Most of the food birds can. Handbook of ornithology: bird nutrition. Presentation on theme: "Bird Nutrition"

It's no secret what urban birds eat (sparrows, pigeons, etc.), which, in addition to their trade in the form of insects, seeds, herbs, and food waste receive support from people who build special feeders and drinkers for them, but not many will be able to answer what birds eat in the wild. In their natural habitat, they have to find food on their own, respectively, depending on the period, their diet changes.

Bird food in the summer

In the warm season, birds have a fairly diverse diet, which may also differ depending on the species and habitat. As a rule, their diet consists of:

• various invertebrates;
• insects;
• small rodents;
• carrion;
• cereal crops;
• fruits and fruits;
• eggs.

Of course, in summer time plant food is also included in the diet of wild birds, but to a lesser extent, since their task is to gain weight and make preparations for the cold weather in order to safely winter. To get food, birds often destroy seedlings in fields or gardens, as seeds, vegetables and fruits are also included in their diet.

The diet of birds in the cold season

It is much more difficult for these animals to feed themselves in winter time when all the vegetation is covered with snow, and small rodents hid in holes. But even in the cold they find something to profit from. Below is a list of what birds eat during the winter:

• berries;
• seeds;
• acorns and nuts;
• coniferous leaves;
• insects;
• roots.

Separately, it should be said about the birds that live near the places of fishing. They manage to profit from waste, as well as dead fish washed ashore. In addition, mollusks and crustaceans are found in their diet, which are found in the upper water layers or near the coastline.

The nature and conditions of nutrition are importance in the life of birds. They affect their distribution in space, seasonal movements, reproduction and mortality rates, interspecific and intraspecific relationships, etc.

The composition of bird feed in general is very diverse. A huge number of plants and animals inhabiting the globe serve as objects of their food. A significant set of food is also found in many individual bird species. Thus, the ptarmigan of the Timan tundra feeds on more than 40 species of plants and animals, while the hazel grouse in Primorsky Krai has more than 80 species. The total number of plant and animal species eaten by birds in the entire range is much greater.

You should pay attention to one of the features of birds - easy switchability from one food to another. One cannot but agree with Peterson (1973), who writes that due to this feature, probably not a single bird has ever completely destroyed the source of its food - because by doing so it would doom itself to death. Usually, when one type of food becomes scarce, the bird looks for another within its diet. It collects surpluses, rarely causing significant damage to the main "capital". However, only a few predominate in a significant amount of food eaten. Therefore, most birds occupy an intermediate position between stenophagous and omnivorous and have a well-defined specialization in the nature of nutrition.

The nature of nutrition and its variability.

According to the nature of their diet, birds are conditionally divided into three groups: herbivorous, animal-eating, and with mixed nutrition (birds that consume both vegetable and animal food). Among our birds, the latter group is the most numerous in terms of the number of species, which is associated with seasonal changes in the food supply. The appearance of new foodstuffs (berries, seeds) in autumn, a reduction in winter period animal food forces a significant number of birds to switch completely or partially from animal food to vegetable food, and vice versa in spring.

Within these groups, ecological subgroups are distinguished, reflecting a well-defined narrower food specialization in birds. So, in the group of herbivorous birds, one can name granivorous, frugivorous, in the group of animal-eating - insectivores, myophages (feeding on mouse-like rodents), ichthyophages (feeding on fish).

The ratio of animal and vegetable feed in birds with a mixed diet varies within very wide limits. The noted narrow food specialization in most birds is not absolute. For example, granivorous and frugivorous birds in the summer not only feed on insects themselves, but also feed their chicks. Many insectivorous birds switch to vegetable food in winter, myophages switch to birds, etc. Nevertheless, it well reflects the predominance of food eaten by birds.

According to the variety of food eaten, birds are divided into stenophages (birds with a narrow range of food) and polyphages or omnivores (birds with a wide range of food). However, there are, in fact, few omnivorous birds: each natural group is characterized by a certain specialization in the choice of food and in the methods of obtaining them. This specialization is typical for each species and even for individual groupings within a species that have adapted to a particular type of food.

The geographical distribution of birds largely depends on the nature of the diet. Omnivorous birds, as a rule, have very extensive ranges. For example, the corvid family, most of whose species are omnivorous, has populated almost the entire globe. Raven settled almost throughout the northern hemisphere. Conversely, stenophages (species of birds with a narrow range of food) have limited ranges. So, the nutcracker, feeding on cedar seeds for a significant part of the year, lives only where this plant is found. The crossbill feeds mainly on the seeds of spruce, with the distribution of which it is closely associated. The vulture eagle feeds mainly on the fruits of one type of palm and lives only where this palm is found in Africa. A remarkable example of monophagy is the slug-eating kite living in Florida, which feeds only on snails of one species. The guajaro, common in South America, is the only "vegetarian" in the nightjar order. Unlike their relatives, who feed on animal food, mainly insects, the guajaro feeds on the fruits of trees. Spending the day in deep mountain caves, after dark, he begins to fly over the rainforest and pluck fruits mainly from palm trees and laurel trees. In addition to keen vision, a well-developed sense of smell helps him find food (eaten fruits, as a rule, have a strong groin). Particularly associated with the spread of certain plant species are those birds in whose nutrition the nectar of flowers plays an important role (lorises, hummingbirds, etc.).

Broad food specialization in birds is beyond doubt. At the same time, in a number of respects, this issue has not been sufficiently studied, in particular with regard to specific features chemical composition of feed. Meanwhile, it is precisely certain certain substances that are absorbed by birds regularly or periodically that are extremely important for their body. So, for some grouse necessary condition for a normal existence is the ingestion of needles, which apparently serves as a means of cleansing the intestines from worms. For the normal development of young birds of prey (falcon, hawk, etc.), it is necessary to introduce bones into the diet, which dissolve in their stomach. The absence of bones, even with abundant meat feeding, causes rickets in young birds of prey and disruption of the normal development of plumage. This shows that with a fairly varied diet, some of it constituent parts may be of decisive importance.

Regardless of whether the bird eats a variety of or the same type of food, the composition of its food usually changes depending on the time of year. Seasonal changes in the environment cause a change in food conditions, and consequently, the diet. The seasonal change of food is pronounced in birds of northern and temperate latitudes. Very often, a change in the economic value of a particular bird species depends on a change in feed. So, for example, starlings feed mainly on insects in summer, fruits and berries in autumn and winter, being at that time pests in Central Asia and especially in North Africa. The ability to switch over in winter to feeding on new foods available at this time of the year is an important biological adaptation that allows one to live settled life or be limited to migrations.

A special type of seasonal variation in food composition is found in birds feeding their chicks a diet different from that which they feed themselves. So, some, predominantly herbivorous, birds (for example, hazel grouse, chaffinch, linnet, etc.) feed their chicks only with insects. However, pigeons, which are also herbivorous, feed their chicks with seeds, supplementing this food with a special secret, the so-called "pigeon milk", which is formed in the wall of the crop. It is rich in proteins and its formation is stimulated by the hormone prolactin. Sometimes birds for feeding their chicks (great tit and motley kingfisher) pick up smaller prey. In addition, the kingfisher chooses juvenile salmon and brown trout for chicks, while he himself feeds on three-spined stickleback.

In some species, significant changes in food are observed in different years. So, the long-eared owl in normal years usually feeds mainly on voles, but when there are few voles, it eats a significant number of other animals, including passerine birds. This is observed both in summer and winter.

There is also geographic variability in food composition. Naturally, a bird that feeds on a certain food substrate in one area can switch to another in those places where it is absent. So, in Finland, the great spotted woodpecker feeds mainly on the seeds of coniferous trees in winter, while in England it feeds mainly on insects from the trunks of broad-leaved trees. The nutcracker in Siberia and Switzerland feeds mainly on the seeds of cedar and spruce, while in the Baltic region it lives mainly on the seeds of hazel. The gyrfalcon eats mainly sea birds on the Arctic coast, and partridges in the northern forests.

Despite the possible change of food, birds are very specialized in terms of food composition. Thus, the yellow-headed beetle eats representatives of all the main groups of insects found in the habitats of these birds, but prefers beetles, mosquitoes and sawfly larvae and, if possible, avoids hay-eaters, ants and some others. In the diet of the titmouse, the largest percentage is made up of sawfly larvae, caterpillars of butterflies and aphids, although their prevalence in nature is the lowest compared to other insect species.

Food preferences have been studied in detail in titmouse feeding their chicks with caterpillars and sawfly larvae in the pine forests of Holland. Tits choose prey according to their size, except when they carry food to newly hatched chicks. Moreover, in the food of birds, some forms of insects make up a larger percentage than others. In addition, different individuals prefer different types: some, for example, specialize in small butterflies, others eat larger specimens.

Food specialization in individuals and populations within a species is a common phenomenon. And there is every reason to believe that such specialization is acquired by inheritance. For example, the offspring of falcons, whose parents specialized in feeding on pigeons, also feed mainly on pigeons and pay less attention to other bird species; duckling falcon chicks also become "ducklings". There are falcon families that from generation to generation specialize in hunting gulls, etc. A similar food specialization of individual families also takes place in other species, in particular in passerines.

Birds are accustomed to eating certain feeds from a very early age, in the same way they are adopted by chicks from their parents and methods of obtaining them. Young birds eat the same food and obtain it in the same ways as their parents. This circumstance opens up prospects for a targeted impact on birds in terms of their choice of one or another food. Breeding of birds "accustomed" to eating the most dangerous or highly breeding pests may be promising in the fight against them in agriculture and forestry.

The food of birds is extremely diverse and includes substances of both animal and vegetable origin, which can be obtained on the surface of the earth, in air and water, in particular by diving to a depth of 10 meters.

Unlike mammals - moles, mole rats and many other diggers - birds do not use underground prey, do not dig holes in search of insect larvae or root parts of plants, and can only go slightly deeper into the soil, raking it with their beak and legs, in search of roots, insects and etc.

The food of most birds is quite diverse, although there are, of course, no omnivorous species in the narrow sense of the word, the so-called panthophages, that is, completely illegible in food, eating literally everything that is horrible, among birds, just as there are none among other animal groups .

Among the polyphagous is, for example, the majority of crows. So, the jay feeds on acorns, insects and small vertebrates. Ravens peck at corn cobs, eat carrion, mice and chicks, drink eggs, etc. Birds with a very wide choice of food are called euryphages.

These include, for example, the house sparrow. His food usually lacks the meat of vertebrates, but nevertheless it is quite diverse, since, in addition to grains, seeds, berries, etc., it includes insects, worms and human waste. Birds that are highly specialized in obtaining any one type of food are called stenophages.

Such, for example, is the wryneck, which mainly feeds on ants, or the osprey, which mainly extracts live fish from the water. Between euryphages and stenophages, of course, there are a number of transitions.

Birds are very characteristic of changes in the composition of food depending on age and season. As you know, in mammals, cubs are raised on milk. " bird's milk” does not exist, but pigeons feed their chicks with a substance that resembles colostrum in mammals.

In the male and female pigeon during the breeding season, the epithelium of the mucous membrane in the goiter grows and undergoes fatty degeneration. Its surface cells are destroyed, forming an emulsion, which the pigeons, having mixed with the food contained in the goiter, burp into the throat of the chicks. The rest of the birds feed their offspring with more delicate food than adults eat: they crush it, overexpose it in the esophagus or partially digest it, and finally, they simply give a different food.

Sparrows, being predominantly granivorous, feed their chicks with insects. The same is observed in grouse and many other birds, herbivores in adulthood. Young sparrows, as soon as they fly out of the nest, immediately switch to plant food. It is very rare for sparrows to be foster parents of a cuckoo, which they probably feed mainly on insects, as they would feed their own chicks.

Once, it happened to get a cuckoo, which was fed by a field sparrow, and the stomach of the stepson chick turned out to be filled with grains of wheat, and he himself was very fat. This unusual food for the cuckoo, apparently, was safely digested by him. The cuckoo was late, taken on August 22, when the sparrows switched almost exclusively to feeding on grain.

Young pink starlings, fed on locusts, attack vineyards upon departure from the nest. The common starling, as well as thrushes and other birds, bring some insects to their chicks, and some plant food. Based on the study of the food of chicks, it is impossible to judge the nutrition of an adult bird of the species under study.

Due to the fact that the availability of this or that food depends on the time of year, the composition of food eaten by birds also changes. Most of them are forced to switch to other food in the fall or fly to other countries. Insectivorous birds that feed on insects in the larval and adult phases fly away with the onset of the cold season.

During this period, unfavorable for vigorous activity, insects hide in shelters and become inaccessible to birds, or their life continues in the egg phases, as well as the initial stages of larvae, and the body weight becomes too small. With the ripening of the fruits, abundant resources of plant substances appear on the life arena, which are consumed by birds, in particular, by many representatives of the thrush and warbler family.

The latter, in their organization, would seem to be the most adapted to getting insects: they have a narrow, pointed beak, at the base of which there are bristles. Nevertheless, at the end of summer, whitethroats also switch to berries and other plant foods. Woodpeckers and nuthatch have adaptations that allow them to get insects in winter.

With a strong beak, these birds are able to crush wood or bark and extract insects hiding there in various phases of development, but they are often forced to switch temporarily or partially to plant food from autumn. Woodpeckers pinch the cones of coniferous trees in specially hollowed out recesses, the so-called "forges", and, having firmly fixed them, extract the seeds.

Nuthatches ripening in autumn, nuts, especially hornbeam and beech nuts, arrange similar "forges". Having picked a nut, they fly with it to the recess, strengthen it, hammer and split it until they get the core. So do some tits.

In birds that have approximately the same range of food throughout the year, there is often a change in the amount of food by season.

Thus, it was found that 67.5% of mice were contained in 820 buzzard stomachs during the cold season and only 62% during the growing season of plants. In the first case, there were 2.4 mice per buzzard, in the second - only 2. At the same time, it was noticed that in December and March, predators exterminated the largest number useful wild animals, as well as poultry, in the summer, from June to August, is the least.

The diet of birds is usually highly variable, and includes seeds, nuts, fruits, vegetables, insects, small animals, fish, and even other birds. Different types of birds consume different foods. The taste preferences of domestic and wild individuals vary greatly. Also, the seasons of the year can influence the diet of birds, for example, when berries and nuts ripen in spring or summer, they become staples.

All birds need basic things to survive, including water, shelter and food. Most people have water supplies and live in similar dwellings, but everyone has different dietary preferences. In wild nature natural products food for many birds are insects, fruits, berries and nectar from flowering plants. Some species even suck the sap from tree buds, while others choose small termites, worms and other insects from grass and tree bark. Large birds such as hawks, vultures, and owls may feed on larger prey such as fish, other birds, and small rodents. Many birds eat fresh food, but some, namely vultures, also feed on carrion.

Like humans, birds have different dietary needs and preferences depending on the season. In winter, birds (especially those that migrate long distances) need food sources high in protein, fat and carbohydrates. Nuts are ideal for this time of year, and human legumes such as peanuts, almonds, hazelnuts and pistachios are also a great way to replenish energy lost on a long flight.

For people who want to attract or provide birds a good place for a stop and a snack, it is worth making feeders with seeds and grains. Like us, some birds prefer a variety of seeds and grains, and you can attract different species by adding certain foods to the feeder.

Of the wide variety of seeds and grains, some are more readily available and at the same time popular with many birds. For example, sunflower seeds are a favorite among songbirds. They contain rich reserves of fats and oils that help them survive the cold winter nights. Safflower seeds are consumed mainly by smaller birds such as cardinals, chickadees and nuthatches. Millet is preferred for birds that can eat medium to hard shelled nuts such as sparrows, cardinals and juncos.

Finally, corn is a popular bird food. They can eat the kernels whole, as well as in the form of corn grits or flour. Corn is ideal for feeding birds in winter, as it contains high level carbohydrates and other essential nutrients.

Birds use a lot of energy to fly and maintain a high body temperature, so most birds are very voracious creatures. Birds feed on all kinds of insects and other invertebrates, seeds, fruits and green parts of plants, flower nectar, and fish. Birds of prey prey on rodents, birds, reptiles, and even larger prey - hares, monkeys, ungulates; There are also carrion birds.

Woodpeckers

The great spotted woodpecker captures the habitat - a piece of forest ranging from 5 to 15 hectares - and does not let other woodpeckers into it

Representatives of the woodpecker family hollow out holes in tree trunks, extracting insect larvae.

These birds have a beak strong as a chisel, powerful neck muscles, and hard tail feathers and tenacious claws create a reliable support. Having found a passage made by an insect, the woodpecker takes out its inhabitant, using a long, serrated tongue at the end. The insect is either pierced by the tongue or sticks to it and is drawn into the mouth. Woodpeckers also feed on the seeds of coniferous trees. To get seeds from cones, they arrange "anvils": they gouge a hole in the trunk, where they insert a cone, and then peck it.

Some species of woodpeckers eat ants and drink tree sap.

owls

The eyes of the owl are huge and keen, he sees perfectly both day and night

Owls are nocturnal.

Among them there are both very small birds, about 12 cm in size (elf owl), and large ones, up to 70 cm in length (fish owl).

What do birds eat

Owls feed mainly on rodents, as well as reptiles, insects, and small birds. Soft plumage makes their flight almost silent. The paws of owls are armed with sharp curved claws. The eyeballs of owls are motionless, so their field of view is small. This disadvantage is compensated by the incredible mobility of the neck, the owl can turn its head 180-270 ° C. A feature of owls is the asymmetrical arrangement of the auditory openings.

Thanks to this, owls, even in complete darkness, accurately determine the position of the victim by sound.

Crossbills

The pine crossbill has a powerful beak and easily copes with cones

Crossbills are common in the coniferous forests of Eurasia and North America.

They have a very distinctive beak structure: the upper and lower mandibles intersect, forming an excellent tool for shelling seeds from cones. Many granivorous birds feed their broods with insects (they are more nutritious and easier to digest), but crossbills feed their chicks with conifer seeds, which is why they nest in winter when their main food “ripens”.

Flamingo

The long legs of flamingos are equipped with special mesh membranes that help them to walk on liquid clay without falling through.

Flamingos have a flexible neck, long legs and a swollen, curved beak at the end.

The edges of the beak are equipped with small horny plates, which form an ideal filtering apparatus. Having lowered its beak into the water, the flamingo wanders through shallow water on graceful legs, moving its head from side to side, straining small crustaceans from liquid silt and water, which are its main food.

The pink or red plumage of adult birds is provided by the red pigments contained in the shell of crustaceans, and in captivity on a different “diet”, flamingo feathers may lose their color intensity or even become white.

Scavengers

The black vulture is one of the largest birds of prey in the world and the largest in Russia. This is a rare, endangered species listed in the Red Book of the Russian Federation.

Vultures, condors, vultures have a very characteristic appearance.

A powerful beak allows them to tear off pieces of meat from the carcasses of dead animals, and the lack of plumage on the head and neck is a tribute to hygiene, because these birds have to dig in half-decomposed entrails. In search of prey, they soar high in the sky for hours, but as soon as one of the birds notices carrion and dives down, neighbors immediately notice its maneuver, and in a matter of minutes, scavengers from all over the area gather for a feast.

Tens of thousands of birds of different sizes and colors live in our forests, but all of them can be divided into several groups according to who eats what. And here we find that there are not so many such groups. There are birds of prey that prey on other, smaller birds. These are eagles, kites, falcons. Or they catch rodents like owls.

Other birds - and there are a lot of them in our forests - eat beetles, aphids, caterpillars. These are very useful birds: they destroy harmful insects and thereby save green spaces from destruction.

The well-known woodpecker, for example, tirelessly hammers the bark of trees with its strong beak, then, sticking its beak into the hole, takes out the larvae of bark beetle, woodcutter, goldfish and other insects with a sticky jagged tongue.

People do not really approve of cuckoos, they consider them frivolous for not hatching their eggs, but throwing them into other people's nests.

But cuckoos are also of great benefit, eating hairy caterpillars, caterpillars of gypsy and pine silkworms, nun butterflies, moths. They even eat insects that other birds reject.

A small bird, the kinglet, also feeds on insects and eats as much of them in a day as it weighs itself, and for this it needs to eat 8-10 million insects.

Exterminates insects and a large tribe of titmouse: blue titmouse, moskovok, chickadees. They look for them on branches, leaves, on the ground. Sometimes they even accompany a woodpecker and help him pull insects out from under the bark. But the swift swift finds insects high in the sky.

It would seem, what kind of insects can be there? And yet, over the summer, he catches them there so much that if you put them in one line, then it would stretch for a whole kilometer.

A large group of birds that feed on grains are called granivorous.

They feed plant food: grains, berries, cones peel, and at the same time destroy the seeds of various weeds. These are carduelis, and hazel grouse, and black grouse, and capercaillie, and bullfinches.

There are such omnivorous birds that eat everything that comes across to them.

Perhaps the most famous of them is the sparrow, as well as crows.

Predator birds

Predators are characterized by a strong hook-shaped beak at the end, the base of which is dressed in bare brightly colored skin - cere, into which the external openings of the nostrils open. The legs of birds of prey are of moderate length, with curved and usually sharp claws (only secretaries have long legs). The claws and beak serve to kill, and the latter to dismember the prey.

The toes are relatively long, with pads on the plantar side that serve to hold food. The physique is dense, the plumage is rigid and close to the body. The color is usually not bright, mostly gray, brown, red or black, often with an admixture of white.

In some carrion-feeding species, the head and part of the neck are bare, unfeathered.

Birds of prey, hunting for other birds and animals, play a certain positive role as an instrument of selection. A known number of predators contributes to the maintenance of the health of the species that are their prey, since in the first place they prey on sick or weak specimens.

Carrion-eating birds bring certain health benefits. From the point of view of human economic interests, the features of birds associated with nutrition can be summarized in general terms as the extermination of useful wild animals and wild plants, to compete with more useful species animals to harm cultivated plants, to eating pets, animals.

At the same time, it should be borne in mind that we have no reason to say that this or that bird: should be considered absolutely useful or absolutely harmful.

Birds do not bring any benefit or harm "in general". Therefore, the question of absolute protection or absolute destruction of any bird species cannot be raised.

Both a useful and harmful bird, like any other animal, can only be in certain conditions and at certain times. The situation is changing - the economic importance of birds is also changing.

Greater Spotted Eagle - Aquila clanga

Starlings, for example, which bring benefits in the spring and children by exterminating insects, in some areas on migration and wintering can be definitely harmful to gardens, and more recently in Tunisia, the fight against starlings was carried out by the massive use of explosives.

Ravens harm by destroying the nests of useful birds, in particular waterfowl, but at the same time exterminate insects, mice and voles. The great spotted woodpecker feeds on insects that are harmful to the forest, but at the same time it destroys a certain number of tree seeds, and sometimes harms the trees themselves (so sometimes, as in the Buzuluk pine forest, damage from a large spotted woodpecker that interferes with the normal renewal of pine trees, more than useful).

Sparrow eats berries, displaces useful insectivorous birds from nesting places, but also feeds nestlings with insects.

The peregrine falcon feeds on waterfowl and other useful birds, but at the same time, in the tundra near its nests, arctic foxes leave the nests of other birds alone, as the falcon vigorously attacks arctic foxes and drives them out of the vicinity of its nest, thereby providing significant assistance to the entire surrounding bird population . The goshawk feeds on useful birds, but promotes natural selection and is rightly valued in places as an excellent bird of prey.

We will not touch here on the very important question of the aesthetic significance of birds. It is useful to emphasize that in the fauna of Russia, numbering more than 750 species of birds, at least less than a dozen species are essentially harmful. Borrowed from Western European owners of hunting grounds and their rangers and, unfortunately, firmly rooted and widespread opinion about the "harm" of birds of prey should be resolutely discarded.

The vast majority of predators benefit from the extermination of rodents and insects; others, for example, large falcons - peregrine falcons, gyrfalcons, although they hunt mainly birds, are rare, and besides, they live in any noticeable number in such areas (north) where wild riches have not yet been sufficiently used by man.

They are in no way competitors of the latter, but at the same time they serve as one of best jewelry our nature; and the reproduction of birds of prey is relatively slow. This does not mean that we should not fight with predators who are used to catching pigeons, poultry, or with a hawk that disperses the flow of black grouse in an organized hunting economy, etc.

Feeding conditions are reflected in the geographical and stationary distribution of birds. This applies in particular to those species that are stenophages, i.e.

What do birds eat

highly specialized in nutrition. The African vulture eagle is found only where the kind of palm grows, the fruits of which it feeds on. Many birds that feed on certain plants, or in which a certain type of plant predominates in the diet, are found only where these plants are available. So, for example, the Scottish grouse is closely related in its distribution to wild rosemary, crossbills - with certain types of conifers, honeysuckers, hummingbirds, etc. - with the presence of those plants whose nectar they feed on.

There are, in fact, few omnivorous birds: crows can serve as an example of them. In general, for each species of birds, a certain specialization is characteristic both in the choice of food and in the methods of obtaining it.

Unfortunately, these issues have not yet been studied enough. Meanwhile, some certain substances, absorbed by birds, at least in small quantities and occasionally, apparently have a very great importance for the normal functioning of the bird's body. For example, in young birds of prey that do not receive bones, rickets develop and the normal course of molting is disrupted. For grouse, it is necessary, at times, to swallow needles, which probably serve to cleanse the stomach of worms.

Change external conditions, which determine the conditions of nutrition, is of great importance for birds. These changes are especially pronounced in areas where climatic changes are significant during the seasons or where various types of meteorological conditions (snow cover, humidity, temperature, etc.)

n.) fluctuate greatly.

Snow cover is also of great importance for ground-feeding species. Therefore, for example, many granivorous birds winter in Mongolia, where winters are very severe, but there is little snow. On the other hand, for example, in In Lapland, beyond the Arctic Circle, one can also find a rather diverse composition of small passerines in winter: chickadees, great tit, pika, etc.

These birds forage from trees and are less dependent on snow cover. For the same reason, birds that get food from cracks and other shelters or on vertical tree trunks in the bark, etc., for example, wrens, nuthatches and pikas already mentioned, do not fly away for the winter, but remain in the cold and temperate zones at home.

Even in the conditions of the Arctic polar night, birds hibernate, if only they have the opportunity to get their own food. For example, off the coast of Greenland, the polar guillemot hibernates near polynyas and breedings at 77 ° and even 78 ° 30 \ ’ north latitude, near Svalbard - even at 80 ° north latitude.

In the tropics and subtropics, the main climatic reason for the change in the feeding conditions of birds is the onset of the dry season of the reptile.

The disappearance of insects, the decrease in the number of insects, periodic changes in plant life - all these factors determine the diet of birds and, accordingly, affect their distribution.

If in some species these changes cause movements, then in others they are associated with seasonal changes in the diet. Partridges, for example, feed mainly on berries and insects in summer, berries in autumn, and willow shoots in winter. The raven in northern Siberia is omnivorous in summer, and feeds mainly on pied beetles in winter.

Starlings feed mainly on insects in summer, in autumn and wintering, in addition, on fruits and berries. Many such examples could be cited.

Ecological groups of birds

To environmental groups by habitat (rice.

180) combine birds that have the most characteristic adaptations (adaptations) to life in certain conditions, for example, in the forest, in open spaces, reservoirs, their coasts, swamps.

This takes into account not only the structure, but also the behavior.

Often the ecological groups of birds determine by nesting sites : crown-nesting, shrubby, ground-nesting, hollow-nesting, norniks.

Ecological groups of birds are distinguished and by type of food : herbivorous (including granivorous), insectivorous, carnivorous, omnivorous, scavengers.

Birds from different, sometimes distant from each other, systematic groups often fall into the same ecological group, since taxonomy is based on genetic proximity, degree of relationship, and common origin.

Birds of the forest. Most modern birds are associated with the forest.

Everyone knows our forest birds: tits, woodpeckers, thrushes, hazel grouse, black grouse, capercaillie well adapted to life in forests. They have short, rounded wings and long tails. This allows the birds to take off quickly and tack between trees.

Among forest birds there are herbivorous (granivorous), insectivorous, predatory and omnivorous (Fig. 181).

Depending on the nature of the food, beaks and limbs are differently developed in birds.

So, insectivores tits, pikas, kinglets, warblers they have thin pointed beaks that allow them to get insects from the crevices of the bark, grab them from the leaves, and get them out of the scales of the cones. Sharp claws and long fingers allow these birds to hold on to branches.

Granivorous birds – greenfinches, schury, grosbeaks. They have a powerful beak, which splits the dense shells of fruits. So grosbeak successfully breaks the strong fruits of bird cherry and cherry.

The sharp ends of the crossed beak crossbills allow them to deftly extract seeds from pine and spruce cones.

Large forest birds hazel grouse, black grouse, capercaillie- Spend a lot of time on the ground. With strong legs, armed with large claws, they rake the forest floor, select the seeds of plants, insects, and earthworms.

Strong beaks bite buds, young shoots of trees and shrubs, feed on juicy blueberries, blueberries, lingonberries.

They have a typical appearance for forest birds. magpie and goshawk(Fig. 182): relatively short rounded wings and a long tail. These birds perfectly maneuver among forest trees, have a nimble flight. However, due to the use of different food, their legs and beaks are developed differently. Hawk - predator: its prey are various small birds.

With strong legs, armed with powerful claws, the hawk grabs the prey, dismembers it with a bent predatory beak. The magpie has a small cone-shaped beak, which helps it eat a variety of foods (be omnivore ): collect fruits and seeds from the ground, grab insects, worms, a large beetle, and even catch a small mouse.

Birds of open spaces live in meadows, steppes, deserts.

They spend a lot of time on the ground looking for food among plants. They have strong legs and a long neck, allowing you to detect the enemy at a great distance. One of the typical representatives of the steppe regions of our country - bustard(see fig. 179, 6 ). This is a large bird weighing 15-16 kg, it feeds mainly on plant foods. Possessing a protective coloration, it often hides among the vegetation, becoming completely invisible. The nest is arranged on the ground, in areas of the virgin steppe.

Brood type chicks.

Where does it live, what does it look like, how long does it live and what does a black grouse bird eat

In connection with the plowing of virgin steppes, the number of bustards has sharply decreased, and it is included in the Red Book of Russia.

Typical birds of open spaces are ostriches.

waterfowl swim well, many dive. They have a flattened, boat-shaped body, webbed feet, and their legs are set far back.

On the ground they move, awkwardly waddling, with a duck's gait. The plumage is dense, with water-repellent properties: the feathers are prevented from getting wet by the secretion of the coccygeal gland, with which the birds carefully lubricate the plumage. Representatives of waterfowl - ducks, geese(Fig. 183) , swans.

A typical representative of waterfowl - mallard duck(cm.

rice. 179, 9 ) that feed in shallow water. Along the edges of its flattened wide beak are horny teeth . With incomplete closing of the jaws through the lattice formed by the teeth, the ducks filter the water, leaving food objects in the mouth: crustaceans, insect larvae, small fish, vegetative parts of plants.

The mallard feeds at shallow depths. Sometimes, lowering her head into the water, turning over and exposing the back of her body from the water, she collects food from the bottom and strains it. Mallards make nests on the ground among plants. The lining for the nest is its own downy feathers, plucked from the chest and belly.

Clutch 8-14 eggs. Brood type chicks.

Birds of the coasts of reservoirs and swamps live on the banks of water bodies and in swamps, have many common structural features.

They have long, thin legs and a neck, a large beak (see Fig. 179, 5, 10 ). In swampy places, their body, raised high above the ground, does not get wet. They feed on frogs, fish, insects, worms, and molluscs. Moving through swamps and coastal shallows, they seize prey with their beak, like with tweezers. These are storks, herons, waders.

Many of them nest on the banks, not far from the water, others make their nests in trees. Storks have long lived next to humans. People take care of them, arranging platforms for nests.

sea ​​birds - guillemots, puffins, seagulls- form bird colonies on steep cliffs.

They are adapted for hovering over the sea surface (Fig. 184).

Ecological groups of birds according to the ways of feeding. A peculiar group of birds foraging in the air - swallows and swifts(Fig. 185 and 180, 1 ). They spend almost their entire lives in the air, hunting insects from morning to evening.

They have long sickle-curved wings. The beak is small, and the slit of the mouth is huge, the corners of the mouth go behind the eyes. With a wide open mouth, they catch flying insects, while the size of the mouth funnel is increased by bristles located at the corners of the mouth. In good dry weather, insects rise high above the ground, and when the humidity of the air rises, the wings of insects get wet, they fly low above the ground.

Swallows and swifts follow them, so the flight of swallows and swifts predicts the approach of rain.

Predators have common features (Fig. 186 and 180, 3 ). They have large strong legs, armed with sharp claws, and a hook-shaped beak. Such features are diurnal predatory birds, owls and even shrikes pertaining to songbirds.

The prey of many predators are small animals, which they look out for from a great height, flying over the fields. Other predators catch small birds, feed on fish, large insects. Birds of prey fly beautifully, among them there are long soaring ones, for example buzzards, eagles and vultures. Falcons pursue prey in the air, and then, diving at it, can reach speeds of up to 300 km / h.

They have sharp sickle-curved wings that enable them to fly quickly.