Beavers in Britain
Hunted to extinction over 400 years ago, beavers have only been seen in zoos and wildlife parks, until recently. Now, following some unexplained appearances and a number of official release projects, they are back in Britain once more. However, their reintroduction is not welcomed by everyone.
What is a beaver?
Beavers are large, semi aquatic rodents which can be found in many European, Asian and American countries. There are two species, the Eurasian beaver and the North American beaver.
The Eurasian beaver is the largest living, native rodent in Britain. Growing up to 1.7 metres in length, including the tail, they can weigh up to 30 kilograms. They have stout bodies, large heads and big teeth. Their thick fur is usually reddish brown, but colours vary and can sometimes be almost black. Beavers have webbed hind feet and a big tail, which helps them when swimming. Their eyes, ears and nostrils are positioned so they remain above water, while the rest of them is under the surface. With the ability to close their nostrils and ears, beavers can swim under water and remain submerged for up to 15 minutes. They are mainly nocturnal, but can occasionally be seen during the day.
Beavers live in areas of fresh water, such as streams, rivers, ponds and lakes. They prefer wide, slow running streams, flat terrain with mixed vegetation and plenty of trees nearby. They like willow, but will use other species including alders, beech and hornbeam. Beavers are herbivores and eat tree bark, aquatic plants, sedges, grasses and ferns. They do not, as some people think, eat fish.
Tree branches, along with rocks and mud are used to construct dams, and shelters known as lodges. The dams are used to slow the flow of water in streams and small rivers to create ponds in which the beavers can live. The lodges are accessed from under the water, and provide a safe refuge.
Why were they extinct?
Beavers were hunted in the past for their fur, meat and castoreum. The fur was used primarily to make hats, but it was also used for collars, cuffs, muffs and even whole coats. Their meat is high in protein and the tail was considered a delicacy by some, so although the animals were trapped initially for their fur, the meat was an added bonus for the hunters.
When beavers scent mark their territories, they don’t just use urine. Located near the base of the tail are two castor sacs, which produce a yellow secretion known as castoreum. With its musky, leathery smell, it was often used to make perfume, but it has also been used as a flavouring in food and drink.
Beavers in Scotland?
The first sightings of wild beavers living in Britain in recent times, were in Tayside, Scotland, between 2001 and 2005. It is not known where the animals came from, but it is likely they escaped from a wildlife park or were possibly released illegally. By 2010 the sightings included young beavers, known as kits, which meant they were successfully breeding in the wild. Stories started to appear in the press, and the authorities started to take an interest.
In August 2010 the National Species Reintroduction Forum decided that the Tay beavers should be trapped and removed to zoos. They justified this decision because the beavers were unlicensed, could be carrying diseases and might even be the wrong species. After hearing this, certain members of the public launched a campaign called “Save the Free Beavers of the Tay", and even founded a charity, the “Scottish Wild Beaver Group”. In March 2012 the Environment Minister stated that the Tay beavers could remain in the wild until 2015, when a final decision would be reached. This would be based on the study results from a project at Knapdale.
In May 2009, 11 beavers were officially released into freshwater lochs in Knapdale Forest, Mid-Argyll, Scotland. The project was led by the Scottish Wildlife Trust, and partnered with the Royal Zoological Society of Scotland and the Forestry Commission Scotland. Discussions regarding the reintroduction of mammals into Britain had been on going for years, and recent rewilding ideas have included wolves, lynx and even bears. However, following the approval by the Scottish Government, beavers became the first mammal to be legally reintroduced into Britain.
The Knapdale project ran for five years, and within one year the first beaver kit was born. The animals and their effect on the environment were carefully monitored. At the end of the initial project, it was generally agreed to have been a success. Further beavers were added to the area over the next few years to help bolster the numbers, and to diversify the genetics.
In Novemer 2016 the Scottish Government announced that beavers could remain in Scotland, and in 2019 they became a protected species.
Beavers in England?
There may have been beavers living in south Devon as early as 2005, with various sightings in 2008. By 2014 it had become obvious they were successfully breeding, and the authorities threatened to remove the animals from the river Otter area. However, the Devon Wildlife Trust opposed their removal and presented Natural England with a plan to let them remain as part of a five year trial.
The project was agreed, subject to the beavers being the correct species and free from non native diseases. By March 2015 they had been captured, tested and re-released. In June of the same year, three new kits were born. After five years of study, a report was published showing that the beavers benefited people and other wildlife, and in August 2020 Defra approved their right to remain in the wild.
Beavers in Wales?
In 2014 two beavers were sighted in the river Dyfi, mid Wales, and since then they have started to breed, with numbers now estimated at around ten. There have been no official release projects in Wales so far, meaning the two original beavers must have escaped or been introduced illegally.
Following feasibility studies, a licence application has recently been submitted by the Welsh Beaver Project to Natural Resources Wales, for a managed reintroduction of beavers in Wales. Led by North Wales Wildlife Trust, the scheme aims to release ten pairs in the river Dyfi area and monitor them over a five year period.
What good can they do?
Beavers are known as a keystone species, because a small number can change their habitat significantly, often benefiting other wildlife. When beavers build dams they help create a wetland habitat, which then encourages new species to the area. These include amphibians, birds, bats, fish, insects and plants.
The building of dams can help reduce the risk of flooding by slowing the flow of water and spreading it over a wide area. The structures, which consist of branches, rocks and mud, also act as filters by trapping pollutants and silt.
What problems can they cause?
The reintroduction of beavers to Britain is not welcomed by everyone. If they settle in an area where there are no lakes or large rivers, beavers will construct dams across streams or small rivers. These slow the flow of water to a trickle and create deep pools behind them. Depending on the terrain, the area that becomes submerged can be quite extensive. This may cause problems for land owners, particularly farmers, who use the land for grazing or growing crops.
To create dams, beavers use wood, which they acquire by felling trees. Using their sharp incisions, they gnaw right around the trunks until they break off. Although some species like willow will grow back, not all will recover. Most trees chosen will be young and thin, but beavers have been known to fell quite large specimens. This can obviously cause issues for anyone trying to grow trees for environmental or commercial purposes.
Beavers are herbivores and eat a mix of grasses, leaves, twigs and aquatic plants, but they also like the bark from young trees. If they strip off too much this can cause damage and may lead to the tree becoming diseased or even dying altogether.
The future for beavers in Britain
After a shaky start, beavers are now back in Britain, but only in a few isolated locations. However there are a number of enclosed beaver projects already in place, with more planned for the future. Each group released is monitored and studied carefully, and all this information helps guide new schemes.
The general consensus so far is that beavers are beneficial to other wildlife and can help humans by preventing flooding. But where beavers live close to farmland, problems can arise.
If beavers are going to be part of new rewilding projects in the future, it would make sense to use unproductive land, and then everyone will be happy.