Talk on ‘Beavers’, 4 November 2021

Exeter Branch members recently enjoyed an up-to-the-minute report on the environmental impact of reintroducing badgers to this country, and an overview of current plans for monitoring them at specific sites.

The presentation was given by Dr Alan Puttock, an Exeter geography graduate and Research Fellow at the University of Exeter who has specialised in hydrology and is thus well placed to explore the work of beavers and their environmental impact in the landscape.

With increasing awareness of the importance of water quality, water management and carbon capture in a warming world, issues of water pollution, flooding and soil erosion pose major challenges. Re-introducing native species can help a lot. Beavers are a keystone species that were hunted to extinction in Britain 400 years ago and today their activities are being monitored at a number of protected sites in England. Beavers, said Alan, do not adapt to their environment, they change it.

Beavers can weigh up to 20 kg and grow to over a metre in length and while somewhat ungainly on land are adept in the water. Once hunted by wolves and bears they have no natural predators in Britain today: however, in what is now a densely populated country with intensively managed rural areas, beavers have a major impact on the landscape which can bring them into conflict with some landowners and farmers. Thus monitoring their introduction and impact is vital.

Alan showed footage taken by a drone from a Devon site where beavers had built 13 dams in 11 years, transforming the hydrology and geography of the area and having a positive impact on water purity by filtering out sediment, slowing water flow by some 20 per cent, increasing carbon capture and widening the range of aquatic ecology. This in turn has provided a favourable environment for smaller mammals such as water voles to flourish. In times of drought, water continues to trickle through the dams, thus reducing the immediate impact of both floods and droughts. Alan considers beavers to be Nature’s ecosystem engineers.

The beavers’ activities are monitored in Devon by the Devon Wildlife Trust and data are sent to the Environment Agency, along with data from about 30 other sites across the country, for use in flood management planning. Alan concluded his talk by highlighting the benefits of working in a collaborative way across a number of agencies, describing the activities of the River Otter beavers in East Devon which have involved farmers, landowners and the eco-tourism industry as well as scientists, the environment agency and local residents. He was also pleased to report that at national level, policy documents have started to note the work and impact of beavers on the environment. After taking questions we thanked Alan for a most informative and fascinating talk and for his generous donation of our speaker’s fee to the Devon Wildlife Trust.

Louise Clunies-Ross


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