of Neocene. This fish is New Zealand eversmolt, dwarf descendant of trout introduced to New Zealand. Actually it is simply dwarf variety of trout quickly maturing, keeping in adult condition juvenile attributes, and living not for long.
New Zealand eversmolt has kept characteristic for trouts propensity to live in cool and rich in oxygen water. The torpedo-like shape of body with pointed snout helps this fish to resist to current successfully. Fins of New Zealand eversmolt are peaked; tail fin is high and crescent. These are attributes of quickly swimming fish: actually, these fishes all the day struggle with current only to remain at the same place – near the chosen stone or bush of aquatic moss. Body length of New Zealand eversmolt is about 12 cm; the female is larger and approximately 25 % heavier, than male.
Colouring of this fish in details is similar to coloring of its ancestor, brook trout (the river form of Salmo trutta). Out of spawning season male and female are coloured similarly: black and red spots on the body form marble pattern on silvery-green background. At this fish there are large silvery eyes: New Zealand eversmolt hunts mainly with the help of sight.
The mouth of fish opens widely; on tips of jaws well advanced sharp teeth grow. Usually this fish keeps in schools in current near water surface. New Zealand eversmolt eats basically flying insects – dragonflies and May flies. Hunting fish waits for insects, keeping near stones or leaves of water plants fluttering in current in order to be not too appreciable at sight from above. When above surface of water an insect flies, fish catches it right in air in well-aimed jump. Planning jump, fish instinctively makes the amendment to refraction of water, and on average each third jump appears successful. Occasionally fish gathers insects from surface of water and catches aquatic larvae of dragonflies and May flies between stones.
The courtship season at New Zealand eversmolt begins in spring (in Southern hemisphere it is October – November) when mountain snows thaw. At this time males get more saturated colouring: they turn velvety-black with silvery eyes and red spots on the body. Only on stomach and near anal fin they keep sites of silvery background colouring. Females, on the contrary, brighten, and their colouring becomes almost completely silvery with dark grey back and speckled anal fin. Similarly to salmons of Holocene epoch, New Zealand eversmolt spawns on current, on sites of bottom covered with fine pebblestone. On spawning places these fishes gather to schools numbering up to hundred individuals and stay there within several days. These fishes dig eggs in pebble where clutch is reliably kept from the majority of predators.
Spawning act of New Zealand eversmolt takes place in the morning. At this time schools of fishes approach to riverbank, and keep in shallow water. From water fins of males behaving rather aggressively relatively to each other stick up. Males combat with each other for place more convenient for spawning, and gradually the school breaks up to separate groups. The appearing of females at spawning place results in excitation at males. Their colouring turns brighter, and they by two or three chase females when they swim near to male groups. Gradually each female chooses the certain site of bottom, and males surround her. During the spawning female digs a hole for eggs by lateral movements of stomach and tail, and after it one or two males throw ground in sides. At the following attempt female throws up eggs in made furrow, and males immediately fertilize them. After that fishes dig eggs in ground and do not care of it more. Spawned individuals are very weak, and at this time various aquatic and ground predators actively hunt for them. Fishes keep on sites of rivers with slower current, and sometimes hide in cracks between stones and have a long rest there. The most part of fishes spawns eggs no more than three times per life.
Eggs develop among pebblestone within approximately three weeks. For this time part of it perishes from various predators – mainly from worms and larvae of insects. Fry hatch translucent and helpless, and start to swim at week age. Up to this moment the significant part of fry perishes, but the number of survived ones is enough to keep the stable populations of species. The maturity of New Zealand eversmolt comes at 2-nd year of life, and life expectancy makes up to 5 – 6 years.

Rahirahi galaxia (Serpogalaxias umbreocollum)
Order: Galaxiiforms (Galaxiiformes)
Family: Galaxiids (Galaxiidae)

Habitat: New Zealand, rivers and lakes, spawning in river estuaries.

Picture by Carlos Pizcueta

Galaxiid fishes are very characteristic for fresh waters of Southern hemisphere. Before the introducing of various freshwater fishes by people they represented the dominant group of freshwater fishes of New Zealand. In Neocene the positions of these fishes in island ecosystems were substantially lost – descendants of nonnative fishes have occupied the most part of ecological niches. In New Zealand ichthyofaunal there are no large kinds of galaxiid fishes, but there is a plenty of smaller kinds. One of them is rahirahi galaxia similar to loach and occupying a similar ecological niche.
Rahirahi galaxia is a medium-sized species of fishes: body length of an adult individual is about 8 cm. It is a fish with thin, lengthened (“rahirahi” in Maori language means “long”) and flexible body, inhabiting benthonic layers of water. Skin of rahirahi galaxia is naked and slimy; the seized fish secrets a plenty of slime and tries to escape from predator’s jaws by strong movements of body. Background colouring is beige with pinkish shade, on body the set of dark and rounded spots is scattered. In forward part of body large saddle-like spot covering the area of gill covers, nape and forward part of back is present. Fins of fish are transparent, but edges of paired fins have narrow black border. Also the small crescent spot is present in the basis of tail fin. For this species the variability of colouring depending on time of day is characteristic: at night the fish becomes pale, white-pink, and dark marks almost vanish.
Fins are short and wide, back and anal fins are shifted to the back part of body. Tail fin is trapezoid, with small cut in the middle of back edge. This fish swims in benthonic layers of water and keeps close to shelters - usually among driftwood and plants in coastal zone. In case of danger it is dug in in sand or silt dexterously, and at attempt to seize it only buries even deeper.
Rahirahi galaxia eats larvae of insects, catches small tadpoles and digging crustaceans. For search of prey on the top jaw of this fish in corners of mouth the pair of wide lobe-like wattles supplied with set of sensitive cells grows.
It is catadromous species of fishes, which life cycle proceeds in part in sea water. In the beginning of years rahirahi galaxias gather to small schools and move downstream to river mouths. In estuaries during the high inflow these fishes spawn eggs at sandy shoalinesses, not reached by tidal waves in the rest of the time. For this purpose fishes gather in close groups of 10-20 individuals and bury in sand back parts of their body. At this moment females lay eggs, and males impregnate them. When fishes get out of sand, eggs appear dug at the depth of several centimeters. Parents do not care of posterity anymore and return to the rivers shortly before outflow. Clutch numbers only 100-120 rather large eggs containing large stock of yolk. Within 28 days, before the next high inflow, eggs develop, but the significant part of this term is spent by fry in a condition of rest. During the inflow fry crawl through the thickness of sand to the surface and swim off to the sea with outflow.
Young fishes will spend in sea for about half-year. They live in thickets of seaweed in shallow water, and to the beginning of winter migrate to freshened water of river mouths, move upstream the rivers in spring and settle in habitats typical for their parents. Sexual maturity comes at the age of 2 years; life expectancy is up to 8 years.

The idea about the existance of this species is proposed by Carlos Pizcueta

Native thick-lipped carp (Labiocyprinus indigenus)
Order: Cyprinoid fishes (Cypriniformes)
Family: Cyprinids (Cyprinidae)

Habitat: rivers of New Zealand.
Before the human arrival to New Zealand the freshwater ichthyofauna of this archipelago was rather poor. People have changed a course of evolution when have introduced to New Zealand various freshwater fishes from other continents, and carp – a domestic kind of fishes – among them. After the extinction of mankind descendants of carp settled widely in freshwater habitats of archipelago, having formed a lot of life forms – from tiny up to large ones, from swamp dwellers up to inhabitants of crystal-clear ice-cold water of the mountain rivers.
Thick-lipped carp lives in rivers of New Zealand, preferring moderate current and clear water. It is especially numerous in foothills where the rivers are not so fast, but have not grown turbid yet from soil suspension. The length of native thick-lipped carp reaches 40 cm, though usually these fishes are smaller.
Native thick-lipped carp belongs to omnivorous fishes, and eats algal layers and sedentary animals living on stones. The mouth of this fish is transformed to sucker and is shifted downwards. Lower jaw is shorter compared to upper one and consequently the mouth of fish is constantly open. Thick lips of native thick-lipped carp are covered with fleecy corneous outgrowths helping scraping of algal film from stones more effectively. Upper lip is separated to two mobile halves which can move independently from each other. The frontal edge of muzzle of this fish is covered with corneous “callouses” helping in ground digging in searches of forage in case of need. Mouth of fish is surrounded by eight short wattles – two ones stick forward, two are directed in sides, and four are turned back. Wattles are covered with various receptors, including taste and tactile ones. They provide fish with adequate information on world around. Eyes of native thick-lipped carp are directed upwards and in sides.
Thick-lipped carp has a convergent similarity to Labeo and other fishes living in fast flowing water. Body of this fish is triangular in cross-section, with wide flat stomach. Back of fish colored brown, sides are greenish, and stomach and the bottom side of head are white. Fins of fish are grey with dark spots in the basis. Out of spawning season male and female at this fish are practically indiscernible in colouring. Fish spends the most part of time at the bottom; therefore the swimming bladder at native thick-lipped carp is reduced and represents a simple tissue taenia filled with fat. Caudal peduncle is short; tail is strong, equipped with wide two-lobed fin. On the top blade of male’s tail fin the long “thread” is advanced – some extended and flexible fin rays connected with membrane. “Thread” has a pattern of cross black strips.
All fishes living at the current face with the common problem, the necessity to keep on the same place. Thick-lipped carp has left this difficulty, having developed “clawed” fins: tips of thick forward rays of pectoral and abdominal fins stick out from edges of fin membrane and are slightly bent downwards. They allow fish clinging against smooth stones and to keep firmly even in strong current. Usually each fish has some favourite places of rest – small holes in river bottom, where it is almost not necessary to cling by fins.
In way of life native thick-lipped carp represents solitary territorial fish. Each individual occupies a territory of about twenty square meters, extended along the watercourse. At the areas poor in food territories of these fishes can be even larger. Borders of territory are well-known to each individual, and it is ready to die in the last ditch, protecting the possession against congeners.
In spawning season male gets very bright colouring – its body becomes emerald-green with iridescent shine, and fins get red colouring. “Thread” on its tail fin becomes more contrast in colouring and well appreciable. Male ready to spawning begins “singing” – with the help of pharyngeal teeth it utters loud clicks. This way it warns other males about its rights to this territory and involves females to the place of spawning.
These fishes spawn in pair and lay eggs in simple hole dug out in the river bottom near to riverbank. After spawning male fills hole up and protects the territory, where the nest is located, against congeners and even against other fishes of rather large size. It attacks newcomers aggressively, striking them impacts by strong snout. But at the same time in fact it does not pay attention to small animals; therefore aquatic invertebrates – insects and freshwater crabs – cause great damage to posterity of this fish.
Young thick-lipped carps since the first days of life are given to themselves. Death rate among young fishes of this species is very great, and at times only 1-2% of the number of the brood survives until the second year of life. But life expectancy of these fishes may reach 100 years and more. From 4-years age young native thick-lipped carps can take part in spawning, and to 8-9 years they reach the size characteristic for adult fish of this species.

Ika-taikaha (Perca taikaha)
Order: Percoid fishes (Perciformes)
Family: Perches (Percidae)

Habitat: rivers and lakes of New Zealand.

Picture by FanboyPhilosopher

Human epoch has left a significant mark in ichthyofauna of New Zealand. The intentional introduction of various kinds of European fishes has resulted in extinction or sharp reduction of number of native species of fishes. But introduced species have shown perfect adaptive opportunities, and New Zealand ichthyofauna of Neocene epoch is submitted mainly by their descendants. Among them one of the main predators is ‘ika-taikaha, very large kind of perches, the descendant of the introduced European perch (Perca fluviatilis). Translated from Maori language, the word “taikaha” means “furious”, and this name is attributed to fish occupying the top of food pyramid in rivers and lakes of archipelago.
‘Ika-taikaha in fact is only a huge version of ancestral form. Because of absence of competition it has changed a little, having only increased in size. Body length of adult individual is about 100-120 cm. Fish has deep body, rising like a “hump” right after head and covered with characteristic rough ctenoid scales. Adult fishes prefer to live in deep water far from land and occupy mainly the central part of lake or river channel. Due to it body colouring of adult individual is bluish with white stomach and dark grey vertical strips and back. Large eyes have yellow color. Spiny back fin includes 15-16 strong prickles. At adult fishes soft back fin has black base and pinkish border. Tail fin is two-lobed.
Mouth may be widely opened and pushed forward a little; it is supplied with pointed teeth. ‘Ika-taikaha is a predator and eats any animals it is able to catch and to swallow entirely – fishes, frogs, false salamanders. Young fish eats mainly insect larvae and fish fry. Adult ‘ika-taikaha frequently attacks chicks of waterfowl, mountain penguins and also waitoreke – local aquatic rodent.
Spawning occurs at the end of spring in shallow water – more often near lake shores or in shallow backwaters with slow current. In courtship dress colouring of male becomes azure-blue, and strips and back get velvety-black colouring. Head is colored black, and yellow eyes look especially impressively against this background. Soft back fin and anal fin of male in courtship dress get orange-red colouring. During the spawning pair of fishes splashes noisily at the surface of water, and male chases female and bites its caudal peduncle. Clutch of this species represents the mucous tape strongly inflating in water and containing some tens of thousands of eggs. Fishes leave clutch to the mercy of fate. Egg development lasts about two weeks. For ‘ika-taikaha cannibalism is characteristic at all stages of development. Sexual maturity comes at the age of 5-6 years, life expectancy makes more than 60 years. Intensive growth proceeds until reaching the age of 10 years, when fish reaches the length of about 60 cm.

‘Ika-kaihopu (Kaihopu esocinus)
Order: Toothcarps (Cyprinodontiformes)
Family: Live-bearers (Poeciliidae)

Habitat: rivers and lakes of New Zealand (Southern Island).
From the point of view of biogeography human epoch was an epoch of blurring of borders between biogeographical realms – at this time mass introduction of representatives of various groups of live organisms to habitats unusual for them had taken place. Among fishes such immigrants represented mainly food fishes, but one species – mosquitofish (Gambusia affinis) – had been settled to various continents and islands for struggle against larvae of blood-sucking insects. Gambusia had survived the time of human extinction and its descendants live in many places where it had been introduced. In New Zealand the competition to local fish species was insignificant, and one descendant of Gambusia has turned to active predator.
‘Ika-kaihopu is a large viviparous fish of fresh waters of New Zealand. Its length reaches 30-40 cm (female is larger and heavier than male). The head of fish is lengthened, with extended jaws and wide mouth which opens and extends forward like a tube, permitting fish to suck prey in. Body shape allows ‘ika-kaihopu to swim under the surface of water – back and head of fish form almost straight line. Eyes of fish are large, slightly shifted above the top edge of head. Back and anal fins are shifted back; caudal peduncle is short and thick, with fanlike tail fin. ‘Ika-kaihopu prefers to swim slowly near the water surface, making fast rushes only to catch prey. Stomach of fish is strongly convex and may stretch considerably. On male’s anal fin forward beams form gonopodium – the mobile copulating structure.
Colouring of back of ‘ika-kaihopu is green with brown “marble” pattern stretching to sides. Background colouring of sides is yellowish-green, stomach is white. Male’s colouring is more sated, than female’s, and the marble pattern is present only on the top part of back. Fins of fish are transparent, only in the basis of back fin there is a brown spot, and at male there are also brown speckles on anal fin.
It is exclusively predatory fish that is reflected in its name: in Maori language “kaihopu” means “hunter”. Small fishes, frogs and false salamander larvae, and also large aquatic insects form a diet of this species.
Breeding of ‘ika-kaihopu lasts for all year, though in winter it proceeds less intensively. Approximately once in 2-3 weeks female gives rise to several large juveniles of brownish colouring with silvery sides. Length of young individual at birth is about 3 cm. In winter the interval between delivery acts is increased and the number of young fishes is reduced up to 1-2 at once, but winter-born fry has length up to 5 cm at birth. Male chases the female ready to breeding, trying to keep as cautiously, as possible – female is capable to attack it, and even to eat smaller male. If female does not display aggression, male nestles against its side, quickly impregnates it and swims out immediately. Young fish reaches sexual maturity at the age of 1 year, and life expectancy makes about 10 years.

‘Ika-‘iti, leaf-mimic live-bearer (Paragambusia foliomima)
Order: Toothcarps (Cyprinodontiformes)
Family: Live-bearers (Poeciliidae)

Habitat: rivers and lakes of New Zealand (Southern Island).
In historical time people had introduced some species of live-bearing fishes to New Zealand, but in due course of evolution descendants of Gambusia appeared the champions on speciation; these ones formed a significant number of species differing in shape and ecology in reservoirs of archipelago. Some species have turned to large predators, and others have remained smaller creatures.
One of small species of live-bearing fishes lives in lakes of Southern island – it is ‘ika-‘iti, or leaf-mimic live-bearer. It is a small fish about 4 cm long, but usually even smaller (the word ‘iti in Maori language means “small”), eating insects and their larvae. It has deep body compressed from sides, leathery keel on the bottom side of body from throat up to anus, short head with small eyes and wide mouth capable to extend like a tube. Fins of this species are short, rounded and transparent.
Colouring of ‘ika-‘iti is very original. In it two contrast colors are combined: light green background and dark, blackish-brown color with reddish blotches. Dark blotches on body form a pattern with irregular edges, resembling strongly destroyed rotten plant leaf, hence the another name of this species. In case of danger ‘ika-‘iti freezes motionlessly and floats near the surface of water, imitating dead leaf. Thus one fin hidden from predator by body of fish continues movement and fish swims away slowly. In it the convergent similarity of this fish to some representatives of Nandidae family is shown. But, while Nandidae are predators, leaf-mimic live-bearer needs such masking for protection. If the attack proceeds, fish seeks safety in flight. Thus it alternates the directions of movement sharply and due to narrow body squeezes easily into thickets of aquatic plants.
Habitats of this species include rivers with slow current, lakes overgrown with plants and coastal zone of large reservoirs. ‘Ika-‘iti swims rather slowly and is able only to short rushes during feeding. The main food of this species includes insect larvae and other small invertebrates, including snails newly hatched from eggs. ‘Ika-‘iti keeps more often in thickets of coastal plants and under groups of floating plants.
Male differs from female in smaller size, less expressed belly keel and large gonopodium. In 2 weeks after pairing female gives rise up to 20 tiny young fishes, which hide in thickets of floating plants. The subsequent litters differ in lesser number of fry. For this kind cannibalism is characteristic.

Next

Main page of the project