Eurasian beaver
Castor fiber
Nature’s busy aquatic architect is a formidable tree feller, river changer and wetland creator

At a glance
Status
Reintroduced in Scotland and England. Wild beavers are now in Argyll, Tayside and Devon.
Shapes the landscape through
Bark stripping, damming, tree cutting
Preferred hangout
rivers, lakes, streams, wetlands, woodlands
Weight
19 kg
Length
1 metre
Speed
55 km/h
How it shapes the landscape
The beaver is a keystone species and one of nature’s most awesome ecological engineers. Through the building of dams, the digging of canals, and the creation of dead wood, beavers create and maintain habitats where an abundance and diversity of life can flourish. Dams prevent soil eroded from fields from being lost to the sea. Carbon and nutrients are trapped, improving water quality downstream. The flow of water is slowed, helping to ameliorate flooding.
Beavers are vegan and don’t eat fish or other animals. Studies have shown that young salmon grow faster and are in better condition in areas where beavers live. A host of other creatures benefit from their presence including insect, amphibian, bird, and mammal species.
Where it likes to be
Beavers require freshwater habitat with lots of woody vegetation. They’ll build dams to create ponds where they can construct their lodges and stay safe. They are herbivores, feeding on grasses and trees. They’ll forage the land around their homes, felling trees and moving branches and twigs into the water.
How much space they need
Beavers need a minimum of a couple of hectares, including freshwater habitat and ample supply of trees and shrubs. Final territory size depends on food availability.
Background story
Europe’s largest rodent was hunted to extinction in the UK for its fur and a natural secretion called castoreum, which was used for both perfumes and medicine. Similar declines followed in mainland Europe, with the population plummeting to almost 1000 across the continent. Beavers have since been successfully reintroduced and protected in many countries, including Scotland and England.
Special Power

Can we have them in Britain?
Wild beavers, and those in captive release schemes, can be found across Britain. The largest wild population lives in Scotland in the Tay catchment, and has spread into the River Forth catchment. The River Otter in Devon is also home to a wild beaver population.
In summary
- Keystone species
- Europe’s largest rodent
- Extraordinary ecosystem engineer, creating habitat for a multitude of wildlife
- Hunted to extinction around 400 years ago, now successfully reintroduced at locations across Britain
- Dam building helps ‘slow the flow’, reducing flooding and improving water quality
Images: Philip Price/scotlandbigpicture.com and Peter Cairns/scotlandbigpicture.com