Habitat and lifestyle features of birds. Why does a heron stand on one leg? Versions and assumptions

Heron(lat. Ardea) is a large bird, belongs to the order Storkidae, the heron family, the genus of herons. The closest relatives of these birds are bitterns and night herons, and they are connected with storks only by distant kinship.

Basically, the heron lays from 2 to 7 eggs, which immediately incubate. Both parents do this, and after 28-33 days the chicks are born. Often, heron eggs are prey for vultures and raccoons. Heron chicks appear in different time, sighted, and only after a week they are covered with sparse and sloppy fluff. Out of the entire brood, only one heron chick can survive, but if there is a lot of food, 2-3 chicks survive. Growing chicks emit a monotonous crackling cry. The sounds of the heron resemble something like “cuong-ka-ka-ka”.

The chicks can fly after 55 days, and form family groups with their parents. Only after 2 years does the heron chick reach sexual maturity.

It is worth noting that gray and red herons nest in Russia.

When I asked my six-year-old son: “Have you seen how a heron hunts?”, he answered me: “She gets tired of standing on two legs.” When visiting bodies of water or in wild places, you can watch a heron, which for a long time may be motionless in the water. At the same time, she alternately presses her legs, as if trying to maintain balance.

Why does the heron draw in its legs?

Scientists substantiate several main reasons for this bird behavior:

to warm the chilled ones cold water legs;
to disguise themselves as grass stems while hunting;
to quickly escape in case of danger.

The heron lives and hunts all day in shallow water. The water in any body of water is cool, so the bird alternately tucks its legs under its belly. The limb warms up in the warm feathers, and the heron continues to look out for prey, prudently tucking its other leg.

This bird is a born hunter by nature. Chicks learn the art of catching fish, snakes, frogs and various insects from their parents. IN early age the kids watch their older relatives and instinctively tuck their legs when in the water. The reason for this is the art of camouflage. Animals or fish swimming underwater think that the heron's leg is a plant stem. As soon as the prey enters the bird's field of vision and swims close enough, one lightning-fast throw is enough. The heron grabs its food and enjoys its meal.

Amazing facts about the life of a heron

Herons are unique birds that inhabit all continents globe, with the exception of Antarctica. It is known that during their annual migrations they rise to a height of over 2000 meters (this is the flight altitude of helicopters).

Among the herons there are also giants (some individuals grow up to 1.5 meters). Birds live in families, some pairs family life may last 2 years. Females lay eggs that are oblong in shape and greenish in color.

Despite the fact that the heron feeds on fish and other inhabitants of water bodies, it never swims or dives. This bird feeds exclusively on food of animal origin and is an absolute predator.

Heron

The heron is a large aquatic bird that, despite its massive body, walks on two long thin legs. In addition, the bird has amazing ability stand on one leg. Simple, but interesting riddle nature: why does the heron stand on one leg?

This frequently asked question, which is asked by zoo visitors and biologists, due to the presence of different theories, has several answer options.

Rest on one leg

The reason why the heron stands on one leg, researchers initially called the bird's rest. Zoologists have concluded that this position of the legs helps reduce stress on the legs and reduce fatigue, and also allows you to quickly escape from predators. This theory is confirmed in practice, since herons have a habit of sleeping, leaning on only one leg.

Heron sleeps on one leg

Scientists later ruled out this possibility because studies showed that a heron required more effort to move forward after standing on one leg than after resting on two. Scientists have also found that herons have no preference regarding which leg to stand on: left or right.

Other assumptions

Another proposed theory, that standing on one leg helps herons maintain balance in windy conditions, has since been rejected. The researchers abandoned some other original speculations, such as the idea that standing on one leg helps the heron circulate blood better by limiting the effect of gravity on the circulatory system.

Body Thermoregulation Hypothesis

Researchers have found that the heron prefers to stand on one leg much more often when in the water than on land. Because water absorbs body heat, this behavior in birds supports the thermoregulation hypothesis.

The thermoregulation hypothesis is that the heron stands on one leg in order to maintain body temperature. While in the water, the heron alternates legs so that the supporting limb does not get too cold, since the water temperature is lower than the air temperature. If the bird were to constantly stand on one leg or put both legs down, it would risk greater heat loss and resulting tissue damage from colds as it spends a lot of time in the wetland. This is evidence that thermoregulatory function is the main reason why the heron uses only one lower limb when standing.

Rete mirabile complex

Thermoregulation in the heron's body occurs through a form of vascular branching called rete mirabile (lat. " wonderful network"), which minimizes heat loss from the bird. This complex of plexus of arteries and veins is a heat exchanger, which consists of: internal temperature the bird's feet gets much closer to temperature environment, and therefore the limbs do not lose as much heat as they would at body temperature.

Heron stance as a hunting method

Another popular theory suggests that the heron stands on one leg to appear less suspicious to aquatic prey. Animals, seeing one leg of a bird, mistake it for a plant stem and thus do not see the danger. The bird hunts not only while motionless in the water, but also by approaching its prey in shallow water.

The heron stands on one leg for easy hunting

The characteristic pose of the heron ensures constant readiness for movement: the bird can take a step without difficulty and grab the living creatures of the reservoir (fish, frog, crayfish) with a sharp jerk.

However, British ornithologists believe that heron hunting does not depend on the position of the legs, and, leaning towards the theory of thermoregulation, they came to general conclusion regarding the heron’s legs: when one leg is in the water, the second, raised and tucked under the belly, dries out and warms up.

Thus, the most probable and fully substantiated the reason why the heron stands on one leg is due to the thermoregulation of the bird's body, which is to maintain heat and avoid hypothermia lower limbs during prolonged stay in an aquatic environment.

The position of the legs of a heron is also determined by other factors - reducing the load on the limbs, maintaining balance, improving blood circulation, readiness to move, obtaining food, etc. - which remain only the assumptions of researchers.

Other aquatic birds - flamingos, storks, ducks - also often stand on one leg, apparently for the same reasons as the heron.

Herons are large birds that live near lakes, rivers and other bodies of water. They are often represented as standing on one leg, and this is completely true. They can remain in this position for quite a long time. But why do they need this? Let's learn more about these amazing birds, and at the same time find out why herons stand on one leg.

Who are herons?

In appearance, these birds are somewhat reminiscent of storks, which is not at all surprising. According to the classification, they belong to the family of herons and the order of storks. Their closest relatives are night herons, bitterns and agams.

Heron birds are very diverse in color and size. Characteristic feature All representatives of the genus have a long cone-shaped beak, thin long legs and elongated necks, which the animals constantly bend with a hook. Many species have a tuft of feathers sticking up on the back of the head. In flight, their neck remains curved, so the birds are easy to distinguish from storks and cranes.

Herons are quite large, but there are also small representatives. For example, the average white, yellow-billed and magpie herons reach only 45 to 70 cm in height. The largest heron is a gigantic one, up to 160 cm high and with a wingspan of up to 230 cm.

So why does a heron stand on one leg?

Those lucky enough to observe these secretive birds may have noticed their bizarre stance on one leg. It would seem that this position is completely uncomfortable. However, the bird can stay in it for hours without losing balance.

There has not been a consensus on why the heron stands on one leg. There are several theories about this. The main version says that in this way the bird warms up. She usually spends a lot of time in bodies of water, the temperature of which is not always favorable. Featherless legs quickly freeze, and in order to maintain normal blood circulation in at least one limb, the bird tucks it under itself. After some time, she changes their position.

There is another answer to the question of why the heron stands on one leg. Perhaps she needs it for hunting. For a bird tracking its prey, its invisibility is important. Having tucked one limb under itself, it disguises itself as a branch of a tree or bush, without arousing suspicion among the prey. In addition, the bird acts much more efficiently this way. She does not wait until the prey gets too close, but when she sees it from afar, she takes a big step and immediately grabs it with her beak. If both legs were down, the reaction would be much slower.

Habitat

Herons are common on all continents except Antarctica, as well as on some islands. Their diet is based on small inhabitants of water bodies, so the main condition for their settlement is the availability of water.

Birds cannot be found in ice-covered polar regions or dry deserts. Their favorite places are swamps, reed and mangrove thickets, water meadows, slow-moving rivers and small lakes. They live extremely rarely in large open bodies of water.

The great white, red, great blue, giant, and black-necked heron have an extensive habitat. The magpie heron has a very limited territory. She lives only in Tasmania and northeastern Australia. The Madagascar heron lives on the island of the same name, the white-bellied heron lives only in the foothills of the Himalayas and some areas of Asia.

Lifestyle

In nature, herons prefer to live alone, uniting in groups only during the nesting period or in water bodies rich in food. The main food for them is fish. Birds also feed on frogs, small rodents, lizards, snakes and shellfish.

They spend most of their lives near water, but cannot swim or dive. Herons do not have a coccygeal gland, like waterfowl, which would allow them to lubricate their feathers with water-repellent oil. Instead, they have brittle down on their chest, with crumbs of which they cover their feathers. But it does not protect against getting wet.

Only tropical species live in one place year-round. Herons that live in temperate and subtropical regions fly away for the winter. From the north of Eurasia they move to the south of the continent or to Africa, and those that live in North America, flying to South America. These birds maintain their isolation even during their travel and never form a wedge or a flock.

Their breeding season begins in early spring. Herons form pairs for one season and do not change partners until next year. Their life expectancy is different. Depending on the species, they live from 10 to 23 years.

Introduction

Birds are an integral part of nature; they add charm to groves, forests, and steppes. They best decoration city parks and gardens. Birds completely transform even the most dull landscape and with their bright colors and sonorous songs make it joyful and noticeable. The boring large landscape of winter immediately becomes different, as soon as the chirping white-sided or the frisky titmouse, or the handsome red-breasted bullfinch appears.

At the zoo I watched an amazing bird - a heron. For hours without moving, herons stand on the water, peering into it and looking for food in the form of various living creatures. If we look closely at them, we can see that they stand in the pond on only one leg, tucking the second under their abdomen. I wondered: what is this connected with and what do I know about herons?

Relevance of the topic: Despite its extremely wide distribution, the number of this species by the end of the 19th century declined catastrophically everywhere due to its extermination for the sake of beautiful feathers.

Hypotheses:

· the heron stands on one leg, because this promotes heat exchange in the bird.

I was interested in the peculiarities of the life of a heron, and I decided to find out about it. Purpose my research work is to study the habitat features of herons.

Object of study: herons.

Subject of study: heron structure

Tasks:

· explore the species composition of herons using scientific literature;

· get acquainted with the structure of herons;

· observe herons and their plumage

In accordance with the assigned tasks, the following are used in the work: research methods: scientific search, comparative analysis, analysis of specialized literature, observation.

The work has practical significance. It is aimed at studying and disseminating the experience of preserving the life of herons.

1. Amazing bird - heron

1.1. What kind of bird is a heron

The heron is a very amazing bird; watching it, questions involuntarily arise about its habits, character, and the strange behavior of this bird.

On average, the lifespan of a heron is 20–25 years, and only those individuals that are safe, i.e., in zoos or nature reserves, live their entire lives. But such herons forget that they are herons and do not use their hunting instincts, do not hunt and cease to be as strange and funny as nature made them.

By studying this beautiful bird, we learned a lot interesting facts which we will now share with you.

When choosing a heron for study, we chose the great white heron, because this species is found in our area and is listed in the Red Book.

The great egret is a large wading bird of the heron family. The height of the bird is 94 - 104 cm, and the wingspan reaches 145 cm. An adult heron weighs 912 - 1140 grams, but males are usually larger than females. The plumage is completely white. The beak is long, straight, colored yellow in the shape of a dagger, and the color of the beak changes depending on the time of year. The neck is long and bent back when flying. The sixth cervical vertebra is elongated and built in such a way that the bird is able to quickly extend or, conversely, pull it into itself. The heron's tail is short and wedge-shaped.

Herons inhabit all parts of the world, all zones and countries with the exception of the Far North. They are migratory birds and arrive to us in late March - April. For their summer stay, they choose swamps and waters overgrown with thick reeds or bushes, or marsh plants. While studying the habitats of the heron, we visited the swampy area on the Neman River and the Grodno Zoo.

They often live on small ponds, in close proximity to villages, and no one here is even aware of their presence. During the day, the heron sits motionless, hidden so well in the reeds or on a tree branch that it cannot be immediately noticed; it is excellent at finding places that match the color of its plumage. The bird moves slowly and majestically, stretching its neck and peering ahead in search of food. She hunts alone or in groups during the daytime and twilight, and at nightfall they flock together with other herons in search of shelter. Very often, a heron takes food from other smaller herons, and also gets into fights with other birds of its species. The heron has a cunning look, she is a treacherous bird. If an enemy approaches her and she cannot escape from him, she suddenly attacks herself and inflicts severe blows on him with her beak. The blows are usually aimed at the eyes, and at the person's hands or other exposed parts of the body, and are very often dangerous.

The heron sleeps lightly, and notices the troublemaker much earlier than he notices her.

Not everyone knows about the heron that when they reach a certain age, they begin to make holes. To do this, they fly vertically without spreading their wings. When maintaining an angle of 90 0 relative to the horizon, the heron enters the ground and makes a hole for itself. Herons willingly nest in the company of their brothers, relatives and completely alien birds. Their large, crudely made nests are found in trees, reeds or bent stems. The chicks remain in the nest until they learn to fly or almost until this time; after flight, their parents feed them for some time.

Herons can take the most amazing poses, but none of them can be called beautiful.

1.2. Types of herons

It is easy to recognize a heron when it flies: its neck is not stretched forward, like that of a stork or a crane, but is curved like the Latin letter S. It flaps its wings slowly, smoothly and rarely soars.

There are 63 species of herons in the world ( Appendix 2) . Which, in turn, are divided into subspecies. The differences between them are in the size of the birds and their coloring. The smallest bird reaches a maximum height of sixty centimeters, and the largest - almost one and a half meters. Some individuals can reach one and a half meters in height and weigh up to 2.5 kg. They are white, red, black, gray, and sometimes two-colored. Most herons have dark feet and yellow beaks, but sometimes there are herons with black beaks. The plumage of birds is smooth, and heron head often decorated with a crest, the size of which depends on the species, but the crest is not present in all species. Herons living in northern latitudes fly south in winter.

1.3. The structure of a heron and its vital functions

The bird's body is streamlined and consists of a small head, neck, torso and tail. The forelimbs are wings, the hind limbs are legs. On the head is a beak consisting of a mandible and a mandible. The beak is covered with a horny sheath. At the base of the beak are the openings of the nostrils; adjacent to them is an area of soft bare skin - the cere. On the sides of the head are large eyes, protected by the upper and lower eyelids and the nictitating membrane. Behind the eyes are the external auditory openings. The neck is long and mobile.

Long thin legs (very long toes and small membranes) and neck, long beak (compressed from the sides). The skin is thin and dry. A single skin gland located at the base of the tail (coccygeal gland) secretes a fat-like secretion for lubrication.

When herons fly in the sky, it looks as if their knees are pointing backwards. But this impression is deceptive. The structure of a bird's leg is in principle similar to that of a mammal's leg. What appears to be a bird's knee is actually ankle joint. That is, birds walk on their toes, and the knee itself is hidden under the feathers. Leg structure (Application 3)

1.4. Why does a heron stand on one leg?

One of the mysteries of the heron is that the heron stands on one leg. Why does the heron stand on one leg?

This question interests not only children, but also adults, and there are several answers to it. The heron obtains its food by hunting small fish, frogs, beetles. These creatures are very nimble, and a bird of prey has to work hard to grab them. There are only fractions of a second to throw, so the heron takes one leg out of the water in advance in order to have time to make a lightning-fast lunge for the prey. For many centuries, chicks repeat the behavior pattern of their parents.

The heron has an interesting structure knee joint: when the leg is extended, a kind of lock is activated, and the bird can stand for a very long time, while allowing the second leg to rest. In addition, this pose is a very good camouflage for hunting, since one leg of the bird does not stand out so much against the general background of the swamp and it can be mistaken for tall grass or a reed stalk. The inhabitants of the reservoir calmly swim past, unaware of the danger, and become victims of the predator. Herons stand motionless for a long time, watching for prey in the water, and then with lightning speed they pierce it with their long beak. Then they shake the catch from the beak and swallow it.

Another reason that the heron stands on one leg is to carry out thermoregulation of the body. The feathered predator spends most of its life standing motionless waiting for prey, so good thermoregulation is of great importance.

2. Study "Heron Feather Diversity"

I conducted a survey in class to study students' knowledge about the heron. The following questions were asked for students :

1. Do you know what herons are?

2. Where have you met or could you meet a heron?

3. Why does a heron stand on one leg?

4. Why are herons called birds?

Judging by the guys' answers, we can say that general ideas about this bird they have. They saw a heron at the zoo. But the answers to the remaining two questions caused difficulties. Appendix 4.

In many sources, herons are called feathered, since feathers are the main distinguishing feature of birds. So in my research I looked at heron feathers.

My actions	My observations and conclusions
Experiment 1. Examining the feathers of a heron with my eyes and with a magnifying glass	Feathers differ in size, shape, color; The feather has a strong and flexible shaft from which fibers - barbs - extend. They are connected to each other using hooks and notches. This creates a single surface of the pen
Experiment 2. I blow on a feather, placing it on my palm	The feather is flying. It's very light. The question arises: why is it light?
Experiment 3. I cut off the tip of the feather with scissors and examine the feather inside	The feather is empty inside: that's why it flies so easily
Experiment 4. Testing the flexibility of feathers	There is a protective film on the shaft of the flight feather that strengthens the feather; without it, the shaft of the feather is fragile and tiny. There is no such film on a down feather.
Experiment 5. I drop a drop of water from a pipette onto the pen	The droplet rolled off, but the pen did not get wet. This means that the feathers protect the bird from rain. Question: Why don’t feathers get wet? It turns out that birds clean, style and lubricate their plumage. For lubrication, they use fluid from a gland above the tail. That's why feathers don't get wet.
Experiment 6. I compare 2 feathers of the same bird: One feather is soft and fluffy, and the other is elastic and hard. Question: why does she need different feathers?	The bird has large, elastic feathers on its wings. They are called flight feathers and serve the bird for flight. Soft and fluffy feathers keep the bird warm. They are called coverts. Birds have down feathers under their coverts. They keep you warm. Watching birds on cold days, you can see that they ruffle their feathers and sit with their feathers ruffled. They push more air between the feathers, which does not conduct heat well. This is how birds escape from the cold. The viscous and thick substance applied to the feather glued the fibers together. As a result, the bird loses the ability to push water and drowns.
Experiment 9. Let’s separate the locks on the flight feather and see if they can be reattached to each other	The hairs on the flight feather separate perfectly, and if you press them with your fingers and move them from the base to the tips, the clasps on the hairs will close and connect with each other. The heron performs this process daily with its beak.

Conclusion

During my research, I found out that the heron is truly an amazing bird. It is fraught with many secrets and mysteries. It amazes with the variety of species, and each of them is beautiful in its own way, interesting not only for its habits and behavior, but also for its rapidly changing mood, because the bird is dangerous. During my research, I became convinced that my hypotheses:

· heron feathers are one of its main distinctive features

· the heron stands on one leg, because this promotes heat exchange in the bird -turned out to be correct.

Yes, all herons are different from each other, no birds are the same. The varied plumage amazes with its structure, lightness, and variety of colors. And standing on one leg allows the heron not only to exchange heat, but also helps it in hunting prey.