Why is the bear yelling after hibernation. How do bears hibernate? Preparing a den for wintering

For those who have wings, well - that’s all. well and brown bear  through thickets and wild forests you can’t reach places where the climate is warmer.

And he finds a rather practical solution. In summer, the bear eats away, then to go into hibernation until spring. But not everything is as simple as it might seem at first glance. Imagine who you would look like if you hadn’t drank or eaten for six months. Let's get acquainted with some amazing processes that occur in the body of a bear during hibernation.

Busy summer

In order to prepare for the six-month “post”, the bear needs to make energy reserves. ” So she is not worried about her figure. Its main goal is to accumulate more subcutaneous fat (in some places, its thickness reaches eight centimeters). Although she likes sweet berries most of all, she is not picky about food. She eats everything: roots, small mammals, fish and ants. By fall, she can gain weight up to 130-160 kilograms, a third of which is fat. (The male’s weight can reach 300 kilograms.) Before plunging into the world of dreams, she stops eating and frees her intestines. For the next six months, she eats nothing, does not urinate, and does not defecate.

Bears choose a place for a den in a cave, an abandoned anthill or a depression under the roots of trees. The main thing is that it was quiet and no one was disturbed by a sweet dream. Bears collect fir branches, moss, peat and other materials to make a warm and cozy bed. The lair is not much larger than the bear’s massive body. When winter comes, snow will cover the den and only an attentive observer will be able to discern a hole through which air enters.

Hibernation

Some small mammals, such as hedgehogs, bats and dormouse, fall into the present hibernation, that is, they spend most of the winter in a state similar to death. Their body temperature is approaching ambient temperature. But the bear's body temperature drops only 5 degrees Celsius, so his sleep is not so deep. “It cannot be said that the bear“ sleeps without hind legs. ”The bear raises its head and flips from side to side almost every day,” says Raimo Hissa, a professor at the University of Oulu in Finland, who has devoted many years to studying the hibernation of bears. And yet, the bear rarely leaves from its den in the middle of winter. During the winter hibernation, the animal’s body works in “saving mode.” The heart rate decreases to 10 per minute, and the metabolic process slows down. When the she-bear sleeps sweetly, fats begin to burn in her body. Fat cans are broken down by enzymes and supply the animal with the necessary calories and water. Despite the fact that the processes that support life in the body are slowed down, a certain amount of waste is generated as a result of metabolism. How can a she-bear get rid of them and keep her lair clean? Instead the body processes them to remove waste!

Professor Hissa explains: "The urea from the kidneys and bladder is reabsorbed into the bloodstream and carried by the circulatory system to the intestines, where it is hydrolyzed by bacteria to ammonia." Even more surprising is the fact that this ammonia goes back to the liver, where it is involved in the formation of new amino acids, which form the basis of proteins. Turning waste products into building materials, the bear’s body nourishes itself for a long period of hibernation!

In the old days, people hunted bears sleeping in lairs. Sleepy Toptygin became easy prey. First, the ski hunters found a lair, then they surrounded her. After that, the bear was awakened and killed. Today, winter bear hunting is considered a cruel occupation, and it is banned almost throughout Europe.

Studying the hibernation of bears

For several years, studies of physiological processes have been carried out at the Department of Zoology of the University of Oulu, with the help of which animals adapt to the cold. Brown bears began to be investigated in 1988, and in total over 20 individuals were observed over the years. For them, a special den was created in the zoological garden of the university. To measure body temperature, study metabolism, vitality, as well as changes that occur during hibernation in the blood and hormones, scientists used computers, video cameras, and did laboratory tests. Biologists collaborated with specialists from other universities, even Japanese. They hope that the research results will be useful for solving problems related to human psychology.

New life

The bear sleeps all winter, turning from side to side, but an important event takes place in the life of the bear. Bears mate in early summer, but the fertilized cells inside the body of the expectant mother do not develop until the bear falls into hibernation. Then the embryos attach to the wall of the uterus and begin to grow. After only two months (in December or January), the expectant mother's body temperature rises slightly, and she gives birth to two or three cubs. After that, her body temperature drops again, although it does not become as low as before childbirth. Papa Bear does not see how his children are born. But the sight of the newborns would probably disappoint him. It would be difficult for a huge dad to recognize in these tiny creatures weighing less than 350 grams of his offspring.

A bear feeds cubs with nutritious milk, this drains her already weakened vitality. Bear cubs grow quickly, by the spring they become fluffy and already weigh about five kilograms. And this means that in the small "apartment" of the bear, revival reigns.

Spring

March. The cold winter has passed, the snow is melting, the birds are returning from the south. At the end of the month, male bears crawl out of their dens. But the bears remain in their shelter for several more weeks, perhaps because the babies take away a lot of their strength.

After a long hibernation from a well-fed bear, skin and bones remain. The snow melted, and her fat melted with it. For all that, the she-bear is surprisingly mobile - no bedsores, cramps or osteoporosis. Some time after exiting the den, she cleanses the intestines. Usually, bears begin to eat only two or three weeks after waking up, because the body does not immediately get used to new conditions. But then they have a remarkable appetite. But since nature itself has recently awakened from winter sleep, at first in the forest there is not much food. Bears chew larvae and beetles, eat old corpses, and sometimes even hunt reindeer.

The care of raising cubs falls on the shoulders of the bear, and she protects her cubs like the apple of an eye. An ancient parable says: “It is better to meet a bear bear, deprived of children, than a fool with his stupidity” (Proverbs 17:12). In other words, it is better not to meet either one or the other. “Mother Bear has a lot of worries. If a male bear approaches, it immediately makes the cubs climb a tree. The fact is that the male can harm them, even if he is their father, ”Hissa explains.

Bears spend another winter in the den with their mother. Well, the next year they have to look for their own lair, as the dipper will have new tiny babies.

We already know a lot about the complex and unusual phenomenon of winter hibernation of bears, but much remains a mystery. For example, why does a bear become drowsy in the fall and why does it lose its appetite? Why doesn't he have osteoporosis? Revealing bear secrets is not easy, and it’s understandable. Everyone has their own secrets!

It is no secret that Siberian winter is not an easy test for many animals, and bears are no exception.

In vernacular it is said that the bear hibernates, biologists say - in a winter dream. Details about this interesting process are few. The main reason is the difficulty of collecting data.

Brown bear is found everywhere in the reserve, both in all types of forests and in the mountain-tundra belt. On the territory of the reserve, it makes seasonal movements from forests to the alpine zone and vice versa, often using trails and country roads for roaming.

What does the bear eat before hibernation

Before bedding, the owner of the taiga needs to accumulate nutrients. A bear is an omnivorous animal, but most of its diet in Kuznetsk Alatau, as in many other places, is made up of plant foods: berries, herbaceous plants, acorns, nuts.

Cedar cones - one of the favorite treats of bears and one of the best bait feeds. Young animals can climb trees and break branches behind them. But mostly they collect fallen cones from the ground. To get to the nuts, the bear collects the cones in a heap and crushes them with his paws, whence, then, lying on the ground, he chooses with his tongue the nuts along with the shell. The shell is partially thrown out during the meal, and partially eaten.

Often the attention of bears is attracted by stocks of nuts made by chipmunks. Digging holes of animals, bears get to the nuts and eat them, often together with the owner. Do not miss the opportunity to enjoy the larvae of ants, eggs of birds or fish, they also get small rodents and ungulates. A brown bear rarely kills wild ungulates itself, it mainly devours them in the form of carrion or selects prey of other predators (wolf, lynx, wolverines).

The facts of eating by a predator such species of wild ungulates as elk, deer, roe deer are known. He fills up the prey or found carrion with brushwood and keeps it nearby until he has completely eaten the carcass. If the beast is not very hungry, it often waits several days until the meat is softer.

It is very important how fruitful the year was for feed. Barren years can greatly delay the timing of bears in dens, and animals can continue to feed even in twenty-degree frosts and almost half a meter of snow, digging up cones from under the snow, trying to gain the fat reserve necessary for wintering. In years favorable for food, adult bears accumulate a layer of subcutaneous fat up to 8-12 cm, and the weight of fat reserves reaches 40% of the total weight of the animal. It is with this fat accumulated over the summer and autumn that the bear’s body eats in the winter, experiencing the harshest winter period with the least deprivation.

The hungry years lead to the emergence of connecting rod bears

These are animals that did not manage to gain sufficient fat reserves, which is why they cannot fall into hibernation. Cranks, as a rule, are doomed to death from hunger and frost or from a hunter. But not every bear that met in the winter in the forest will be a connecting rod. During "after school hours" bears appear in the forest, whose sleep in the den is disturbed. Normally well-fed, but torn out of hibernation, the bear is forced to look for a new, calmer, haven for sleep. Often the sleep of animals is interrupted by anxiety on the part of man.

The den of the bear

Before heading to the den, the bear diligently muddles the tracks: it winds, winds through the windbreak and even goes backwards in its own tracks. For lairs, deaf and reliable places are usually chosen. Often they are located along the edges of impassable swamps, along the shores of forest lakes and rivers, in windbreaks and in cutting areas. The brown bear arranges its winter dwelling in depressions under twisted roots or tree trunks, sometimes on a pile of brushwood or near an old woodpile. Less often, he chooses a cave for his house or digs deep earthen burrows - soil lairs. The main condition - the home should be dry, quiet and isolated from the presence of unexpected guests. One of the signs of the den's proximity is large bald spots in moss, gnawed or broken trees. With branches, the beast warms its shelter, and with layers of moss lining the litter. Sometimes the litter layer reaches half a meter. It happens that several generations of bears use the same lair.

At the beginning of winter, the daughters

One to four, but more often two, cubs are born. Toddlers are born blind, without hair and teeth. They weigh only half a kilogram and barely reach 25 cm in length. It is interesting that the nipples of the bears are not located along the abdominal line, as in most animals, but in the warmest places: in the axillary and inguinal cavities. Teddy bears feed on milk of a 20 percent fat content of their still sleeping mother, and grow rapidly. In a few months of such a diet, the cubs completely transform, and from the den they come out already shaggy and nimble. True, it is still very non-independent.

How a bear sleeps in a den

In the den, in warmth and safety, bears sleep all long and cold winters. Often, the bear sleeps on its side, curled up in a ball, sometimes on the back, less often sits, lowering its head between its paws. If the beast is disturbed during sleep, it is easily awakened. Often, the bear itself leaves the den during prolonged thaws, returning to it at the slightest cooling.

Hibernating animals (for example, hedgehogs, chipmunks, etc.) become numb, their body temperature drops sharply, and although life activity continues, its symptoms are almost invisible. In a bear, the body temperature decreases slightly, only by 3-5 degrees and fluctuates between 29 and 34 degrees. The heart beats rhythmically, although more slowly than usual, breathing becomes somewhat less frequent. The animal does not urinate or defecate. In any other animal, in this case, fatal poisoning would have occurred in a week, and in bears a unique process for the recycling of waste products into healthy proteins. A dense plug forms in the rectum, which some call "bushings." The predator loses it as soon as it leaves the den. The cork consists of tightly pressed dry grass, the bear’s wool, ants, pieces of resin and pine needles.

Brown bears sleep one by one, and only females that have young yearlings are laid with their cubs. The duration of hibernation depends on weather conditions, health and age of the animal. But usually this is the period from the second half of November to the first half of April.

Why a bear sucks a paw

There is a funny opinion that a bear sucks its paw during hibernation. But actually in January, February change of hard skin on the paw pads, while the old skin breaks, peels, and itches severely, and in order to somehow reduce these unpleasant sensations the animal licks its paws.

It took more than one thousand years of natural selection to form such a complex system of adaptations, as a result of which the bears acquired the ability to survive in territories with severe climatic conditions. One can only wonder at the diversity and wisdom of nature.

Earlier on Bears:

The bear is a formidable forest predator that belongs to the mammalian family, but has the most stocky physique. A special phenomenon is the winter hibernation, in the causes and features of which we will understand in detail today.

Which bears hibernate?

The bears have a nomadic spirit, and many species move year-round, with the exception of a brown and Himalayan bear, just these species go to a cozy den for the winter and refuse to wander around the world, preferring to them a measured sleep. Females of a polar bear also sleep, falling asleep while bearing offspring.

Reasons for hibernation in bears

The causes of hibernation in bears are as follows:

• Serious difficulties with food in the cold season. It is not difficult for bears to provide themselves with food of animal origin in winter, but such a diet will not be complete and sufficient for their survival. True, the smell of this predator allows him to easily find berries and fruits in snowdrifts, but all the same - these findings are too scarce for wintering. That is why there is no better way out than to plunge into a long and healthy sleep.
• Bear size plays a role in this important biological process. The average weight of the clubfoot is about half a ton. So imagine how much food is needed so that this whopper is full all winter. There is practically no vegetation, and catching a hare, a fox, or fish on an ice-bound river is not an easy task. And in winter, like in any living organism, energy consumption is much higher than in summer - a lot of energy is spent on maintaining the optimal body temperature in the cold.

Hibernation and its features

The duration of hibernation can stretch to six months, so you need to stock up energy for future use. During sleep, the body will extract it from subcutaneous fat, carefully deposited in bear bins in the summer.

In the sleepy period of the year, the body begins to function differently - in the scientific literature such a restructuring is called a process suspended animation in which the heart rate slows down and breathing becomes rarer. Such a regimen contributes to a reasonable consumption of oxygen in a bear's den and saves valuable nutritious subcutaneous fat - these two important resources last for months.

Interestingly, during hibernation, a bear can lose almost 2 times its weight.

The animal sleeps quite sensitively - it can be confidently said that he simply doesze for a long time. Therefore, if a flock of hungry howling predators sweeps past the den, this can easily wake the bear. As you know, there is nothing worse than waking up a sleeping sleeper, and even more so a bear - he is angry and hungry, so he can go to the nearest village for food to open a couple of warehouses there.

Bears often do not lose time in the winter and give birth to cubs in the den, sometimes even up to 5 per litter. The weight of a newborn clubfoot is only a few hundred grams. Cubs are born blind, helpless nonsense and their food in the first months is mother's milk. With a bear, kids spend up to 1.5 years of their lives.

Probably everyone knows that to stumble upon a bear with a cub is a dangerous sight, which even the worst enemy would be scared to wish, because when you meet a bear it might not be too good for you - the maternal instinct of the bear will make you tear the threat to shreds.

Why hibernate suck paw: interesting versions

People say that a bear in hibernation sucks its own paw, supposedly because of this it is easier for it to survive severe Russian cold. True, few can say for sure what kind of paw is actually in question. Yes, and having opened the search engine, finding a photo with this spectacle is almost impossible - the photos come across strange and diverge from expectations, given that even hunters and foresters today have mobile phones with a camera. How then to find out the truth?

Version one

Everything is extremely simple:

1. Scientists say that the bear's paw is covered with a thick layer of skin, thanks to which they easily overcome stony ledges, without experiencing discomfort.
2. During hibernation, new skin builds up, preparing the paws for the new summer season.
3. To make the process faster, the bear places its paw closer to the face and bites over unnecessary skin. This process is unpleasant because the sole itches during itching.

Second version

The second interesting hypothesis is related to cubs, which can suck their paw, not living outside. This is due to the fact that the baby in nature, as we have already said, feeds on mother’s milk for a long time, and the nipples of the bear are not on the stomach, but in the armpits and in the groin. If the little bear grows in fatherlessness and without a mother, then he is fed a pacifier, like a child. But instincts take their toll: the teddy bear is sorely lacking contact with mom, so he begins to suck on the paw, considering it a maternal nipple. By the way, in nature such a phenomenon is not common.

Bear after hibernation: what is it?

In the video below, you can see unique shots captured by random eyewitnesses, in which the bear just got out of the den after a long hibernation - his hair does not shine, but hangs in shreds, and nothing remains of impressive size, the bear is still sleepy and a little bewildered . As soon as the bear eats the first berries, digs up someone’s food reserves in last year’s grass and catches fish hurrying to spawn along the turbulent rivers, it will soon regain its impressive size.

Nature is ingenious and prudent, proof of which is the hibernation of bears. Thanks to this phenomenon, they successfully survive the winter, spending fat, which has accumulated special for this period.