Beavers are real landscape architects: they build castles and dams, dam streams, and cut down trees. This creates new habitat for plants and animals.
What do beavers look like?
Beavers are the second largest rodents in the world. Only the South American capybaras get bigger. Their body is quite clumsy and squat and grow up to 100 centimeters long. A typical feature of the beaver is it’s flattened, up to 16 centimeters wide, hairless tail, which is 28 to 38 centimeters long. An adult beaver weighs up to 35 kilograms. The females are usually a bit larger than the males.
The thick fur of the beaver is particularly striking: on the belly side, there are 23,000 hairs per square centimeter of skin, on the back, there are around 12,000 hairs per square centimeter. In contrast, only 300 hairs per square centimeter grow on a human head. This super-dense brown fur keeps the beavers warm and dry for hours, even in the water. Because of their valuable fur, beavers used to be mercilessly hunted to the point of extinction.
Beavers are very well adapted to life in the water: while the front feet can grip like hands, the toes of the hind feet are webbed. The second toe of the hind feet has a double claw, the so-called cleaning claw, which is used as a comb for fur care. The nose and ears can be closed when driving, and the eyes are protected underwater by a transparent eyelid called the nictitating membrane.
The beaver’s incisors are also striking: They have a layer of orange-colored enamel (this is a substance that makes teeth hard), are up to 3.5 centimeters long, and continue to grow throughout their lives.
Where do beavers live?
The European beaver is native to France, England, Germany, Scandinavia, Eastern Europe, and Russia to northern Mongolia. In some regions where beavers were wiped out, they have now been successfully reintroduced, for example in some areas in Bavaria and on the Elbe.
Beavers need water: They live on and in slow-flowing and standing water that is at least 1.5 meters deep. They especially like streams and lakes surrounded by lowland forests where willow, poplar, aspen, birch, and alder grow. It is important that the water does not dry out and does not freeze to the ground in winter.
What types of beavers are there?
In addition to our European beaver (Castor fiber), there is also the Canadian beaver (Castor canadensis) in North America. Today we know, however, that both are one and the same species and hardly differ from each other. However, the Canadian beaver is slightly larger than the European, and its fur is more reddish-brown in color.
How old do beavers get?
In the wild, beavers live up to 20 years, in captivity, they can live up to 35 years.
How do beavers live?
Beavers always live in and near water. They waddle rather clumsily on land, but in the water, they are agile swimmers and divers. They can stay underwater for up to 15 minutes. Beavers live in the same territory for many years. They mark the territory boundaries with a certain oily secretion, the castoreum. Beavers are family animals: they live with their mate and the children of the previous year and the young of the current year. The main residence of the beaver family is the building:
It consists of a dwelling cave by the water, the entrance to which is under the water surface. Inside it is padded with soft plant material. If the river bank is not high enough and the layer of earth above the dwelling cave is too thin, they pile up twigs and branches, creating a hill, the so-called beaver lodge.
The beaver lodge can be up to ten meters wide and two meters high. This building is so well insulated that even in the depths of winter it doesn’t freeze inside. However, a beaver family usually has several small burrows near the main burrow, into which, for example, the male and the young of the last year withdraw as soon as the new beaver babies are born.
The nocturnal beavers are master builders: if the water depth of their lake or river falls below 50 centimeters, they begin to build dams to dam up the water again so that the entrance to their castle is submerged again and protected from enemies. On a wall of earth and stones, they build elaborate and very stable dams with branches and tree trunks.
They can fall tree trunks with a diameter of up to one meter. In one night they create a trunk with a diameter of 40 centimeters. The dams are usually between five and 30 meters long and up to 1.5 meters high. But there are said to have been beaver dams that were 200 meters long.
Sometimes many generations of a beaver family build the dams in their territory over a period of years; they maintain and expand them. In winter, beavers often gnaw a hole in the dam. This drains some water and creates a layer of air under the ice. This allows the beavers to swim in the water under the ice.
With their building activities, the beavers ensure that the water level in their territory remains as constant as possible. In addition, floods and wetlands are created, in which many rare plants and animals find a habitat. When beavers leave their territory, the water level sinks, the land becomes drier and many plants and animals disappear again.