Eurasian BeaverCastor fiberWhere and when to see them

The Eurasian beaver is Europe's largest native rodent and a highly adapted freshwater mammal. Once reduced to scattered populations by hunting, it has recovered across much of Europe through protection, reintroductions and natural expansion. It now occurs in the Danube, Rhine and Saône river systems, although its distribution varies locally. By felling trees, digging channels and sometimes building dams, it modifies waterside habitats and can create valuable wetlands for other wildlife.

Size

Body length about 80–100 cm, plus a flattened tail about 25–50 cm long.

Weight

Usually 15–30 kg.

Lifespan

Typically 10–15 years in the wild, sometimes up to 20 years.

Status

Least Concern (IUCN).

Eurasian beavers are mainly active at dusk and during the night, although daytime activity sometimes occurs. They usually live in family groups consisting of a breeding pair and their young. Family members maintain a territory and mark it with scent, including castoreum deposited on small waterside mounds. They shelter in bank burrows or lodges with underwater entrances. Dams are built where they help maintain suitable water depth, but beavers living beside large rivers often have no need to build them. They use their strong incisors to cut vegetation and fell trees for food and building material. Beavers remain active throughout winter rather than hibernating, and in colder areas they may store branches underwater near their shelter.

• Its orange incisors have iron-rich enamel and grow continuously.
• Its broad tail helps with steering and can slap the water as an alarm signal.
• It can close its lips behind its incisors to gnaw underwater without filling its mouth with water.
• Beaver-created wetlands can provide habitat for amphibians, aquatic insects and birds.

Wildlife opportunities depend on the river reach, water levels and species. River-specific viewing months have not been confirmed; general species seasons are not a local sighting forecast.

Eurasian beavers inhabit rivers, streams, lakes, ponds and wetlands with dependable freshwater. Suitable sites provide accessible vegetation, especially deciduous trees and shrubs close to the bank. They need banks suitable for burrowing or places where lodges can be constructed. Along the Danube, Rhine and Saône, wooded banks, sheltered side channels, tributaries and floodplain waters can offer suitable habitat. Their presence depends on local bank conditions, food availability and water levels rather than simply the size of the river.

The Eurasian beaver is strictly herbivorous and does not eat fish. In spring and summer, it feeds extensively on grasses, herbs, leaves and aquatic plants. Bark, twigs and the living tissues beneath bark become particularly important in autumn and winter. Willows, poplars and aspens are commonly used food trees where available.

Common name

Eurasian Beaver

Scientific name

Castor fiber

Animal group

Mammals

Size

Body length about 80–100 cm, plus a flattened tail about 25–50 cm long.

Weight

Usually 15–30 kg.

Lifespan

Typically 10–15 years in the wild, sometimes up to 20 years.

Status

Least Concern (IUCN).

Identification

Look for a large, stocky brown rodent with a blunt muzzle, small rounded ears and a broad, flattened, scaly tail. A swimming beaver may show mainly its head, so the diagnostic tail is not always visible. Coypu have a narrower muzzle, often conspicuous pale whiskers and a long, rounded tail rather than a paddle-shaped one. Eurasian and North American beavers are extremely difficult to distinguish reliably in the field by appearance alone.