Grass-colored predator

 

Tour to Neocene

 

11. Grass-colored predator

 

 

 

When in a Neocene South America has moved to the south, in more cool latitudes, the area of a subtropical dry pampas has considerably extended, having substituted southern part of tropical and subtropical forests. Only due to the large rivers which are flowing down from Andes, a pampas have not promoted further to the north.
Conditions of life in a South-American pampas are very favorable for numerous herbivore animals. Plentiful thickets of grasses are easily restored after feeding of numerous herbivores, giving new growth the most part of year, except for unless dry season. Here and there on valleys of the rivers and in foothills there are woods and bush thickets. But the most part of subtropical South American plains is occupied with seas of meter height grasses.
One of numerous inhabitants of grasses is the deermara, a large rodent of light and graceful constitution. Herds of these animals numbering up to half-hundred individuals, wander on plain, coming into thickets of bushes to have a meal soft juicy leaves. The basic food of these animals includes graminoids. Deermara males differ from females by rings of white wool around of eyes. They are peacefully grazed near to females, there will not come yet a breeding season. Then each of them will turn to the aggressive sovereign of the harem of several females. While all herd peacefully eats grass on a coast of the river. One male leaves herd to browse leaves of high grasses, grown on damp coastal ground. Its meal interrupts, when one more herbivore, the giant paca noisily lefts bushes. This animal by the constitution looks more to the capybara, but it is the pig-sized creature: weight of this female mounts to 200 kg. After her there is a male weighing, perhaps, about 300 kg. The graceful deermara departs a little aside but when the spotty giant having horn scutes on cheeks yawns, showing huge orange incisors, the male headlong rushes to herd. Some deermaras, having caught his steps, run off in sides, and one animal highly jumps up in air and looks back. Giant pacas absolutely do not pay attention to these timid creatures. They run slow by a jog-trot on a coast and hide themselves in bushes.
Every these instants did not remain unnoticed for round yellow eyes observing animals from a high grass. Some pairs of eyes traced each step of deermaras, and they have seen everything they wanted to see.
One of deermaras is sick: on its leg there is a large aposteme. Some days ago this animal had wounded the leg, and the wound had been infected. When the herd goes, this animal lags behind, appreciablly laming. When deermaras move through high grass, behind them, becoming transfixed at the slightest alarm of long-legged rodents, striped grey-brownish-golden shadows run a jog trot. When they become transfixed, it seems, that here there is nothing, except for grass stems. But when animals calm down and start grazing, motley shadows slide among grasses closely and closely to the herd. The encirclement starts to tighten...
The silence was broken off with desperate loud chirp of the motley bird flown out of a grass. And its red-green colouring of belly in deermara’s eyes was so unexpected, as flash of lightning in the clear sky. The herd has taken to their heels, but at this moment from the huge figure of a longbill bird has literally risen from grass directly for a way of the scared rodents. And at the same time the same birds were standing up straight in full two-meter growth around of the herd. Massacre began.
Beaks of giant birds struck selected before deermaras with ruthlessness of spear and speed of lightning. The most part of speedy rodents nevertheless was rescued, simply having jumped through heads and backs of monstrous birds, but some ones could not leave the battlefield. When the herd has run up, on the ground some animals had remained: the dead deermara having an aposteme on a leg, the half-dead young animal at whom the chest was punched, and the adult male with broken backbone. Catch was more than plentiful. Eight huge birds began to gather around of prey. Having seen them, the male had tried to run away, but his back legs were helplessly dragged by the ground. One of birds had stepped on his body a leg and has struck mercies to a head of animal. And the youngster of the deermara had died of loss of blood in one minute after killing of the male.
Monstrous birds are the most successful hunters of a pampas. They are similar to fossil bird Phorusracus by some features, but they are not its relatives. These birds are herons, huge flightless hunting herons. Their cryptic motley colouring allows come closely to selected prey, and accuracy of deadly beak impact is the pledge of success at hunting. Herons of the majority of species live in large colonies. And these birds had developed collectivism in relations even more - they hunt in pack. But all collectivism is lost somewhere during the prey sharing - each bird turns to the greedy egoist and tries to snatch the big chunk of catch in every way.
Usually birds of group Ciconiiformes are not able to dismember catch, and swallow it entirely. Few exceptions of this rule are only marabou stork and... the hunting heron. The beak of a hunting heron is adapted to a partition of catch: in forward part on its edges tooth-like formations were developed, allowing to tear meat and skin of prey. Due to such beak the bird literally "saws" soft tissues from bones, leaving to scavengers wretched leavings of meat. Having eaten plenty and having filled craws by meat, successful hunters abandon a battlefield and run to nesting place.
Several kilometers far from hunting lands of herons, on a small island in the middle of the river there is a heronry, nesting place of these birds. Easily having overcome channel almost one meter deep, successful hunters come to the ground of a heronry. And each hunter immediately appears literally attacked by its own hungry fledglings. The young growth about a meter tall, flapping by scanty winglets, jumps up, trying to get up to a beak of parent. After fledglings from behind trees adult birds being on duty on a nesting place appear. Pairs join together, birds show the favour to each other. The beak, had broke a skull of the deermara and tore meat of an animal half an hour ago, gently touches feathers on a head of the partner. Birds touch beaks of each other, and then simultaneously throw up heads and click beaks, clapping short wings. And fledglings do not like to wait a meal, and they accompany these scenes of tenderness with hungry shouts. But now it is not a reason to feed them: in crowd especially impudent fledgling will easily take not only its own share, but also the another's one. And pairs of birds accompanied with chirping fledglings, go to nests.
The nest of a hunting heron is built on the ground and represents the rounded construction slightly pressed from above. It is build of branches collected on the ground and stolen at neighbours, and is covered by grass and dry leaves. Having crossed edge of a nest, parents at last pay attention to violently shouting offspring, and it receives a long-awaited meal. The successful hunter belches a piece of meat on edge of nest, giving a fledgling the opportunity to tear and to swallow it itself. And parents at this time are engaged to each other: clean feathers, repair the nest, feed each other. Sometimes as if exchanging the meat the partner which had not participating in hunting, submits the partner in life a branch which is diligently stacked in a nest. Life in group is really effective when it is accompanied by strengthening of connections between partners. Therefore a lot of time is devoting to an establishment of hierarchy and strengthening of connections between nesting partners.
Next day partners vary roles - the nurse turns to the hunter, and the yesterday's hunter is necessary to look at fledglings. It is not such a simple task: they have already grown up and easily run across the heronry, constantly getting involved in fights. Therefore frequently parents should preserve the offspring against sharp beaks of elder fledglings.
When midday heat comes, fledglings go to shadow and doze, laid on the ground under bushes. And the parent receives a respite during which it can engage in itself. Someone is cleaned, someone sleeps, and one of males has gone fishing. He leaves to shallow water and starts look, where the fish side flashes at the bottom. Sharp impact of a head and jerk - and the thrown fish shines in air. The male is successful in fishing - he succeeded to catch and to have eaten some fishes. Last fish is for the fledgling. Having griped it in a beak, the giant walks to the nesting place. His descendant has already got hungry, and a fish is very opportunely to him. But the fledgling has not had time to tear off even a small piece of the large fish as it is taken away immediately by a stranger only one week elder. Fight is fastened: fledglings snatch each other by jaws for a beak and try to tumble adversary down. They still do not have "teeth" on beaks, therefore such fight is rather safe. When parents run up to separate fledglings (more precisely - to drive off another's offspring), fledglings fight downright seriously. And the third fledgling is quietly eating this fish in bushes, trying to not give itself out with a superfluous sound. Having cluck beaks against each other, adult birds go away and withdraw fledglings.
Time passes, and fledglings start to investigate the world. The nesting place becomes close for them, and all of them glance more often where adult birds go every day - on a coast of the river. But water while is deep for them, and they remain at home. And now both parents go to hunting: the young growth is gluttonous and grows quickly.
Some fledglings investigate a coast of a small island. On a sandy spit they see a school of small birds came flying to the watering place. They are prairie pipebirds - usual species of local birds. Usually they meet in prairie, but once a day they fly to the watering place. And now birds come into water and greedy drink, lifting heads.
Heron fledglings observe pipebirds from afar. Pipebirds perfectly see them, but they are not anxious at all: while the young hunting heron will reach them, they will have time to fly up. But not only young herons observe pipebirds drinking water.
Sand at the bottom starts to move in dangerous affinity from birds, and soon the strange barbed creature covered by shell gets out of it. It reminds something average between crawfish and fish. Some time this creature observes legs of birds, and then makes a prompt throw. One of birds, shortly having peeped, instantly disappears under water, and the others promptly fly up in air.
The craycatfish has seized one of birds. Somactids of its fins, operating similarly to pincers, have caught it’s legs, as if the alive trap. Some time predator keeps a bird under water while it will sink, and then snaps it and swallows, widely opening mouth with tiny teeth.
One of fledglings comes into water near to a place where the catfish has drowned the pipebird. It wanders on a shallow water, and suddenly promptly jumps out on a coast. On its leg the live trap, another craycatfish, dangles. Trying to shake unexpected and very painful "present", the young heron draws attention of neighbours. Fledglings are very curious: is a valuable quality of the hunter, allowing to study. They try to examine and peck a strange creature, but it suddenly lets off the bird’s leg and clumsily crawls out in water, pulling by tail.
Some days later young birds venture to overcome the shoaled channel between island and river bank. The heronry has become empty, and this year birds already will not return any more to it. On the river bank there is plenty of interesting things, here animals unknown to heron fledglings live. Through a high grass a strange long-tailed creature with a narrow muzzle hastens, waddling on two paws. It is the shell anteater – armadillo specialized to eating insects. Some young herons tag after it, and soon one of them pecks animal’s shell. Reaction of this mammal is immediate: the shell anteater turns around and starts to run into the taken aback fledglings. Thus it makes fast lunges and waves by claws of forepaws and grunts loudly. One of young birds appears too close, and the tip of a claw of the shell anteater puts to it a deep scratch on a hip: game is finished. Birds recede, and the armored small mammal continues its way.
And other animal, covered with white spots a short-legged creature, similar, is not so aggressively. Even opposite, it tries to hide at the sight of young hunting herons. And this fear of a spotty animal gives confidence to young birds: it is not dangerous, it is not the enemy, but catch is. And they begin chase it. Having extended by crescent, they cut off spotty creature’s path to saving bushes. Edges of crescent approach, and the small mammals is encircled. One by one young hunting herons try to peck possible prey, but it evades from their clumsy impacts. And one of them hits small mammal in a leg, and it squeals shrilly. Having forgotten about care, young birds try to slaughter small mammal by impacts of beaks. But this imprudence can cost dearly: from bushes some large heavy animals with spotty backs and large heads are shot up. They are giant pacas, and the spotty small mammal is their cub. The male of paca with the big cornificated scutes on cheeks loudly growls and opens the mouth wide, showing large incisors. But herons are too silly to recede reasonably. And it dearly manages to them: the massive animal attacks. Three centners of furious flesh run into one of birds and break its fragile body. The male does not calm down even then when under his legs the young heron turns to a flat mass of feathers, bones and blood. He shakes head and growls, and the crest of a long wool on his back stands on end. The escaped birds abandon this terrible place, running fast and searching for rescue at parents. For today it is enough vital lessons for them.
Ability to study is important for hunters - it allows to search for new sources of food and ways of its catch. Only it is necessary to be attentive. High growth allows hunting heron to see rather far. Keen sight of this bird pays attention to everything. And might allows the bird such luxury, as curiosity without fear to be preyed. Having noticed slowly walking giant paca, one of adult hunting herons leaves group and starts to watch it. Bird knows, that the clumsy animal can give out to it the small animals hidden in grass - tasty and harmless catch. And expectation of a bird is not deceived - the large rodent frightens away the whole flight of birds. But they do not depart, and are hovering above an area of rich grass, as if adhered. And the hunting heron decides to check up, what is there so interesting. Had passed after huge beast, it finds in grass some conic clay constructions, similar to nests of termites. But termites do not build their termitariums so closely to each other – it means, these constructions aren’t their houses. Besides from within the muffled peep is uttering: these things are nests of prairie pipebirds. They are very firm, as are constructed of clay and burnt by the hot pampas sun. One nest has cracked - the giant paca had trod on it. And the heron tries to pick open the damaged nest. Having looked around, it hangs head and starts to break off pieces of clay of the nest wall. Unexpectedly the hunting heron feels, that prehensile small claws have seized skin on its head. In the same second above a head of a feathered predator whistle is uttering, and air becomes full of flapping of tens wings. The set of pipebirds is hovering above a head of huge bird. It seems, all world was filled with these agile birdies. And every bird tries to peck the giant of plains in a head, closely to eyes. Some birds pinch skin of a heron on a head, diligently pecking wounds. It is more than predator can stand, and the hunting heron goes fast to neighbours left far forward. As if on command prairie pipebirds abandon the predator and are hidden in grass - they don’t like to risk any superfluous instant.
Hunting heron is the best expert among predators. It hunts so successfully, that this species had superseded predatory beasts on plains of South America as fossil birds Phorusracidae have once made it. It survives not only due to force, but also due to difficult behaviour. It studies and learns lessons from own victories and defeats. Lessons which are given to the bird by life, pleasant, unexpected or dangerous, are very important. And the one who will know it and study diligently, becomes the real lord of a pampas - one bird from ten fledglings.
To the north of a pampas, in valley of the great Amazon river, the kingdom of woods was stretched. Having completely restored after accident of the end of Holocene, they grow everywhere where can do it. Forest and the river are the most productive and rich in life ecosystems. And there life literally is in full swing.

Bestiary

Craycatfish (Astacidoras chelopterus)
Order: Catfishes (Siluriformes)
Family: Doradidae

This fish is a representative of the family Doradidae (armored catfishes). Similarly to modern representatives of family, the craycatfish has the forward part of body covered with strong osseous carapace, and along sides line of osseous plates passes. Length of a fish is up to 50 - 60 cm (the female is larger, the male is more harmonously and more brightly painted). The forward somactid of a pectoral fin is very strong and thick, it is separated from other fin and supplied with the special joint. This somactid has set of sharp spikes on the internal side. Turning forward, it forms together with lateral part of the head the original "pincers". In a spawning season males use these "pincers" for fight, but outside of spawning season "pincers" are used for defense, capture and killing of catch - fishes and large invertebrates. With the help of "pincers" this catfish is able to catch birds on a watering place; by fast throw the fish jumps out from ambush to a bird drinking water, grasps its legs and tries to drown it. In case of a unsuccessful throw the catfish can, using the same somactid of a fin as a leg turn around and creep away in water. The fish traps catch, having dug in ground silt, sand or leaves.
Forward part of a body is flattish, head is large, having wide mouth. Eyes are large, shifted on the top part of the head, protected by wide spikes. Coloring of the body is cryptic: grey background with non-uniformly scattered black and yellowish spots.
The fish spawns in small hole at the bottom of the slow-current river, eggs and fry are protected by the male.

Hunting heron (Graviardea venatrissa)
Order: Stork (Ciconiiformes)
Family: Graviardeidae

Picture by Timothy Morris

Initial image by Pavel Volkov

After mass extinction in the epoch previous to a Neocene, in ecosystems many free ecological niches had appeared. So, after herbivores large predators had become extinct. Simultaneously with occurrence of numerous herbivores of a Neocene also new predators had developed and evolved. Hunting heron is one of these predators.
This species of birds is one of the largest ones: height of an adult bird is up to 2 meters, weight - 60 - 80 kg (female is larger than male). At such sizes the heron has lost ability to flight: its wings are underdeveloped, not more chicken’s ones by size. The increase of size is connected with the adaptation of heron to hunting large ground animals. Having abandoned places of its ancestor’s inhabiting (bogs and rivers), this bird had adapted to life in thickets of high pampas grasses successfully hunting rodents, reptiles and large insects. When rodents began to be increased in size, the heron also "had grown up". The behaviour of a bird had changed also: it became the running pack hunter. It had allowed birds to prey much larger catch, than lone predator can kill.
The body of a bird is adapted to chase and killing of large prey. Legs are long and strong, fingers are short. The beak is especially remarkable: it is long, straight, on edges of its forward part were developed large tooth-like outgrowths, allowing to tear meat or to render serious wounds to chase. Coloring of the body is cryptic, similar to coloring of bittern (Botaurus) feathering. Eyes are large, bird has keen sight and hearing.
At hunting this species of heron applies two basic tactics: ambush and pursuing. Cryptic coloring allows birds to be hidden in grass in immediate proximity to the planned prey then to attack suddenly, when possible catch will approach too close itself. Pursuing catch, herons at first creep to it, using cryptic coloring, and then actively cut the planned prey’s way to herd and drive it, putting wounds (similarly to predators from canine family (Canidae)). Also birds successfully fishing on the rivers and lakes. At appearing of flights of locusts or other large insect species heron are willingly fed with them: having stretched in line, birds walk on a grass and knock down frightened away insects by impacts of a beak.
Nesting is on the ground in places protected from other land predators, for example, on a small island, separated by shallow water from a coast, or in thickets of prickly bushes. When adult birds go hunting, in a nesting place always there are some adult birds (as a rule, one partner from pair) for protection of posterity. In clutch there are 3 - 4 eggs, an incubating lasts about 35 days. Nestlings hatch blind, but covered by down. In 3 days they begin to see clearly, in 10 days feathers start to appear. Nestlings and fledglings have no tooth-like outgrowths on beaks. 20-day-aged fledglings freely move in colony. Parents food nestlings by meat, small vertebrates and fishes. At the age of 6 months "teeth" on a beak of young birds start to grow, and they start to hunt together with adult ones. Birds become independent at the age of 1 year, sexual maturity is in 3 years.

Prairie pipebird (Geofurnaria pseudotermita)
Order: Passeriformes
Family: Furnariidae

The specific name of this small bird of order Passeriformes occurs that this species of birds builds clay nest, similarly to the ancestor - stovemaker bird (Furnarius). But this bird settles not on trees, as at modern stovemakers, but on the ground, and nests look like termitaries (name "pseudotermita" means "false termit").
Bird is like modern starling in size. Its feathering is motley, the basic background is brown, on wings, nape and back with short yellow strokes (cryptic coloring). Belly and feathers under wings are bright, metallic green, throat at males is bright red. In time of courtship display the male is in air above the unfinished nest and twitters courtship song - melodious warble. Thus he shows its bright shining belly. If the female accepts his courtship, she sits down on a nest and starts to simulate actions of nest-building, runs its beak over the uncompleted part of the nest. These actions alternate with the actions showing readiness for pairing: demonstration of a pose of copulating.
During the nesting season birds keep by pairs, nesting in large congestions numbering up to 40 - 50 nests. The nest is making of dirt and clay, looking like conic hollow construction. In the bottom part of a nest there is a false entrance which comes to an end impasse, sideways from it there is a real entrance, so narrow, that the bird hardly squeezes into it. In a clutch there are up to 5 eggs. The bird is capable to collective protection of nesting place, a signal of “the general alarm” - sharp whistle.

Shell anteater (Myrmedillo destructor)
Order: Edentates (Edentata)
Family: Dasypodidae

One of few species of edentate group (Edentata, Xenarthra), survived in mass extinction. The descendant of a modern nine-banded armadillo (Dasypus novemcinctus). This species of armadillos successfully moved in XX century to territory of USA and the common expansion of its living area have shown the big adaptive opportunities of this species. The euryphagy has made possible survival of this species after decrease of ecosystem efficiency.
The shell anteater is the species specialized to feed by social insects. At lack of the basic forage animal eats soft plants, carrion and large soft-covered invertebrates, worms. Powerful shell and cornificate skin on a belly partly protects animal from stings of insects. The size of animal is about 40 cm, length of a tail – up to 50 cm, weight up to 10 kg. Jaws are weak, teeth numerous, but very small. Forepaws are armed with strong long claws (length up to 8 cm), intended for breaking and digging nests of social insects. The animal can move on two and on four paws. Being attacked by medium-sized predator, animal defends actively, making aggressive attacks by forepaws. Attacked by large predators it prefers to run away or quickly bury itself in the ground, but at absence of an opportunity to be rescued by a different way animal defends actively.
Solitary animal, keeping activity in gloaming and on dawn. It prefers to hide in grass thickets at the afternoon, night spends in temporary holes. In the beginning of rain season the female gives birth to 2 or 4 cubs, always enzygotic twins. They are capable to follow mother after 4 hours after birth. Newborn cubs have soft shells hardening to the end of 1-st day of life. Sexual maturity is at the age of 3 years.

Giant paca (Megapaca deinodonta)
Order: Rodents (Rodentia)
Family: Dasyproctidae

The large rodent of Neocene living in various biotopes - from crude meadows and rather thin woods up to pampas. An adult individual is the pig-sized animal. Head is massive, on cheeks there are plates of a cornificate skin under which there is strongly developed malar arch inherited from an ancestor - modern rodent paca (Cuninculus paca). Animals use this adaptation during intraspecific duels, striking each other by head side. In the mouth there are long (up to 15 cm long) orange-colored incisors, successfully available as for getting of food (plants, fruits, tubers and roots), and for defense against a predator: the animal prefers to run away, but, protecting the cub or not having a way to deviation, actively attacks an aggressor and puts terrible wounds by incisors. Legs are short and strong, the animal is capable to accelerate momentum up to 50 kms per hour and to make sharp turns on full speed. Claws on fingers are thick and more similar to hoofs, 3 ones on forepaws and hinder legs, middle toe is larger than lateral ones. Fingers are covered by the common integument up to the claws. Tail is very short. Body is covered with a short brown wool with some white spots on crupper and back. On a back of males the wool is longer, at irritation and aggression it stands on end. The skin on cheeks of adult males is light - from yellow to almost white, at females it is dark, a horn plate is smaller. Cubs keep coloring, characteristic for an ancestor: plenty of white spots and longitudinal strip along the body; cheeks are covered with wool.
This rodent keeps by herds on 20 - 30 individuals, among males and females the hierarchy is observed. Within one year there are about 2 packs. In a pack there is up to 4 well developed cubs in weight about 5 kg everyone. Cubs are suckled by all feeding females of herd that provides high survival rate of posterity. From week age the young growth starts to try vegetative food, at the age of 1 month completely passes to a diet of adult animals. The young growth becomes independent at the age of 4 months, sexual maturity comes at the age of 2 years. Animal lives till 15 years.

Deermara (Cervimara saltata)
Order: Rodents (Rodentia)
Family: Cervimaridae

Picture by Alexander Smyslov

Initial image - picture
by Pavel Volkov

This species is the graceful, easily combined herbivore, the descendant of a modern South-American rodent mara (Dolichotis patagonica). In comparison with an ancestor it has strongly increased in size (height at a shoulder is up to 1 meter, length of a body - up to 1.3 m, weight - up to 35 kg). It does not dig holes, occupies an ecological niche of running herbivores - antelopes and deer, lives on plains, sometimes comes into light forests. Animal keeps by herds on 30 - 50 individuals, at a fodder shortage herds break to small groups on 5 - 6 animals.
Deermara eats grass and leaves of bushes, at fodder shortage can eat ends of branches and bark of bushes and young trees. It drinks seldom, usually is content with a moisture received from plants. Due to unpretentiousness and endurance the present species was widely settled in South America and had passed over Antilles to the southern part of Northern America, having formed on territories of semi-deserts and grassy plains the separate close species distinguished by more graceful and fragile constitution.
Legs are long, on foot the middle toe, on hand - III and IV fingers are especially advanced. On these fingers claws have turned to small hoofs. Lateral fingers concern the ground only a tip. Hind legs are longer than forepaws, croup of an animal is raised above shoulders. The animal is timidly and cautiously, runs quickly, accelerating momentum up to 60 kms per hour on a short distance. During run some animals in herd make single jumps on height up to 2 meters, looking over district. The neck is rather long, animal resembles by proportions small deer, for example musk deer (Moschus). The head is similar to rabbit’s one, eyes are large and ears are long. Near the mouth there are long whiskers. Tail is not present. Colouring of body is ginger-brown; back is darker and stomach is white. At males around of eyes there are white rings; head is colored darker, than at females. Cubs are similar to the female in colouring. Per one year female usually gives birth to twin cubs. They are well advanced, in some hours after birth are able to follow mother. At the age of 5 months cubs are completely independent, but keep in herd with parents.

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