Large sharp front teeth and a flat broad tail that can make loud splashes in the water are some of the characteristics many people associate with the rodent that goes by the Latin name Castor fiber, but is better known as the beaver.

The beaver is certainly a rare sight, not just because of its distinctive appearance, but also because the Danish population only counts a few hundred individuals. Although the number of beavers is not impressive, their mere presence in the Danish countryside is remarkable because the beaver has been extinct for more than a thousand years. So says Jørn Pagh Berthelsen, a forest and landscape engineer at Aarhus University, who has coordinated the monitoring of the Danish beaver population in collaboration with the Danish Nature Agency. He is pleased the furry rodent is back.

“The beaver is a popular animal. Many of us know it from the Donald Duck comic strips of our childhood. Now we can also see them in nature. It’s a win-win situation for the public, who like to see the beaver in its proper element, and for Danish flora and fauna,” says Mr Berthelsen.

The population was threatened by man’s greed

The beaver is indigenous to Denmark and lived here in large numbers after the last Ice Age. However, a ravenous interest in their warm soft fur, in particular, as well as their tasty meat decimated the population to the extent that the beaver disappeared from its natural territories. About a century ago, there were actually only around 700 beavers left in the whole of Europe.

“When people became aware that the beaver was threatened with extinction in many European countries, the species became protected, but by then the damage was done. The population was so small that it was unable to propagate naturally again. Or at least it would have taken a very long time,” says Mr Berthelsen.

To remedy the damage, the Danish Nature Agency launched a reintroduction project in 1999 in which eighteen beavers from the Elbe River in Germany were released near lakes at Klosterheden in West Jutland, and there is no doubt about the outcome of the project: the beaver has come to stay, and it is thriving in Denmark!

“Once we’d released the beavers in six different locations, we soon noticed that they moved to other areas where they chose to settle down and build nests with dams, beaver lakes and dens. You could almost feel tempted to think that the beavers had read the management plan, because they’ve fulfilled many of the project’s objectives. The beavers appear to thrive in coexistence with the other plant and animal species near their habitats,” says Mr Berthelsen.

The beaver makes our nature more diverse

But why is it necessary to reintroduce the beaver in Denmark? According to Mr Berthelsen, the answer is that the beaver plays an important role in our ecosystem.

“It’s the beaver’s nature to want to change watercourses and drainage conditions by building dams, and this creates wetlands that are a favourable environment for insects, birds, amphibians, bats, fungi and a large number of other species of both flora and fauna,” says Mr Berthelsen.

He also emphasises the beaver’s role as a key ecological species because of its ability to change natural conditions. Its habit of clearing dense scrub and building dams from the trees and bushes it fells creates clearings and new wetlands that are fertile ground for increased biodiversity.

The beaver can cause problems for landowners

Not everyone is equally enthusiastic about the reappearance of the beaver, however.

“If we look at the beaver’s impact on the state forest, we often describe it as an enrichment of nature, but some of the landowners living next to their habitats would describe it as wildlife damage,” Mr Berthelsen says.

The farmer’s fields can actually become flooded when the beaver blocks drainpipes and builds dams with the result that the soil cannot be used for crops or grazing cattle. It is not easy to fight the beaver either, because it is a very stubborn animal.

“The beaver often blocks smaller streams where it can be hard work to remove the dams it builds. Once they’ve decided that they want to flood a certain area, it’s hard to get them to change their minds. They often keep rebuilding the dams so the amount of material that has to be removed from the stream is huge,” says Mr Berthelsen.

He nevertheless has the impression that the problems have been relatively minor, and the landowners have received good advice and assistance from the Danish Nature Agency, which implements certain preventive measures if the activities of the beavers become too much of a nuisance. Many local farmers and nature enthusiasts assist in the annual spring count of beavers, and the general view is that the beaver project is interesting.

Facts

• A beaver can become 95–135 cm long and weigh up to 35 kg.
• The beaver is Europe’s largest rodent and lives entirely on plants.
• Beavers live in families. Male and female beavers mate for life and live in small family groups.
• Beavers can become up to 25 years old, but most of them only live for seven to eight years.
• The beaver is best known for building dams across shallow streams to raise the water level.
• In 1999, 18 beavers were released at Klosterheden in West Jutland. Since then, other beavers have been released at Arresø in North Zealand.
• The Danish Nature Agency: Bæveren er tilbage (The beaver is back – in Danish only)
• The Danish Nature Agency: Dansk bæverbestand er tidoblet (Danish beaver population increases tenfold – in Danish only)
• The Danish Nature Agency: På sporet af bæverne i Klosterheden Plantage (Tracking the beaver in Klosterheden Plantation – PDF file in Danish only)

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