Bird group ecological project. Ecological groups of birds at nesting sites. General characteristics of the class

Into environmental groups by habitats (Fig. 180) unite birds with the most characteristic adaptations (adaptations) to life in certain conditions, for example, in a forest, in open spaces, reservoirs, their coasts, swamps. This takes into account not only the structure, but also the behavior.

Often ecological groups of birds determine on nesting sites : crown-nesting, shrub, ground-nesting, hollow-nesting, burrowing.

Ecological groups of birds are distinguished and by type of food : herbivores (including granivores), insectivores, carnivores, omnivores, carrion eaters.

Often birds from different, sometimes distant from each other, systematic groups fall into the same ecological group, since the taxonomy is based on genetic proximity, degree of kinship, common origin.

Birds of the forest. Most modern birds are associated with the forest. Everyone knows our forest birds: tits, woodpeckers, blackbirds, hazel grouses, black grouse, wood grousewell adapted to life in the forests. They have short, rounded wings and long tails. This allows the birds to quickly take off and maneuver between trees.

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

Depending on the nature of the food, birds have different beaks and limbs. So, insectivores tits, pikas, bloodworms, warblers have thin pointed beaks that allow you to get insects out of crevices in the bark, grab them from leaves, and pull out cones from the scales. Sharp claws and long fingers allow these birds to hold onto branches.

Granivorous birds – greenfinches, shura, grosbeaks... They have a powerful beak, which cleaves the dense shells of the fruit. So grosbeak successfully breaks down the strong fruits of bird cherry and cherry. The sharp ends of the crisscrossing beak crossbills allow them to deftly extract seeds from pine and spruce cones.

Large forest birds - hazel grouse, black grouse, wood grouse - spend a lot of time on the ground. With strong legs, armed with large claws, they rake the forest floor, select seeds of plants, insects, earthworms. Strong beaks bite buds, young shoots of trees and shrubs, feed on juicy berries of 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 foods, their legs and beaks are developed differently. Hawk - predator: various small birds serve as its prey. With strong legs armed with powerful claws, the hawk seizes the victim, dismembers it with its bent predatory beak. The magpie has a small cone-shaped beak, which helps it eat a variety of foods (to be omnivorous ): to 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 the plants. They have strong legs and a long neck, allowing them to spot 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 patronizing coloration, it often hides among the vegetation, becoming completely invisible. It makes a nest on the ground, in areas of virgin steppe. Chicks of brood type. Due to the plowing of virgin steppes, the number of bustards has sharply decreased, and it is included in the Red Book of Russia.

Typical birds in open spaces are ostriches.

Waterfowl swim well, many dive. They have a flattened boat-like body, webbed feet, and legs are shifted far back. They move on the ground, waddling awkwardly, with a duck gait. The plumage is dense, with water-repellent properties: the secretions of the coccygeal gland prevent the feathers from getting wet, with which the birds carefully lubricate the plumage. Waterfowl representatives - ducks, geese(fig. 183) , swans.

A typical representative of waterfowl - mallard duck(see fig. 179, 9 ) feeding in shallow water. Along the edges of its flattened wide beak are horn teeth ... When the jaws are incompletely closed through the lattice formed by the teeth, the ducks filter the water, leaving food objects in their mouths: crustaceans, insect larvae, small fish, vegetative parts of plants. The mallard feeds on 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 out. Mallard duck nests on the ground among the plants. The lining for the nest is its own down feathers plucked from the chest and belly. There are 8-14 eggs in a clutch. Chicks of brood type.

Birds of the shores of water bodies and swamps live on the banks of reservoirs 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, molluscs. Moving through swamps and coastal shallows, they seize prey with their beak, like tweezers. These are storks, herons, waders... Many of them nest on the banks, not far from water, others arrange nests in trees. Storks have long lived next to humans. People take care of them by arranging nest platforms.

Seabirds - guillemots, puffins, seagulls - form bird colonies on steep cliffs. They are adapted to hover over the sea surface (Fig. 184).

Ecological groups of birds by feeding methods. A peculiar group of birds foraging in the air - swallows and swifts (fig. 185 and 180, 1 ). They spend almost their entire life in the air, hunting for insects from morning to evening. They have long, sickle-curved wings. The beak is small, and the mouth is huge, the corners of the mouth go behind the eyes. With their wide open mouths, they catch flying insects, while the size of the oral funnel increases the bristles located at the corners of the mouth. In good dry weather, insects rise high above the ground, and when the air humidity rises, the wings of insects get wet, they fly low above the ground. Swallows and swifts follow them, therefore, according to the flight of swallows and swifts, they predict the approach of rain.

Predators have common features (Fig. 186 and 180, 3 ). They have large strong legs, armed with sharp claws, a hook-like curved beak. These signs are possessed by daytime predatory birds, owls and even shrikerelated 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 on it, can reach speeds of up to 300 km / h. They have sharp, sickle-shaped wings that allow for fast flight.

On this basis, four groups are distinguished. Representatives of each of them eat a certain type of food:

Insectivorous birds (for example, tits or pikas) have thin pointed beaks, thanks to which they can pull their prey from leaves or take out from thin cracks.

Herbivorous birds, including granivorous birds (for example, greenfinches) have a powerful beak due to which they can break through the dense shells of the fruit. And the sharp ends of the beak help us to pull out seeds from the cones of various trees.

Birds of prey (eg eagle) feed on various small birds. They have strong legs with powerful claws, thanks to which they grab prey.

Omnivorous birds (eg magpies) have a tapered beak that helps them feed on various types of food.

Insectivorous tits, pikas, beetles, chiffchaffs have thin pointed beaks that allow you to get insects out of crevices in the bark, grab them from leaves, and get cones out of the scales. Sharp claws and long fingers allow these birds to hold onto branches.

A peculiar group of birds foraging in the air are swallows and swifts. They spend almost their entire life in the air, hunting for insects from morning to evening. They have long, sickle-curved wings. The beak is small, and the mouth is huge, the corners of the mouth go behind the eyes. With their wide open mouths, they catch flying insects, while the size of the mouth funnel increases the bristles located at the corners of the mouth. In good dry weather, insects rise high above the ground, and when the humidity rises, the wings of insects become wet, they fly low above the ground. Swallows and swifts follow them, therefore, according to the flight of swallows and swifts, they predict the approach of rain.

Granivorous birds - greenfinches, pike-holes, grosbeaks. They have a powerful beak, which cleaves the dense shells of the fruit. So the grosbeak successfully breaks the strong fruits of bird cherry and cherry. The sharp ends of the crossing beak of the crossbills allow them to deftly extract seeds from pine and spruce cones.

Predators have common features. They have large strong legs, armed with sharp claws, a hook-like curved beak. These are the characteristics of diurnal birds of prey, owls and even shrikes, which are related 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 well, among them there are long soaring ones, for example, buzzards, eagles and vultures. Falcons pursue prey in the air, and then, diving on it, can reach speeds of up to 300 km / h. They have sharp, sickle-shaped wings that allow for fast flight.

In the course of evolution, a large number of various forms have developed among birds, adapted to life in a variety of conditions. Some birds inhabited forests and shrubs, where they developed an appropriate paw arrangement for life among the branches. Other forms have adapted to life on the water, and their further development followed the path of specialization in swimming and diving. Some forms, to a greater extent than others, have mastered the air environment and spend most of their lives on the wings, revealing various adaptations in the wing structure, which ensure the soaring flight of large predators, the rapid active flight of swifts and swallows. The steppes and deserts are inhabited by a number of species that have adapted to walking and running on solid ground.

Based on the preferred types of landscapes and the characteristics of movement, the following are distinguished main ecological groups of birds: arboreal-shrubby, terrestrial-arboreal, terrestrial, semi-aquatic, aquatic, hunting on the fly ... It should be noted that, as with any other attempts at biological classifications, a fairly large number of species occupies, as it were, an intermediate position and their assignment to one or another group turns out to be rather arbitrary, therefore the boundaries between the identified groups are indistinct and rather arbitrary.

Arboreal and shrub birds. They feed mainly in the crowns of trees and bushes, in thickets of reeds and other emerging plants, where they nest. Nests of varying degrees of difficulty, in some species very skillfully woven, warm and durable; some species nest in hollows. The main mass of species of this group is made up of various families of passerine birds, oriole, some corvids, titmice, warblers and many others. This also includes cuckoo and woodpeckers.

Collecting food, birds jump from branch to branch, sometimes helping with flaps of their wings. Small birds of this group, clinging to the irregularities of the bark with strong fingers with sharp claws, can move along the vertical trunks of trees (titmouse, nuthatch, pikas). In real woodpeckers, the structure of the paws changes: two fingers are directed forward, two - back; all fingers bear powerful, highly curved, sharp claws that securely cling to any irregularities in the bark. The tail made of strong rigid tail feathers is pressed against the trunk and serves as an additional fulcrum. These features allow woodpeckers not only to move along vertical trunks, but also to gouge.

The species of this group feed on various insects and other invertebrates, fruits, berries and seeds, some species eat the buds, anthers of flowers, drink nectar. Some of the larger species (corvids, woodpeckers) simultaneously eat eggs and chicks of other birds. The shape of the beak and tongue corresponds to the nature of food specialization. In predominantly insectivorous species, an elongated thin beak allows (like with tweezers) to pull out prey from cracks in the bark, from the axils of the leaves. Flycatchers, shrikes and others often lie in wait for prey, quietly sitting on a twig and, taking off, catch an insect that has flown close. Such fishing is facilitated by a slightly widened, flattened beak (flycatchers). Seed-eating species with a strong conical beak are capable of splitting or gnawing the dense shells of seeds (grosbeak gnaws at the bones of cherries and olives). With the sharp, strongly crossed ends of the powerful beak, the crossbills deftly open the scales of cones of coniferous trees, taking out seeds; the sharp keratinizing end of the tongue cuts off the wings of the seeds.

Woodpeckers with a powerful chisel-like beak hammer bark and wood, opening the passages of Insects and their larvae. The long tongue can protrude from the mouth almost the length of the beak, has spines directed backwards at the end and is covered with sticky saliva. The woodpecker inserts its tongue into the opened passage and pulls out its prey with its tongue.

Terrestrial and arboreal birds. They are close to the first group in appearance and differ only in that they are equally successful in collecting food both in the crowns and on the ground. Some species build nests in the crowns of trees and shrubs, nest in hollows, or arrange a nest on the ground.

This includes some of the black grouse (capercaillie, black grouse, hazel grouse), many corvids, blackbirds, wrens, starlings, many weavers, finches, buntings. In this group, there are both insectivorous species and omnivores, feeding on various invertebrates (and some, for example, corvids, and vertebrates), berries, seeds, and vegetative parts of plants. Variations in beak structure correspond to food specialization and are similar to many beak variations in the first group. In the crowns, they jump from branch to branch, on the ground small species usually move in leaps, and larger ones (grouse, pigeons, parrots) - in steps. Species of similar sizes can also differ in gait: for example, blackbirds and magpies jump on the ground, and starlings, jackdaws, rooks, crows walk. Some species, in search of food, rake the top layer of litter (black grouse, blackbirds).

Land birds . A team group that brings together birds with varying degrees of adaptation to the terrestrial lifestyle. Quite a few species retain the appearance of arboreal-shrub or terrestrial-arboreal birds, but they feed almost only on the ground where they build a nest, however, for rest and in case of danger, they willingly sit on trees and bushes. The terrestrial way of life of these species is provided primarily by the peculiarities of behavior.

Morphological adaptations are not clearly expressed: usually the claws are somewhat less curved, the strong hind limbs of many species make it possible to rake the litter in search of food, some species develop a protective coloration. They walk and run on the ground, not jump. They feed on various insects and other invertebrates, collecting them on the ground and grass (jumping up and down, some catch flying insects), eat seeds and berries. These species include some passerines (larks, skates, wagtails, chisels), hoopoe. More distinct adaptations to the terrestrial lifestyle are characteristic of most chickens. The strong hindquarters in these species are relatively short. Strong short fingers end in blunt claws; the hind (first) toe is usually small or completely reduced. All these land birds walk and run well. In case of danger, they run away or fly away; many species are lurking. The food is mainly vegetable (vegetative parts of plants, seeds, berries, tubers), but willingly, and sometimes in large quantities, they eat a variety of invertebrates and small lizards. Beaks in all species are strong, of varying length, usually with a pointed end, ensuring the capture of both animal and plant food.

This also includes a number of long-legged species that resemble near-water birds in appearance: some cranes (Demoiselle crane) and the secretary bird from daytime birds of prey. Elongated limbs (especially tarsus and tibia) with strong toes allow these birds to easily run on tall grass, chasing reptiles (lizards, snakes) and large insects. The prey is seized with its beak (cranes) or with its paws (secretary), then killing it with its beak.

Near-water birds. They inhabit a variety of damp habitats: overgrown and open shores of reservoirs, vast swamps. This includes all the ankles, or storks, many cranes and charadriiformes.

Most species of this group are characterized by elongated limbs (the tarsus and tibia are lengthened, the lower part of the latter is usually not feathered) with long thin toes (all four in herons, many shepherds, in the rest the hind toe is small or absent), sometimes connected at the base by a rudimentary swimming membrane ... This makes it possible to walk and run on thick grass and in shallow waters without wetting the plumage and without falling into the muddy muddy ground; some species (small shepherds) run easily on floating aquatic vegetation. As a rule, the lengthening of the limbs is accompanied by the lengthening of the neck: the bird reaches the ground with its beak, only slightly tilting the body. In some species, the body is clearly compressed from the sides, allowing it to slide between the stems in dense thickets. A casually built nest is located on the ground, on reed creases, sometimes in trees (egrets, storks, ibises).

A very wide range of food in this group is provided by various adaptations. Cranes feed mainly on a variety of plant foods (seedlings, rhizomes and bulbs, young shoots, seeds, berries), along the way they catch (sometimes in large quantities) various invertebrates, amphibians, and lizards. They have a strong, elongated beak with a pointed top. Some of the shepherds also use vegetable food; these species have a powerful, relatively short beak. The rest of the semiaquatic bird species are predominantly animal-eating. Herons and storks consume a variety of animal food (invertebrates, fish, amphibians).

Aquatic birds.A very diverse group of birds, swimming and diving for food; some feed on land. They inhabit the coasts of the seas and various continental water bodies. These include toadstools, goose, or lamellar-billed, some shepherd (coots).

In species of this group, the body is usually flattened in the dorsal-abdominal direction, which provides greater stability on the water. The plumage is tight-fitting, successfully resists wetting. Well-developed down and down portions of the fan contour feathers improve thermal insulation; this is also facilitated by the strong development of subcutaneous fat deposits. All this allows

swim and dive in cold water for a long time. The hind legs are relatively short; the forward-pointing three fingers are connected by a well-developed swimming membrane. Only in toadstools, shepherds (coots) and waders-phalaropes, the swimming membrane does not form, but each of the three forward-facing toes is equipped with elastic and strong horny edges, which also noticeably increase the rowing surface of the paw. In well-diving species, the sternum usually lengthens and the number of ribs increases (better protection of internal organs from external pressure), the pelvis narrows, and in some good divers, the legs shift back (toadstools).

Aquatic birds usually nest near water bodies, more often - on the ground, less often - on reed creases and trees. Grebes and coots build floating nests in the thickets of emergent vegetation.

The vast majority of species of this group are animal-eating: they feed on fish and various aquatic invertebrates. Swimming waders peck various small invertebrates from the surface of water and leaves of emerging plants with a thin tweezers beak. Coots of moderate length, feeding mainly on plant food, have a strong beak that makes it possible to tear off pieces of plants and seize aquatic animals. In Anseriformes, at the end of the widened beak, a thickened area is well developed - the marigold, which forms a small hook; horny plates along the edges of the beak and mandible and on the sides of the fleshy tongue form a filter apparatus that releases water and silt, but retains food objects in the oral cavity: various small animals and seeds. A strong marigold allows you to tear off attached mollusks, parts of plants, etc. In ducks that feed on small animals, especially in broad-nosed, the plates of the filter apparatus are thin, long, very densely set. In eiders, which feed mainly on relatively large attached mollusks, and geese, feeding largely on land with terrestrial plants, a strong marigold at the end of the beak and coarse, more rarely sitting plates along its edges make it easy to tear off and crush mollusk shells, pinch fresh greens. In mergansers, these plates turn into denticles, making it easier to hold the fish.

Among the passerine birds, dippers should be included in this group. They feed on insects, their larvae and other invertebrates, collecting them on the banks and at the bottom of rivers and streams, and retain the typical appearance of a passerine (only the plumage is somewhat denser, dense fluff is developed on apterias, the wings and especially the tail are short). They cannot dive in stagnant water.

Birds hunting on the fly. A heterogeneous and diverse group, including representatives of many families, whose close relatives are included in the previously described groups. More common in open landscapes.

Quite a few species of this group are associated with water. These are birds with long, narrow peaked wings, possessing maneuverable flight and usually capable of long hovering. The fingers are connected by a swimming membrane. They rest on the water or on the shore. The most common way of hunting is flying at different heights above the water and diving swiftly for prey (fish, large invertebrates) seen on the surface or in the upper water layer. Due to the energy of diving, birds can submerge in water, seizing prey with their beak at this moment. This is how gulls, terns and phalaropes hunt. Seagulls often gather food by wandering in shallow waters and on land.

Many birds of prey (eagles, buzzards, kites) soar high in the air for hours, looking for prey, and then catch up with an active flight, dive and seize on the ground (and birds and air). Unlike birds hunting over water, their wings are somewhat shorter, but noticeably wider, with a blunt top. The prey is seized by powerful paws armed with sharp claws, killed and torn apart by a strong beak with a sharp hook at the end. Osprey and many eagles feed mainly on large fish: they hover over water bodies and, diving, grab the prey that has risen to the surface with their paws.

Hawks use two methods of hunting: the predator sits in a shelter and suddenly rushes at an approaching prey, or flies more often along the edges, and seizes the scared prey in a quick throw. They are characterized by relatively short wings and a long tail, allowing them to pursue their prey among the branches. Falcons possessing a swift maneuverable flight usually fly around their hunting area and in a swift throw - a dive - seize the encountered prey in the air or on the ground. When looking out for prey on the ground, small falcons are able to hang in the air for a short time in fluttering flight. In addition to the main method of hunting - looking out for prey in flight and grabbing it on the fly - many predators catch large insects, wandering on the ground, watching out for rodent holes and dragging chicks from their nests.

Owls look for their prey in flight or sit in ambush, and catch in a short throw, grabbing the victim with their paws. Unlike diurnal birds of prey, the main receptor for detecting and seizing prey in owls is not sight, but hearing. Goat-like, like owls, are twilight and nocturnal; feed mainly on large insects, which they catch in the air or, less often, peck branches off the ground in flight. They also have a quiet, maneuverable flight, the plumage is soft, although not to the same extent as that of owls. Long sharp wings, rapid maneuvering flight, a small beak, but a very wide opening of the mouth, bordered in the corners by rigid bristles, are the features of swifts and swallows ecologically close to them. Swallows catch prey only in flight, they do not use other methods of hunting. They feed on small insects. Swallows are capable of pecking on insects from branches and leaves on the fly. Only in flight are they catching large flying insects, bee-eaters. Fairly long, thinning towards the end, slightly curved downward beak, no long bristles in the corners
mouth - these features of bee-eaters are associated with the larger sizes of their prey compared to the food items of swallows and swifts.

This classification is schematic, but it gives a fairly complete picture of the ecological diversity of the class of birds. They have mastered almost all niches suitable for life: only sea depths over 50-60 m and the soil thickness remain inaccessible to them (although some species dig nesting holes).

Within each ecological group, there is a great diversity in biotopic confinement, in nesting places and types of nests, in the sets of forages used and methods of obtaining them, correlating with many species characteristics - the proportions of limbs and the nature of movement, feathering properties, the shape of the beak and tongue, and structural details. digestive system, receptor structure, etc.

Despite the obvious ecological diversity, the general appearance of birds, as well as their morphophysiological features, varies within relatively small limits. The variety of appearance, size and morphophysiological features among mammals is much more pronounced. This large, in comparison with mammals, morphophysiological homogeneity of birds, apparently, is due to adaptation to flight, which created severe restrictions on variations in body shape and its functioning systems.

Trophic groups of birds

The range of food for the class of birds is quite wide and includes a variety of plant and animal food. The variety of bird feeds used is usually divided into three groups: polyphages, stenophages and intermediate.

Polyphages (omnivores) feed on a wide variety of plant and animal feed. This group includes about 1/3 of families, and within each family, omnivorousness is more pronounced in larger species. An example of the most typical polyphagous birds can be large corvids (crows, crows, etc.), large gulls, and cranes.

Stenophages - species that consume homogeneous food and use uniform methods of catching prey. Stenophagy is relatively rare among birds. Swifts and many nightjars, feeding only on flying insects, and swallows, which also catch insects in the air, but can also peck them on the fly from plants, should be attributed to stenophages. This group also includes typical scavengers, as well as species that feed only on large fish, such as osprey. Crossbills, which feed mainly on seeds of coniferous trees, also belong to stenophages.

Intermediate group makes up the majority of birds that use a fairly wide range of feed for feeding. These are the many passerines that feed on both various insects and seeds. Grebes feed on fish and various large aquatic invertebrates; green parts of plants, berries, seeds and various invertebrates - chickens.

The degree of food diversity in different species is expressed differently. For example, in loons and cormorants, aquatic invertebrates are usually only a small addition to the fish diet, while in many grebes they may even be the predominant food group.

A number of ecological groups are also distinguished by the composition of food in the class of birds. Species that feed mainly on plant foods are called Phytophages . Geese, swans, some ducks, coots feed mainly on a variety of coastal and aquatic vegetation, simultaneously eating various aquatic animals. Green parts of plants, berries, seeds, buds, catkins are the basis of nutrition for chickens. Most of the seeds feed on many passerines - weaver, finches (especially crossbills, grosbeaks, greenfinches), larks. However, all phytophages, if possible, to some extent use a variety of animal feed; their consumption especially increases during the breeding season, since most of these birds feed their chicks mainly with animal feed.

Species that feed mainly on animal food are called Zoophagous . Although many of them, albeit to a small extent, eat plant foods. Almost a third of living bird families are exclusively or predominantly insectivorous (entomophages ); almost all birds use insects to one degree or another. Many aquatic and semi-aquatic species feed primarily on fish (ichthyophages), along the way, eating aquatic invertebrates.

Many birds of prey and owls belong to Myophages,that is, they feed mainly on small rodents. Few birds of prey can be called ornithophages : hawks, falcons (peregrine falcon), marsh harrier and some others feed mainly on birds.

TO herpetophages (feed on amphibians and reptiles) include the snake eagle, the secretary bird, and some large kingfishers. However, such a division by types of food is largely arbitrary and schematic.

The change in diet is typical for all groups. Typical ornithophages, for example, catch mammals, lizards and large insects on occasion.

Due to the seasonality of the appearance of different types of food in many bird species, seasonal changes in nutrition are observed. The degree of variability is determined by the nature of the food specialization.

Rather sharp differences in the quantity and degree of availability of different groups of food in different years determine the change in the dietary spectrum of many birds from year to year. There are many examples of such seasonal, geographic and annual variations in nutrition. It is well expressed even in stenophagous birds. For birds, the opposite feature is also characteristic - when a massive, readily available feed appears, species that usually do not use it begin to feed on it. When puddles and small lakes dry up, mollusks, tadpoles and fish fry remaining on the mud are picked up not only by crows and magpies, but also by pigeons, blackbirds, and shrikes. The number of birds sharply increases in places of mass reproduction of insects or mouse-like rodents, in orchards when cherries ripen, on plantations when berries ripen. This ability to quickly find accumulations of food and use them determines the participation of birds in limiting and eliminating foci of pests.

In almost all birds, age-related changes in feed are expressed to one degree or another. In mature hatching chicks that feed on their own (anseriformes, chickens, many waders), this age-related change in food is primarily due to the fact that, due to their small size and poorly developed methods of foraging, part of the food obtained by adults is simply not available. As the chicks grow, these dietary differences gradually disappear.

Immature hatching chicks eat what their parents bring them. In many species, age-related variability in nutrition is well expressed, due to the selective delivery of food by adult birds, which undoubtedly significantly accelerates growth and increases the survival rate of chicks. Thus, great tits try to carry spiders to newly hatched chicks, and sometimes only their “contents” are squeezed into the open beak of the chick, and the “shell” is swallowed themselves. After two or three days, parents begin to carry small larvae, caterpillars, butterflies with torn wings, aphids and other soft insects to the chicks, and they often feed the already grown, fledging chicks with beetles. Adult birds themselves eat at this time any insects available to them. Other passerines do the same.

How to get food

The methods of obtaining food from birds are not very diverse. The vast majority of species take prey with their beak. In accordance with food specialization, the shape and relative size of the beak vary within wide limits. Straight or curved, very long and slender beaks of waders and some passerines allow foraging from wet soil or narrow and deep shelters. The sharply conical beaks of many granivorous birds, which are powerful at the base, facilitate grasping and gnawing seeds. Powerful beaks of birds of prey, owls, partly shrikes, with a sharp "hook" varying in length on the upper beak, help to hold and tear food; beaks with numerous plates along the edges, which allow filtering small prey, are characteristic of anseriformes. Small beaks with a very large opening of the mouth and bristles in its corners in swifts, nightjars and swallows form a kind of "net" that facilitates catching small flying insects.

No less varied is the shape of the tongue, which in many birds not only helps in swallowing the food lump, but also participates in the seizure and retention of prey. So, the strongly protruding tongue of woodpeckers, usually equipped with sharp spikes at the end, allows you to find the larva in the hollowed out course and pull it out. The fleshy mobile tongue of many Passeriformes, along with the ridges on the palate, allows you to conveniently place a seed or nut on the edge of the beak to break the shell. In birds fishing and various aquatic invertebrates, numerous sharp spines directed towards the pharynx are located on the tongue, facilitating the holding and swallowing of prey (grebes, mergansers). the fleshy and mobile tongue of the anseriformes, bordered with plates, participates in the filtration of food.

Daytime predators and owls grab prey, especially large ones, with their paws. Depending on the food specialization, I vary the shape and length of the claws, the mobility of the fingers, the nature of the stratum corneum on the soles of the toes (for example, the development of sharp horny spines in the osprey). Some birds, when pecking at prey, support it with their paws (tits, some corvids). Nuthatches - nuts, and woodpeckers - nuts and cones are thrust into cracks and, thus strengthening them, peck. Shrikes prick large prey on dry, sharp knots, and then peck and tear.

Sometimes crows and large seagulls, seizing hard prey (toothless, crabs, etc.), take off and then throw the prey to the ground; this technique is repeated many times until the shell or carapace cracks. Perhaps, some birds of prey do this with turtles (vulture) or with large bones (bearded man). The use of a woodpecker finch by birds is also described, holding a cactus needle or a dry twig in its beak by one end, picking it in cracks in the bark, driving the insect out and then grabbing it with its beak. Flying from tree to tree, the finch sometimes drags a thorn behind it.

The vast class of Birds is represented by thousands of species that have adapted to different environmental conditions. The birds have mastered forests, meadows, mountains, swamps, learned to build complex nests and get various food. Depending on the place of residence and behavior, ecological groups of birds are distinguished.

By habitat

Birds belonging to different families and species have developed similar traits under the influence of the environment. The table describes the features of ecological groups by habitat.

Fig. 1. Water-air birds.

Table "Ecological groups of birds"

*Group*	*Description*	*Morphology*	*Nutrition*
Forest - owl, woodpecker, wood grouse, thrush, cuckoo	Predatory, insectivorous, herbivorous, omnivorous birds. They live in all layers of the forest - on trees, bushes, in grasses	Small body size; Short wide wings; Long tail; Short sharp beak; Tenacious paws	Seeds, berries, nuts, cones, caterpillars, small rodents, lizards
Open air spaces - swallow, swift, flycatcher	Active in the air. They feed on the fly. They nest in forests, parks, in the city	Small body; Short paws; Developed pectoral muscles; Elongated wings and tail; Small, wide-opening beak	Insects
Waterfowl - ducks, swans, geese	Feeding and nesting is associated with fresh water bodies - rivers, lakes, ponds. They nest on land. Dive and swim well	Wide body with tight-fitting plumage; Legs wide apart; Webbed feet; Abundant fluff; Thick subcutaneous fat; The coccygeal glands abundantly secrete a water-repellent secret; Flat beak with filtering apparatus (transverse plates)	Worms, molluscs, algae, crustaceans
Water-air - terns, gulls, cormorants, crested grebe, pelican, albatross	They are associated with water, but spend most of their lives in the air. They fly well. They can be on the waves, but they don't swim well. Diving from the air	Wide wingspan; Dense streamlined body; Short or missing membranes Powerful elongated beak, sometimes bent down	Fish, crustaceans, crabs, molluscs
Steppe and desert - ostriches, demoiselle crane, bustard	Flying and flightless birds. They run fast, have excellent eyesight and hearing. Flying birds cover long distances. They nest on the ground in primitive nests. Some species are scavengers and predators	Camouflage painting; Strong long legs; Elongated neck; Powerful beak	Omnivores
Birds of swamps and coastal areas - stork, heron, sandpiper, flamingo	They feed on wetlands. They fly well. They nest on land.	The body is dense, shifted downward; Long legs without membranes; Elongated sharp beak or filter beak; High neck	Amphibians, crustaceans, fish
Meadow and field - lapwing, wagtail, corncrake, quail, Dubrovnik, lark, hawk, meadow harrier	Small to medium sized birds. They nest on the ground. There are birds of prey with a curved beak, excellent eyesight, fast flight.	Small head; Large elongated body; Short and wide wings; Elongated and short beak; Camouflage painting	Insects, lizards, small rodents, seeds, berries

Fig. 2. Crake.

Penguins are active underwater and stand out as a separate group of divers. They have an elongated body with a center of gravity shifted downward, a sharp beak. Can't fly. They feed on fish.

By the nesting site

There are five groups:

crown-breasted - on trees (oriole);
shrubby - on bushes (robin);
terrestrial - on the ground (oatmeal);
hollow-nesting - in hollows (pika);
burrowers - underground (shore swallows).

Fig. 3. Nests of shore swallows.

Some species (guillemot, nightjar, owl) lay their eggs on bare rocks or in hollows without building nests.

What have we learned?

From the 7th grade biology article, we learned about the main ecological groups by habitat and nesting. Groups of birds, depending on the living conditions, have similar signs that help them survive (camouflage in the grass, water-repellent lubricant in the water, excellent vision in open spaces).

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Ecological groups of birds stand out for the following reasons:

by the nature of the diet,
by habitats,
by the nature of nesting.

Often, birds from different, sometimes distant from each other, systematic groups fall into the same ecological group, since the taxonomy is built on the basis of genetic proximity, degree of kinship, common origin.

By habitat there are four groups of birds:

Forest birds differ from other groups in that they have rather small legs and a medium-sized head. Their necks are not visible, the eyes are on the sides.
The bird of the coasts of water bodies and swamps has a very long neck and long legs. They need them in order to get food in the swamps.
Birds of open spaces are adapted for migration and therefore have very strong wings. Their bones weigh less than those of other types of birds.
Waterfowl that live near bodies of water or in bodies of water. These birds have a rather powerful beak that helps them feed on fish.

Ecological groups of birds by nesting places:

Crown-nesting birds build their nests, as the name implies, in the crown of trees (orioles, blinks).
Shrub birds locate their nests near or in the bushes themselves (wren, robin).
Nesting birds decide to place their nest right on the ground (larks, skates, buntings, waders).
Hollow-nesting birds live directly in hollows (woodpeckers, tits, pikas, flycatchers).
A group of birds, burrowing birds (shore swallows, bee-eaters, kingfishers), live in burrows, underground.

Ecological groups of birds by type of food:

Insectivorous birds (titmice or pikas) have thin pointed beaks, thanks to which they can pull their prey from leaves or take out from thin cracks.
Herbivorous birds, including granivorous birds (greenfinches) have a powerful beak due to which they can break through the dense shells of the fruit. And the sharp ends of the beak help us pull out seeds from the cones of various trees.
Birds of prey (eagle) feed on various small birds. They have strong legs with powerful claws, thanks to which they grab prey.
Omnivorous birds (magpies) have a tapered beak that helps them feed on various types of food.

Birds open spaces there are two directions in the development of adaptations. Some birds are adapted to locomotion on the ground in search of food. Fleeing from enemies, they almost do not use their wings, but quickly run away. Others, on the other hand, mostly use their wings when moving and hardly use their legs. First group of birds lost the ability to fly and they had wing reduction... At the same time, they have strong legs developed, toes were shortened and the back toe disappeared... All of these traits are helpful for running fast. An example of birds adapted to running can be various types of ostriches, chickens, etc.

The second group of birds (daytime predators, owls, etc.) has improved wings, and their legs can maintain normal development or even be reduced to a certain extent.

Birds of the forest use all the horizons of woody vegetation both for nest shelter and food. Due to the arboreal lifestyle, the legs of most birds are arranged in such a way that free fingers are opposed to each other... This gives them the ability to wrap around the branches from two sides. A number of bird species have adapted climb vertically growing trunks trees (nuthatches, pikas and woodpeckers). All such birds the toes are very sharp and very curved. Woodpeckers and pikas also use their tail for climbing, which serves partly for support, and partly for balance during the period of reclining the front of the body. Finches, titmice and many other bird species have adapted to climb branches and hang from below. Climbing trees, birds get their own food. Fewer people find their food using wings. Thus, the birds of the forest also show an adaptation in two directions - in the development of the legs and in the development of the wings.

Among birds of prey distinguish:

a detachment of daytime birds of prey hunting during the day,
a detachment of owls hunting at night.

All these birds have powerful legswho are armed with large, sharp and strong claws, and crocheted beak.

Daytime birds of prey settle in the steppes, deserts, forests, plains, mountains. They do not eat vegetable food at all. They are fed by animals, birds, fish and insects. Some types of predators catch live prey (falcons, hawks, eagles, buzzards, etc.), while others eat only dead animals (vultures, vultures, vultures).

Ecological features of swamps and coasts of small reservoirsvery similar. Therefore, some bird species are common both for the shores of water bodies and for swamps.

When getting food, some wading birds use mainly kicking, others - wings.

In the first group of birds, the legs are characterized by a number of features:

long length,
deprivation of plumage on the ankle joint (ankles),
considerable length of the front toes, often connected by membranes.

All these are adaptations to living in places with viscous soil and the presence of shallow waters. Sandpipers, herons, cranes, storks, ducks, daytime predators, gulls, etc. live in swamps and on the shores of water bodies.

Birds of the steppes and deserts... Due to the fact that it is difficult for birds to hide in open spaces, in the conditions of steppes and deserts, they have formed during evolution long legs and neck... Thanks to this adaptation, birds can survey the area far and see the approach of various predators. Birds of the steppes and deserts walk a lot in search of food among vegetation, so their legs, as a rule, are well developed. Fleeing from danger, some birds of the steppes and deserts do not fly away, but run away.

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