Beavers are one of the largest rodents on the planet. In nature, there are 2 types of animal: an ordinary beaver, which is settled throughout Eurasia, and a Canadian one, living in North America.
They are very similar in appearance and habits, but recently scientists have found that the species differ at the genetic level: the common beaver has 48 chromosomes, while the Canadian beaver has 40. This difference makes it impossible for them to interbreed.
What does a common beaver look like?
This rodent grows up to 1 meter in length, excluding the length of the tail, which is 0.4-0.5 meters. An adult young beaver weighs an average of 30-32 kg, and an old one can weigh up to 45 kg, as these animals grow all their lives.
Large head with a narrow muzzle, small eyes and ears, 2 large protruding incisors in front. The fur of the animal is most often brown, but there are auburn, chestnut and even black beavers. Long, shiny coarse hair on top and a soft, delicate thick undercoat keep this rodent dry and warm even in harsh winters. Beavers carefully look after their “fur coat” - they comb it with a forked claw of their hind legs, at the same time lubricating it with a special fatty secret, thanks to which the fur does not get wet in water. A thick layer of underskin fat also protects from the cold.
Five-fingered paws have special membranes between the fingers, strong thickened claws.
The beaver has an amazing tail - flat, like an oar, without hair, covered with horny scales with a horny "keel" in the middle line.
Beaver teeth are self-sharpening.
Lifestyle and nutrition of beavers
Beavers are semi-aquatic rodents. On land, they are clumsy and slow, but in the water they are fast, dexterous swimmers, excellent divers. They are perfectly adapted to the water: webbed feet, a flat paddle tail, transparent eyelids that protect the eyes and allow excellent vision under water, labial growths behind the main incisors allow you to sharpen wood in the water, while protecting the oral cavity. They can stay under water for up to 15 minutes, sometimes swimming up to 1 km.
These animals are strict vegetarians. They feed on wood, preferring soft species - aspen, alder, willow, birch. Also eat leaves, branches, young shoots, sedge, water lilies, water lilies.
They are very peaceful, they prefer to avoid danger, but there are cases of an open attack, then the enemy has a hard time - beavers are strong fighters, if they have already entered into a fight (which happens extremely rarely), then they fight fiercely and bravely.
Beavers are twilight and nocturnal. In the wild they live up to 20-25 years, in captivity - up to 35 years.
beaver family
Matriarchy reigns in the beaver family. The female is the main one, she is outwardly larger than the male. Having united once, they remain true to each other throughout their lives. Scientists studying the habits of beavers have come to the conclusion that even in the event of the death of one of the partners, the second often does not acquire a second pair, but remains alone forever.
Mating takes place in the water (often under ice) in February. After 3.5 months, from 2 to 6 woolly cubs weighing 500 grams are born. Within a few days they can swim, after a couple of weeks they begin to feed on leaves and thin stems, although they receive mother's milk for up to 3 months.
A complete family consists of the main female, male father, last year's brood and beavers of the current year. Young animals leave the family only at the age of 3. They live very friendly, do not fight for food, build huts and dams together.
Do beavers have a higher education in hydroengineering?
Throughout their lives, they build dams, choosing the right places, using precise technologies and verified calculations. Scientists are amazed at such abilities today. It is still not clear how beavers measure distance or the weight of building material, but they never make mistakes. Their dams are so strong that they can support the weight of a horse. Beavers strictly monitor the integrity of their structures, immediately repairing damage.
For the construction, not only the trunks of trees felled by beavers (they have a characteristic hourglass shape) are used, but also branches, stones, silt, and clay.
For housing, they dig holes - these are complex labyrinths, or build huts - surface structures from branches held together by silt and clay. The entrance to the dwelling is always located under water.
It is interesting that “tenants” often settle in huts and peacefully cohabit with the beaver family. This is a water snake, water vole, muskrat.
Beavers are remarkably clean animals. They always keep the dwelling clean, recover outside the house, take out the remnants of food.
The territory used by beavers for the construction of dams and huts has been in the sole use of one family for many decades. Beavers mark "their" places with a beaver stream - a dark, odorous oily liquid. It is interesting that this secret is highly valued by perfumers, using it to give special durability to perfumes.
Today, beavers are listed in the Red Book. Active work is underway to restore the population, which was practically destroyed for the sake of valuable fur and beaver secret.
Beaver Information By Savannah
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 their own dwellings and even build dams.
Among the representatives of the order of rodents, the beaver takes the second place (after the copybara) in terms of 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. In prehistoric times (during the Pleistocene), beavers were much larger, their height reached 2.75 m, and weight 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 turned out that there is still a genetic difference between these species, since the common beaver has 48 chromosomes, while there are only 40 Canadian beavers. 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 dwellings, it serves as a rudder when swimming. The beaver is a semi-aquatic animal, so much in the appearance of this mammal shows its adaptability to stay in the water: between the fingers there are swimming membranes, especially strongly developed on the front paws, in the eyes of the beaver there are blinking membranes that allow you to see under water, 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 from cold.
Beavers are exclusively herbivorous, they feed on 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 fell 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 butchered overnight. The beaver gnaws, rising on its hind legs and leaning on its tail. Its jaws act like a saw: in order to fell a tree, the beaver rests its upper incisors against its bark and begins to quickly move its lower jaw from side to side, making 5-6 movements per second. The beaver's incisors are self-sharpening: only their front side is covered with enamel, the back consists of less hard dentine. When a beaver gnaws on something, the dentin wears down faster than the enamel, so the front edge of the tooth stays sharp all the time.
Trees gnawed by beavers:
Video about the life of beavers, where you can see how beavers gnaw trees:
Beavers live along the banks of slowly 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 right in the water - a hut. A beaver hut is a pile of brushwood held together with 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 for water and a platform that rises above the water level. The bottom of the hut is lined with bark and herbs. With the onset of the first frosts, beavers additionally insulate the hut with new layers of clay. Air enters through the ceiling. In frosts, clouds of steam are visible above the beaver huts. In the coldest weather, the temperature remains above zero in the hut, and even if the reservoir is covered with ice, the polynya under the hut does not freeze, which is very important for beavers, because beavers store food supplies for the winter, prepared in winter, under the overhanging banks directly into the water, from where they then take them when the cold comes.
beaver hut
Beavers live alone or in families. A complete family consists of 5-8 individuals. The mating season for beavers is in the winter. Cubs are born in April-May and after one or two days they can swim. At the age of 3-4 weeks, beaver cubs switch to feeding on leaves and soft stems of grasses, but the mother continues to feed them with milk for up to 3 months. The grown up young animals usually do not leave their parents for another 2-3 years. In captivity, beavers live up to 35 years, in nature 10-19 years.
The head of the beaver family marks the limits of its territory with the so-called "beaver stream" - special secretions that were previously actively used in medicine, and are now used to create expensive perfumes.
In case of danger, beavers give their relatives an alarm signal by striking the water with their tail.
So that water does not flood the hut during the flood, or, conversely, the reservoir does not suddenly become shallow, beavers often build dams. Construction begins with the fact that beavers stick branches and trunks into the bottom, strengthening the gaps with branches and reeds, filling the voids with silt, moss, clay and stones. As a supporting frame, they often use a tree that has fallen into the river, gradually surrounding it from all sides with building material. The longest dam built by beavers was 850 meters long. If the dam somewhere begins to let in more water than necessary, the beavers immediately close up this place. Thanks to their excellent hearing, beavers accurately determine the place where the water began to flow faster. Once, scientists conducted an experiment: a tape recorder was turned on on the shore of a reservoir with the recorded sound of flowing water. Despite the fact that the tape recorder was on land and there was no flowing water at all, the beavers' instinct worked and they immediately covered up the "leak" with mud.
Although beavers may appear to be forest pests, beaver activities are actually beneficial to the ecosystem. For example, the number of ducks in water bodies well-maintained by beavers is on average 75 times higher than in water bodies without beavers. This is due to the fact that beaver dams and calm water attract mollusks, aquatic insects, which, in turn, attract waterfowl, desmans. Birds bring fish caviar on their paws and there are more fish in beaver ponds. Trees felled by beavers serve as food for hares and many ungulates, which gnaw bark from trunks and branches. Butterflies and ants love the juice flowing from undermined trees in spring, followed by birds. In addition, the dams contribute to water purification, reducing its turbidity, because. silt lingers in them.
Beavers have long been hunted for their valuable fur and beaver plume. As a result, at the beginning of the 20th century, beavers were completely exterminated in many European countries, and the total number of beavers in Eurasia was only 1,200 individuals. In the 20th century, largely due to the active restoration of 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 were created for beaver breeding. Beavers from the Voronezh Reserve were settled throughout the USSR, as well as in Poland, China, the GDR and other countries. At present, the number of beavers in Russia exceeds 340 thousand, almost half of them are of Voronezh origin. The reserve works to this day, visiting it, you can take home photos of beavers (about 300 individuals live here), made with your own hands. In addition to beavers, there are 333 species of vertebrates in the reserve.
In North America, beavers were also on the verge of extinction, but their protection in the United States and Canada was already taken up at the end of the 19th century, and now there are 10-15 million beavers on the American continent, which is many times greater than the number of beavers in Eurasia (where there are about 640 of them). thousand as of 2003), but much inferior to the time when the fur trade in America was not yet in fashion (then 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 Tierra del Fuego to start the beaver fur trade in the region. However, beavers, once in an ecosystem where they had no natural enemies, bred so much that they threatened the local forests. Now 200 thousand beavers live on the territory of the archipelago.
In addition to Argentina, Canadian beavers were brought to Sweden and Finland, from where the beavers moved to the North-West of Russia, where they began to compete for territory with the Eurasian beavers. The number of Canadian beavers in the North-West of Russia can reach up to 20 thousand individuals.
In Russian there is the word "beaver", but this is not a synonym for the word "beaver". "Beaver" is an animal, and "beaver" is a beaver's fur.
The more you learn about these unusual aquatic rodents and how beavers live, the more you are surprised at their ingenuity, diligence and resourcefulness. Nature endowed these animals not only with strength and beauty, but also with intelligence.
Appearance
It is believed that the river beaver is the largest rodent in Russia and neighboring countries. . Beaver size, or beaver length , is a little over a meter, the height reaches 40 cm. The weight of a beaver is about 30 kg.
He has a beautiful shiny fur, almost waterproof. Above - coarser thick hair, below - soft thick undercoat. The color of the coat 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 paddle-shaped, up to 30 cm long, covered with horny scales and sparse hairs. The eyes of the rodent are small, the ears are short and wide. This description of the beaver will prevent confusion with other aquatic rodents.
Varieties
The beaver family has only two species: the common beaver, or river beaver, and the Canadian beaver. Consider the types of beavers in more detail.
River
This is a semi-aquatic animal, the largest rodent in size, inhabiting the Old World, the 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 a less elongated body, a short head and larger ears. Coloration is blackish or reddish brown. It lives almost throughout the United States (except 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 the Leningrad region and Karelia.
These two species of beavers have different numbers of chromosomes and do not interbreed.
habitats
Where beavers live is not very difficult to determine. Noticing fallen trees with a characteristic cone-shaped cut near water bodies, as well as ready-made dams built by animals, one can conclude that they are somewhere nearby. It will be a great success to stumble upon a beaver's dwelling - this is already an unequivocal marker of the presence of a friendly family. They settle in forest, with a slow flow, rivers, streams, reservoirs, lakes.
In the first decade of the last century, beavers in nature could have completely disappeared in most countries of the world. Russia was no exception. Fortunately, the situation was corrected thanks to the measures taken to protect these animals.
The river beaver now feels free almost throughout the country. The European part of Russia, the Yenisei basin, the southern part of Western Siberia, Kamchatka - these are the places where beavers live.
Lifestyle and habits
Without air, a beaver can stay in water for about a quarter of an hour. Sensing danger, the animal dives under the water. At the same time, he loudly slaps his tail on the water, which serves as an alarm signal for his fellows.
His carefully fortified hut serves as reliable protection from enemies (bear, wolf, wolverine) and frost. Even in severe frosts, it is warm in it, steam flows through the holes of the dwelling in the winter - it becomes clear how beavers hibernate.
In the summer, rodents get food, build dams and huts. They work from dusk to dawn. Powerful sharp teeth of a beaver gnaw through, for example, an aspen 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 for a hundred meters.
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 water bodies, aquatic plants. They like to eat the bark of aspen, linden, willow. Reeds, sedges, nettles, sorrel and other plants are what beavers eat.
Scientists who have observed their life and what beavers eat in nature have counted up to 300 different plants that serve as food for animals.
For the most part, beavers live in families and touchingly take care of the well-being of their “relatives” - they build houses, stock up on food for the winter. They painstakingly pile tree branches on the bottom of the reservoir, which they eat in winter. Such stocks per family reach a dozen or more cubic meters.
If, due to the current of the river, it is not possible to lay down their “cellar”, beavers go out to land at night for food in winter. They are very risky: 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 holes. The entrance to them is located under water. The beaver hole is a difficult labyrinth with several branches, chambers, entrances and exits. The partitions between the "rooms" are tightly packed, cleanliness is maintained inside. The remains of food are thrown into the river, and they are carried away by the current.
What is the name of the beaver's dwelling, which differs from the hole, can be understood by its appearance, resembling 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, leveling them, biting the protruding branches. Wood shavings cover the "floor". This is the beaver's hut.
With the increase in the family, his caring head completes and expands his living space. The beaver hut is replenished with new “rooms”, one more floor is built on.
The beaver's house can reach more than 3 meters in height! The painstaking work and engineering ingenuity of the animal are amazing.
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 shallowing of the river and contribute to its flooding. And, therefore, they contribute to the resettlement of animals in flooded places, to increase the possibilities for finding food. That's why beavers build dams.
This tactic is aimed at improving the safety of living. This is another explanation why beavers build a dam.
The width and depth of the river, the speed of the current determine what the beaver dam will be. It must block the river from one bank to the other and be strong enough not to be swept away by the current. Animals choose where there is a place convenient for starting construction - a fallen tree, a narrowing channel.
Hard-working beavers build a dam by sticking twigs and stakes into the bottom and filling the gaps between them with cobblestones, silt, and clay. Beaver dams need to be strengthened constantly, month after month, year after year, so that they are not washed away. But that doesn't stop the beavers! As a result, the dam is getting stronger, bushes and trees grow on it. It can even be used to cross from one side to the other.
And this is not the only thing that beavers are useful for. The dams they built raise the water level, which is favorable for aquatic insects, and contributes to an increase in the number of fish.
reproduction
Mating takes place 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 the mother feeds them with milk for the whole summer. Inexperienced and weak kids also spend the winter with their parents. As a rule, they leave the parental home after 2 years.
It is quite precisely known how long beavers live. Under natural conditions - about 15 years.
The only rodents, beavers can confidently walk on two legs. In the front they hold branches, stones, tree bark. Females thus carry their cubs.
Economic importance
Since ancient times, beavers have been hunted for their beautiful, valuable fur. In addition, a beaver stream is used, which is used in medicine and the perfume industry.
Beaver meat is used for food. Interestingly, the Catholics attributed it to lean food. The scaly tail was misleading, because of which the rodent was considered a fish. The beaver is a danger when eaten because of its natural carriage of salmonellosis.
Video
Watch a fascinating video about the life of beavers.
river beaver , or, as it is otherwise called, ordinary, lives in the territories of Asia and Europe on the banks of reservoirs with a non-freezing bottom, in forests. The abundance of trees, shrubs and grass is very important for these mammals. Therefore, most often animals can be found on small canals, rivers, lakes, oxbow lakes, and they avoid rivers with a rapid current. The beaver is diligent and builds amazing natural buildings, dams. The ancestors of the current beavers come from Asia, while they were very large - they reached almost three meters in length and weighed more than 300 kg!
Description of the river beaver
The beaver itself is about a meter long, and the flat tail, shaped like an oar, does not exceed 30 cm (but not less than 20 cm, about 15 cm wide), the weight of an adult is just over 30 kg. It is the largest rodent in the Old World and the second largest in the world, second only to the capybara. Interestingly, the females are slightly larger than the males.
The beaver has a strong squat body, short limbs, ending with special membranes, thanks to which the animal can swim. The round head ends with a blunt muzzle with small eyes and ears. The teeth are strong and powerful. Sharp claws on the paws help the beaver to comb the fur.
The color of thick fur is dark brown, light chestnut, less often black. But the tail is covered with rather sparse hair growing between the horny plates. The beaver is distinguished by conscientiousness in caring for the fur, which it constantly lubricates with a special substance secreted by the tail glands. This helps the wool keep its water resistance. It was the luxurious fur that caused the animals to be hunted intensively, which is why they were on the verge of extinction.
The life expectancy of these animals reaches an average of 17 years.
The value of the tail is great: when swimming, it performs the functions of a rudder, and also highlights a special secret that serves to lubricate the wool. With its tail, the beaver notifies its relatives of danger by splashing on the water.
Beaver food
beavers- herbivores, in the summer the basis of their diet is the bark of trees, branches of shrubs, fresh grass. And in winter, strong teeth allow them to feed on tree bark. In the summer they make stocks, keeping them in the water.
Among the trees, aspen, birch, and willow are most loved by them. They also enjoy eating acorns.
River beaver habitat
The distribution zone of this rodent, due to mass extermination, has significantly narrowed compared to the original range. If earlier the beaver lived almost everywhere in Europe and Asia, now it is found exclusively in Scandinavian countries, in the basins of large rivers in France, Poland, Germany, Russia, Belarus, it can also be observed in China and Mongolia.
On the territory of the Russian Federation, beavers have survived in Kamchatka, the Khabarovsk Territory, the Baikal region and some other areas.
Beaver lifestyle
Leads a semi-aquatic lifestyle. They prefer to live in burrows, and if the swampy terrain makes digging a hole impossible, they build huts from shrub branches, which are glued together with silt and insulated with clay. Such a dwelling also guarantees protection from predators. To prevent the dwelling from being flooded by rising water, beavers build their dams. It also helps to keep the water level from falling, which will make the hut (burrow) accessible to a predator. For construction, tree branches are used, sometimes whole trunks, connected with earth, silt and clay. Often stones are also involved.
Impeccable hearing allows these rodents to determine the damage to the dam and “pat up” it in a timely manner.
The beaver is an excellent swimmer, he dives well, he can survive in the underwater environment for up to 15 minutes. And the entrance to their dwelling is securely hidden under water.
In summer, they are most active at night, especially at night, but in winter they switch to a daytime lifestyle. These are very sociable and friendly animals, they live in families.
In early January, the mating season begins, which will last until the end of winter. After pregnancy, which lasts an average of three and a half months, from 1 to 6 cubs are born. They develop very quickly and at the age of only a couple of days are capable of independent swimming.
River Beaver Conservation
river beaver included in the Red Book and is under protection. Hunting for it is prohibited.
Now the number of these animals is not critical, which allows us to speak about the effectiveness of conservation measures.
Video about the river beaver
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Common, or Eurasian, or river beaver (Castor fiber)- a species of semi-aquatic mammal from the beaver family (Castor). This is one of two species of the beaver genus (the other is (Castor canadensis).
Description
Common beavers weigh from 13 to 35 kg. The body length is 73-135 cm, and the height at the withers is up to 35 cm. They have two layers of fur: the first is a soft and dense undercoat, dark gray in color. The outer (second) layer is longer, with a coarse reddish-brown coat or guard hairs. In northern populations, the coat color is darker. River beavers have two castoreum glands located near the anal region. These glands produce an aromatic, chemical called beaver spray, which is used to mark territories. The muzzle is blunt, the ears are small, and the paws are short. Both ears and nostrils have valves, and there is a nictitating membrane over the eyes.
The tail is hairless, with black scales, and broad, oval and horizontally flattened in shape. The color of the paws varies from dark brown to black, each has 5 fingers. The hind feet have webbing between the toes, while the inner two toes are joined at the base and are used for grooming. In their mouths, beavers have a skin fold that allows them to chew on branches underwater without getting water in their mouths. They have two large orange incisors. Females and males are similar to each other, although females are larger.
area
Eurasian beavers once densely populated all of Europe and Asia. However, excessive killing of animals due to fur and beaver stream, as well as loss of habitats, has significantly reduced the population, almost to the point of extinction. In the 19th century, there were no beavers left in most of Europe and Asia. In the 20th century, there were about 1,300 beavers in the wild. Efforts to control and reproduce have led to an increase in the population of European beavers. Currently, beavers live in France, Germany, Poland, southern Scandinavia and central Russia. However, their populations are small and scattered throughout these areas.
Habitat
River beavers are semi-aquatic animals and inhabit freshwater systems, including lakes, ponds, rivers, and streams, usually in forested areas but occasionally in swamps. Permanent access to water is essential and willow, aspen, birch and alder are considered to be the preferred tree species. Beavers choose slow moving, calm or deep waters and can create these conditions if necessary. Water quality is less important than access to it, availability of food, and depth.
reproduction
Common beavers are monogamous. The female's estrus lasts from January to February, but sometimes warm winter weather can lead to breeding as early as December. Most often, mating occurs at night, in the water, but, in some cases, it also happens on land. The duration of copulation is from 30 seconds to 3 minutes. If the female is not fertilized the first time, she has repeated estrus (2 to 4 times) throughout the breeding season. All family members take part in the upbringing of offspring.
The gestational period is 60 to 128 days. The female is born from 1 to 6 cubs, but most often 1-3. Newborn beavers weigh 230-630 g. As a rule, breastfeeding lasts up to 6 weeks. During this time, the female takes care of the cubs, cleans them and feeds them. After the young are weaned from their mother's milk, other family members help feed them by bringing small twigs and soft bark until the young are about 3 months old. At 1.5-2 years old, young beavers gain independence, leave the parental family and create their own.
Lifespan
Eurasian beavers, in the wild, can live from 10 to 17 years, but rarely live longer than 7-8 years. Some sources indicate that beavers can live up to 35 years in captivity, but these data are unconfirmed. The longest confirmed lifespan, in captivity, was 13.7 years.
Nutrition
River beavers are herbivores, feeding mainly on woody vegetation during the winter months. Beavers prefer willow, aspen, and birch less than 10 cm in diameter. In autumn, rodents stock up on these foods and store them in water to eat in the winter until the ice melts. During the summer months, common beavers feed on aquatic vegetation, shoots, twigs, bark, leaves, buds, and roots. In agricultural areas, rodents consume agricultural crops. Beavers do not have cellulase, an enzyme used to process cellulose. However, beavers feed on excrement, as a result of which the intestinal microflora is able to digest cellulose.
Behavior
Common beavers are primarily nocturnal, although they may be active during the day. Their burrows are usually found on the banks of rivers or ponds. In huts, beavers live in families of up to 12 individuals. These families consist of only one dominant, monogamous pair. The dominant female decides when young beavers leave the family. Beavers are semi-aquatic rodents and can stay underwater for 4-5 minutes. They are active throughout the year. In the northern regions, these animals do not come to the surface of the ice. For this reason, beavers spend the fall season gathering food so that they have something to eat during the winter. The reserves consist of woody vegetation such as willow and aspen branches.
Beavers can change the speed of the current and the depth of the water through construction. However, Eurasian beavers are more conservative than their North American cousins, Canadian beavers, and tend to build significantly fewer dams and lodges. Common beavers are very territorial and mark their territory with a beaver jet. Beavers are very aggressive towards unknown scents on their mounds, often hissing and slapping their tails in the water. More often than not, they will leave their scent on or near the mound.
River beavers must groom their coat and keep it water-repellent at all times. They use the split toes of their hind feet and distribute the oil from the sebaceous glands to the guard hairs. This makes the outer coat waterproof and the undercoat never gets wet. Without these fats, beavers would not be able to spend so much time in the water or withstand low temperatures.
home range
The size of a beaver's home range depends on the abundance of food, the size of the river basin, the size of the family, and the time of year. During the winter months, the home range is equal to the area that a beaver can patrol under water daily in one trip, due to the presence of ice cover. During the warmer months, the home range size can be 1-5 kilometers along the coastline.
Communication and perception
River beavers communicate using beaver jet markings. They also use postures, tail slaps, and vocalizations. Vocalizations include whining, whistling, and hissing. Tail slaps are used when rodents are frightened or upset.
Threats
Huts and burrows provide beavers with reliable protection from predators. So far, the biggest threats to ordinary people are humans. The rodents were hunted for their valuable skins and beaver stream, which led to near extinction. Nowadays, thanks to conservation efforts, beaver populations are legally protected. Poaching, getting caught in nets, and traffic accidents are the main causes of death for these rodents. Wolves and red foxes are considered natural predators. Today, one of the main causes of death of river beavers is infectious diseases.
Role in the ecosystem
Common beavers have an extraordinary ability to impact ecosystems. Through the process of building dams, they change the flow of water, resulting in the flooding of many hectares of forest land. The decrease in nitrogen and acidity, along with the increase in carbon, prevents the growth of tree vegetation for some time, but eventually the trees begin to grow and the forest recovers. Dams collect waste and debris, which increase carbon and decrease nitrogen and acidity, resulting in habitat modification for invertebrates. This new water source attracts various species of birds, fish and fish. River beavers also control woody vegetation. The flooded wood dies off within a year and then becomes part of the aquatic ecosystem.
River beavers host 33 different types of ticks that can live on rodents at any time of the year.
Economic importance for humans
positive
Eurasian beavers have valuable fur, meat and beaver stream. Previously, skins were used as currency until the almost complete extinction of animals. Fur was used to make clothes, felt, and felt hats. The beaver stream was used as a medicine and as a base in perfumery. Beaver meat has nutritional value. In the 16th century, the Pope argued that the scaly tail and semi-aquatic lifestyle made the beaver a fish and could be eaten during Catholic Lent. Even at present, in Europe, about 400 tons of beaver meat are consumed during Lent.
negative
Common beavers are considered destroyers when they cut down trees and flood territories. The most numerous complaints are related to the flooding of agricultural land and, as a result, the destruction of crops. Beavers flood roads and drainage pipes, causing serious damage.
conservation status
The beaver population is of Least Concern according to the IUCN, but their numbers and protection remain low. Beaver subspecies (Castor fiber birulai) are endangered according to the US Fish and Wildlife Service.
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