The more you learn about these unusual aquatic rodents and how beavers live, the more amazed you are at their ingenuity, hard work and resourcefulness. Nature has endowed these animals not only with strength and beauty, but also with intelligence.
Appearance
It is believed that the river beaver is the most big rodent in Russia and neighboring countries . Beaver size, or beaver length , is a little more than a meter, height reaches 40 cm. The weight of the beaver is about 30 kg.
He has beautiful shiny fur, almost waterproof. On top there is coarser thick hair, below there is soft dense undercoat. The coat color is dark and light chestnut, dark brown or black.
The animal has a squat body, short limbs with five-fingered swimming membranes and strong claws. The tail is shaped like an oar, up to 30 cm long, covered with horny scales and sparse hairs. The rodent's eyes are small, its ears are short and wide. This description of the beaver will not allow it to be confused with other aquatic rodents.
Varieties
The beaver family has only two species: the common beaver, or river beaver, and the Canadian beaver. Let's take a closer look at the types of beavers.
River
This is a semi-aquatic animal, the largest rodent in size, inhabiting old light, forest-steppe zone of Russia, Mongolia, China. They settle along the banks of slow-flowing rivers, irrigation canals, lakes and other bodies of water, the banks of which are covered with trees and bushes.
Canadian
In appearance it differs from the river beaver in having a less elongated body, a short head and larger ears. The color is blackish or reddish brown. It lives throughout almost the entire United States (except for Florida and most of Nevada and California), in Canada, except for the northern regions.
It was brought to the Scandinavian countries, from where it independently penetrated into Leningrad region and Karelia.
These two beaver species have different quantities chromosomes and do not interbreed.
Habitats
It is not very difficult to determine where beavers live. Having noticed fallen trees with a characteristic cone-shaped cut near reservoirs, as well as ready-made dams built by animals, one can conclude that they are somewhere nearby. It would be great luck to come across a beaver’s home - this is already an unambiguous marker of the presence of a friendly family. They settle in forests, with slow flow, rivers, streams, reservoirs, lakes.
In the first decade of the last century, beavers in the wild could have completely disappeared in most countries of the world. Russia was no exception. Fortunately, the situation was corrected, thanks to measures taken for the protection of these animals.
River beaver Now he feels free throughout almost the entire country. European part of Russia, Yenisei basin, South part Western Siberia, Kamchatka - these are the places where beavers live.
Lifestyle and habits
A beaver can stay in water without air for about a quarter of an hour. Sensing danger, the animal dives under water. At the same time, he loudly slaps his tail on the water, which serves as an alarm signal for his fellows.
Reliable protection from enemies (bear, wolf, wolverine) and frost is his carefully fortified hut. Even in severe frosts it is warm, steam flows through the openings of the home in winter - it becomes clear how beavers winter.
In the summer, rodents forage for food and build dams and huts. They work from dusk until dawn. Powerful sharp teeth beavers gnaw through, for example, an aspen tree with a diameter of 12 cm in half an hour. Thick trees can be worked on for several nights in a row. This sound of a beaver can be heard hundreds of meters away.
Nutrition
The main criterion for choosing a place of residence for animals in nature is the sufficient availability of food. The diet of beavers is quite varied.
They eat the bark of trees growing near bodies of water and aquatic plants. They love to eat the bark of aspen, linden, and willow. Reeds, sedges, nettles, sorrel and other plants are what beavers eat.
Scientists who observed their life and what beavers eat in nature counted up to 300 various plants, which serve as food for animals.
Most beavers live in families and touchingly care about the well-being of their “relatives” - they build houses and stock up on food for the winter. They painstakingly place tree branches on the bottom of the reservoir, which they eat in winter. Such reserves for one family reach ten or more cubic meters.
If, due to the river flow, it is not possible to build their “cellar”, beavers go out onto land at night to find food. They take great risks: beavers, slow on the ground, easily fall into the clutches of four-legged predators, most often wolves.
Dwellings
On high banks with hard ground, beavers dig burrows. The entrance to them is located under water. A beaver's burrow is a complex labyrinth with several holes, chambers, and entrances and exits. The partitions between the “rooms” are tightly compacted, and the inside is kept clean. The animals throw the leftover food into the river and are carried away by the current.
The name of a beaver's dwelling, which differs from a burrow, can be understood by its appearance, which resembles a small house with a sloping roof. The animal first builds one small “room” up to one and a half meters high.
Uses branches of different lengths and thicknesses, clay, grass. The walls are compacted with silt and clay, leveled by biting off protruding branches. The “floor” is covered with wood shavings. This is the beaver's hut.
As the family grows, its caring head completes and expands his living space. Beaver lodge is replenished with new “rooms”, another floor is added.
A beaver's house can reach more than 3 meters in height! The painstaking work and engineering ingenuity of the animal amazes the imagination.
Dam construction
What else surprises and delights in the way of life of animals is how beavers build a dam. They are located downstream from their habitat.
Such structures prevent the river from shallowing and contribute to its flooding. This means they contribute to the settlement of animals in flooded areas and increase the ability to find food. This is why beavers build dams.
This tactic is also aimed at increasing residential safety. This is another explanation why beavers build a dam.
The width and depth of the river, the speed of the flow determine what it will be beaver dam. It must block the river from one bank to the other and be strong enough so that it does not get carried away by the current. Animals choose where there is a convenient place to start construction - a fallen tree, a narrowing riverbed.
Hardworking beavers build a dam by sticking twigs and stakes into the bottom and filling the spaces between them with cobblestones, silt, and clay. Beaver dams must be strengthened constantly, month after month, year after year, to prevent them from being washed away. But that doesn't stop the beavers! As a result, the dam becomes stronger and bushes and trees grow on it. You can even cross it from one bank to the other.
And this is not the only benefit beavers have. The dams they built increase the water level, which is beneficial for aquatic insects and helps increase the number of fish.
Reproduction
Mating occurs in January-February. And after three months, 3-6 half-blind cubs are born. Newborns weigh only 400-600 g. They gain weight gradually while their mother feeds them milk throughout the summer. Inexperienced and weak children also spend the winter with their parents. They usually leave the parental home after 2 years.
It is known quite accurately how long beavers live. IN natural conditions- about 15 years.
Beavers are the only rodents that can walk confidently on two legs. In the front ones they hold branches, stones, and tree bark. Females carry their young in this way.
Economic importance
Beavers have long been hunted for their beautiful, valuable fur. In addition, beaver stream is used, which is used in medicine and the perfume industry.
Beaver meat is eaten. Interestingly, Catholics considered it a Lenten food. The scaly tail was misleading, because of which the rodent was considered a fish. Beaver is dangerous when eaten because it naturally carries salmonellosis.
Video
Watch a fascinating video about the life of beavers.
Common beaver (river beaver)- a mammal from the order of rodents, distinguished by a wide, horizontally flattened tail covered with scales and the fact that the toes on the hind legs are connected to each other by a swimming membrane.
The red-brown incisors are very strongly developed and protrude significantly outwards, the upper two have a wedge-shaped crown, the molars, of which there are eight in each jaw, namely four on each side of the upper and lower jaw, are equipped with enamel protrusions. The legs are short, five-toed, with a double claw on the second toe of the hind legs.
Beaver or beaver— how to speak and write correctly? Although both of these words are present in the Russian language, still the right option the word for this animal is "beaver". Its analogue, the word "beaver", is also an acceptable option, especially in oral speech, however, it refers more to the beaver's fur than the animal itself.
The life of a beaver appearance, behavioral features have always attracted the attention of naturalists and nature lovers. The value of this animal as an object of fur trade has been and remains the reason for the increased interest of hunters, game specialists, and fur experts. The domestic bibliography on beaver alone contains many hundreds of works, and with foreign sources it amounts to several thousand. Most of them are devoted to biogeocenotic and economic consequences life activities of beavers, principles and methods of managing and monitoring their populations. And despite this, under the influence of various factors, and especially economic activity person per modern stage, the issues of studying the life of beavers are becoming even more relevant.
Beaver appearance
Beaver - rodent, but its appearance differs significantly from the appearance of typical representatives of this order. The contours of the beaver are soft and rounded. Small ears are hidden in thick fur and are barely noticeable from a distance of 10-15 steps. The head is valval-shaped, flattened on top. Large incisors, painted in Orange color(in young animals they are lighter, in old ones they are darker). The length of the visible part of the incisors in adult beavers is 20-25 mm, the lower ones - 35-40 mm with a width of 8-10 mm. 
Above the forked upper lip, overgrown with relatively long tactile hairs - vibris, rather large nostrils are located, the head without a noticeable cervical interception (especially in Canadian beavers) passes into the body. On the surface of the chest there are two pairs of pigmented nipples, dark in black females and light in brown ones. In young animals and males they are almost completely hidden in dense underfur.
The beaver's forelimbs are relatively short, tenacious, with sharp claws. They serve him for movement, digging holes and constructing other buildings, as well as for putting things in order. hairline, holding branches and other food while eating.
The beaver's tail is massive and shaped like the rowing part of an oar, lying in a horizontal plane. It is covered with small horny diamond-shaped scutes, between which there may be hairs. The beaver's tail serves as a rudder, additional support, signaling device, and thermoregulatory organ.
Average body length European beavers 110 cm, head a little more than 16 cm, body - 65 cm, tail - about 28 cm. The body length of the largest individuals can slightly exceed 130 cm.
The Canadian beaver is slightly shorter than the European beaver, which is due to its slightly shortened muzzle and relatively shorter tail length.
The beaver is one of the largest modern representatives squad of rodents. Average weight adult male beaver about 18 kg, females - about 19 kg.
Newborn beavers weigh on average 500 g. They grow very quickly. In the first 2 months of life, the average daily weight gain of animals is 40-50 g. By the end of the first year, their weight reaches about 7 kg, and when bred in captivity - 10 kg or more.
The beaver's skin protects the animal from mechanical damage and ensures the preservation of body temperature. In different individuals, the density of hair per 1 cm2 of skin is not the same and ranges from 12 to 23 thousand. The density of hair in beavers increases with age, and also depending on the seasons: in winter, compared to summer, it increases by 2-2.5 times, but the ratio of hair types (guard hairs, guide hairs and downy hairs) remains the same.
The density of a beaver's fur is such that it absolutely does not allow water to pass through. It only reaches the ends of the guide hairs. The height of guard hairs in an adult beaver is 70 mm, guide hairs are up to 40 mm, and down hairs are up to 25 mm.
The beaver has 20 teeth: 2 incisors and 16 molars. There are no fangs. In their place large diastemas develop. This is due to the fact that he has to gnaw, in particular under water, thick trees and their branches, and endure all this clenching his teeth. The presence of a large diastema allows using a special skin fold to isolate the working incisors from the oral cavity. Characteristic of incisors constant growth, as a result of which their continuous grinding is simply necessary.
U European beaver the fur is usually painted in single-color tones - from light, almost sandy, to dark brown. There are completely black melanistic beavers.
Among the animal skins collected from yasak people in 1630 in Western Siberia, there were black, brown and red ones. As a rare exception, beavers and white, partial or complete albinos.
The color of brown beavers depends on the thickness of the awn and the concentration of red pigment in it. The spine is especially strongly developed in the area of the head, neck and spine. On the belly it is softer and shorter, as a result of which the fur here is lighter than on the back.
Canadian beavers differ from European beavers in color. They are dominated by chocolate and brownish-red tones. The general color is characterized by deep dark chestnut tones. The color of Canadian beavers shows well-defined geographic variability: from dark brown, almost black underfur in the north of their range to light in the south. The best Canadian beaver pelts from Eastern Canada and the Northeastern states have a bluish-brown underfur, while beavers Rocky Mountains- light brown or even straw color.
IN North America Both completely white albino beavers and black melanistic beavers are rare.
The beaver is a semi-aquatic animal, amphibious, in the language of zoologists. Famous explorer Kamchatka S.P. Krasheninnikov characterized mammals of this lifestyle as follows:
“Under the name of water animals are those animals that Latin They are called amphibians because, although they mostly live in water, they breed near the ground and often come ashore.”
Our country has 37 large river systems with thousands of rivers, rivers, streams, channels, and eriks. Yes, lakes, and reed supports with reaches, and marshy swamps. There is a place for the “beaver people” to live (the expression of the Indian writer Wesh Kuonnesin, known among us as the “Gray Owl”). And the beaver was not found everywhere, of course, but in many places suitable for habitation. This is how it was in medieval Rus'. But by the 20th century, its small populations remained in the basins of the Sozh, Berezina, Pripyat, Konda, Sosva, and in the Voronezh province.
In 1930, the beaver began to be re-acclimatized, but before the war the volume of this work was small - only 300 animals were relocated. Professor B. M. Zhitkov, a great enthusiast for the enrichment of domestic fauna, wrote about this:
“I think that there is no area in the Union in which there would not be suitable places for a beaver to settle. Both the value of the animal, and some of its living conditions, and nutrition make this species preferable to many other species when working to restore and improve the fauna.”
After the war, acclimatization work with beavers expanded greatly. Over two decades, 11 thousand heads were released. Undoubtedly, protection and the ban on long years his trade. Special reserves were organized: Voronezhsky, Berezinsky, Kondo-Sosvinsky.
Beaver nutrition
Beaver eats plant foods. Its digestive organs are adapted to digest roughage: the intestines are 12 times longer than the body, and have a voluminous caecum. The composition of food varies depending on local conditions and the season of the year. In summer, the basis of its diet consists of herbaceous plants, of which there are many near bodies of water near the coasts, green bark and branches. However, the vegetarian rodent does not neglect shellfish.
Closer to autumn, tree and branch food takes up everything bigger place in the beast menu. With powerful incisors, the beaver gnaws trees at a height of 25-35 cm. The thickness of the tree does not dampen the working enthusiasm of the toiling lumberjack. And he always throws it in the direction he wants. After which he can “chop” him into pieces. And this is often required for rafting to your home or dam, to create supplies for a rainy winter day. However, in addition to logs, branches, rhizomes of egg capsules, water lilies, calamus and others are also harvested. aquatic plants. Supplies are stored closer to home. IN cold water the food retains its nutritional properties until the end of winter. The size of the reserves depends on the size of the family, sometimes they are quite large: for example, food warehouses of up to 20 cubic meters were found in Belarus. m.
beaver hut
Beavers live in huts they build. Hut It is usually located near the shore and is made of twigs, branches, stumps of trunks, plant debris, silt, and earth. Its average height is about 1.5 m, base diameter - 3m, but there are more.
In the presence of high banks, the beaver digs holes that have access to the water at a depth of about half a meter. The total length of a hole with burrows can reach several tens of meters. Both from the hut and from the hole there can be, and more often than not, several exits to different heights— the water level is not constant, so you have to make a wise architectural decision.
Lifestyle
The beaver is an excellent builder and a great worker. In addition to dwellings and shelters, he builds dams and canals. Dams are made in shallow reservoirs in order to increase the water level and expand its area, and therefore their living space. When constructing a dam, the beaver places tree stumps upstream. He uses everything that is suitable as building material.
Also in Soviet time in the Dmitrovsky district of the Moscow region, land reclamation workers drained quarries from old peat mines, which had long been populated and developed by beavers, who built a whole network of canals and dams, many holes and huts. A stubborn struggle with varying success lasted about a month: powerful equipment destroyed the structures of beaver families - the owners of the land quickly restored it. And the beavers won! True, with the help of allies. They turned out to be game managers and the hunting community. The reclamation workers left the battlefield. A beaver reserve was created there.
Beavers work and feed at night. For most of the day, the animals sleep in their secluded and cozy shelters.
Reproduction
When winter passes halfway through, the animals begin their rut. It is almost always accompanied by fights, in which both females and even almost one-year-old beavers can take part. The fact is that beavers live in families, they are monogamous, the family has its own territorial and equatorial possessions. And when a male stranger, driven by sexual instinct, invades these domains, in addition to the struggle for the female, a border incident arises. The mating period is extended to two to three months.
Pregnancy lasts 105-107 days, and according to the rut, the time of childbearing is extended. It happens in the brood up to 5 newborns, but on average 3
. Chalky compared to other types? But they are quite viable: sighted, well furred, quite large - up to 25 cm. Moreover, they are well protected: the parents’ house is their fortress. After a day or two they can swim. The beaver feeds them with milk for up to 2 months; at the age of 3-4 weeks, the beavers begin to join the usual food for the species, at first, of course, eating green, which is more tender.
Beaver lifespan
Compared to other rodents, the beaver lives a long time. There is a known case when an animal lived in captivity for 35 years. But in natural conditions they live on average 10-20 years. Both males and females retain their reproductive abilities until old age.
Neither the water element nor a homemade shelter guarantees complete safety. In addition, an amphibiont cannot live without the firmament of the earth, where there are more dangers, but also more food. A beaver can become prey for a wolf, wolverine, lynx, bear, fox, or stray dog. The young can be destroyed by otter, mink, eagle owl, pike, and catfish. Yes, you can get sick, and how? dirtier water, the greater the probability, although compared to other fur-bearing animals the beaver is more resistant to infectious diseases. However, it is susceptible to helminthiases, pasteurellosis, tuberculosis, and paratyphoid fever. Death from the vagaries of nature is possible: drying out of reservoirs and their excessive filling are equally dangerous. And considering that many rivers are blocked by dams, the water level in them may change.
And finally, about the meaning of the beaver. It has the most valuable fur and edible meat. Licensed beaver fishing has been underway for many years. Its very life activity can be useful for dendrophagous animals: the bark of the trees it fells serves as food for moose and hares, and the reservoirs enlarged as a result of the construction of dams expand the habitats of waterfowl.
And that's not it. As the famous naturalist and writer E. Seton-Thompson wrote:
“Of all the large animals of America, the beaver is the best known and the earliest known: from a historical point of view, it can be considered the most important. There can be no doubt that the beaver did more to open up Canada than any other creature or commodity. The pursuit of the beaver attracted the first scouts here, and the first colonists followed them.”
Approximately the same can be said (along with sable and other fur-bearing species) about our beaver in the development of Siberia in the 14th century.
The common or river beaver (Castor fiber) is a semi-aquatic mammal belonging to the order of rodents. Currently, it is one of two representatives of the small beaver family, as well as the most large rodent, belonging to the fauna of the Old World.
Description of the common beaver
The river beaver is the second largest rodent after. A mammal like the common beaver has quite impressive size, as well as a rather menacing, but very representative appearance.
Appearance
Range, habitats
Ordinary beavers live in burrows or so-called huts, the entrance to which is always under water. The burrow is dug by a rodent in a steep and steep bank; it is a rather complex labyrinth with several entrances. The walls and ceiling of the hole are leveled and thoroughly compacted. The hut is built in areas where setting up a hole is simply impossible - on flat and low, swampy shores and on shallows. Construction begins no earlier than the end of summer. The finished hut has a cone-shaped appearance and is different great height with a diameter of no more than 10-12 m. The walls of the hut are carefully coated with silt and clay, thanks to which the building is an impregnable fortress for most predators.
Common beavers are very clean mammals that never litter their home with food debris or excrement. On reservoirs that have changing water levels, beaver families prefer to build the famous dams, the frame foundation for which is most often trees that have fallen into the river, lined with a variety of building materials. The standard length of the finished dam can reach 20-30 m, with a width at the base of 4-6 m and a height of 2.0-4.8 m.
This is interesting! The record size belongs to the dam built by beavers on the Jefferson River in Montana, the length of which reached as much as 700 meters.
For construction needs and for the purpose of procuring food, the common beaver cuts down trees, first gnawing them with its teeth at the very base. Then the branches are chewed off, and the trunk itself is divided into several parts.
An aspen with a diameter of 50-70 mm is felled by a beaver in about five minutes, and a tree with a diameter of just under half a meter is felled and cut in one night. During this type of work, beavers climb hind legs and rest on the tail, and the jaws work like a saw. Beavers' incisors are self-sharpening, consisting of fairly hard and durable dentin.
Some of the branches from fallen trees are actively eaten by beavers directly on the spot, while the other is demolished and towed or floated through the water towards a dwelling or to the site of a dam construction. The paths trampled during movement are gradually filled big amount water and are called “beaver channels”, which are used by rodents to melt woody food. The area transformed in the process active work common beavers is called a “beaver landscape.”
Diet of the common beaver
Beavers belong to the category of strictly herbivorous semi-aquatic mammals that feed exclusively on tree bark or plant shoots. Such animals give particular preference to aspen and willow, poplar and birch, as well as a variety of herbaceous plants, including water lilies and egg capsules, iris and cattails, and young reeds. Abundance of wood soft rocks is a necessary condition when an ordinary beaver chooses a place to live.
Plants of secondary importance in the daily diet of the common beaver are represented by hazel, linden and elm, as well as bird cherry. Alder and oak, as a rule, are not used for food purposes by mammalian rodents, and are used only in construction and for arranging buildings.
This is interesting! Beavers also eat acorns very readily, and the daily amount of food consumed should be about 18-20% of total weight animal.
Thanks to large teeth and a powerful bite, common or river beavers very easily and quickly cope with almost any plant solid food, and cellulose-rich food products are digested through microflora in the intestinal tract.
As a rule, a mammal eats only a few types of wood, since in order to switch to new type beavers require an adaptation period to allow intestinal microorganisms to adapt to the new type of diet. With the onset of spring and summer, the amount of grassy food in the beaver's diet increases significantly.
In autumn, the semi-aquatic rodent begins to prepare woody food for the winter.. The reserves are stored in water, which allows them to almost completely preserve all their food and taste qualities. The average volume of winter food reserves per family is about 65-70 cubic meters.
Beavers are one of the most interesting animals on our planet. Self-sharpening incisor teeth help beavers not only cut down trees, but also build homes for themselves and even build dams.
Among the representatives of the rodent order, the beaver ranks second (after the copybara) in body weight, which reaches 32 kg. (sometimes 50 kg.) with a body length of up to 80-100 cm and a tail length of 25-50 cm. prehistoric times(during the Pleistocene era) beavers were much larger, their height reached 2.75 m, and their weight was 350 kg.
Modern beavers are divided into two species: the common beaver, common in Eurasia, and the Canadian beaver, whose natural habitat is North America. Due to the great similarity in appearance and habits between the two beaver populations, until recently the Canadian beaver was considered a subspecies of the common beaver, until it became clear that there is still a genetic difference between these species, since the common beaver has 48 chromosomes, while the Canadian one is only 40. In addition, beavers of two species cannot interbreed.
The beaver has a squat body, five-fingered limbs with strong claws and a wide paddle-shaped tail. Contrary to popular belief, the tail of beavers is not at all a tool for building their homes; it serves as a rudder when swimming. The beaver is a semi-aquatic animal, therefore, much in the appearance of this mammal shows its adaptability to being in water: between the toes there are swimming membranes, especially strongly developed on the front legs, in the eyes of the beaver there are nictitating membranes that allow you to see under water, the ear openings and nostrils close under water, large lungs and liver provide such reserves of air and arterial blood that beavers can stay under water for 10-15 minutes, swimming up to 750 m during this time. A thick layer of subcutaneous fat protects against the cold.
Beavers are exclusively herbivorous; they feed on the bark and shoots of trees, preferring aspen, willow, poplar and birch, as well as various herbaceous plants(water lily, egg capsule, iris, cattail, reed). In order to obtain bark and shoots, as well as for construction needs, beavers cut down trees, gnawing them at the base. An aspen with a diameter of 5-7 cm is felled by a beaver in 5 minutes, a tree with a diameter of 40 cm is felled and cut up overnight. A beaver gnaws, rising on its hind legs and leaning on its tail. Its jaws act like a saw: to fell a tree, the beaver rests upper incisors into its cortex and begins to quickly move the lower jaw from side to side, making 5-6 movements per second. The beaver's incisors are self-sharpening: only the front side is covered with enamel, the back side consists of less hard dentin. When a beaver chews on something, the dentin wears down faster than the enamel, so the leading edge of the tooth remains sharp all the time.
Trees chewed by beavers:
Video about the life of beavers, where you can see how beavers gnaw trees:
Beavers live along the banks of slow-flowing rivers, as well as ponds, lakes, and reservoirs. For housing, beavers can dig holes in steep banks with several entrances, each of which is located under water so that land predators cannot penetrate there. If digging a hole is impossible, beavers build a special dwelling - a hut - right in the water. A beaver lodge is a pile of brushwood held together by silt and clay. The height of the hut can reach up to 3 meters, and the diameter up to 12 meters. Like a hole, a hut is a reliable shelter from predators. Inside the hut there are manholes under the water and a platform rising above the water level. The bottom of the hut is lined with bark and herbs. With the onset of the first frost, beavers additionally insulate the hut with new layers of clay. Air penetrates through the ceiling. In cold weather, clouds of steam can be seen above the beaver lodges. At the very cold weather the hut maintains a positive temperature and even if the reservoir is covered with ice, the ice hole under the hut does not freeze, which is very important for beavers, because beavers store food reserves for the winter, prepared in winter, under the overhanging banks directly into the water, from where they then take them when cold weather sets in .
beaver hut
Beavers live alone or in families. A complete family consists of 5-8 individuals. The mating season for beavers is in winter. Cubs are born in April-May and can swim within one or two days. At the age of 3-4 weeks, beaver cubs switch to feeding on leaves and soft stems of grass, but the mother continues to feed them with milk until 3 months. Grown-up young animals usually do not leave their parents for another 2-3 years. In captivity, beavers live up to 35 years, in the wild 10-19 years.
The head of the beaver family marks the boundaries of his territory with the so-called “beaver stream” - special secretions that were previously actively used in medicine, and are now used in the creation of expensive perfumes.
In case of danger, beavers give an alarm signal to their relatives by striking the water with their tail.
To prevent water from flooding the hut during a flood or, conversely, the reservoir suddenly becoming shallow, beavers often build dams. Construction begins with beavers sticking branches and trunks into the bottom, strengthening the gaps with branches and reeds, filling the voids with silt, moss, clay and stones. They often use a tree that has fallen into the river as a supporting frame, gradually covering it on all sides. building material. The longest dam built by beavers was 850 meters long. If a dam starts leaking somewhere more water than necessary, the beavers immediately seal up this place. Thanks to their excellent hearing, beavers accurately determine the place where the water began to flow faster. One day, scientists conducted an experiment: on the shore of a reservoir, a tape recorder with recorded sound was turned on. flowing water. Despite the fact that the tape recorder was standing on land and there was no trace of any flowing water, the beavers’ instinct worked and they immediately covered up the “leak” with mud.
Although beavers may seem like forest pests, beavers' activities actually have beneficial effects on the ecosystem. For example, the number of ducks in reservoirs improved by beavers is on average 75 times greater than in reservoirs without beavers. This is due to the fact that beaver dams and calm water attract shellfish and aquatic insects, which, in turn, attract waterfowl and muskrats. Birds bring fish eggs on their paws and beaver ponds become more fish. Trees felled by beavers serve as food for hares and many ungulates, which gnaw the bark from the trunks and branches. The sap that flows from undermined trees in the spring is loved by butterflies and ants, followed by birds. In addition, dams help purify water, reducing its turbidity, because silt lingers in them.
Beavers have long been hunted for their valuable fur and beaver stream. As a result, at the beginning of the 20th century, many European countries beavers were completely exterminated, and the total number of beavers in Eurasia was only 1,200 individuals. In the 20th century, largely due to active efforts to restore the beaver population in the Soviet Union, the situation began to gradually improve. In 1922, beaver hunting was banned in the USSR, and in 1923 the Voronezh Beaver Reserve was founded, where ideal conditions for beaver breeding. Bobrov from Voronezh Nature Reserve resettled throughout the USSR, as well as in Poland, China, the GDR and other countries. Currently, the number of beavers in Russia exceeds 340 thousand, almost half are of Voronezh origin. The reserve is still open today, and when you visit it, you can take home photos of beavers (about 300 of them live here) taken with your own hands. In addition to beavers, the reserve has 333 species of vertebrates.
In North America, beavers were also brought to the brink of extinction, but their protection in the USA and Canada began at the end of the 19th century, and now there are 10-15 million beavers on the American continent, which is many times higher than the number of beavers in Eurasia (where there are about 640 of them) thousand according to data for 2003), however, it is much inferior to the time when the fur trade in America was not yet in fashion (at that time there were 100-200 million beavers in America).
Canadian beavers now live far beyond their natural range. In 1946, the Argentine government imported 25 pairs of Canadian beavers to the Tierra del Fuego archipelago to begin the beaver fur trade in the region. However, beavers, having found themselves in an ecosystem where they had no natural enemies, multiplied so much that they threatened local forests. Currently, 200 thousand beavers live on the archipelago.
In addition to Argentina, Canadian beavers were brought to Sweden and Finland, from where beavers moved to Northwestern Russia, where they began to compete for territory with Eurasian beavers. The number of Canadian beavers in North-West Russia can reach up to 20 thousand individuals.
In Russian there is a word "beaver", but it is not a synonym for the word "beaver". "Beaver" is an animal, and "beaver" is the fur of a beaver.
There are two types of beavers in nature: the common beaver, which lives in Eurasia, and the Canadian beaver, which lives in North America. How these two types differ and how they are similar, we will consider further...
Both species have related roots with, as evidenced by the similarities in the lower jaw. But the behavior of these representatives of rodents is different. They live near water, which is their native element. Neither the Eurasian nor the Canadian beaver can exist without water. The common and Canadian beaver have certain differences, which is why they are classified as different populations.
Differences between Canadian and common beavers
Externally, both representatives of the species are extremely similar, but the Eurasian beaver is larger in size. It has a less round and larger head, while its muzzle is shorter. The common beaver has smaller undercoat and a narrower tail. In addition, the Eurasian has shorter limbs, so he walks poorly on his hind legs.
The nasal bones of the common beaver are longer and the nostrils are triangular in shape, while the Canadian has triangular nasal openings. The European beaver has larger anal glands. There are also differences in the color of the fur.
Almost 70% of Eurasian beavers have light brown or brown fur, 20% have chestnut fur, 8% have dark brown fur, and 4% have black fur. 50% of Canadian beavers have a light brown skin tone, 25% have brown skin, and 5% have black skin.
Besides external differences, these two members of the family have differences in the number of chromosomes. Canadian beavers have 40 chromosomes, while common beavers have 48. Various quantity chromosomes was the reason for the unsuccessful crossing of these representatives of different continents.
Beavers are the owners of thick, valuable fur. After repeated attempts to breed a Eurasian female and an American male, the females either did not become pregnant at all or gave birth to dead babies. Most likely, interspecific reproduction is impossible. Between both populations there is not only a barrier of thousands of kilometers, but also differences in DNA.
Beaver sizes and appearance
Female beavers are larger than males, and females are dominant. Average weight Canadian beavers weigh 15-35 kilograms, most often they weigh 20 kilograms with a body length of 1 meter. Canadian beavers grow throughout their lives, so older individuals can weigh up to 45 kilograms.
Eurasian beavers, on average, weigh 30-32 kilograms, with a body length of 1-1.3 meters, and a height of 35 centimeters.
Canadian beavers have a squat body. They have 5 fingers on their limbs with flat claws. There are membranes between the fingers. The tail is similar in shape to the body, its width is 10-12 centimeters and its length is 30 centimeters. The top of the tail is covered with horny plates, and hairs grow between them. From the middle of the tail stretches a horny protrusion, similar to the keel of a ship.
The animal's eyes are small and its ears are short. Canadian beavers have a thick, practical undercoat with coarse guard hairs. Beautiful fur is highly prized commercially.
Beaver behavior and nutrition
Beavers are herbivorous mammals, their favorite treat– water lilies and sedge. Beavers eat bark from alder, poplar, maple, aspen, and birch trees, but still prefer young shoots.
At first glance, it may seem that beavers are harmful surrounding nature, but this opinion is erroneous. Beavers create wetlands that are very important to the ecosystem. These animals cut down trees, but not in any place, but only where it is convenient to drag the tree to the water. Beavers use trunks to build dams, and they gnaw branches, bark, and leaves.
All beavers are herbivores. By constructing dams, beavers create dams in which insects settle; as a result, birds fly to the dams, bringing fish eggs on their paws and feathers. Thus, fish are bred in the dams.
The water seeping through the dams is cleared of silt and heavy suspended matter. Some plants die in the dams, and a large number of dead wood, which is important for the existence of certain plants and animals.
The remains of fallen trees are used as food for ungulates and various insects. That is, the construction activity of beavers benefits nature. But such dams can cause inconvenience to humans: the dams overflow and flood crops, and wash away railway embankments and roads.
Beavers live in burrows that they dig in steep banks. These burrows are very long and are a real labyrinth with several entrances. Beavers make the floor in their burrows above the water level; if the pond overflows, the rodent scrapes the earth from the ceiling and thereby raises the floor level.
Beavers build not only burrows, but also “houses.” They pile branches in the shallows and then cover them with clay and silt. Inside, there is free space rising above the water. Beavers enter the house from under the water. Beaver houses reach a height of 3 meters, and their diameter is about 10 meters. Such houses have very strong walls that protect the owners well from predators.
Beavers build their houses using their front paws. By winter, houses are additionally insulated with a layer of earth and clay, thanks to which they always maintain a positive temperature, even when it is frosty outside. The water at the entrance to the burrow does not freeze. These rodents love cleanliness; there is no excrement or food waste in their homes.
Beavers are social animals; they form own families. One family consists of approximately 10 individuals - parents and young animals that have not reached sexual age. Beaver families can live in the same territory for a whole century. The size of the territory owned by the family along the coast is 3-4 kilometers. As a rule, beavers do not move further than 200-300 meters from the shore.
Young mature beavers, after leaving their family, live alone for some time, in built holes, but over time they acquire their own family.
Dam construction
The famous beaver structure is the dam. Why do beavers build dams? So that they have more water. Quite often, a family of beavers settles on a small river or stream in order to raise the water level in them, rodents and erect these grandiose structures. Thanks to the dam, the river turns into a small lake, which is a favorite habitat for beavers.
Listen to the beaver's voice
The life of beavers depends entirely on the river. In water, beavers mate, enter shelter and escape from predators. These rodents can stay under water for no more than 15 minutes. When there is obvious danger, the ability to hold air is of great help to beavers.
Before building a dam, beavers determine the construction site. Rodents choose places where opposite banks are located close to each other. Beavers also pay attention to the presence of trees on the shore, since they are the main building material. Rodents gnaw tree trunks and stick them vertically into the river bottom; the space between the trunks is sealed with stones and silt. The surface part is strengthened with branches and clay. Such structures are very strong and reliable.
The dam built by beavers can reach a length of 30 meters. At the base the dam is wider - about 5-6 meters, and at the top the structure narrows to 2 meters. The height of the structure reaches 3-5 meters. Dams built by beavers have been recorded as being 500 and 850 meters long.
If the current on the river is strong, then the beavers build additional dams and make special drains that prevent the destruction of the structure when the river floods. Rodents constantly monitor their creations, instantly eliminating minor damage and leaks.
Reproduction and lifespan of beavers
Canadian beavers mate for life; separation occurs only after death. The mating season for animals begins in winter. The mating process takes place in water. Pregnancy in Canadian beavers lasts 128 days, and in common beavers it lasts 107 days.
2-6 babies are born weighing up to 400 grams. The female feeds the beavers with milk for 3 months. 1 week after birth, babies are already able to swim. Males are fully formed by the age of 3. Most females puberty also occurs at 3 years. Females are capable of producing offspring once every 2 years.
In wild nature Canadian beavers live 20-25 years, and when favorable conditions They live up to 35 years of life.
Number of species
Not so long ago there were 100 million Canadian beavers in North America, but end of the 19th century centuries, rodents were almost completely exterminated. Only minor remnants of the once large population remain.
At the beginning of the 20th century, a ban on the destruction of beavers was established. Today in America the number of Canadian beavers is more than 10 million individuals. In Eurasia, the situation was much worse - by the end of the 20th century, no more than 1,200 individuals remained in this vast territory.
The ban on their destruction has been in effect for 100 years, as a result the number has increased to 700 thousand rodents. In many European countries, beavers were completely exterminated XVII-XIX centuries, and today they received a second birth there.
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