Eurasian beaver

Status
Small population reintroduced in Scotland and extinct in England and Wales
Population
At least two breeding pairs and two kits
Scientific name
Castor fiber
The Eurasian or European beaver was once widespread in Great Britain and Europe but was hunted across its range for its fur and for its musk scented secretions, called castoreum. It was extinct in Britain by the 16th century and the Eurasian population was just 1 200 individuals in 1900. Since then, the population has partially recovered and there have been successful reintroductions to Scotland, parts of France, southern Germany and Austria. In Nov 2016 the Scottish population was formally recognised as a native species.
Beavers are excellent swimmers and dive for periods of five to six minutes, using their broad, flattened tail as a rudder. They burrow into the bank or use existing holes for dens (called lodges), which have entrances below the water level. If there are no suitable banks, lodges are built from branches, soil and woody debris. In addition, beavers construct dams, creating floodplains that extend the protection around their lodge and provide increased opportunities to forage.
Head-body length: 75 – 90cm
Tail length: 28 – 38cm
Weight: Up to 38kg
Lifespan: 7 – 8 years
Reproduction
Beavers breed mainly from December to April and litters of usually 2 – 3 kits are born in May or June. The young learn to swim within hours and leave the nest at 1 – 2 months. They are weaned in their first summer but may not disperse until two years old. They are unlikely to successfully breed until their third year.
Diet
Aquatic and herbaceous plants in summer and bark of broad-leaved trees in winter. They sometimes fell young trees in October and November to store as food during the winter.
Habitat
Areas with year-round access to water – ideally, slow-flowing rivers or lakes with deciduous woodland on their banks. They can colonise non-ideal habitat by dam-building, which extends foraging habitat.
Predators
Historically, wolf and lynx; fox and some raptors such white-tailed eagle.
Threats
They were extensively hunted in the past.
Conservation & status
Following a reintroduction project the Eurasian beaver is now formally recognised as a native species in Scotland. Previous to this they were extinct for over 400 years in Scotland and longer in England and Wales where there are still no recognised populations. The existing small population in Scotland is made up of individuals introduced from Norway.
Population size & distribution
There are about 11 adults, including two breeding pairs, and two kits in Scotland. Beavers were once widely distributed in Great Britain but were never present in Ireland.
Did you know?
Beavers are not very vocal, sometimes growling or hissing, but they warn each other of danger by slapping their flattened tails on the surface of the water as they dive to escape.