Birds have a well-developed sense of sight and smell. The sense of smell in birds is poorly developed. Organs of taste and smell in birds

These mysterious feelings

Organs of taste and smell in birds

The organs of taste in birds are represented by taste buds that lie in some parts of the beak and tongue, near the ducts of the glands secreting sticky or liquid secretions, since the sense of taste is possible only in a liquid medium. A pigeon has 30-60 taste buds, a parrot has about 400, and ducks also have a lot of them. For comparison, let us point out that there are about 10 thousand taste buds in the human oral cavity, and about 17 thousand in a rabbit. Nevertheless, birds clearly distinguish between sweet, salty and sour, and some, apparently, also bitter. Pigeons develop conditioned reflexes to substances that create such sensations - solutions of sugar, acids, salts. Birds have a positive attitude towards sweets.

Smells are not as indifferent to birds as previously thought. For some of them, they play a very significant role in the search for food. It is believed that corvids, such as jays and nutcrackers, search for nuts and acorns under the snow, focusing mainly on smell. Obviously, the sense of smell is better than others in petrels and waders, and especially in the nocturnal New Zealand kiwi, which, apparently, forage, guided mainly by olfactory sensations. The peculiarities of the microstructure of the olfactory receptors in birds led some researchers to the conclusion that they have two types of smell perception: on inhalation, like in mammals, and the second on exhalation. The latter helps the odor analysis of food already collected in the beak and formed a food portion in its rear part. Such a lump of food in the choanal area is collected before being swallowed in the beak of chickens, ducks, waders and other birds.

Recently, it has been suggested that the olfactory organ plays a role in the period preceding reproduction. Along with other rearrangements in the body of birds at this time, there is a strong increase in the coccygeal gland, which has an odorous secret specific to each species. In the pre-nesting time, members of one pair, along with other ritual poses, often take a pose in which they touch each other's coccygeal gland with their beak. Perhaps the smell of her secretion serves as a signal that triggers a complex of physiological processes associated with reproduction.

The olfactory abilities of birds are questioned by many. The differences in the complexity of the organization of the olfactory organs in birds and mammals are too great for them to use this sense equally. Still, many bird watchers admit that tropical honey guides find wild bee hives in part because of the peculiar smell of wax. During the breeding season, many tube-noses often regurgitate from the stomach a dark, pungent-smelling liquid - "stomach oil", which is often soiled on nests and chicks. It is believed that in a dense colony, individual differences in the smell of this receptor help them find their offspring. The South American nightjar guajaro probably detects the fragrant fruits of the trees by smell as well.

The olfactory analyzer is developed in different birds to varying degrees. But the mechanism of its functioning is in many ways the same as that of other vertebrates. This is confirmed, in particular, by electrophysiological studies.

Created: 22.11.2013 12:52

The rarest bird on Earth is the kiwi bird. Kiwis belong to the order of ratites. Its length is 50-80 cm. The body is evenly covered with hair-like feathers. The wings are reduced (they are not visible), there is no tail, the legs are short, with sharp claws. It lives in New Zealand and is related to the giant moa destroyed here about two centuries ago. Kiwi - small auburn night-bird, feeds on snails, worms and other digging animals. This is the only bird with a good sense of smell. She also uses antennae on her beak. Running quickly on strong legs, kiwi every minute plunges into the ground in search of food a long beak with nostrils at the end. Clearing the "nose", the bird sniffs like a dog sniffing the soil.

At the beginning of the XX century. it was almost completely exterminated because of its feathers, from which artificial flies were made for catching trout. It is with these hair-like feathers that the body of this bird is covered.

Since 1921 she has been under protection.

A hummingbird is the smallest bird on earth, sometimes no larger than a bumblebee (we are talking about a bee hummingbird). In addition, hummingbirds are also the smallest among warm-blooded animals (birds and mammals). The smallest species inhabits Cuba and the island of Pinos. Adult males reach a length of 57 mm, with the beak and tail accounting for half of this length. Females are somewhat larger than males. It weighs a little less than a two-kopeck coin - 1.6 g. The hummingbird family is very numerous - it includes 319 species. She has the smallest eggs - smaller than a pea and weighing about 0.2 g (its size is 11.8 x 8 mm). The hummingbird has a high body temperature - plus 43 ° C and the strongest heart of all birds. Hummingbirds feed on the same food as spiders and bees. These birds constantly fly around the spider tackle and steal insects from their owners entangled in a web. In addition, hummingbirds catch insects in flower cups. Using a long tongue, they "wash down" this meal with flower nectar. At the same time, hummingbirds, like bees, pollinate plants. They live mainly in Central and South America, but some species are also found in North America.

One of the most amazing birds the world is a quadruped belonging to the family of nightjars. The tetrawing is found in Africa, from Senegal and Gambia in the west to Zaire in the south. The name was given to him for a reason: the male quadruped in breeding plumage has a very long feather in each wing. In flight, these feathers, like flags, flutter over the bird, then behind it. It seems to the observer that the bird has four wings, and sometimes it seems that two small dark birds are chasing it.

The length of the pennant feather reaches 43 cm with a body length with a tail of 31 cm and a wing length of 17 cm. It is believed that at the end of the mating season, the male breaks off jewelry that interferes with flying. Indeed, sometimes you can find birds with "stubs" of long feathers sticking out of the wings. They persist until the next molt.

The opportunity to photograph a quadruple is very rare, because, like all nightjars, it flies at dusk. English zoologist Michael Gore found a male quadruped in a daytime hideout, scared it off and took a good picture.

The greatest speed for the animal world is developed by the peregrine falcon during a rapid dive for prey - 300 km / h and more!

Other birds are significantly inferior to the record holder. An eagle, for example, develops a speed of 190 km / h, a hobby and a black swift - 150, a swan - 90, a starling - 80, a swallow - 75 and a sparrow - 55 km / h. Note that the bird develops its maximum speed when attacking prey or, on the contrary, when rescuing from a predator.

In normal flight, the speed of birds is much slower.

In horizontal flight among birds, there is no equal to the black swift (Apus apus). His usual speed -180 km / h. The indicator is slightly lower in the white-breasted needle-tailed swift.( Hirundapus caudacutus), common in the Asian region. However, science knows a rare species of swift under the Latin name chaetura, which demonstrates simply fantastic speeds - 335 km / h, easily overcoming powerful air resistance.

The marsh harrier is also very good (Circus aeruginosus ) - 288 km / h This slender bird, half a meter long, flies, swaying in a peculiar way and keeping as close to the ground as possible.

Best of all, the peregrine falcon from the falcon family dives. Back in the 1960s, with the help of electronics, ornithologists absolutely accurately measured the maximum possible speed diving peregrine falcon. Note that in level flight it does not exceed 100 km / h. While hunting for prey, the peregrine falcon falls down like a stone at a speed of 290 to 380 km / h.

The most "slow moving" bird is the American woodcock.(Philomela minor). His maximum speed flight - 8 km / h.

The longest living birds are falcons. They live to be 160-170 years old.

The rest of the birds are significantly inferior to falcons in life expectancy, but many of them do not live less man... So, a captive parrot can live up to 135 years. Kites and vultures have lived for over 100 years. Vultures live up to 100 years, condors, golden eagles, wild geese and other birds live up to 80 years. Unfortunately, in nature, few birds live to their maximum age, since most of them do not die from old age.

The longest living bird is the goose. He lives to be one hundred years old. Chickens usually live much shorter - up to 30 years, ducks - up to 40 years.

The sense organs of birds. Tactile, temperature, pain sensitivity and hearing are well developed in birds. They perceive sounds with a vibration frequency of 200 to 20,000 Hz per second (absolute thresholds in chickens are in the range of 90-9000 Hz), the sound power should not exceed 70-85 dB, although they can adapt to sound power up to 90 dB ( stronger sounds negatively affect the state of the central nervous system and productivity).

Sound alarm. In chickens, 25 sounds are described that they emit "when communicating." This is more than that of cats and piglets. Only seven types of danger signals were found in them.

It was found that chick embryos communicate with each other by "tapping", making clicking sounds. Following the example of the leader who first made the sound, his brothers also begin to try their voice and switch to pulmonary breathing, which accelerates their growth and formation. Sound signaling during the period of embryonic development of birds provides synchronization of hatching of chicks from eggs, allowing them to leave the shell amicably and in the wild, the whole family quickly leave the nest, avoiding meeting with predators. For better synchronization of the hatching of chickens, the incubator is sounded with the help of an electronic device. The device turns on on the 17th day of egg incubation. It broadcasts clicking sounds recorded in embryos, which makes it possible to reduce the hatching of chickens from a batch of eggs obtained from different layers to one day. Additional connection of the imitation of the voice of a brood calling for chickens, accelerates their exit from the trays and the desire to move to the call of "mom" - "follow me."

The organs of vision in most species poultry(pigeon, goose, duck, turkey) play an important role and are therefore relatively well developed. The structure of the eye is somewhat different from the structure of the mammalian eye. So, the eyeball in a bird is not spherical, but flattened in front and behind, and in ducks it has a conical shape. The cornea is most convex in predators, the least convex in waterfowl. The cornea and bone plates do not allow the eyeball to deform under air pressure during flight, under the pressure of water when immersed in it, or under the action of the oculomotor muscles.

The bird's eye is distinguished by unusually fast and accurate accommodation, especially developed in predators. Accommodation is carried out not only by changing the curvature of the lens, but also by changing the shape of the cornea. The next feature the eye is a comb. This is an irregular quadrangular plate located in the thickness of the vitreous body at the entry point of the optic nerve. The function of nutrition of the vitreous body and the retina is attributed to the ridge. It is also assumed that the ridge regulates intraocular pressure (which changes with rapid accommodation) and serves as an auxiliary device for observing moving objects. He is also credited with the function of heating the eyeball, which is important mainly for birds flying at high altitudes. In birds, as in mammals, there is a layer of cones in the visual part of the retina (they are especially numerous in day birds). Cones provide visual acuity. They contain oily, colorless, blue, green, orange and reddish droplets that determine color perception. There is only one zone of best vision in the retina of mammals, while birds of these zones can have two or three. This is due to the nature of the location of the eyes, which in most birds are turned in opposite directions. This arrangement of the eyes limits the field of binocular vision to a very small area at the level of the beak extension, where the visual field of the left and right eyes overlaps. The visual field of each eye produces a predominantly flat image. It is very large: birds can see objects behind them. In pigeons, the angle of view of each eye is 160 °. The bird compensates for the lack of volumetric (binocular) vision by changing the position of the eyes when turning the head. In birds, the third eyelid is well developed - the nictitating membrane, which is usually collected in the inner corner of the eye, but can overlap the entire visible part of the eyeball.

Different types of birds have different visual acuity. Geese recognize individuals of their species at a distance of up to 120 m, ducks - up to 70-80 m.To peck the grain again, the chicken must increase the distance between the grain and the eye by at least 4 cm. the size of its particles. They have an innate sense of proportion with respect to the size of a particle that they are able to easily swallow. This measure changes with age in proportion to the increase in the size of the esophagus and beak. The particle shape of the chicken feed is not essential. Only during their life do they learn to recognize the shape of food objects.

Hearing. Birds do not have an external ear; instead, most species have a skin fold or a bundle of thin feathers surrounding the entrance to the external auditory canal. In a waterfowl, feathers at the entrance to the external auditory canal are located so that during their stay under water it is completely closed. The external auditory canal is short, wide and covered with an eardrum. The connective tissue membrane does not have its own bone base, but is attached directly to the cranial bone. Sound waves are perceived by the eardrum and transmitted in the form of vibrations through the column (the only auditory ossicle) of the perilymph and endolymph of the inner ear. The inner ear consists of a bony canal and membranous labyrinths located inside it, divided into an organ of hearing and an organ of balance. The organ of hearing is formed by the cochlea, the organ of balance - by the vestibule and semicircular canals.

The bird's hearing is very well developed. Predator birds they hear the squeak of a mouse even at a distance of 60 m. Of domestic birds, hearing is best developed in chickens, whose ancestors lived in virgin forests, where, in dense bushes, good hearing was a better means of protection than keen eyesight. The good development of hearing in chickens is also evidenced by the fact that the chick in the egg, already a day before hatching, reacts to changes in external environment with a frightened squeak, but calms down when the brood hen calms him down with a deep cough. Immediately after hatching, the chickens can by ear find their mother in the dark at a distance of up to 15 m. By their characteristic clucking, they individually recognize the mother and run to her, not paying attention to other hens sitting next to her. Heaters can also recognize their chicks by squeaking at the same distance, even if there are other sources of noise around them, even within a 1m radius. Mother's voice attracts chicks more efficiently than hers appearance, even at a distance of about 50 m to the sound source. come from these sources from the same distance.

If the chick has lost its brood, it emits high-pitched pitiful sounds, to which the brood hen responds with increased frequent cackling. The chick locates her by running fast in different directions and listening to the hen's signal from different points... It determines the correct direction when sound waves are perceived successively by the right and left ear. The absence of an auricle, which improves the location of sounds, is apparently compensated for by the high flexibility and mobility of the neck, which makes it possible to quickly turn the head in different directions.

Everyone is familiar with the cries of birds, which serve as an alarm signal; they were recorded and even managed to be used to protect crops from crows and fisheries - from seagulls. The sentinels even report with their shouts what kind of enemy is approaching and from the ground or from the air it is necessary to wait for him. After the signal, all birds freeze in immobility and remain silent, especially chicks, which immediately stop squeaking. Cubs, feeling hungry or fear, yell with might and main, and sometimes (more often chickens and ducklings) make a sound that expresses, as it were, pleasure. Everyone knows the cry of a chicken. With it, you can call chickens to the speaker through which it is broadcast; therefore, chicks do not need to see the hen. Likewise, a mother can be attracted by the inviting sound of a chicken; but put the chicken under a soundproof glass cover - and the chicken, seeing it perfectly, will pass by indifferently.

Skin feeling in birds it is carried out mainly by tactile bodies located on non-feathered parts of the body, especially in the beak wax. However, sensitive nerve endings that are closely adjacent to epithelial cells penetrate the skin of other parts of the body. They also contribute to the perception of heat and pain sensations. Significantly more often in birds, there are organs of touch that lie under the epidermis of the connective tissue (Herbst's little bodies), under large feathers (tail and flight), as well as in the skin of the paws and thighs. They are credited with the property of responding to pressure changes. Large bodies of this type, embedded in the mucous membrane of the tongue and along the edges of the beak, make it possible to determine the size, shape, texture and degree of hardness of food objects.

Birds are constantly looking after their feathers. This is especially important for water birds, which ensure the non-wetting of the feather, lubricating it with the secretion of the coccygeal glands.

The composition and properties of the secretion of the coccygeal gland. On visual examination, the secret of the coccygeal gland can be characterized as a thick liquid of light yellow color with a faint smell of goose fat. In a biochemical study, it turned out that the dry matter content in the secretion of the coccygeal gland is 37.30-44.2%. The reaction of the secret is slightly alkaline. Most of the secret consists of lipids. The secret of the coccygeal gland contains a number of minerals. Interestingly, the amount of some components of the secretion in drakes and ducks is different. For example, the total protein content in ducks is 16.9 mg / g more and sodium is 0.97 mg / g more than in drakes.

It was found that when cultured on Staphylococcus aureus agar and Escherichia coli in the area of application of discs moistened with the secretion of the coccygeal gland, a zone of enlightenment of 15 mm for Escherichia coli and 10 mm for Staphylococcus aureus is formed. This confirms the bacteriostatic properties of the secretion of the coccygeal gland both in relation to gram-positive and gram-negative microflora. The relative mass of the coccygeal glands depends not only on age, nutrition, but also on the intensity of contact of ducks with water. With prolonged restriction of access to water for bathing, the relative mass of the coccygeal glands in Peking ducks decreases by 0.02-0.03% to body weight. Extirpation of the coccygeal glands in Peking ducks, both at an early age and in adults, does not cause exhaustion and rickets. After extirpation of the coccygeal glands in Peking ducks, there are no changes in the number of erythrocytes, leukocytes, blood volume, hemoglobin concentration, hematocrit, and acidic blood capacity. Extirpation of the coccygeal glands in Peking ducks entails significantly pronounced changes in the concentration of proteins, lipids, glucose, inorganic phosphate in the blood.

The taste organs in birds are poorly developed. Organs that perceive taste stimuli are either barrel-shaped formations (like the taste buds of mammals), or low, highly elongated formations, equipped with a relatively thick layer of supporting cells (as, for example, in lamellar beaks). The tongue and hard palate are covered with a thick stratum corneum, in which taste buds can hardly be located. Gustatory bodies are embedded in the root of the tongue on the sides and bottom of the mouth, in the soft palate and near the larynx. Birds of all species distinguish between salty, sour, bitter and sweet, and the sensitivity to bitter in poultry is only slightly developed. Waterfowl, however, reject bitter solutions in a concentration that is unpleasant for humans. Sensitivity to sweets is also poorly developed in birds. Malt and milk sugar for poultry has practically no taste, and synthetic sugars, such as saccharin, are perceived as sour rather than sweet. The taste of glycerin, which a person evaluates as sweet, is also perceived by birds, the same can be said for weak salty-bitter solutions. However, the question remains whether these substances taste sweet or bitter for birds. The sensitivity to bitter in all species of birds is similar to that in humans. In chickens, when choosing food, the taste plays very minor role... Although chickens prefer some foods over others, they are guided by visual or tactile perception.

The organs of smell in birds are very poorly developed. The goblet-shaped sensitive cells, studded with very short hairs, are located in the epithelium of the nasal mucosa, which lines the dorsal concha and septum. The bird has absolutely no structures that perceive smell. In numerous experiments, it was not possible to teach a pigeon to distinguish between the smell of aniseed and rose oils. The weak development of the bird's sense of smell is also evidenced by the fact that laying hens drink slurry. The smell of spoiled eggs does not bother them, and they often peck on strong-smelling substances, such as droppings, compost, etc.

The bird's memory is poorly developed. It depends on the species of birds, age, duration and intensity of stimuli, and many other factors. Teaching a chicken to peck on the larger of two corn kernels takes about 100 repetitions. It takes 24 repetitions to recover after a seven-month break, and 15 repetitions after the next four-month break. Adult chickens, if they are not allowed to walk for two weeks, no longer remember that an attractive-looking sorrel is almost inedible for them. On the other hand, chickens prefer corn kernels for many months if they have been eating it for at least two days and should have learned to peck it despite the large size of the kernels. The bird is very poor at remembering familiar places. Chickens remember the placement of the feeders in which they received their favorite food for three weeks; in chickens, this time is shorter - up to 10 weeks of age, chickens, as a rule, do not remember their favorite walking area at all. They quickly find other similar places and forget them just as quickly. The pullets remember their former premises or walk for about three weeks, and after four weeks they are treated like strangers. An adult hen finds its place in the same environment after 30 days, after 50 days she does it with difficulty, and after 60 days everything here is already new for her.

The duration of the period after which the members of the flock still recognize the temporarily removed individual after its return was studied. It turned out that if young cockerels, who grew up together in a herd with an established social hierarchy, are returned there after their two-week absence, then the members of the group perceive these individuals as strangers, since the social order in the herd has changed during this time. The period of adaptation of adult birds to each other is 3-4 weeks on average. The duration of the habituation period depends on the breed, physique, social status and individual characteristics of the individual. Males of light breeds renew their relationship by fighting after 14 days, while males of heavy breeds take a month or more to do this. It is not surprising that the rooster does not forget its defeat even after six months, especially if it was persecuted by a despotic individual.

Group behavior. All poultry species are social, and each individual's behavior is influenced by its relationship with the rest of the flock. In ducks at the end of winter, the sexual instinct increases, which entails a spring increase in pugnacity both among drakes and among ducks. Weak individuals obey the stronger ones after repeated defeats. After that, all individuals are guided in their relationship by the newly emerged social connections... By the end of the mating season, this order fades away, and ducks rarely interact with each other. The superiority of the stronger individuals does not remain strong due to the frequent resistance of subordinates. Therefore, individuals dominating mainly in feeding and mating can often change.

In geese, the leader of the herd is the gander, all other individuals obey him. He and other high-ranking individuals provide themselves with certain advantages in obtaining food and in conflicts with other herds. The social unit is the family, where, in natural conditions, goslings usually grow up under the supervision of their parents. Upon reaching puberty, new hierarchical relationships are formed between the goslings. High-ranking individuals use their superiority not only when feeding, but also in all other cases when subordinate individuals try to counteract them.

A flock of birds is not an unorganized gathering of individuals whose behavior is determined by random circumstances. There is a strict hierarchy here. The whole group obeys the leader. An individual is considered dominant if it is more aggressive than others in the group and enjoys advantages in reproduction, feeding, and locomotion.

When they counted the beaks that young cockerels reward each other with, we found out that among them there is an "alpha" that bites everyone, while no one dares to touch him, and an "omega" that everyone bites and sometimes pecks to death - he doesn't even trying to defend himself. The first three days after hatching from the egg, any moving object puts the chicken to flight: it hurries to hide under the wing of its mother. A week passes, the chickens begin to scamper around the poultry yard in all directions, their wings spread out; from the second week, similarities of battles arise between them: two chickens jump on each other exactly like adult roosters, but they still do not use their beak.

Between the fifth and sixth weeks, the fights become more serious, the opponents are already putting their beak into action, although not too hard; one of the fighters can retreat, then comes back and again hits the opponent with his beak.

The contractions, during which the relationship of domination and submission is established, begins later. At what age, it is difficult to determine: it depends to some extent on external conditions, on the characteristics of the group, etc.

Apparently, chickens recognize birds of their breed - in Leghorns this ability is manifested at ten days of age. Chickens are much less aggressive than males, which also attack females; however, by the time of puberty, roosters stop attacking chickens.

In chickens, a special hierarchy is also established, and a certain order is finally formed for them by the ninth week, while in males by the seventh. This order is not so immutable; changes are possible due to the fact that not all individuals develop at the same rate. Such changes can be controlled by temporarily isolating individual birds, and they are able to recover from beak blows.

Chickens can be isolated from the day of birth, and re-attached to the group only after the control individuals growing in the group have already established order in themselves.

The bettas are another matter: when they are combined after being kept in isolation, they quickly establish new order, proving in such a way that they do not need to live with early age... Isolated bettas, after combining, turn out to be even more aggressive than those raised in a group.

Interestingly, the introduction of male sex hormones to young cockerels almost does not change the established relations of submission and domination, whereas with the introduction of female hormones, they seem to become more "phlegmatic" - they avoid fights and do not seek to respond to blows with their beaks. Similar results were obtained in females: those of them that receive male hormones somewhat "increase in rank" (however, the difference from the control birds is very small); the female hormone acts much more strongly, significantly lowering the "rank" of the individual. After the order is finally established in the group of young chickens, you can transfer some of them to another group, and then after a few days return back to the first. The same individuals in different groups can stand at different levels of the hierarchy.

Chickens have a particularly strong relationship of superiority and submission. Here, each individual has its own definite place and recognizes it without resistance (unlike what we see in ducks and pigeons). How relationships are formed in the flock can be judged by observing the behavior of growing chickens. In the first days after the transfer to the poultry house, the chickens can be observed manifestations of a social instinct: they run among other chickens and look for their company. At the same time, their behavior is not related to the behavior of partners: each chick does everything by itself. Only when he notices that he is alone does he begin to squeak plaintively, looking for partners or a mother hen. In relation to strangers, chickens are indifferent as long as there are no too sharp age differences between them. At the age of 2-3 weeks, the older ones begin to peck the younger ones in the head, tail, etc.

The tendency for the formation of social ranking occurs in chickens at the age of 2-3 weeks, when fights begin to arise between them, while still in the form of a game. These encounters, involving both males and females, give them the opportunity to get to know and appreciate each other. After a short time, such tests of forces cease and a free union is formed, which exists until puberty.

With the onset of puberty, new, more serious, often bloody fights for dominance begin, the consequence of which (at the age of 8-10 weeks) is the emergence of a social hierarchy. This is a very solid order, which allows individuals of higher ranks to drive low-ranking birds away from feeders, drinkers, nests, peck them, etc., or prevent low-ranking cockerels from mating. Once the social hierarchy is established, the number of attacks by which individuals previously sought to consolidate their position usually decreases in the herd. This period of formation of the hierarchy lasts 2-3 weeks in newly formed communities or flocks.

As long as the number of chickens raised together remains within natural limits (50-100 per group), the birds are able to individually identify each other, and social status each is completely regulated. Among roosters, social ranking is more pronounced than among chickens. If a stronger hen is usually satisfied with the fact that he drives the lowest in rank from the feed with a peck or a sharp movement, the rooster does not tolerate his opponent at all near him and drives him out of his sphere of activity with a radius of about 5 m.

Feeding behavior of birds. Evaluation of food by birds, that is, the preference given to a certain food over another, is a product of optical and tactile perception. This preference depends on the type of food offered and on the time the bird has to eat it. Turkeys and chickens, when eating mealy forages, take much longer to saturate than when eating grains or pellets (turkeys, for example, need 16 minutes to saturate with pellets, and mealy forages - 136 minutes).

The structure of the beak greatly influences the eatability of food. The small and pointed beak of chickens and pigeons is adapted for grasping relatively small hard grains. Geese with their firm and flat beak nibble grass and grab grains with equal ease. The wide and long beak of the ducks is adapted for grasping soft, moist food, consisting mainly of aquatic plants and animal organisms. Therefore, it is difficult for ducks to pick up individual small grains 3-4 mm in size, while chickens and pigeons can peck gravel grains 0.5-1 mm in size. If given a choice, they prefer grains of 1.5-2 mm in size. The optimum particle size for poultry feed is primarily determined by the size of the beak and the width of the esophagus.

In chickens and geese, these parameters are satisfied by wheat grains, in pigeons - by hemp, in ducks - by corn.

Poultry usually consume pelleted feed of an appropriate size immediately; in the absence of feed with the required particle size, preference is given to smaller particles. The bird must be taught to eat large grains, for which it usually needs to starve. If the bird overcomes the initial dislike, then subsequently it always chooses from the feed, first of all, the largest grains. Only with the onset of saturation does she begin to eat more small grains, which are easier for her to swallow.

Big role the state also plays the environment... As the ambient temperature rises, feed intake decreases rapidly. If at the same time the body temperature rises above 42 ° C, the chickens stop pecking food, worry and run excitedly from place to place. It is of interest to observe the rate of feed consumption with different methods of distribution in the conditions of the cage keeping of chickens. Cell batteries with a feeder chain, in most cases they are switched on automatically at regular intervals. Chickens get so used to these intervals that just a few minutes before turning on the feeder, they stick their heads out of the cage and rarely take feed from the feeder. As soon as the chain starts to move, all the chickens begin to peck at the same time, although before the chain was turned on, there was the same feed in the feeder. Something similar happens when the feed is dispensed by gantry forklifts. Chickens begin to peck feed mainly after the loader passes, even in those cases when an empty cart passes, which does not feed any feed into the feeders.

The feed intake rate also depends on whether the bird has free access to feed or this access is limited by time. Changes in the form of feed (free-flowing mixture, granules, grains) also caused its increased consumption if the bird got used to the new type of diet. So, when the pellets are replaced with a free-flowing mixture for a bird that has been constantly fed with granulated feed, the eatability of the latter decreases and increases again only after getting used to it (after a few days). When placing feeders and drinkers in the poultry house, it is necessary to remember about the tendency of birds to form groups, for which it is necessary to provide areas of about 12-15 m in size. Therefore, the distance between these points should not exceed 3-5 m.

The relationship of social superiority is clearly manifested when there is a lack of feeding and drinking fronts. Thus, interesting results were obtained from observations of laying hens placed on a slatted floor. For distribution of feed, two conveyor belts were used, which were switched on 4 times a day, and thus there was 7.62 cm of feeding area per layer. When distributing the wet mixture, the chickens crowded around the feeders, and here the strongest pushed the weaker aside, who later, after the strongest had been saturated, did not dare, as a rule, to approach the feeders. With this method of feeding, the average egg production over the last week was 2,460 eggs. After the frequency of feeding increased to 7 times a day, the chickens no longer crowded around the feeders, and weaker individuals approached the food. As a result, egg production has gradually increased. After 3 weeks, when the frequency of feeding was again reduced to 4 times a day, egg production began to decline, reaching a level below the initial level.

Along with habituation, the frequency of feeding is also important in those cases when the chickens do not have constant access to feed. When hens were fed with a chain feeder 6 times a day, the average monthly egg production was 22.8 eggs with a feed intake of 122 g / head / day. Since a significant part of the feed was returned back to the hopper, the frequency of feeding was reduced to 2 times a day. In this case, part of the feed was also returned to the bunker. However, the movement of the feeder chain prompted the birds to consume more feed, and the average feed intake over a month was 103 g / bird / day. Due to the decrease in feed consumption, egg production dropped to 19.4 eggs per month. With a repeated increase in the frequency of feeding, it increased to 21.9 eggs, which was accompanied by an increased feed intake.

For chickens and adult bird a certain rhythm in the consumption of food is characteristic, which depends on the intensity of metabolism, the time of emptying of the goiter and stomach. Chicks eat better with constant access to feeders; this creates an equal opportunity for individuals who eat food quickly and those that eat slowly. It is also important whether the chicks are fed singly or in groups. In an adult bird, under natural conditions, a special rhythm of alternating periods of increased activity and rest can be observed.

In pullets, the greatest activity is observed in the periods between 04:45 and 06:45, 10:45 and 12:45, 16:45 and 18:45 hours.

Chickens over 12 weeks of age have significantly limited activity and go to feed less often than to drinkers. IN free time they seek out roosts and sleep on them.

After the establishment of the social hierarchy, the hens of the lower ranks remain perched and begin to search for food later, when individuals of the highest ranks return to the roosts.

2 Research object, materials and equipment: 1. Chickens, goslings, ducklings, chickens, geese and ducks of both sexes. 2. Drawings and diagrams on the topic. 3. Forms of ethograms, pen (pencil); photo camera, film or video camera, tape recorder; a clock, a device for measuring the intensity of movement (pedometer), measuring and recording equipment for telemetry; kit different types grain and flour feed; areas in the house with different air temperatures, with different air speed.

Sound alarm. In chickens, 25 sounds are described that they emit "when communicating." This is more than that of cats and piglets. Only seven types of danger signals were found in them.

The organs of vision in most species of poultry (pigeon, goose, duck, turkey) play an important role and therefore are relatively well developed. The structure of the eye is somewhat different from the structure of the mammalian eye. So, the eyeball in a bird is not spherical, but flattened in front and behind, and in ducks it has a conical shape. The cornea is most convex in predators, the least convex in waterfowl. The cornea and bone plates do not allow the eyeball to deform under air pressure during flight, under the pressure of water when immersed in it, or under the action of the oculomotor muscles.

The bird's eye is distinguished by unusually fast and accurate accommodation, especially developed in predators. Accommodation is carried out not only by changing the curvature of the lens, but also by changing the shape of the cornea. The next feature of the eye is the ridge. This is an irregular quadrangular plate located in the thickness of the vitreous body at the entry point of the optic nerve. The function of nutrition of the vitreous body and the retina is attributed to the ridge. It is also assumed that the ridge regulates intraocular pressure (which changes with rapid accommodation) and serves as an auxiliary device for observing moving objects. He is also credited with the function of heating the eyeball, which is important mainly for birds flying at high altitudes. In birds, as in mammals, there is a layer of cones in the visual part of the retina (they are especially numerous in daytime birds). Cones provide visual acuity. They contain oily, colorless, blue, green, orange and reddish droplets that determine color perception. There is only one zone of best vision in the retina of mammals, while birds of these zones can have two or three. This is due to the nature of the location of the eyes, which in most birds are turned in opposite directions. This arrangement of the eyes limits the field of binocular vision to a very small area at the level of the beak extension, where the visual field of the left and right eyes overlaps. The visual field of each eye produces a predominantly flat image. It is very large: birds can see objects behind them. In pigeons, the angle of view of each eye is 160 °. The bird compensates for the lack of volumetric (binocular) vision by changing the position of the eyes when turning the head. In birds, the third eyelid is well developed - the nictitating membrane, which is usually collected in the inner corner of the eye, but can overlap the entire visible part of the eyeball.

The bird's hearing is very well developed. Birds of prey hear the squeak of a mouse even at a distance of 60 m. Of domestic birds, hearing is best developed in chickens, whose ancestors lived in virgin forests, where in dense bushes, good hearing was a better means of protection than keen eyesight. The good development of hearing in chickens is also evidenced by the fact that the chick in the egg, already a day before hatching, reacts to changes in the external environment with a frightened squeak, but calms down when the hen calms him down with a deep cough. Immediately after hatching, the chickens can by ear find their mother in the dark at a distance of up to 15 m. By their characteristic clucking, they individually recognize the mother and run to her, not paying attention to other hens sitting next to her. Heaters can also recognize their chicks by squeaking at the same distance, even if there are other sources of noise around them, even within a 1m radius. The mother's voice attracts the chicks more effectively than her appearance, even at a distance of about 50 m to the sound source. is able to establish the direction of sound sources, since sound waves arrive from these sources from the same distance.

If the chick has lost its brood, it emits high-pitched pitiful sounds, to which the brood hen responds with increased frequent cackling. The chick determines its location by running quickly in different directions and listening to the hen's signal from different points. It determines the correct direction when sound waves are perceived successively by the right and left ear. The absence of an auricle, which improves the location of sounds, is apparently compensated for by the high flexibility and mobility of the neck, which makes it possible to quickly turn the head in different directions.

The taste organs in birds are poorly developed. Organs that perceive taste stimuli are either barrel-shaped formations (like the taste buds of mammals), or low, highly elongated formations, equipped with a relatively thick layer of supporting cells (as, for example, in lamellar beaks). The tongue and hard palate are covered with a thick stratum corneum, in which taste buds can hardly be located. Gustatory bodies are embedded in the root of the tongue on the sides and bottom of the mouth, in the soft palate and near the larynx. Birds of all species distinguish between salty, sour, bitter and sweet, and the sensitivity to bitter in poultry is only slightly developed. Waterfowl, however, reject bitter solutions in a concentration that is unpleasant for humans. Sensitivity to sweets is also poorly developed in birds. Malt and milk sugar for poultry has practically no taste, and synthetic sugars, such as saccharin, are perceived as sour rather than sweet. The taste of glycerin, which a person evaluates as sweet, is also perceived by birds, the same can be said for weak salty-bitter solutions. However, the question remains whether these substances taste sweet or bitter for birds. The sensitivity to bitter in all species of birds is similar to that in humans. In chickens, taste plays a very small role in the choice of feed. Although chickens prefer some foods over others, they are guided by visual or tactile perception.

Group behavior. All poultry species are social, and each individual's behavior is influenced by its relationship with the rest of the flock. In ducks at the end of winter, the sexual instinct increases, which entails a spring increase in pugnacity both among drakes and among ducks. Weak individuals obey the stronger ones after repeated defeats. After that, all individuals are guided in their relationships by newly emerging social ties. By the end of the mating season, this order fades away, and ducks rarely interact with each other. The superiority of the stronger individuals does not remain strong due to the frequent resistance of subordinates. Therefore, individuals dominating mainly in feeding and mating can often change.

Chickens can be isolated from the day of birth, and re-attached to the group only after the control individuals growing in the group have already established order in themselves.

The bettas are another matter: when they are united after being kept in isolation, they quickly establish a new order, thus proving that they do not need to live together from an early age for this. Isolated bettas, after combining, turn out to be even more aggressive than those raised in a group.

As long as the number of chickens raised together remains within natural boundaries (50-100 per group), the birds are able to individually identify each other, and the social status of each is quite regulated. Among roosters, social ranking is more pronounced than among chickens. If a stronger hen is usually satisfied with the fact that he drives the lowest in rank from the feed with a peck or a sharp movement, the rooster does not tolerate his opponent at all near him and drives him out of his sphere of activity with a radius of about 5 m.

In chickens and geese, these parameters are satisfied by wheat grains, in pigeons - by hemp, in ducks - by corn.

The state of the environment also plays an important role. As the ambient temperature rises, feed intake decreases rapidly. If at the same time the body temperature rises above 42 ° C, the chickens stop pecking food, worry and run excitedly from place to place. It is of interest to observe the rate of feed consumption with different methods of distribution in the conditions of the cage keeping of chickens. Cage batteries with a chain feeder are in most cases switched on automatically at regular intervals. Chickens get so used to these intervals that just a few minutes before turning on the feeder, they stick their heads out of the cage and rarely take feed from the feeder. As soon as the chain starts to move, all the chickens begin to peck at the same time, although before the chain was turned on, there was the same feed in the feeder. Something similar happens when the feed is dispensed by gantry forklifts. Chickens begin to peck feed mainly after the loader passes, even in those cases when an empty cart passes, which does not feed any feed into the feeders.

Chickens and adult birds are characterized by a certain rhythm in feed consumption, which depends on the intensity of metabolism, the time of emptying the goiter and stomach. Chicks eat better with constant access to feeders; this creates an equal opportunity for individuals who eat food quickly and those that eat slowly. It is also important whether the chicks are fed singly or in groups. In an adult bird, under natural conditions, a special rhythm of alternating periods of increased activity and rest can be observed.

In pullets, the greatest activity is observed in the periods between 04:45 and 06:45, 10:45 and 12:45, 16:45 and 18:45 hours.

Chickens over 12 weeks of age have significantly limited activity and go to feed less often than to drinkers. In their free time, they look for perches and sleep on them.

After the establishment of the social hierarchy, the hens of the lower ranks remain perched and begin to search for food later, when individuals of the highest ranks return to the roosts.

2 Research object, materials and equipment: 1. Chickens, goslings, ducklings, chickens, geese and ducks of both sexes. 2. Drawings and diagrams on the topic. 3. Forms of ethograms, pen (pencil); photo camera, film or video camera, tape recorder; a clock, a device for measuring the intensity of movement (pedometer), measuring and recording equipment for telemetry; a set of different types of grain and flour feed; areas in the house with different air temperatures, with different air speed.

In general, birds' sense of smell is very poorly developed. This correlates with the small size of the olfactory lobes of their brain and short nasal cavities located between the nostrils and the oral cavity. The exception is the New Zealand kiwi bird, in which the nostrils are at the end of a long beak and the nasal cavities are elongated as a result. These features allow it to sniff out earthworms and other underground food by sticking its beak into the soil. It is also believed that vultures find carrion not only by sight, but also by smell.

The taste is poorly developed, because the lining of the oral cavity and the integument of the tongue are mainly horny and there is little room for taste buds on them. However, hummingbirds clearly prefer nectar and other sugary liquids, and most species reject very sour or bitter foods. However, these animals swallow food without chewing, i.e. seldom keep it in the mouth long enough to subtly discern the taste.

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