The European beaver was once found across large parts of Europe and northern Asia. Many rivers from Britain to Siberia were home to this charismatic mammal. By the 16th century though, it had been almost completely wiped out by hunting. A few small, scattered populations teetered on the brink of extinction.

Global Distribution

The European beaver was once found across large parts of Europe and northern Asia. Many rivers from Britain to Siberia were home to this charismatic mammal. By the 16th century though, it had been almost completely wiped out by hunting. A few small, scattered populations teetered on the brink of extinction.

The good news is that people have returned beavers to over 25 European countries. These releases, along with legal protection, mean that it is now back in many of its former haunts. (The American beaver is a similar, but separate species.)

 

Distribution in Scotland

Humans hunted beavers to extinction in Scotland around 400 years ago. It is possible that small populations hung on until the late 18th century, but in any case their fate was sealed. However, they have recently made a comeback. This was thanks to the first successful reintroduction of a native British mammal.

In 2009 the Scottish Government gave the thumbs up for a trial release in Knapdale, Argyll. There had also been unofficial releases on the Tay catchment some years before that.

In 2016 they were given official leave to remain in Scotland and more releases followed. There are now well-established populations in both these areas. Beavers are well and truly back as a native species.

Beavers are never far from freshwater. Their preferred habitat includes lakes, slow-flowing rivers and wetlands with woodland nearby.

Beavers are over a metre long, weigh up to 30 kg and are well adapted to life in and around the water. Their front feet are dextrous and they can use them to handle food and building materials. Webbed hind feet are ideal for swimming.  Beavers use their flat, scaly tails as rudders which they can also slap against the water as a warning alarm.

Their thick, dense brown fur helps keep their skin dry. ‘Nictitating membranes’ or third eyelids act like swimming goggles. Beavers have valves to close their ears and noses while swimming and can hold their breath for up to 15 minutes. They can even close their mouths behind their front teeth so that they can chew underwater!

Beavers are the second-largest rodent in the world. Like other rodents they have four long incisor teeth which carry on growing throughout their lives. The front surfaces of the incisors are orange, thanks to tooth-strengthening iron within the enamel. This is ideal for gnawing through wood.

They have special glands near the base of the tail that produce a substance called castoreum, which they use to scent mark their territory. Humans hunted beavers not only for their fur and meat, but also for this substance. Castoreum was prized for its medicinal properties and used in making perfume.

Beavers are herbivores, and don’t eat fish as some people think. During the summer months they eat a wide range of leafy plants. In the winter they turn to trees and shrubs, eating the bark and twigs of broadleaved trees. Some of their favourite trees include willow, aspen and alder.

Beavers have an incredible ability to change their surroundings in a way that suits them. They are a ‘keystone species’, meaning that their presence has huge knock-on benefits for a lot of other wildlife.

These mammals are true ecosystem architects. Beaver dams create wetland habitat for many species. These include water plants, frogs, dragonflies, ducks, water voles and spawning fish, to name a few. In turn these species can attract otters, herons, ospreys and other predators.  Beavers and fish such as salmon and trout have evolved together for millennia. Because of this, beaver dams don’t usually present a problem for migrating fish.

Raising the water level kills some trees, which might seem destructive. But it actually creates valuable deadwood habitat for beetles, woodpeckers, fungi and more.

Trees that the beaver cuts down will usually coppice, that is, they send up a thicket of new shoots. In the early stages more light reaches the woodland floor. This often leads to a flush of wildflowers which attract pollinating insects such as butterflies.

The openings created in the woodland canopy offer perfect hunting grounds for bats. As the thicket grows it can then provide ideal nesting sites for birds such as warblers.

Depending on where you are in in their range, beavers (especially kits) are on the menu for a range of predators. They have to be on their guard for wolves, bears, lynx, wolverines, otters, pike, eagles, foxes and humans.

The wetlands beavers create help filter water pollution and silt. They can also reducing flooding downstream, which is a major benefits for humans as well.

The IUCN has classified the European beaver as being of Least Concern globally.  It is Critically Endangered in the UK, where it is protected by law.

Written by Dan Puplett