Birds are usually divided into sedentary and migratory, depending on their lifestyle. But among them there are very special birds. This is an American White-throated Nightjar. Although these birds do not like the cold season, they are in no hurry to leave their native lands in search of best places for wintering. Instead of exhausting and dangerous flights, they chose to hibernate in a cozy place.

The American white-throated nightjar, or sometimes called the California nightjar, is found in the arid regions of western North America. Its habitat extends from the Canadian province of British Columbia in the north to the central regions of Mexico in the south. This is a small bird whose weight reaches only 35-55 grams, and its body size is 20 centimeters.

Nightjars build their nests on the ground, under the cover of bushes or grass. At the end of spring and throughout the summer, the female usually lays two eggs. But there have been cases where the female makes a second nest and lays a new batch of eggs while the male feeds the hatched offspring. In addition to this feature, nightjars have a very interesting defensive reaction to the appearance of predators: nightjars open their mouths wide and hiss loudly, imitating the behavior of a snake.

Nightjars are active at night, as their main food is nocturnal flying insects. With the onset of the cool season, nightjars fall into a special state, reminiscent of hibernation in mammals. At this time of year, their main food - insects - is practically absent. In order not to complicate their life by searching for food, they hibernate. Nightjars find a quiet place in the crevices of rocks and plunge into torpor, which can last from 10-20 days to 3 months. Studies have shown that the metabolic processes in a bird's body slow down so much that their body temperature can drop to 10 degrees Celsius. Cases have been recorded when the body temperature of birds dropped to 3-4 degrees, and oxygen consumption was reduced by up to 30 times. At the same time, their hibernation places are not completely closed from the outside world. The nightjar settles down for the winter so that the sun's rays fall on it and warm it with its warmth.

Interestingly, not all white-throated nightjars have this ability. The northern population of birds, which lives in Canada and the northern states of the United States, still prefers to fly south to Mexico. But nightjars, which originally live in the south, just hibernate.

Interesting feature Zoologists discovered that nightjars fall into winter torpor only in 1947, when half-dead birds were discovered in the rocks. But the Native Americans knew about this feature of birds long before the discovery of scientists, because in the language of the Hopi Indians the white-throated nightjar is called “sleeping.”

Sections: Biology

Goals: increase the areas of student knowledge; learn to analyze the phenomenon of temporary cessation of vital activity in living organisms that use it as a means to adapt and survive in unfavorable conditions.

Equipment: tables of mollusks, crustaceans, insects, fish, amphibians, reptiles, birds, mammals.

The winter season is unfavorable for many representatives of the animal and plant world, both due to low temperatures and a sharp reduction in the ability to obtain food. During evolutionary development, many species of animals and plants acquired unique adaptive mechanisms to survive in unfavorable seasons. In some species of animals, the instinct to create food reserves arose and became established; others have developed another adaptation - migration. Amazingly long flights of many species of birds, migrations of some species of fish and other representatives of the animal world are known. However, in the process of evolution, another perfect physiological mechanism of adaptation has been noticed in many species of animals - the ability to fall into a seemingly lifeless state, which various types animals manifests itself in different ways and has different names (anabiosis, hypothermia, etc.). Meanwhile, all these conditions are characterized by inhibition of the body’s vital functions to the minimum that allows it to survive unfavorable winter conditions without eating. Those species of animals that are unable to provide themselves with food in winter fall into a similar state of imaginary death and are in danger of dying from cold and hunger. And all this, developed in the process of evolution, is subject to strict natural expediency - the need to preserve the species.

Hibernation is a widespread phenomenon in nature, despite the fact that its manifestations vary among representatives of certain groups of animals, be it animals with an unstable body temperature (poikilothermic), also called cold-blooded, in which the body temperature depends on the surrounding temperature, or animals with a constant body temperature (homeothermic), also called warm-blooded.

Among the animals with an unstable body temperature, various types of mollusks, crustaceans, arachnids, insects, fish, amphibians and reptiles go into hibernation, and among the animals with a constant body temperature, several species of birds and many species of mammals.

How do snails winter?

Of the soft-bodied type, many species of snails hibernate (for example, all land snails). Common garden snails enter hibernation in October, which lasts until early April. After a long preparatory period, during which they accumulate the necessary nutrients in their bodies, the snails find or dig holes so that several individuals can overwinter together deep underground, where the temperature will be maintained at 7 - 8 ° C. Having sealed the burrows well, the snails descend to the bottom and lie down with the shell opening facing up. They then close this opening, releasing a slimy substance that soon hardens and becomes elastic (film-like). With a significant cooling and lack of nutrients in the body, the snails burrow even deeper into the ground and form another film, thus creating air chambers that play the role of an excellent insulator. It has been established that during a long winter, snails lose more than 20% of their weight, with the greatest loss occurring in the first 25-30 days. This is explained by the fact that all metabolic processes gradually die out in order to reach the minimum at which the animal falls almost into a state of suspended animation with barely perceptible vital functions. During hibernation, the snail does not feed and breathing almost stops. In the spring, when the first warm days arrive and the soil temperature reaches 8-10 ° C, when vegetation begins to develop and the first rains fall, snails crawl out of their winter shelters. Then intensive activity begins to restore the depleted food reserves in their body; this is expressed in the absorption of a huge amount of food compared to their body.

Pond water snails also enter a state of hibernation - most of them bury themselves in the silt at the bottom of the reservoir in which they live.

Where do crayfish spend the winter?

Everyone knows the popular threat: “I’ll show you where the crayfish spend the winter!” It is believed that this saying appeared during the times of serfdom, when landowners, punishing guilty serfs, forced them to catch crayfish in the winter. Meanwhile, it is known that this is almost impossible, since crayfish spend the winter buried deep in holes at the bottom of reservoirs.

From a systematic point of view, the class of crustaceans is divided into two subclasses - higher and lower crustaceans.

Among the higher crustaceans, river, marsh and lake crayfish fall into a state of hibernation. Males overwinter in groups in deep holes at the bottom, and females alone in burrows, and in November they glue fertilized eggs to their short legs, from which crustaceans the size of an ant hatch only in June.

Of the lower crustaceans, water fleas (genus Daphnia) are of interest. They lay, depending on conditions, two types of eggs - summer and winter. Winter eggs have a durable shell and are formed when unfavorable living conditions occur. For some species of lower crustaceans, drying and even freezing of eggs is a necessary condition to continue their development.

Diapause in insects

In terms of the number of species, insects surpass all other classes. Their body temperature depends on environment, which has a strong impact on the speed of vital influences, and low temperatures significantly reduce this speed. At negative temperatures, the entire development of the insect slows down or practically stops. This anabiotic state, known as “diapause,” is a reversible cessation of developmental processes and is caused by external factors. Diapause occurs when conditions unfavorable for life arise and continues throughout the winter until, with the onset of spring, conditions become more favorable.

The onset of the winter season finds different types of insects at different stages of their development, in which they overwinter - in the form of eggs, larvae, pupae or adult forms, but usually each individual species enters diapause at a certain stage of its development. For example, the seven-spotted ladybug overwinters as an adult.

It is characteristic that the wintering of insects is preceded by a certain physiological preparation of their body, consisting of the accumulation of free glycerol in their tissues, which prevents freezing. This occurs at the stage of insect development in which they will spend the winter.

Even with the onset of the first signs of cooling in the fall, insects find comfortable shelters (under stones, under the bark of trees, under fallen leaves in burrows in the soil, etc.), where after snowfall there is a moderately low and uniform temperature.

The duration of diapause in insects is directly dependent on body fat reserves. Bees do not enter a long diapause, but still become numb at temperatures from 0 to 6 ° C and can remain in this state for 7-8 days. At lower temperatures they die.

It is also interesting how insects accurately determine the moment when they should exit the anabiotic state. Scientist N.I. Kalabukhov studied suspended animation in some species of butterflies. He found that the duration of diapause varies among individual species. For example, the peacock butterfly remained in a state of suspended animation for 166 days at a temperature of 5.9 ° C, while the silkworm needed 193 days at a temperature of 8.6 ° C. According to the scientist, even differences in geographic area affect the duration of diapause.

Do fish hibernate during the winter?

Some species of a wide class of fish also adapt to low water temperatures in winter in a unique way. The normal body temperature of fish is not constant and corresponds to the temperature of the water. When the water temperature suddenly drops sharply, the fish go into a state of shock. However, it is enough for the water to warm up, and they quickly “come to life”. Experiments have shown that frozen fish come to life only in cases where their blood vessels do not freeze.

Some fish that live in Arctic waters adapt to low water temperatures in winter in an original way: they change their blood composition. As the water temperature drops in the fall, salts accumulate in their blood in such a concentration as is typical for sea water, and at the same time the blood freezes with great difficulty (a kind of antifreeze).

Of the freshwater fish, carp, ruffe, perch, catfish and others go into hibernation back in November. When the water temperature drops below 8 - 10°C, these fish move to deeper parts of the reservoirs, bury themselves in large groups in the mud and remain there in a state of hibernation throughout the winter.

Some marine fish also tolerate extreme cold in a state of hibernation. For example, herring already in the fall approach the coast of the Arctic Ocean in order to fall into a state of hibernation at the bottom of some small bay. The Black Sea anchovy also winters in the southern regions of the sea - off the coast of Georgia; at this time it is not active and does not consume food. And before the onset of winter, the Azov anchovy migrates to the Black Sea, where it gathers in groups in a relatively sedentary state.

Hibernation in fish is characterized by extremely limited activity, complete cessation of nutrition and a sharp decrease in metabolism. At this time, their body is supported by nutrient reserves accumulated due to abundant nutrition in the autumn.

Hibernation of amphibians

In terms of lifestyle and structure, the class of amphibians is transitional between typically aquatic vertebrates and typically terrestrial animals. It is known that various species of frogs, newts, and salamanders also spend the unfavorable winter season in a state of torpor, since these are animals with an unstable body temperature, which depends on the ambient temperature.

It has been established that winter hibernation of frogs lasts from 130 to 230 days and its duration depends on the duration of winter.

In water bodies, in order to overwinter, frogs gather in groups of 10-20 individuals, bury themselves in silt, underwater depressions and other voids. During hibernation, frogs breathe only through their skin.

In winter, newts usually roost under warm, rotten stumps and trunks of fallen trees. If they do not find such comfortable “apartments” nearby, they are satisfied with cracks in the soil.

Reptiles also hibernate

From the class of reptiles, almost all species of our fauna fall into a state of hibernation in winter. Low winter temperatures are the main reason for this phenomenon.

Winter quarters are usually underground caves or voids formed around large old stumps with rotten roots, crevices in rocks and other places that are inaccessible to their enemies. A large number of snakes gather in such shelters, forming huge snake balls. It has been established that the temperature of snakes during hibernation is almost no different from the ambient temperature.

Most species of lizards (meadow, striped, green, forest, spindle) also hibernate, burying themselves in the soil, in burrows that are not threatened by flooding. On warm, sunny days in winter, lizards may “awaken” and crawl out of their winter shelters for a few hours to hunt, after which they retreat back into their burrows, falling into a state of torpor.

Swamp turtles spend the winter burrowing into the silt of the reservoirs in which they live, while land turtles climb to a depth of up to 0.5 m into the soil in some natural shelters or holes of moles, foxes, rodents, covering themselves with peat, moss and wet leaves.

Preparations for wintering begin in October, when turtles accumulate fat. In the spring, with temporary warming, they wake up, sometimes for a whole week.

Do birds hibernate in winter?

Most animals with an unstable body temperature, which depends on the environment, fall into a state of hibernation. But it is surprising that many animals with a constant body temperature, such as birds, can also hibernate during unfavorable seasons. It is known that most birds avoid unfavorable winter conditions by migrating. Aristotle, in his multi-volume History of Animals, drew attention to the fact that “some birds fly away to spend the winter in warm countries, while others take refuge in various shelters where they hibernate.”

This conclusion was also reached by the prominent Swedish naturalist Carl Linnaeus, who wrote in his work “The System of Nature”: “In the autumn, when the weather begins to get colder, swallows, not finding enough insects for food, begin to seek shelter for the winter in reed thickets along the banks of lakes and rivers. "

The torpor into which some species of birds fall differs significantly from the hibernation characteristic of many mammals. First of all, the bird’s body not only does not accumulate energy reserves in the form of fat, but, on the contrary, consumes a significant part of it. While mammals hibernate during the winter, gaining noticeable weight, birds lose a lot of weight before going into torpor. This is why the phenomenon of torpor in birds, according to Soviet biologist R. Potapov, should be called hypothermia rather than hibernation.

Until now, the mechanism of hypothermia in birds has not been fully studied. The fall of birds into a state of torpor under unfavorable living conditions is an adaptive physiological reaction that has been consolidated in the process of evolution.

What mammals hibernate?

As in those animals that were discussed earlier, in mammals, hibernation is a biological adaptation for surviving an unfavorable season of the year. Despite the fact that animals with a constant body temperature usually tolerate cold climate conditions, the lack of suitable food in winter has become the reason for the acquisition and gradual consolidation in the process of evolution by some of them of this peculiar instinct - spending the unfavorable winter season in an inactive state of hibernation.

There are three types of hibernation based on the degree of torpor:

1) mild torpor that easily stops (raccoons, badgers, bears, raccoon dogs);

2) complete torpor, accompanied by periodic awakenings only on warmer winter days (hamsters, chipmunks, bats);

3) real continuous hibernation, which is a stable, prolonged torpor (gophers, hedgehogs, marmots, jerboas).

Winter hibernation in mammals is preceded by a certain physiological preparation of the body. It consists primarily of the accumulation of fat reserves, mainly under the skin. In some winter hibernators, subcutaneous fat reaches 25% of their total body weight. For example, ground squirrels gain weight even at the beginning of autumn, increasing their body weight three times compared to the spring-summer weight. Before hibernation, hedgehogs and brown bears, as well as all bats, become significantly fatter.

Other mammals, such as hamsters and chipmunks, do not accumulate large reserves of fat, but store food in their shelter for use during their brief awakening periods in winter.

During hibernation, all species of mammals lie motionless in their burrows, curled up into a ball. This is the best way to preserve heat and limit heat exchange with the environment. The winter quarters of many mammals are the natural cavities of stems and tree hollows.

Among the insectivorous mammals, the hedgehog, in preparation for hibernation, collects moss, leaves, hay in a secluded place and makes a nest for itself. But it “settles” in its new home only when the temperature remains below 10° C for a long time. Before this, the hedgehog eats heavily in order to accumulate energy in the form of fat.

Winter hibernation of brown bears is a slight torpor. In nature, in the summer, a bear accumulates a thick layer of subcutaneous fat and, just before the onset of winter, settles down in its den for hibernation. Usually the den is covered with snow, so it is much warmer inside than outside. During hibernation, accumulated fat reserves are used by the bear's body as a source of nutrients, and also protect the animal from freezing.

From a physiological point of view, hibernation in mammals is characterized by a weakening of all vital functions of the body to the minimum that would allow them to survive unfavorable winter conditions without food.

So, we found out that most animals with an unstable body temperature, which depends on the environment, fall into a state of hibernation. But it is surprising that many animals with a constant body temperature, such as birds, can also hibernate during unfavorable seasons. It is known that most birds avoid unfavorable winter conditions by migrating. But even Aristotle (384 - 322 BC) in his multi-volume “History of Animals” drew attention to the fact that “some birds fly away to spend the winter in warm countries, while others take refuge in different shelters, where they fall into hibernation.” This conclusion was also reached by the prominent Swedish naturalist Carl Linnaeus, who in his work “System of Nature” (1735) wrote: “In the autumn, when the cold weather begins, swallows, not finding enough insects for food, begin to look for shelter for wintering in reed thickets along the banks of lakes and rivers." For a long time, the statements of Aristotle and Linnaeus were rejected by ornithologists, who referred to the well-known fact that some birds migrate to warm countries, while non-migratory birds are active in winter, and birds hibernating in winter, contrary to the statement many, science does not know. Only after American scientists discovered a nightjar (Phalaenoptilus nuttalii) in a hibernating state in a rock crevice in 1937, it became clear that some bird species can fall into a similar state during unfavorable seasons. Both scientists conducted more in-depth studies and found that before hibernating, this bird species loses a significant part of its weight, and at a certain point, as a result of such exhaustion, the mechanism of transition to a state of torpor is activated. In this state, metabolism decreases sharply, the need for oxygen is reduced by almost 30 times, and body temperature from 40 - 41 ° C drops to 18 - 19 ° C and even lower. The birds fell into a stupor that lasted about 3 months, and it seemed as if they were dead. It was found that during hibernation, a nightjar weighing 40 g consumed 0.15 ml of oxygen per 1 g of weight per hour, whereas in the normal state - 2.7 ml. The same scientists banded one of these birds, and in subsequent years it turned out that it always wintered in the same place for 4 years. Later it was found that another of its relatives, the small nightjar (Chordeilis minor), also lives in North America and the Antilles, falls into a state of hibernation. In Denmark, a European common nightjar (Caprimutgus europeus) was found in the same condition at an air temperature of 0°C. Experiments carried out with him showed that when the air temperature was artificially lowered to 4°C, the bird fell into stupor, and its body temperature dropped from 37 - 40°C to 16 - 17°C, and its respiratory rate - from 50 - 70 to several minute. There are observations that some species of swallows (barn and cliff) also hibernate in winter. A state of short-term torpor, which scientists call torpidity, has been observed in newly hatched black swift chicks (Apus apus), which enter this state when their parents leave them for several days under unfavorable conditions (for example, during an approaching cyclone). In a state of torpor, the body temperature of these chicks dropped from 39°C to 20°C and even lower, the pulse and breathing slowed down, and they remained in this state for 7 - 12 days. Appearing again, the parents warmed them with their bodies, and the chicks returned to life. In a favorable season, young swifts flew out of the nest after 33 - 35 days, and in unfavorable times, when they fell into a state of torpor, they needed 40 - 50 days. It has long been known that the chicks of some hummingbird species also fall into a similar torpid state if the mother, having flown away for food, will stay for more than ten minutes (in hummingbirds, only females feed their offspring). After her return, warmed by maternal warmth, they return to life. It has been established that adult hummingbirds of several species (Calypte costae, C. anna, Eugenes lampornis) living on the American continent are also capable of falling into a state of torpor on particularly cold nights, when their body temperature drops to 8.8 ° C. It has been proven that the weight of various species of hummingbirds ranges from 1.7 to 19.1 g, and the oxygen requirement for small specimens at rest is 11 - 16 ml per 1 g of weight per hour, during flight - 70 - 85 ml, and in a state of torpor only 0.17 ml. Hummingbirds have a high energy expenditure, and there is a danger that hummingbirds with a body temperature of 44°C will not be able to survive without food during the period when they sleep, since they will not have enough energy reserves. In this situation, their body, if excessively cooled from exhaustion at night, will lose the opportunity to warm up again at the beginning of its active phase. Meanwhile, as you know, the nights on the South and Central American high plateaus, where hummingbirds live, are cold. That is why hummingbirds have a protective mechanism - they fall into a torpid state at night, and their body temperature is compared with the temperature of the environment; Thus, they do not give up their heat and retain energy, which is not consumed to generate heat in the body. In this case, the law of the Dutch physiologist Van Gough applies, reflecting the relationship between the rate of reactions of chemical processes and temperature (if the body temperature drops by 10°C, metabolic processes will begin to proceed almost 3 times slower). So if a hummingbird's body temperature drops from 44°C to 34°C, this will lead to a threefold reduction in metabolism and, accordingly, to significant energy conservation. Similar regulation of body temperature during torpor was discovered in the purple hummingbird (Eulampis jugularis), which, like other hummingbirds, it easily falls into a torpid state. In a state of torpor, the body temperature of this species of hummingbird is usually close to air temperature, but if the latter drops below 18 ° C, the bird’s body temperature no longer decreases and remains at 18 - 20 ° C. The torpor into which some species of birds fall is significantly differs from hibernation, characteristic of many mammals. First of all, the bird’s body not only does not accumulate energy reserves in the form of fat, but, on the contrary, consumes a significant part of it. While mammals hibernate during the winter, gaining noticeable weight, birds lose a lot of weight before going into torpor. That is why the phenomenon of torpor in birds, according to the Soviet biologist R. Potapov, should be called not hibernation, but hypothermia. Until now, the mechanism of hypothermia in birds has not been fully studied. It is interesting that all birds capable of falling into a state of torpor are systematically They are closely related to each other and have common physiological and ecological characteristics. The fall of these birds into a state of torpor under unfavorable living conditions is an adaptive physiological reaction that has been consolidated in the process of evolution.

Hibernation Hibernation (winter - hibernation, summer - estivation) is a period of slowdown in life processes and metabolism in homeothermic animals during periods of low food availability, when it is impossible to maintain activity and a high level of metabolism. It is characterized by a decrease in body temperature, slowing of breathing and heartbeat, inhibition of nervous activity (the so-called “deep sleep”) and other physiological processes. Usually, before hibernation, animals feed heavily and accumulate large reserves of nutrients in the form of fat (in the case of seasonal hibernation, up to 30-40% of body weight) and take refuge in shelters with a suitable microclimate (nests, burrows, hollows, etc.). Depending on the regularity, the following types of hibernation are distinguished: daily hibernation in hummingbirds and bats; seasonal hibernation - winter (hibernation) in insectivores and rodents or summer (estivation) in desert animals; irregular - with the sudden onset of unfavorable conditions (raccoon dogs, squirrels). Some large mammals (bears, badgers, raccoons) enter hibernation, a type of hibernation with a smaller decrease in the levels of physiological processes and metabolism. In a brown bear, during winter sleep, the body temperature decreases slightly (from 37° to approximately 31°C), and rises easily and quickly upon awakening. Some species spend part of their pregnancy in hibernation, in which case birth occurs immediately after emerging from hibernation. During hibernation, in addition to periods of actual hibernation, there are also periods of increased body temperature to normal levels. Among mammals, rodents, one species of lemur, the European hedgehog and other insectivores and marsupials hibernate. Pliny the Elder believed that swallows are also capable of hibernation, but this is erroneous - birds, with the exception of nappers, usually do not hibernate. Hummingbird and swift chicks fall into a state similar to hibernation (sharply lowered body temperature and torpor) in the absence of their parents. It has long been believed that primates do not hibernate. But in 2004, evidence was published that the little dwarf lemur from Madagascar hibernates in tree cavities for seven months of the year. This is especially interesting in light of the fact that winter temperatures in Madagascar can exceed 30°C. Apparently, the hibernation of this lemur is not caused by the need to wait out low temperatures. Hibernation can last from several days to several months depending on the species, external temperature and other environmental conditions. During hibernation, there are periods when body temperature is restored to normal values. During hibernation, the animal’s body is nourished by the reserves of nutrients accumulated the day before (fat, etc.). The animal traditionally considered capable of hibernation is the bear. But the degree to which a bear's metabolic processes slow down in winter is much less than that of rodents, insectivores and other animals - so biologists usually believe that this cannot be called hibernation in the real biological sense. Also, during hibernation, a bear’s body temperature does not decrease very much (from 37° to about 31°C), and is easily and quickly restored; while in ground squirrels (genus Xerus) the body temperature during hibernation can drop to −2°C. A process similar to hibernation is known in several species of reptiles, but it is not yet known whether it is true hibernation. Typically, before hibernation, animals feed heavily and accumulate relatively large reserves of nutrients in the form of fat. Several species spend part of their pregnancy in hibernation, in which case birth occurs immediately after emerging from hibernation. For several decades it was believed that the giant shark in winter period, descending to the bottom horizons of the northern regions of the ocean, hibernates. But research conducted in 2003 by David Sims refuted this, showing that sharks are actively moving at this time in search of places with the largest number plankton. According to the depth of hibernation, they are distinguished: Seasonal or facultative hibernation. It is characterized by the fact that the animal’s body temperature, respiratory rate and overall metabolic rate decrease slightly. If you are anxious, sleep can easily be interrupted. Characteristic of bears, raccoons, raccoon dogs, badgers. True continuous seasonal hibernation. It is characterized by loss of the ability to thermoregulate (heterothermia), a sharp decrease in the frequency of respiratory movements and heart contractions, and a decrease in metabolic activity. Summer hibernation or aestivation, also called summer diapause, is characteristic of organisms at low latitudes and ensures their survival during the dry season. It can often be observed in rodents deprived of summer period complete and water-rich food. For example, the sand squirrel in Central Asia enters summer hibernation in June - July. In gophers, summer hibernation usually passes into winter hibernation without interruption. Summer hibernation is also observed in some inhabitants of the tropical zone. In the African hedgehog Atelerix albiventris it lasts up to three months, and in the Madagascan insectivores tenrecs it lasts up to four months. List of animals that hibernate[edit | edit wiki text] Rodents Lesser dwarf lemur Bear Hedgehog American white-throated nightjar Australian echidna Australian pygmy possum Chilean possum Bat Hamster Dormouse Marmot Chipmunk Gopher Badger Frogs

Hibernation is more than just an adaptation for animals to survive the cold season. For hedgehogs, dormouse and horseshoe bats, this is the only way to avoid starvation. echidna photo: myopixia The echidna and platypus hibernate from monotremes. They sleep intermittently for 5-10 days, after which they lead an active life for the same amount of time. When they sleep, their body temperature drops to 22 ° C, although it is usually 36 ° C. The koala and bob-tailed marsupial rats living in Tasmania are the only few marsupials that sleep for 6-12 days in winter, curled up in a hollow tree. Rodents, insectivores and bats are those animals that hibernate in winter. These include chipmunks, marmots, dormouses and hamsters; the hedgehog is one of the most famous sleepers. The hedgehog spends the cold season curled up in its nest. The mountain bat spends the winter in deep, damp caves. Wrapped in their leathery wings, horseshoe bats sleep underground in winter. Brown and black bears hibernate during winter. Only some mammals go into true hibernation. During this period, the body temperature reaches a little more than 0 ° C, but animals can produce so much energy that, when necessary, they “come back to life.” black bears photo:picyak Winter sleep Some animals, such as badgers, sleep in their burrow most of the winter, but these animals do not truly hibernate. Their metabolism decreases, but not by much. The heart rate is reduced to 10-12 beats per minute, and the body temperature is kept at 30 ° C, that is, they do not fall into the characteristic state of lethargy. If their body temperature dropped, it would mean certain death for them. Raccoons and skunks also sleep in winter, but they, like badgers, maintain a high body temperature. Sleep is different from hibernation. Warm-blooded animals hibernate to survive the hungry and most unfavorable times. Therefore, they hibernate to conserve precious energy. The body temperature of animals decreases greatly, digestion stops, the heartbeat decreases, and breathing becomes less frequent. badgers photo: Santi Guese Hibernation Small warm-blooded mammals, such as the marmot, chipmunk and ground squirrel, maintain a temperature of approximately 37.3 ° C during the summer months, and this is independent of ambient temperature. The heart rate under normal conditions is about 88 beats per minute, and breathing is 16 breaths per minute. At the beginning of winter, when the temperature drops below 15 ° C, the marmot curls up in its hole and hibernates. The saying “sleeps like a groundhog” did not appear by chance - after all, these animals sleep from 6 to 8 months a year. Hibernation is a deep sleep during which the animal loses control over its body temperature. The animal regularly wakes up from hibernation only to defecate, or in a very critical situation, for example, if the nest is flooded with water or the animal’s life is threatened by another danger. A baybak that sleeps takes only two breaths per minute, its heart can only beat once every 12 seconds, and sometimes even stop for a whole minute. marmot photo:jasonwain In winter, the development of most plants stops, and cold-blooded animals fall into a state of torpor. Warm-blooded animals, birds and mammals, cannot respond to environmental changes in this way. Some of the animals survive in the icy desert of Antarctica, but they have to keep their body temperature at a constant level, since reducing it would mean death. For warm-blooded animals, it is very important to maintain a constant temperature, since it is always higher than the ambient temperature. To maintain temperature, the animal needs food, which becomes difficult to obtain in winter. Many birds solve this problem in their own way - they fly away to warmer regions for the winter. Large herbivores, e.g. reindeer, also migrate to the southern regions. For small mammals such travel is impossible. Many animals living in polar regions grow thick fur during the winter, which protects them from the bitter cold. Eskimo dogs have such thick and warm fur that they can sleep in the snow even at an air temperature of -30 ° C. Small animals lose heat faster than they produce it. For example, a mouse uses twice as much energy as a sheep. reindeer photo: amortize Therefore, many small animals build very well-protected warm nests. To maintain body temperature at +37 ° C, mammals must eat regularly. Animals often store fat to help them survive times of famine. Many animals have a chance of survival only when they reduce their energy use to a minimum, so that it is enough to survive during hibernation. A small animal, the hazel dormouse, which has spread to Europe. As soon as the air temperature drops below 15 ° C, she climbs into her nest, curls up and falls asleep. Sometimes they wake up Some animals sometimes wake up during winter sleep. The bats They sleep longer without interruption, but their sleep lasts no more than a month. From time to time they wake up and, having moved to another place, fall asleep again. Some species even catch insects in their wintering grounds. The hedgehog sleeps for no more than 2-3 weeks, and then wakes up for a short time. Frequent awakenings during warm winters do not benefit the hedgehog, since in this case fat reserves are used up faster. Other insectivores, for example, the little shrew, which weighs 2 g, are an example of the other extreme: in cold weather they fall into a state of torpor for several hours. However, this is not true hibernation. hedgehog photo: Chris Sharratt The vital activity of an animal that is sleeping does not decrease as much as during hibernation. This is evidenced by the fact that a bear wakes up in the middle of winter and leaves the den, and then returns to “get some sleep.” The mother bear gives birth to cubs, and she takes care of them. In a state of torpor, some animals remain completely motionless, even if you move them. Others wake up momentarily if their sleep is disturbed. The first signs of awakening are movement and trembling in the limbs, due to which the body temperature gradually rises. To keep warm, the animal uses a lot of energy. Once upon a time, in ancient times, people believed that in winter swallows hide under water and sleep at the bottom of a pond or river. Nowadays, it is known that with the onset of autumn, these birds fly to the southern regions, since there are no flying insects at their nesting sites in winter - the main food for birds. However, it turned out that some species of birds do hibernate, at least for a short time. nightjar photo: Sam White The American White-throated Nightjar feeds on insects. There are no flying insects in winter, so this bird hibernates to conserve precious energy. For a short time, the nightjar's body temperature drops to about 6 ° C, whereas it is usually about 40 ° C. Many species of hummingbirds fall into a torpor at night, reminiscent of hibernation. At this time, their body temperature drops to 8-9 ° C. It is known that hummingbirds spend a lot of energy, so they have a very intense metabolism: during the day they absorb an amount of food that is twice their weight.

Hibernation (hibernation) is a slowdown in vital processes and metabolism for a certain period of time. At the same time, body temperature decreases, breathing and pulse slow down, nervous activity and other body processes are inhibited. During the winter, many animals find it difficult to find food for themselves and they choose this method of survival in order to survive until warmer days. Before hibernation, they feed with a vengeance, thus accumulating the energy they need during the hibernation period. Animal hibernation is a perfect way, invented by nature, to save its offspring from conditions unusual for their normal life. There are a huge variety of animals that hibernate in winter. Most of them live in a temperate climate, characterized by warm summers and cold winters, during which it is difficult for them to find food. Some of them will be discussed below. Bear The most famous representative of the animal kingdom that hibernates in winter is the bear. It should be noted that its hibernation is considered shallow. It's more like a nap. Its body temperature does not become as low as that of other animals in true hibernation. The same goes for his heartbeat. This means that if you try to touch him in this state, he can wake up very quickly and immediately begin a fight. Bears are animals that hibernate in winter without losing their orientation in space and time. However, bears can remain in this state without touching food or water for seven months. This becomes possible thanks to the fat accumulated over the summer, the layer of which can reach 15 cm. In the summer, a bear not only eats food, it brutally overeats. This process is somewhat reminiscent of fattening a pig, and is also equal to 30 full meals eaten per day by a person. What animals hibernate in winter? Common hedgehog Hedgehogs are engaged in active life from 4 to 7 months, dividing this period into three stages: awakening, reproduction, preparation for long hibernation. With the onset of cold weather, they hibernate. The main reason for this phenomenon for hedgehogs is lack of food, the secondary reason is cold. They do not store food for the winter because they feed on insects. Therefore, they have to store fat in summer season , and hibernate in winter. In addition, their thermoregulation is imperfect, which leads to the need for prolonged winter torpor. Gophers Gophers, in terms of hibernation, are among the animals that are in a state of torpor for the longest time, to be more precise, up to nine months a year. Moreover, the cyclical nature of their stay in this state is noted. A short active period of life alternates with long-term torpor, after which active life begins again. It is replaced by prolonged hibernation, etc. This feature of their body is hereditary. Frogs Frogs, in comparison with animals that hibernate or are in a torpor, can be in a state of deeper suppression of vital activity - in suspended animation. At the same time, their metabolism slows down as much as possible, and survival is carried out at the expense of internal energy reserves. Depending on the species, frogs can hibernate in burrows they have dug, in crevices that they themselves fill with leaves, and also at the bottom of reservoirs. Bats In winter, bats, having found a suitable shelter, fall into torpor for 7-8 months. Their sleep is interrupted every 2-3 weeks by awakenings to search for warmer shelter and matchmaking, since winter for these animals is the period of reproduction. Animals that hibernate also include rodents, Australian echidnas, Chilean opossums, hamsters, dormice, chipmunks and badgers. All animals, without exception, prefer rest, either at night or during the day, to active wakefulness. They especially like to fall into a state of stupor or catalepsy. In countries with cold and temperate climates, the usual pastime of animals is six-month hibernation. Hibernation is a hereditary reaction of living organisms to temperature changes, formed millions of years ago. It was possible to survive these changes only by learning to regulate your own temperature during the onset of cold or heat. The life of the animal depended on the ability to sleep through difficult times. Why do animals hibernate? This is how nature took care of its creatures - this skill will be useful to them if the climate on Earth changes again. Hibernation is characterized by a slowdown in life processes and metabolism in animals during periods when food is inaccessible, which means it is impossible to maintain activity and a high level of metabolism. Preparing for hibernation. In preparation for a long sleep, animals accumulate reserves of nutrients, their weight due to fat can increase by 40%, and also store food. Nutrition during the preparatory period is rich in fatty acids, which increase immunity and resistance to prolonged torpor. Rodents spend the winter in families or alone. The burrows they dig can stretch three meters or more inward. They store grains, nuts and seeds to maintain vitality. The shelter (hollow, nest, cave, burrow) is selected taking into account safety, protection from predators, and microclimate: the temperature of the shelter should be slightly above zero, even in severe frosts outside. Based on the method of maintaining body temperature, animals are divided into: Endothermic, which maintain thermoregulation using internal resources. These include all warm-blooded organisms: mammals, birds. Ectothermic, their temperature depends on the environment. These include cold-blooded organisms (reptiles, amphibians, fish). Types of hibernation by duration: Daily (in bats and hummingbirds). This type of deep sleep can occur in any season, in both mammals and birds. Physiological processes are less slow than during seasonal hibernation. Body temperature usually drops to 18°C, in rare cases - below 10°C, metabolism decreases by a third. Seasonal - winter (hibernation) or summer (estivation). Yandex.Direct Services IFZ Imperial porcelain LFZ. Delivery throughout Moscow and Russia. 10% discount! SetsTea pairsTeapotsPromotions posuda40.ruAddress and phone number Winter (hibernation) hibernation is not a uniform state and is interrupted for short periods of “warming up” of the body: body temperature briefly rises and energy exchange increases. The body temperature usually drops to 10°C or lower. In long-tailed ground squirrels it drops to 3°C. Metabolism is 5% and sometimes slows down to 1% of normal. Irregular, in squirrels and raccoon dogs, when unfavorable conditions occur suddenly. Hibernation. Winter is a difficult experience for many animals. Migratory birds To get to warm regions, they travel enormous distances. Animals that cannot leave places with a cold climate adapt to the change of season in their own way: they plunge into a sleep-like state. When the ambient temperature drops to five degrees Celsius, beetles and butterflies, toads and frogs, lizards and snakes, bears and hedgehogs go to sleep. Ciliates, amoebas and algae, gathering into a large ball, are wrapped in a protective shell. Crucians and carps burrow into the mud. Bats sleep in caves for six months, hanging upside down. Aestivation. Summer hibernation or diapause (temporary cessation of development, a state of physiological rest) ensures the survival of organisms during dry periods of the year. Fish sleep, wrapped in silt at the bottom of dry reservoirs. Turtles and rodents, deprived of food, fall asleep until winter, when the swamps and plants dry out from the heat. Some inhabitants of the tropics also tend to fall asleep for a long period: African hedgehogs They sleep for about three months, while the insectivores of Madagascar sleep for about four months. The hibernation record is broken by rodents. The sand squirrel sleeps for nine months in a row. Falling into summer hibernation at the end of July, the animal enters winter hibernation without waking up. Periodic awakenings. Some animals wake up from sleep from time to time. Scientists do not know exactly the purpose and reason for this behavior. Awakening can last from several minutes in small organisms to several hours in large ones. So many living organisms go into hibernation that it is very difficult to list them all. Soviet zoologist N.I. Kalabukhov argued that there are much more animals in a state of torpor in winter than those who are awake. Physiology of hibernation. Body temperature. Sleeping animals are only a fraction of a degree warmer than the surrounding air. The body temperature of the dormouse drops from 38 degrees to 3.7 (ten times!). In some species it can drop to zero or even minus five degrees Celsius. The dalliya fish, a rare warm-blooded fish, falls asleep when the water bodies of Chukotka freeze through. If a dallia frozen in a piece of ice is placed in warm water, then as soon as the ice melts, the fish will come to life. Thanks to the unique glycerin-like impregnation, ice crystals that can rupture cell membranes do not form in dahlia tissues. The hypothermic state in everyone else is manageable. Brain regulators, led by the tireless hypothalamus (the part of the brain responsible for constant internal environment body) turn on the fat heating in a timely manner so that the body temperature does not fall below a critical level. Metabolism during hibernation decreases in animals to 10-15% of normal. Breathing in sleeping mammals decreases 40 times. In many species, it alternates: rapid superficial breathing is replaced by apnea (lack of breathing), lasting more than an hour, which causes oxygen starvation. Gas exchange decreases by 10 times. The hedgehog, curled up into a ball, takes a subtle breath just once a minute. Brain activity is preserved only in the hippocampus, a section adjacent to the hypothalamus. The heart slows down the rate of contractions per minute to 5-10 beats; in a hedgehog, it beats even at zero body temperature. This is surprising, because in animals that do not hibernate, the heart stops at a body temperature of 15 degrees. Blood pressure decreases slightly, from 20% to 40, as blood viscosity increases due to a decrease in temperature. Thanks to increased blood viscosity, the heart is better supplied with “brown fat,” a source of energy. Before hibernation, the hormonal system adjusts to a new rhythm: the animal accumulates fat, enzymes, vitamins, especially vitamin E, which inhibits metabolism. In the summer, animals get fat, increasing their weight three times by the fall, and in the spring they wake up thin and weakened. An interesting fact: the hibernation of the brown bear, squirrel and prairie dog is not real - they fall into a state of superficial torpor. Their metabolism slows down slightly, and their body temperature, pulse and breathing are at levels typical for normal sleep. Most of them hide in their shelters and support their existence from the food and fat reserves they have collected for this occasion. A bear's consciousness does not turn off during hibernation; it is easy to wake him up. Pros and cons of hibernation. An undoubted advantage is the reduction in the animal’s energy consumption: it spends only 15% of the energy that it would need to maintain normal body temperature in winter when awake. For 4-7 months they can exist due to accumulated reserves of fat and other nutrients. Disadvantages: the possibility of dying from desiccation or exhaustion, the development of atrophy of the skeletal muscles, decreased immunity, freezing at extremely low temperatures is possible, defenselessness against predators. Scientists' research into the mechanisms of animal hibernation has a practical purpose: the formula of chemical substances that immerse animals in long-term suspended animation will make it possible to carry out surgical operations, cooling the human body to the required temperature.