Eurasian Beaver

Castor fiber

The beaver is the "master builder" of riverine landscapes. By felling trees, the beaver makes a significant contribution to biodiversity by providing habitats for many other species.

Description
Body length 75-100 cm; tail 30-40 cm; weight 13-35 kg; shoulder height 35-40 cm; life span of up to 20 years. Body is heavily built, hair ranges from light brown to black. The large hind feet are webbed while the forelegs can be used like hands to grasp things. The broad hairless tail is known as a "scoop". When alarmed or disturbed while in the water, beavers slap the scoop loudly on the water's surface before diving.

Distribution
Woodlands of the northern hemisphere, from Europe to Northeast and Central Asia. In Austria, in the Danube-March-Thaya wetlands; migrates to the Weinviertel ("Forest Quarter") and the Vienna Woods, but also from the Inn and Salzach down the Danube to Linz.

Endangerment and Conservation Status
In Austria, beavers had been extinguished by the middle of the 19th century. Starting in the 1970s, they were restored on the Salzach and Inn rivers as well as in the Danube wetlands east of Vienna. Protecting the riparian forests is essential to the conservation of the beaver. There are currently between 800-1000 individuals in the Danube wetlands, on the Danube tributaries in the Vienna Basin extending to the Tulln Basin and on the March and Thaya rivers.

Behaviour
The Eurasian beaver is strictly herbivorous, eating a wide variety – over 170 different types – of vegetation; beavers do not eat fish! During the summer, aquatic plants and others found along rivers make up the beaver's diet, while in the fall and winter the beaver fells trees, preferably willows and poplars, in order to get to the tender shoots and thin bark. By cutting down trees, the beaver enriches the structure of river banks, creating raised perches and hiding places for diverse animal species, from fishes to pond turtles to birds. In the winter, the beaver remains active under the ice, where fallen trees are preserved for the duration of the cold season. In this part of the country, the beaver doesn't inhabit the typical lodges but rather digs burrows into loamy river banks which may be entered from under water. Due to the extreme seasonal fluctuations in the Danube's water level, the beaver doesn't build dams near the main current. But in backwaters further away from the river, the rare dams may be found. Thanks to these dams, the waters around where they are found always maintain a minimum water level (approx. 50 cm). Beavers live in large family groups consisting of the parent animals and the litters from the previous and current years. Beaver pairs mate for life. Mating season is in January/February and births occur around three months later, with a litter size of 1 to 4 babies. Older offspring may be hunted off the territory, which usually encompasses 100 to 1500 meters along the riverbank. This leads to a pronounced tendency for beavers to spread. By felling trees and burrowing holes to create shelter, beavers massively impact the riverine ecosystem. Beavers are primarily nocturnal and are most active at dusk or during the night.

Special Characteristcs
The extreme persecution which ultimately led to extinction was due mainly to demand for castoreum oil (a syrup-like secretion produced by the beaver), beaver fat, testicles and blood, which were believed to have curative powers and which were sold by so-called beaver chemists. The valuable furs and beaver meat's consumption during fasting periods also led to the species' extinction. In 1863, the last beaver in Lower Austria was hunted near Fischamend. The many town and field names containing reference to the animal point to just how widespread the beaver once was in the area.