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A predator is an animal that kills other animals and feeds on them, and its actions are called predation. Domestic cats are also predators, they catch mice; the life of predators is a world-famous game of cat and mouse, it is constantly and everywhere repeated in ecosystems, millions of animals participate in it, each in its own way.

Lions, cougars, wolves, eagles, hawks, herons, crocodiles, sharks, pikes are indisputable predators. Toads and frogs are also predators, although not as obvious. Predators and all insectivorous birds. And tiny shrews. And a wasp carrying a caterpillar to its larva. And water beetle larvae sucking out a tadpole. And the tadpole himself. Even a whale that feeds on marine zooplankton is a predator. Man, a universal predator, is no exception, possessing both cunning, dexterity, and the greatest destructive power.

Production range.

There is an upper limit to the size of prey - a predator cannot cope with very large animals; and the lower limit - there is no point in hunting for small fry, wasting time and effort on it. Between these limits lies the prey range of the predator. A predator can only be seduced by game of the wrong size during periods of hunger, when there are very few animals in its range. Thus, European buzzards and golden eagles feed on the chicks of small songbirds when there are very few hares, rabbits, partridges and voles (their usual prey).

It happens that a predator for some time preys on only one species from its range of prey: when this species has multiplied strongly and has become easily accessible. For example, white storks that follow swarms of locusts in Africa; skuas hunting lemmings in Alaska; short-eared owls that settle in places where voles invade, or herons and otters that feed exclusively on frogs during their mass exit from ponds at the end of summer.

Harrier chicks in a defensive posture. Defending themselves from the enemy, they fall on their backs and fight off with clawed paws.

Does the predator get tired of the abundant food that he feeds on day in and day out? Watching the European tit, you come to the conclusion that it is boring. This bird, similar to the North American chickadee, was studied by Luke Tinbergen in pine forests Holland while feeding chicks. Various caterpillars served as food for these tits. When the caterpillars had just appeared, the tits did not eat them very willingly for the first days. Then suddenly they attacked them with greed. Tinbergen decided that the tits gradually developed a specific visual image of the new prey. Simply put, their eyes were getting used to the sight of the new food. There were more and more caterpillars, and then the appetite of tits began to weaken, as if this food began to bore them. Since then, any kind of caterpillars has been only half the diet of tits. This observation shows that tits prefer mixed food, even if it takes more time and effort to find it.

In the case described above, the tits had so much food that they could be picky. But in general, it is difficult for tits, wagtails and our other birds to feed their chicks. Parents have to fly up to the nest almost every minute, and they cannot acquire large families if there is no plentiful food near the nest. The predator did not always go and kill the game as soon as he got hungry. Sometimes he's lucky, and sometimes he's not.

Hard and easy ways.

Not all predators are equally agile and agile. One male Short-eared Owl will miss fourteen times before having lunch, another only four. Some crows in a nesting flock perform parental duties much better than their relatives: they are the best getters, that is, the best hunters and the best breadwinners.

preys mainly on lowland animals: antelopes and zebras. A lion with several relatives forms a family called a pride. Lionesses, unlike lions, do not have a mane, they are smaller and more graceful.

Misses and failures of a predator can be explained by his youth and inexperience. But the sensitivity of the prey must also be taken into account, because the sensitivity of prey animals is as important as the swiftness of predators. the victim has a wealth of life experience. A fox may be left with a handful of feathers in its mouth instead of a bird, or with the wriggling tail of an escaped lizard. Lions often do not kill large ungulates, but only injure them. Many adult salmon caught by fishermen show evidence of tooth or claw marks. This means that the salmon once managed to slip out of the mouth of a predator - a seal.

Why did the predator kill this particular animal this time, and not some other animal? The shortest answer is: it just happened. A prey of suitable size was at the right moment in an accessible place and fell into the clutches of a predator. It is necessary not only the presence of the victim - it must be within reach. It depends on many things: the ability of the animal to disguise itself, its age, state of health, the speed of its legs and its position in the group. Other factors that apply individually to the predator also play a role; first, the weather: rain, frost, deep snow, wind strength and direction; then sounds: the sound of a forest, a nearby river or waterfall; as well as the ability of a predator to withstand competition.

likes to build nests under the canopy of hedges and in dense bushes.

What the prey tastes like is not the main factor, it only plays a role if the predator has a very real choice. The fox, apparently, prefers the pheasant to the rat, but she will not scour half the night in search of a delicacy when rats are swarming underfoot. Sometimes a predator kills an animal that he does not like at all: in the heat of the hunt, he takes the pursued game for someone he would eat with pleasure. A cat, for example, kills shrews but does not eat them. Apparently, she mistakes them for mice and discovers the mistake when it's too late. Shrews, having once made a mistake, do not repeat the mistake again and do not kill “tasteless” game, remembering its smell. No one knows how often mammals make such mistakes and how quickly they learn to recognize inedible animals. Shrews are generally inedible due to their unpleasant odor to all mammals, although some do eat them if nothing else is available. But what is poison for one, says the proverb, is honey for another. Hawks and owls will not miss the opportunity to catch a shrew and eat it with pleasure.

A predator that feeds on a particular species encounters individuals of that species in a wide variety of situations. The pursued animal can run into the thicket, where it is not visible, or, conversely, into the woodlands, where it is more difficult to hide and where it is more accessible to the predator. It is easier for an experienced adult animal to run away from a pursuer than for a young and inexperienced animal, because an adult animal knows better the tactics of the pursuer, the terrain and possible ways to salvation.

Very young and very old, mutilated by predators, sick or hungry are more easily prey than healthy animals in their full bloom. An important factor is the position of the animal in the group: there are parties among the animals, they graze on the worst pastures, where there is little food and there is no good shelter from enemies. The age and experience of the predator, that is, the speed of his legs and cunning, also matter.

These factors play a role wherever there is a predator-prey relationship, but in different situations one or another factor or even a group of factors can become of great importance.

Choice of prey.

What all situations have in common: a predator attacks the one in this moment easier to grab. If there are two types of prey animals and both are equally accessible, the predator preys on both species, and the number of victims will be proportional to the number of animals of each species. If one species is easier to hunt, the predator will prefer that species until the situation changes. A good example of this is the Scottish marten. She feeds on voles and wood mice; voles suffer from it more than wood mice, although there are fewer voles in its territory. In the traps placed there, wood mice came across more often, which means that it is easier for the marten to catch voles. This may be due to the fact that wood mice are more cautious, they run and jump well, while voles are slow and not so nimble.

The European mole is another example of this selectivity. Moles feed mainly on earthworms. When there are a lot of worms, the mole catches them in abundance, cripples them and stores them for future use. Such warehouses of moles have been repeatedly studied; they tend to be dominated by one type of worm, although its grounds are home to a large number of other types of earthworms. Why this happens is still unknown. It can be assumed that the mole stores the type of worm that is easier to catch.

on the hunt. A wolf pack usually includes a male, a female, wolf cubs, sometimes two or three more wolves join them.

Predators also choose within this species, and do not at all rush in pursuit of the first animal that comes across. North American wolves, on the heels of chasing caribou herds, kill calves, old deer, sick and wounded animals. The Zambian wild dog hunts hartebeest antelopes, but is very picky. Most of all, she kills calves that are not a year old; there are slightly fewer one-year-olds, even fewer old animals, and very few healthy adults. Lions, on the other hand, kill age groups in proportion to their number in the herd - also a kind of selectivity. Hyenas hunting antelope in the Serengeti kill only calves - another kind of selectivity.

The European Sparrowhawk and the Peregrine Falcon have been observed to frequently kill those birds that stand out in some way from the flock. Five of the twenty-three birds killed by the hawk turned out to be some kind of aberration. One day a sparrowhawk snatched a lame tit from a flock of twenty-six healthy tits. In Germany, it was recorded: of the seventeen domestic pigeons caught by the peregrine falcon, fifteen were either somehow different from other pigeons or were strangers in the flock. In Poland, they saw how a hawk snatched a white dove from a flock of gray and blue-gray from a flock of whites.

Rivalry.

A man, an outside observer and a predator himself (addition from makuha.ru: if this person is the owner of the psyche of the animal type, which is a violation, because all the same, the Human is predestined from above to have a different type of psyche, different from the animal) , is inclined to consider wild predators, hunting game that he himself needs, as his rivals. General hostility to predators (addition from makuha.ru: among "humanoid predators") this is explained; the above examples, which can be multiplied, show that such an attitude towards predators is hardly fair. As a rule, the number of game does not depend on the number of predators, but vice versa. A loaf of bread can only feed a certain number of mouths.

In Scotland, the number of partridges has declined sharply in recent years. This phenomenon has been investigated and interesting findings have been made regarding predation; the most important: predators in the disappearance of the grouse are innocent, the reason for this is the behavior of partridges.

valuable feathered game. It is found in moorlands and mountain slopes. The partridge needs thick, well-leafed heather for both food and shelter. The most aggressive male takes the best territory. A person artificially maintains the habitat necessary for partridges, periodically burning out the old heather.

A bird that lives in a certain area; she feeds on heather, lives and breeds on the moors. The male owns a certain territory, which he defends from other males. The most aggressive males have the best territories, the less aggressive ones have the worst territories, and so on; in the end, all the land is divided among the married couples. Birds that could not capture any territory become "outcasts", content with the worst marginal lands: bare slopes, floodplain meadows, areas with poor cover, on which there is little food and it is difficult to hide from enemies. These outcasts are six times more likely to be preyed upon, with many dying from starvation or disease. Some move to other places in search of territories; the number of eaters is decreasing, and now the moorland can feed everyone. An ecologist would say that this struggle for territories is a kind of buffer between the bird population and the amount of food.

In August, partridge hunting begins, and the whole system of division of territories is violated. Young broods are equally threatened by wild predators and humans. Human predation causes great damage to the population of partridges, although a person does not always exterminate the entire annual offspring without exception, that is, he does not kill as much as he could. And in the fall, when the birds divide the territory again, outcasts again remain, for whom there was no good land.

Once again, wild predators kill many more outcasts. And again, many die, and many go to other places. Some still remain, taking advantage of the territory, for one reason or another, found itself without a master. Scottish partridges regulate their own population, and a prudent attitude to heather lands does not require the extermination of predators, but care for the protection of the vegetation cover.

"Fixed capital" and interest from it.

The predator feeds on its victims without reducing their population: it regulates their numbers. The predator lives, so to speak, not at the expense of fixed capital, but at the expense of interest from this capital. The mole, which feeds almost exclusively on earthworms, does not have any noticeable effect on the number of worms living in its territory. And the ermine, which hunted rabbits while they were found in Europe, did not pose a threat to the population of these rodents. In the barn owl, which lives in Palestine, in the Levant, half of the diet is voles: the number of all voles eaten, however, is relatively small; barn owls not only do not affect the "fixed capital", which is a population of 25,000 voles, but almost do not even spend interest on capital. In the same way, all the cats of the world can do nothing with the mouse people that are prosperous to this day.

Owl hunts all night, from dawn to dusk; her food is small rodents: voles, mice, rat pups. It happens that an owl will catch and eat a small bird. Owls do not build nests, they live in hollows and abandoned nests of other birds: crows, magpies or kestrels.

And yet it happens that a small predator causes serious damage to the population of its prey. A tiny weasel, for example, has access to the burrows of mice and voles, and once in such a burrow, it can cause real havoc among its inhabitants. The Americans McCabe and Blanchard report that the weasels, having found themselves in an area where there were many deer mice, walked along their minks and destroyed the mice almost without exception.

Insectivorous birds can sometimes delay insect breeding, but in the case of the European tits described by Tenbergen, raptors ate the most caterpillars when there were not so many of them. Birds, as a rule, cannot cope with hordes of insects. The fact that birds at some stage can inhibit the reproduction of insects is very important for humans. In Germany, this was understood long ago; there, everywhere in the forests, small houses are hung, like birdhouses, in which tits arrange their nests. Feathered tenants help people protect the forest - biological protection instead of chemical.

And what about the big predators? Do they control big game populations? In some cases, no doubt, as evidenced by the facts, though still few. A vivid illustration of this is the story of the black-tailed deer living on the Kaibab plateau. At the beginning of the 20th century, a herd of 4,000 black-tailed deer lived on the Kaibab Plateau in Arizona. They shared this habitat with predators: wolves, cougars, coyotes, lynx and a few bears. Herds of domestic animals - sheep and cattle grazed here. The deer population in these conditions did not grow and did not decrease, remaining from year to year within 4000 heads. This area, however, could feed a much larger herd of deer; no one had any doubts: predators were to blame for the small number of deer. And in 1906 the territory was declared state reserve. To increase deer pasture, livestock grazing was banned; hunters were invited to fight the predators. Over the decade, 600 cougars were shot. In sixteen years, 3,000 coyotes have been exterminated. By 1926, the wolves were completely destroyed. The number of deer began to grow, at first slowly, then faster , by 1920 the herd of deer had grown to 60,000 heads, and by 1924 to 100,000 heads. This monstrous figure proved fatal. The plateau could not feed so many black-tailed deer. They multiplied menacingly and trampled pastures clean. In the next two winters, 60,000 deer died. By 1929, the number of deer had dropped to 30,000, by 1931 to 20,000. And in 1939, only 10,000 black-tailed deer grazed on the Kaibab Plateau.

This is an instructive story. Predators obviously held back deer population growth thus protecting natural pastures. The destruction of predators led to the fact that the deer multiplied catastrophically and destroyed the pastures on which they fed.

The same balance exists in nature between lions and the topi antelope, which lives in the Ruin di Rutshuru valley in the former Belgian Congo. From 1918 to 1929, lion hunting in the area was particularly intense; the number of large predators has sharply decreased, and the number of marsh antelopes, as one would expect, has increased greatly.

Close relatives.

Competition between predators of different species living in the same area is more apparent than real, even if several species prey on the same animals periodically or constantly. Changes in habitat, in the number or ratio of animals that feed on predators, can tip the balance in favor of one predator or another. Some predators thus benefit, others suffer.

(lat. Mustela erminea) - a small predatory animal of the weasel family, a typical marten appearance with a long body on short legs, a long neck and a triangular head with small rounded ears. The body length of the male is 17-38 cm (females are about half as long), the tail length is about 35% of the body length - 6-12 cm; body weight - from 70 to 260 g. It looks like a weasel, but somewhat larger in size.

These relationships have been well studied in the case of weasels and stoats living in the Northern Hemisphere. In England, weasels and stoats often live side by side in the same territory; and as long as each species hunts for its prey, there is no rivalry between them. Weasels are much smaller than stoats, the male weasel weighs only 150 grams, and the male stoat 350 grams. If there are a lot of rabbits, the ermine preys mainly on them, while the weasels feed on voles. In such a situation, both predators thrive. If the rabbits are struck by myxomatosis, which mows down these rodents without exception, the number of stoats decreases markedly, but this does not affect the weasels at all. The disappearance of food upsets the balance of the ecosystem to the detriment of the stoat, without affecting the weasels in any way.

Young forest plantations in temperate countries are ideal habitat for voles, which are very fond of dense, tall grasses. In such a biocenosis, both weasels and ermines feed on voles. The relationships of these animals have been well studied in Scotland. Weasel, due to its diminutiveness, can hunt for voles underground, in their minks. An ermine will not crawl into a mouse hole and is content with random prey, that is, those voles that it catches on the surface. For affection, we also reach the main capital: by destroying voles underground, weasel reduces the amount of accidental prey of ermine; but as long as the number of voles does not fall below a certain critical figure, hunger is not terrible for both predators. However, the number of voles is subject to sharp fluctuations, and if there are less than forty-five of them per acre, stoats leave their homes. Weasels continue to exist carelessly in this territory until the number of voles drops to eighteen per acre. With the departure of ermines, the number of voles begins to grow. In the end, there are so many of them that the stoats return again.

, or common weasel (lat. Mustela nivalis) - a predatory mammal of the mustelid family, a species of the genus Weasel and ferrets (Mustela). It is found on all continents of the Northern Hemisphere.

And here is another example of the coexistence of weasels and stoats, this time brought to the Dutch island of Terschelling. On this island, in the early 1930s, water voles began to cause great damage to the forest. They decided to apply the biological protection of the forest and in 1931 102 weasels and 9 stoats were brought to the island. Three years later, there were no weasels left on the island. Five years later, stoats completely destroyed the water voles and drastically reduced the number of rabbits that lived on the island. Now it was necessary to take urgent measures against ermines, which quickly multiplied and began to feed on all kinds of birds: wild, domestic and even waterfowl. Natural equilibrium was reached only by 1939. Stoats have survived on the island, but have ceased to be a problem. In this case, the ermines were in an advantageous position, and the weasels, unable to withstand the rivalry, died.

The USA has its own weasels and its own stoats; the American weasel is no different from the European one, while the American ermine, unlike the European one, can be both a very small animal and a larger one: in different parts of the country they live different types stoats. The largest is distributed in the United States in the eastern and northwestern regions up to Alaska. He shares his habitat with affection. In the West North America only a small ermine lives, no larger than a weasel; and it turned out that in these places weasel is not found at all. She can live in the neighborhood with large ermines, but she cannot stand the competition with the "kids". This example proves that the small species of ermine is a kind of taboo for affection, it can only live where they do not exist.

Reference supplement to the book.

Distribution area of ​​Ermine.