Further information about beavers

Beavers are nature's water engineers. On rivers where beavers are present, their activity provides the following benefits:

• Reducing impacts of flooding downstream by engineering pools and canals that hold water and release it slowly back into the watercourse
• Creating wetland habitats that increase diversity and abundance of wildlife including amphibians, aquatic insects, water voles and wetland birds
• Increasing biomass of fish in rivers: beaver dams provide space for juvenile fish to shelter and feed
• Improving water quality: beaver dams trap silt that has been washed off the land, including soil that has been treated with chemical fertilizer. Water is cleaner after passing through a beaver dam
• Encouraging wildlife tourism and increasing people’s appreciation for - and engagement with – the natural world

Beavers were last widespread on England's waterways 500 years ago. Human use of the landscape has changed dramatically while beavers have been absent so it's important to find a way to minimise conflict between beaver and human activity. For example: while beaver activity can reduce the impact of flooding throughout a river catchment, beaver dams can create localised flooding on land close to a dam. A management framework allows conservation professionals to assist landowners in finding solutions to such localised problems.

Beavers are a native species that was hunted to extinction in Britain.  Although they are now returning, they still exist in small and isolated populations that are still very vulnerable.  Legal measures are now in place to safeguard these recovering populations to prevent persecution by a small number of people, but they must also enable straightforward management of conflicts to ensure ongoing support from landowners. Find out more here.

Beavers are herbivores so do not eat fish. Beavers and fish populations evolved together so salmon and trout historically thrived in rivers heavily impacted by beavers. Research in Europe and North America shows the presence of beavers on a river has more positive than negative impacts on a wide range of fish species. This is due to new habitats created in rivers and streams, the cleaner water and the enhanced flows during droughts.  In some instances, especially in dry conditions, beaver dams can create barriers for migratory fish such as sea trout.  Most beaver dams are likely to be further upstream of important salmon migration routes. The River Otter Beaver Trial showed the beneficial impacts on fish populations and even filmed sea trout jumping a beaver dam.  However further research is needed in different river systems - chalk streams, for example - on how these fish species and beavers can share watercourses that have been heavily modified by humans. 

Beavers rarely move more than 10 metres from water so will only coppice or fell trees that are within this distance from a river. While they will occasionally cut larger trees, the majority of trees felled by beavers on the River Otter have been no more than 3cm in diameter. By far the most favoured tree species is willow, which grows back very quickly when cut. Where beavers might impact on trees situated near a waterway where the trees have commercial value (such as orchards) or sentimental value (such as in gardens) action can be taken to protect the tree(s) either by beaver-proof fencing or beaver-repellent 'paint'.

DWT believes there should be incentives for farmers and landowners to make land close to waterways available where beavers could create wetland habitats. This land would be contributing to increases in biodiversity - and to flood and drought resilience - so it is important that landowners have a way to value these ecosystem services, ensuring benefits to the natural environment are not in competition with commercial use of the land. 

In the short term this is not an issue but in the future some very small beaver populations may need supporting by introducing animals with a different genetic make-up to prevent inbreeding.

Beavers will naturally disperse to other river catchments and they will be allowed to stay there. However, Devon Wildlife Trust or other locally based organisations may need to set up a local management group to ensure that the beaver population is monitored and that the local community are supported to live with their new beaver neighbours and that any potential issues are handled appropriately.