The beaver has been removed from our landscape for a long time. It has even come close to disappearing from mainland Europe, too. However, after approximately 400 years, small-scale reintroductions are being trialled. But is this a good idea?
On 28th May 2009, the first release of beavers into the wild took place in Knapdale Forest in Argyll. Four families were released under a special licence and their impact on the environment will be monitored for five years. There are other beaver colonies in the UK, but they are kept in restricted areas.
Not everybody sees the habitat engineering by beavers in a favourable light and there are groups strongly opposed to the reintroduction of beavers as they fear damage to fishing interests, farm crops and livestock, water flows in rivers and local wildlife.
A particular problem with reintroducing beavers is that formerly there would have been more predators to help control the population numbers. Bears and wolves are major predators of North American beavers but they disappeared along with the beavers from the British Isles. The only possible predators left that could be seen as a threat to young beavers are foxes and maybe weasels or stoats.
There is an argument that says that once an animal has gone from an ecosystem, particularly if a long time has elapsed, you can never reintroduce it and expect the ecosystem to be restored to what it had been. Certainly that argument holds true if the predators have also gone. However, the only basis on which sensible decisions about the reintroduction of beavers can be made is on hard evidence. The trial release of beavers in Knapdale, the experience gained from captive populations like the one at the Aigas Field Centre near Inverness, and the new trials that are planned should provide us with a basis for making a long-term decision.
The Devon Wildlife Trust project
One of the new trials is the three-year project organised by the Devon Wildlife Trust. This project, will investigate the ecological impact of introduced beavers on an enclosed wetland site. The 2.8 hectare project site is located on private property, and securely fenced. An interesting feature of this site is that it is wet Culm woodland, a habitat that typically supports a diverse range of plant, bird and insect species. Two beavers, a male and a female, were released into the enclosure in late March 2011. The introduced beavers showed typical beaver behaviour, having within two weeks constructed small dams across a stream, and so creating two small ponds. It is possible that the beavers may breed in their second year on the site.
During the three years of the project, the beavers will be monitored to investigate whether the habitat changes brought about by their activities will increase the numbers and diversity of aquatic invertebrates. Regular assessments of the hydrology, water quality and general biodiversity of the enclosed area are planned. Potentially, beavers could offer a way of restoring wetland habitats through their natural engineering rather than using human labour.
The waiting game
Some landowners have concerns about the reintroduction of wild beavers, as they feel that beavers’ activities with cutting trees, digging burrows and building dams across streams could damage woodland and riverbanks. The Devon project and others should provide a substantial amount of information about the real ecological impact of beaver activity.
Will we ever see wild beavers in our wetlands and rivers? Only time will tell, but wonderful though it would be for naturalists and wildlife enthusiasts, we must prepare ourselves for a long wait as evidence from these trials emerges.
Spotlight on... beavers