Beaver: how does a rodent live in nature? What threatens Russia with the Canadian beaver, cow parsnip and other aliens What is the difference between the American beaver and the European one

In nature, there are two types of beavers: ordinary beaver and Canadian. The first species lives in Eurasia, the second in North America. These animals are closely related to squirrels. Indicate commonality certain structural similarities mandible and skulls. At the same time, the behavior of these representatives of the rodent order differs significantly. The beaver lives only near water. She is his native element. It cannot exist in any other environment. This applies to both Canadian and Eurasian animals. Both species have certain differences, it is not without reason that they were isolated in separate populations.

Differences between Canadian and common beavers

Outwardly, representatives of two different types very similar to each other. But Eurasian beaver is larger. It has a larger and less rounded head. The muzzle is more graceful, so to speak, and shorter. Shorter undercoat and narrower tail than the Canadian. The limbs are shorter, so the Eurasian is less adapted to walking on its hind legs. Common beavers have longer nasal bones. The nasal openings are triangular in shape. Canadians are oval. The anal glands of the Eurasian are larger. The color of the fur is also different.

Almost 70% of common beavers have brown or light brown fur. A chestnut shade is present in 20% of Eurasians. Dark brown has 8%, and pure black only 4%. Among Canadians, half of all beavers sport light brown skins. A reddish-brown tint boasts 25%. Brown skins are worn by 20%, and black, the remaining 5%.

The two species differ in the number of chromosomes. Canadians have 40 of them, and Eurasians have 48. Despite this, people have made many attempts to cross representatives of different continents. The females were from Europe and the males were from America. As a result, females either did not give birth at all, or gave birth to dead cubs. From this we can conclude that interspecific reproduction is impossible. These populations are separated from each other not only by thousands of kilometers of the ocean surface, but also by DNA features.

Beaver size and appearance

In beavers, females are larger than males. They are dominant over males. Canadian beaver weighs from 15 to 35 kg. The usual weight is 20 kg with a body length of about 1 meter. These animals grow throughout their lives, so old beavers can reach a weight of 45 kg. An ordinary or Eurasian beaver has a body weight of 30-32 kg with a body length of 1-1.3 meters. The usual body height is 35 cm.

The bodies of animals are squat. There are 5 fingers on the limbs. Between them there are membranes. Nails are flat. The tail is shaped like a paddle. Its length does not exceed 30 cm. It is usually 10-12 cm wide. There is no hair on the tail. It is covered with horny plates, between which sparse hairs break through. In the middle of the tail, a horn protrusion stretches for its entire length, resembling a ship's keel. Ears are short, eyes are small. The undercoat is thick, the guard hairs are coarse. The fur is beautiful, practical and in commercial demand.

Reproduction and lifespan

Beavers pair up for life. Only death can separate the betrothed. The mating season falls on the winter. Mating takes place in the water. The gestation period for the common beaver is 107 days, for the Canadian beaver - 128 days. There are from 2 to 6 cubs in the litter. Their usual weight is up to 400 grams. Milk feeding lasts 3 months. Babies start swimming a week after birth. In males puberty comes at age 3. Most females also at 3 years. Every fifth female is able to reproduce offspring at 2 years. The life expectancy of beavers in nature is 20-25 years. Under favorable conditions, the animal lives up to 35 years.

Behavior and nutrition

The beaver is a herbivore. He eats sedge and water lilies with pleasure. Gnawing bark from aspen, poplar, willow, alder, birch, maple. But, in any case, young shoots attract him more. At first glance, it may seem that these rodents cause irreparable harm to the environment. But this is an erroneous opinion. Animals bring undoubted benefits to the ecosystem by creating wetlands. They are simply necessary for many other animal species.

Beavers fell trees, but not anywhere, but in certain places, from which it is very convenient to drag heavy trunks to the river. Animals gnaw at the bark, branches, leaves, and the trunks go to the construction of the dam. It is thanks to her that dams are created. Various insects settle in them, thereby attracting numerous species of birds. Birds bring fish eggs on feathers and paws. Thus, fish appear in the dams.

Water, in turn, seeping through such structures, is cleared of heavy suspensions and silt. In dams, many plants die. That is, a large amount of dead wood appears. It is necessary for certain types of animals and plants. Trees damaged by beavers also serve as food for ungulates. That is, nature only benefits from the activity of rodents, but man loses. Dams created can flood and destroy crops, as well as erode highways and railway embankments.

Building dams by beavers is a special story. These amazing rodents live in burrows or special "houses" that they make themselves. Burrows dig in steep banks. They are long and represent a whole labyrinth with several entrances. The floor in such holes is slightly above the water level. If the river overflows, then the animals scrape the earth from the ceiling and thus "raise" the floor.

In addition to holes, beavers build "houses". On the shallows, they collect dry branches of trees in a heap and coat them with clay, earth and silt. Inside the pile, free space is made, towering above the water. The entrance to it is carried out from under the water. The height of such a structure reaches 3 meters, and a diameter of 10 meters. The walls of the "house" are very strong. They serve as excellent protection against predatory animals. When building their dwellings, animals work with their front paws. In preparation for the cold, they put an additional layer of clay and earth on the walls. Therefore, in the winter months, such structures always maintain a positive temperature, and the water in the manholes does not freeze. Beavers maintain perfect order in their dwellings. They never contain food waste and excrement.

The beaver is a social animal, so all rodents are united in families. Usually in one family there are up to 10 individuals. These are married couples and young animals that have not yet reached puberty. On the same site, one family can live for a century. The length of such land allotment along the coast reaches 3-4 km. Rodents rarely move more than 200-300 meters from the shore. Their whole life is connected with the river. There are also solitary beavers - these are young sexually mature bachelors who have just left their family. They live in burrows and eventually start a family.

Dam construction

Why do beavers build dams?? For them to have more water. Very often, a family of beavers takes a fancy to a small stream or a small river. To raise the water level, rodents build dams. As a result, the river turns into a small lake, and for animals this is a real expanse. In the water, they mate, get into dwellings and, of course, protect their lives from predatory animals. A beaver can stay under water for a maximum of 15 minutes. With a clear danger, such diving results are very helpful for rodents.

First, the beavers are determined with the construction site. Preference is given to those places where the opposite banks are separated from each other at the smallest distance. An important role is also played by the presence of trees near the shore. This is the main building material. The gnawed trunks are stuck vertically into the bottom of the river. Large stones are laid between them and covered with silt. Branches are piled on the surface. Fix them with clay. It turns out a very strong construction.

The length of the dam can be up to 30 meters. At the base it is wider, about 5-6 meters. It narrows with height. At the very top, the dam reaches a width of 2 meters. The height is 3, and 4, and 5 meters. History knows cases when beavers built dams 500 and even 850 meters long. At strong current additional dams are being built and special drains are made so that the structure does not collapse when the river overflows. Rodents constantly monitor the state of the dam. Small leaks and damage are immediately eliminated.

beaver population

As for the number of Canadian beavers, there were once about 100 million of them in North America. By the end of the 19th century, rodents were almost completely exterminated. From the huge population there were miserable crumbs. By the beginning of the 20th century, bans were introduced on catching these animals. There are over 10 million rodents in America today. In Eurasia, the situation was even worse. At the beginning of the 20th century, approximately 1,200 poor animals lived in vast territories. After 100 years, thanks to prohibitions, their number increased to 700 thousand. In most European countries, the common beaver received a second birth, since in these regions it was exterminated back in the 17th-19th centuries.

In nature, there are two types of beavers: the common beaver, which lives in Eurasia, and the Canadian beaver, which lives in North America. What is the difference between these two types and how they are similar, we will consider further ...

Both species have related roots with, as evidenced by the similarities of the lower jaw. But the behavior of these representatives of rodents is different. live near the 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, in connection with which they are classified as different populations.

Differences between Canadian and common beavers

Outwardly, both representatives of the species are extremely similar, but the Eurasian beaver is larger in size. It has less round and more big head, while its muzzle is shorter. The common beaver has less undercoat and a narrower tail. In addition, the Eurasian has shorter limbs, so it does not walk well on its hind legs.

The nasal bones of the common beaver are longer, the nostrils are triangular in shape, while the nasal openings of the Canadian beaver are triangular. The European beaver has larger anal glands. There are also differences in the color of the fur.

Practical in 70% of Eurasian beavers, the fur is light brown or Brown color, 20% have chestnut fur, 8% have dark brown, and 4% have black. In 50% of Canadian beavers, the skin has a light brown tone, in 25% it is brown, and in 5% it is black.

In addition to 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. The different number of chromosomes has led to the unsuccessful crossing of these representatives of different continents.

After repeated attempts to cross a Eurasian female and an American male, the females either did not conceive at all or gave birth to dead young. Most likely, interspecific reproduction is impossible. Between both populations there is not only a barrier of thousands of kilometers, but also differences in DNA.

The size of beavers and their appearance

Female beavers are larger than males, and besides, females dominate. The average weight of Canadian beavers is 15-35 kilograms, most often they weigh 20 kilograms with a body length of 1 meter. Canadian beavers grow throughout their lives, so old 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 with a height of 35 centimeters.

Canadian beavers have a squat body. On the limbs they have 5 fingers 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. From above, the tail is covered with horny plates, and hairs grow between them. From the middle of the tail stretches a horn protrusion, similar to a ship's keel.

The eyes of the animal are small, and the ears are short. Canadian beavers have a thick, practical undercoat with coarse guard hairs. Beautiful fur is highly valued commercially.

Beaver behavior and nutrition

Beavers are herbivorous mammals, their favorite delicacy is water lilies and sedge. Beavers eat bark from alder, poplar, maple, aspen, birch trees, but still prefer young shoots.

At first glance, it may seem that beavers harm the environment, but such an opinion is erroneous. Beavers create wetlands that are very important to the ecosystem. These animals fell 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.

By constructing dams, beavers organize dams in which insects settle, as a result, birds fly to the dams, which bring 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 suspensions. Some plants die in the dams, and a large amount of dead wood is formed, which is important for the existence of certain plants and animals.

The remains of fallen trees are fed to ungulates and various insects. That is, the construction activity of beavers is for the benefit of nature. But such dams can cause inconvenience to a person: dams overflow and flood crops, wash away railway embankments and roads.

Beavers live in burrows that they dig in steep banks. These burrows are long, they are a real labyrinth with several entrances. Beavers make the floor in their burrows above the water level, if the reservoir overflows, then 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 on the shallows, and then cover them with clay and silt. Inside, a free space is obtained, towering above the water. Beavers enter the house from under the water. The houses of beavers reach a height of 3 meters, and their diameter is about 10 meters. These houses have very strong walls that protect the owners well from predators.

Beavers build their houses with their front paws. By winter, houses are additionally insulated with a layer of earth and clay, thanks to which they always keep a positive temperature, even when it is cold outside. The water at the entrance to the hole does not freeze. These rodents love cleanliness; there is no excrement and food waste in their dwellings.

Beavers are social animals, they form their own families. One family consists of about 10 individuals - these are parents and young animals that have not reached puberty. 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 sexually mature beavers, after having left their family, live alone for some time, in constructed burrows, but over time they acquire their own family.

Dam construction

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 voice of the beaver

The life of beavers is completely dependent on the river. In the water, beavers mate, get into the shelter and escape from predators. Under water, these rodents can be no more than 15 minutes. When there is a clear danger, the ability to retain air is of great help to beavers.

Before building a dam, the beavers decide on a 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, as they are the main building material. Rodents gnaw at tree trunks and stick them vertically into the bottom of the river, the space between the trunks is covered 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 erected by beavers, 500 and 850 meters long, have been recorded.

If there is a strong current on the river, then 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 create couples for life, separation occurs only after death. The mating season in animals begins in winter. The mating process takes place in the water. Pregnancy in Canadian beavers lasts 128 days, and in common beavers - 107 days.

2-6 babies weighing up to 400 grams are born. The female feeds the beaver cubs with milk for 3 months. 1 week after birth, babies are already able to swim. Males are fully formed by the age of 3. In most females, puberty also occurs at 3 years. Females are able to produce offspring 1 time in 2 years.

In the wild, Canadian beavers live 20-25 years, and under favorable living conditions, they live up to 35 years.

Number of species

Not so long ago, there were 100 million Canadian beavers in North America, but by the end of the 19th century, rodents were almost completely exterminated. From the once large population, only minor remnants 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 in the 17th-19th centuries, and today they have received a second birth there.

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Canadian beaver- a skilled and tireless builder. Day after day, he is engaged in arranging the habitat, trying to create the most comfortable conditions for his family.

HABITAT

The Canadian beaver ranges from Alaska to the northern border of Mexico, but the largest populations of this rodent live in Canada. Easily adapting to a variety of climatic conditions, beavers are found in the mountains at an altitude of up to 3000 m and feel great both in the warm climate of the southern territories of the United States and in snowy Alaska. Beavers usually settle along the banks of slow-flowing rivers and streams, preferring areas densely overgrown with willows, maples, birches, poplars and alders, which form the basis of their diet.

SECURITY

Before the advent of European colonists, millions of beavers lived in America (24 subspecies are described in science). In pursuit of valuable fur, Europeans began to mercilessly exterminate these rodents, and by the beginning of the 20th century, Canadian beavers were on the verge of extinction, and many subspecies were irretrievably lost. Thinking in time, people took the beavers under guard, introduced strict ban hunting, and in 1920-60. a number of programs to restore their numbers have been successfully implemented. The current habitat of Canadian beavers is close to the original, and the state of their population is constantly monitored. In recent years, limited trapping of animals for furs has been allowed again.

LIFESTYLE

Beavers live in strictly defined home areas, marking the boundaries of their possessions with the secret of paired musky glands located near the anus. Boundary pillars for animals are heaps of brushwood placed at certain points. One family lives on the chosen site, consisting of a pair of adult rodents and their offspring for the last 2-3 years. Partners remain faithful to each other until the death of one of the spouses. The female is slightly larger and more massive than the male. Having occupied the territory near the river, beavers build a dam on the river, which partially delays the flow, and with its help regulate the water level in the resulting dam. Sometimes beavers make canals along which trees, branches and other materials are floated for their structures. In the presence of steep banks, beavers dig deep holes, and on low swampy banks they build surface huts. In both cases, the entrance to the nesting chamber is located under the surface of the water, and the network of underground corridors sometimes reaches a length of 10 m. The “hallway”, located at the water level, serves to dry the fur, and on the floor above there is a bedroom lined with soft shavings. In the roof of the hut built of brushwood, there is certainly a ventilation hole. Beavers have a purely vegetarian diet. With sharp incisors, they gnaw trunks and eat branches, fresh leaves and bark of fallen trees. With no less appetite, they feast on the greenery of aquatic plants - water lilies, pondweed and duckweed. At the end of summer, the animals begin to collect food supplies for the winter and pile up heaps of cut branches at the bottom of the dam, pressing them down with stones. AT cold water plants are perfectly preserved, and thrifty owners have fresh food all winter. Beavers are excellent swimmers and divers, rowing with their hind legs and wide tail, which at the same time serves as a steering oar. Life in the water requires careful care of the coat, and the beaver spends a lot of time cleaning and lubricating the fur with the oily secretion of the anal glands to prevent it from getting wet, using the claws of the hind legs like combs for this. Family members communicate with each other with low grumbling sounds. Beavers are usually active at night, and only in the most remote forest corners feed or build dams during the day. The disturbed animal loudly slaps the water with its tail to warn the whole family, and instantly disappears from sight. Beavers spend the whole winter in the nest, daily visiting their underwater pantries for the next portion of branches.

BREEDING

The breeding season for beavers is confined to January-February. Before mating, partners indulge in mating games for a long time in the water. The estrus, during which the female can be fertilized, lasts only 10 hours. After love foreplay and feigned chases, without which the marriage ritual is indispensable, the partners mate without leaving the ice-bound water. Pregnancy lasts 100-110 days. In April or May, three or four cubs are born, although a healthy female with a sufficient supply of food can bring up to nine cubs. Beaver cubs are born sighted, covered with fur and weigh about 500 g. They can swim from birth, but delicate baby fur does not provide reliable thermal insulation, so the babies sit in the nest for 2-3 weeks until they get used to using the underwater entrance. All this time, the mother feeds them with milk up to 9 times a day. Mother's milk is very nutritious, and beavers quickly grow up, gaining up to 10 kg by the end of the first year of life. At 2-3 weeks old, babies learn to dive.

At about three months of age, milk feeding stops, and juveniles begin to master the skills of building dams. The whole family, including older brothers and sisters, takes care of the youngest beavers, and at first each relative considers it his duty to bring something tasty to the kids. During the first forays, adult beavers drag the babies one at a time, lightly grabbing the scruff of their teeth with their teeth. Throughout the first winter, the cubs continue to grow and reach puberty only by the age of two. In the third year of life, young beavers leave their home and go in search of their territory, where they could establish their own family.

DID YOU KNOW?

• The average length of a beaver dam is about 20 m, but some reach up to 600 m.
• Our European ancestors considered the beaver a fish for quite a long time. Sharing this misconception, the church allowed the consumption of beaver meat on fasting days. As far back as the 18th century, Rhenish monks were preparing sausages from beaver meat, which were considered a Lenten dish.
• Usually a beaver is under water for 4-5 minutes, and the record for the duration of the dive is 15 minutes. During this time, the animal can swim 750 m.

RELATED SPECIES

In the beaver family, two species are distinguished: the Canadian beaver and the European beaver. Because of their similar way of life, they have long been classified as one species. Only genetic analysis and comparison of the structure of the skull revealed significant differences, and today they are recognized as two separate species, the representatives of which do not interbreed.

European beaver( castor fibers ) cannot boast of the same silky fur coat as his Canadian cousin. In the 19th century, intensive human economic activity led to a sharp decline in the beaver population, and today they have survived mainly in Eastern Europe and Scandinavia. Populations of these rodents in other parts of the continent and the upper reaches of the Yenisei are extremely rare, and in some regions they are protected by law. The influence of beavers on the habitat is very great, and sometimes in places of cultural forest management they cause serious damage to the forest stand. In such cases, some of the animals are caught and relocated to special reserves, where they can live and breed freely.

Canadian beaver (Castor canadensis)- a large semi-aquatic rodent, originally from North America. Together with (Eurasian species) it is in the beaver family (Castoridae) and is the second largest member of the rodent order in the world, after the capybara.

Description

Basically, beavers are aquatic animals, as well as the largest rodents on the North American continent. They have a waterproof, rich, glossy, reddish-brown or blackish-brown coat. The undercoat is much thinner than the rest of the protective coat. The ears are short and round, dark brown in color. The beaver's hind legs are longer than the front legs, which makes the back of the body higher than the front while walking. Body length from 90 to 117 cm.

The beaver's skull and teeth are disproportionately large. This is very important for the ability to gnaw on hard woods such as maple and oak. Most of the upper incisors are bright orange in color and are at least 5 mm wide and 20-25 mm long. These teeth grow throughout the life of the animal and are essential for survival, as are the closing nostrils, ears, and transparent membranes over the eyes, ideally suited for life in the aquatic environment. Beavers gnaw at the bases of trees with their strong incisors and thereby knock them to the ground. The front paws are used for digging, carrying and placing building materials.

Also of note are the anal and fur glands found in males and females. Both sets of glands are located at the base of the tail, which is perhaps the most distinctive feature of beavers. The tail is broad, flat and covered, in large parts, with blackish scales. Its length is from 20 to 25 cm, and its width is from 13 to 15 cm. The anal glands measure: 8.6 cm by 5.5 cm, and the fur glands are 7.6 cm by 2.4 cm. The odor emitted from these glands serves as a marking and is also characteristic of beavers.

area

Canadian beavers live throughout North America, with the exception of the northern regions of Canada and the deserts of the southern United States and Mexico.

Habitat

Canadian beavers are active, mostly at night. They are excellent swimmers and can stay underwater for up to 15 minutes. More vulnerable on land, so the slopes stay in the water for as long as possible.

Beavers live on the banks of slow forest rivers, streams and lakes. From fallen trees, they build dams and dams, thereby regulating the level and speed of the flow of water. Beavers create channels through which logs are transported to the dam. Canadian beavers have excellent building abilities and create two types of dwellings - burrows and huts. Huts are floating islands, made of a pile of brushwood, smeared with silt and earth. Their height, on average, is 1-3 meters, and their diameter is up to 10 meters, they also have an underwater entrance. By winter, Canadian beavers often plaster houses with earth, which becomes concrete when it freezes. They make a small hole for air in the upper part of the hut. The floor is lined with bark, grass and wood chips. Beavers spend the night in huts, store supplies for the winter, and hide from predators. Unlike the Eurasian species, the Canadian beaver rarely settles in burrows.

Dams protect Canadian beavers from predators and are built from branches, rocks, grass, and mud. In addition to keeping beavers safe, dams provide excellent habitat for waterfowl, fish, and other aquatic animals. Their dams help reduce soil erosion and flooding. However, beaver dams are not permanent structures and depend directly on the presence of beavers. Typically, beavers focus on building and repairing dams in the fall, in preparation for the coming winter. In the northern regions, they often don't repair otters' holes in the dam, and sometimes partially destroy them themselves to lower the water level in the pond, increase the amount of oxygen under the ice, or gain easier access to the trees down from the dam.

reproduction

Canadian beavers are monogamous, but if one partner dies, the other will look for someone else. Beavers leave their families in their second year of life. Then they create their own family, usually a few kilometers from the parent. Females and males become sexually mature at the age of about 3 years. Depending on environmental conditions, they produce offspring once a year.

Beavers mate during the period from January to March in the northern regions and from the end of November-December in the southern regions. Cubs are born, as a rule, from April to June. The duration of pregnancy is about 3 months, or 105-107 days. Newborn beavers are completely hairy, have open eyes and can swim after a day. After a few days, they are able to dive into the water with their parents to explore the surroundings.

At birth, the cubs are about 38 cm long, including their tails. Typically, they weigh between 250 and 600 grams and can be red, brown, or almost black in color. They stay in the house for a month, after which they start swimming. long time and eat solid foods. Most beavers feed on mother's milk for two weeks, although some take up to 90 days.

Parental care begins before birth and continues until 1-2 years of age, when young beavers have reached the stage of independence. The male and female provide food for their offspring and protect them from predators.

Lifespan

Beavers eat bark and cambium (the soft tissue that grows under the bark of trees). Their favorites are the following trees: willow, maple, poplar, beech, birch, alder, aspen. They also feed on aquatic plants, buds and roots. Cellulose, which is not broken down in most mammals, is the main component of the beaver diet and is digested with the participation of microflora intestinal tract, which digest this element. In zoos, beavers eat yams, lettuce, carrots, and "rodent food."

Behavior

Beavers usually live in family groups of up to 8 individuals who are related by blood. The offspring stay with their parents until they are 2 years old, help care for younger siblings, gather food, and help build dams. Beavers are territorial animals that defend themselves against other families. One of the ways of protection is to mark the territory with the help of a beaver stream, which gets into the mud mounds with urine. Beavers also warn others of danger with a powerful thump of their tail against the water. However, this method is not always effective, as the older generation ignores the warning claps of the younger family members, who often use them during the game.

To a greater extent, beavers are nocturnal and only occasionally come out during the day, usually in the evening. In search of food, rodents travel long distances from their homes. If they find a good source of food, beavers build canals on the water and ferry food to the houses. Logs and twigs are often stored underwater for winter food.

Threats

Young beavers are very vulnerable, threatened by bears, wolves, wolverines, lynxes, anglers and otters. The size of an adult beaver is a deterrent to most predators. And while natural predators pose a very real danger to Canadian beavers, humans have proven to be by far the biggest threat to these rodents. The killing of beavers for their skins, habitat modification, and environmental pollution are detrimental to the Canadian beaver population.

Economic value to humans: Positive

Beaver fur was an important trade item of the last century and allowed sellers to receive large sums of money.

Beavers are incredibly beneficial to the environment. They play an important role in providing habitat for many aquatic organisms, maintaining groundwater at an appropriate level, and controlling floods and erosion through the construction of dams.

Economic value to humans: Negative

Although beavers have a beneficial effect on environment, they can also destroy it. Dams will slow down the flow of water, change the flora and fauna, which sometimes leads to siltation. Dams can flood low-lying areas, sometimes causing the loss of vast areas of forest.

conservation status

To date, the population of the Canadian beaver is of the least concern. In the past, they have been significantly threatened and have almost disappeared from many of their original habitats. However, in the 20th century, Canadian beavers were successfully introduced into many of their former habitats.

Video

Beavers are a genus of mammals of the rodent order, which includes two species: the common beaver (Castor fiber), a resident of the Atlantic coast to the Baikal region and Mongolia, and the Canadian beaver (Castor canadensis), found in North America.

The body weight of a beaver is about 30 kg, the body length reaches 1-1.5 m, females are usually slightly larger in size than males. The rodent has a blunt muzzle, small ears, short, strong paws with powerful claws. The beaver's coat consists of two layers: on top are coarse outer red-brown hairs, and underneath there is a thick gray undercoat that protects the beaver from hypothermia. The tail is naked, black, flattened and wide, covered with scales. Near the base of the tail are two glands that produce an odorous substance known as "beaver plume".

Beavers are herbivorous rodents. Their diet includes bark and shoots of trees (aspen, willow, poplar, birch), a variety of herbaceous plants (water lily, egg capsule, iris, cattail, reed). They can also feed on hazel, linden, elm, bird cherry. Willingly eat acorns. Large teeth and a strong bite help beavers to eat fairly solid plant foods, and the microflora of their intestinal tract digests cellulose food well.

The daily required amount of food reaches 20% of the beaver's weight.

AT summer period Grassy food predominates in the diet of beavers; in autumn, rodents actively prepare tree food for the winter. Each family stores 60-70 m3 of timber. Beavers leave their stocks in the water, where they retain food qualities until the end of winter.

Until the 20th century, beavers were very widespread, but due to their mass extermination, their habitat has recently been significantly reduced. The common beaver is found in Europe, Russia, China and Mongolia. Its closest relative, the Canadian beaver, lives in North America.

Common types of beavers

The body length is 1-1.3 m, height is about 35.5 cm, weight is in the range of 30-32 kg. The body is squat, the paws are shortened with five fingers, the hind legs are stronger than the front ones. Swimming membranes are located between the fingers. The nails are strong and flat. The tail is oar-shaped, flat, reaches 30 cm in length, 10-13 cm in width. The tail is pubescent only at the base, the rest of its surface is covered with horny shields. The eyes are small, the ears are wide, short, slightly protruding above the coat. Under water, the ear openings and nostrils close, there are special blinking membranes in front of the eyes. The common beaver is distinguished by beautiful fur, made of coarse guard hairs and a thick silky undercoat. Coat color from light chestnut to dark brown, sometimes black. The tail and paws are black. Shedding occurs once a year.

In the anal region there are paired glands, wen and the so-called "beaver stream", the smell of which is a guide for other beavers, as it informs about the border of the family's territory.

The common beaver is distributed in Europe (Scandinavian countries, France, Germany, Poland, Belarus, Ukraine), in Russia, Mongolia and China.

Body length 90-117 cm; weight about 32 kg. The body is rounded, the chest is wide, the head is short with large dark ears and bulging eyes. The coat color is reddish or blackish brown. Tail length 20-25 cm, width 13-15 cm, oval shape, pointed end, surface covered with black horny shields.

The species is distributed in North America, Alaska, Canada, USA, Mexico. It was introduced to the Scandinavian countries and Russia.

Sexual dimorphism in beavers is weakly expressed, females are slightly larger than males.

Beavers usually live along the banks of forest rivers, streams and lakes. They do not live on wide and fast rivers, as well as reservoirs that freeze to the bottom in winter. For these rodents, tree and shrub vegetation along the banks of water bodies, and the abundance of aquatic and coastal grassy vegetation are important. In suitable places, they build dams from fallen trees, construct canals, and along them the logs are rafted to the dam.

Beavers have two types of housing: a hole and a hut. The huts look like floating islands made of a mixture of brushwood and mud, their height is 1-3 meters, their diameter is up to 10 m, the entrance is located under water. In such huts, beavers spend the night, store food for the winter, and hide from predators.

Beavers dug burrows on steep and steep banks; these are complex labyrinths with 4-5 entrances. The walls and ceiling are leveled and rammed. Inside, at a depth of up to 1 m, a living chamber is arranged up to 1 wide and 40-50 cm high. The floor is located 20 cm above the water level.

Beavers swim and dive well, they can stay under water for 10-15 minutes, and swim up to 750 m during this time.

Beavers live both individually and in families of 5-8 individuals. The same family has occupied their plot for many years. Beavers do not walk 200 m from the water. Rodents mark the boundaries of the territory with a beaver stream.

The main periods of beaver activity are night and twilight.

Beavers are monogamous rodents. Breeding takes place once a year. The mating season begins in mid-January and lasts until the end of February. Pregnancy lasts 105-107 days. In one brood there are 1-6 cubs that are born in April-May. Babies are born semi-sighted, well pubescent, their weight is approximately 0.45 kg. In a few days they can already swim. The female teaches them to swim, pushing them out of the hut into the underwater corridor. At 3-4 weeks, the beavers begin to feed on the leaves and stems of herbs, until 3 months the mother feeds them with milk. The young live with their parents up to two years, after which they reach puberty and begin an independent life.

In captivity, the life expectancy of beavers is up to 35 years, in nature 10-17 years.

natural enemies

The natural enemies of the river beaver are wolves, brown bears and foxes, but the greatest damage to the population of this species is caused by humans, exterminating beavers because of their valuable fur and meat.

• The common beaver is the largest rodent in Europe and the second largest in the world after.
• The word "beaver" comes from the Indo-European language and is an incomplete doubling of the name for brown.
• Until the middle of the 20th century, beaver fur was very popular in America, Europe and Russia, due to which the population of these animals was noticeably reduced: 6-8 isolated populations of 1200 individuals remained. To preserve the species, beaver hunting was banned. Now the common beaver has a minimal risk status, and the main threats to it are reclamation activities, water pollution and hydroelectric power plants.
• In addition to beautiful and durable fur, beavers are the source of the beaver stream, which is used in perfumery and medicine. Beaver meat is also edible, but may contain salmonellosis pathogens. According to church canons, it is considered fasting.
• In 2006, a sculpture of a beaver was opened in the city of Bobruisk (Belarus). There are also sculptures of this rodent in the Alpine Zoo (Innsbruck, Austria).