With more beavers due to be released into the Knapdale area of western Scotland this spring, focus once again turns to Britain's growing beaver population. But why did beavers go extinct in the first place, how have they returned and what impact are they having on the British landscape?
How big are Eurasian beavers?
"Size of a Labrador – well, at least a cocker spaniel,” says Peter Burgess, conservation manager for Devon Wildlife Trust. They can be up to 1m long, with a 50cm tail and weigh up to 30kg (averaging about 18kg). It is the world’s second largest rodent behind the capybara of South America.
When did beavers become extinct?
Beavers were once native to the UK but were hunted to extinction as recently as 300-400 years ago. They were hunted as vermin, for their fur and also for their meat, which was highly prized.
Where do beavers live in the UK?
There is a small population on the River Otter in East Devon. No one knows how they got here, although escapes from private collections have occured elsewhere in the UK. Others claim the beavers were released deliberately.
In January 2015, Natural England declared that the beavers would be allowed to remain on condition that they were free of disease and of Eurasian descent. The five beavers were caught and tested – DNA testing showed that the animals were the once-native Eurasian beaver, and none of the beavers was found to be infected with Echinococcus multilocularis, tularaemia, or bovine TB.
The Scottish Beaver Trial saw the release of small numbers of beavers in Knapdale in Argyll on the west coast of mainland Scotland.
In November 2016, the Scottish government ruled that the trial had been a success and that the beavers could stay in Knapdale for good. More beavers were released in October 2017 and a further reintroduction is due to take place in spring 2018. See https://scottishwildlifetrust.org.uk/our-work/our-projects/scottish-beavers/
There is a large population of beavers on the River Tay catchment area in eastern Scotland. No one knows where these originated from but there may be as many as 200-300 individuals at large. There have been reports of many ‘Tay’ beavers being shot by local farmers and landowners.
Are there any beavers in Wales?
There are no official releases of beavers in Wales and a feasibility study is being undertaken by conservation charities and government bodies to see if such a reintroduction would be suitable.
Are beavers good or bad news for the British countryside?
Arguments rage as to whether the animals should stay. Conservationists such as Devon Wildlife Trust say that beaver dams improve a river’s water quality and flow, as well as creating mosaics of habitat for a range of wildlife; some anglers fear the dams will impede migrating fish, while some landowners and riverside homeowners are concerned about potential flooding caused by the dams as well as loss of trees and crops.
Do beavers eat fish?
No. They eat vegetation – including shoots, leaves, roots and stems of waterside vegetation and leaves. They fell trees to get at the tender foliage at the top of the tree.
How fast can a beaver chop down a tree?
When editor Fergus visited the River Otter with the Devon Wildlife Trust, he found a newly felled willow tree. Its trunk was a foot in diameter, chiseled through in cartoon-fashion and surrounded by bright wood chips. Peter Burgess from the Trust estimated that it would take a beaver a single night to do this. You can read Fergus’ full account of his trip here
Why do beavers build dams?
The beavers build dams over 1m high using tree trunks and other vegetation to create deep pools as refuges, as well as to make it easier to get around. They also use deep water as a refrigerator to store food in over the winter. The tend to build the dams in the smaller upper tributaries of a river.
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