Dorset Beaver Project

As herbivores, beavers eat a wide range of vegetation and this can include trees.  They forage close to water with activity usually concentrated within 20 metres of the water’s edge. Beavers do selectively fell broad-leaved trees and bushes to reach upper branches, to encourage regrowth, to eat the bark during the winter and to construct their lodges and dams. Many tree species regenerate, which diversifies the surrounding habitat structure and create areas of mixed-height, mixed-age vegetation that benefits many wildlife species. Coppicing has been practiced by foresters throughout history as a method to manage bankside trees. The actions of beavers are very similar, meaning woodlands and trees are more naturally managed. Where needed, there are methods to protect special trees from unwanted attention from beavers and we are testing these in our enclosed site.   

Although they don't eat fish, habitat modification by beavers can affect fish in some circumstances, and anglers are often concerned about the potential impact of beaver dams on the movement of migratory fish. Historically these species will all have been adapted to live together, but our wildlife and rivers have been severely affected by human activity since then and, as nature recovers, any species that is at a low ebb may struggle to cope with change and need a helping hand. The interaction between beaver activity and freshwater fisheries has been the subject of several reviews. Overall the impacts have been found to be positive, the benefits being an increased area and variety of fish habitat, increase in invertebrates and cleaner and more plentiful water. Negative impacts can include the impact of dams on fish movement (though dams are by nature leaky and fish can travel through and up many of them), changes to spawning gravels (cleaner gravels downstream of dams, but more silted upstream) and lower oxygen levels in ponds. We are surveying fish and aquatic invertebrates as part of our enclosed study to show the possible impacts beavers have on other wildlife. 

The Government has now announced that beavers will be protected in England. Dorset Wildlife Trust supports this legislation alongside appropriate and proportionate licensing arrangements that enable timely management measures.  

It is essential that Government makes funding available for land managers to make space for water, including but not just by beaver activity. Beavers can have many benefits for the wider environment, but there can also be localised costs and problems, and funding should be targeted to help address these. Face-to-face advice and support is essential for landowners and those directly impacted by beaver activity. This has been effective in the River Otter beaver trial in Devon - there is more information about that project if you click on the link below.

Reintroductions and translocations of Eurasian beaver have now taken place in more than 25 European countries, starting in the 1920s, so there are years of experience to draw from. Evidence shows that shows that beaver impacts are, in the vast majority of cases, small-scale and localised. Beavers are not normally regarded as pests in Europe and where localised problems have occurred, there are a number of well-established mitigation methods that can be adopted. These include the removal of dams, the introduction of overflow piping, or the installation of fencing (as one does for deer and rabbits). In some cases, the removal and translocation of beavers could be considered. Some countries with sustainable beaver populations permit seasonal hunting and/or lethal control as legitimate management strategies. In the 'Living With Beavers' film (link below) a group from Cornwall visit Bavaria to hear more about managing beavers there.  

The project licence is initially for five years (2020-2025). 

This is a scientific study site and in partnership with the University of Exeter and Wessex Water, we are gathering information on biodiversity and hydrology (water quality and flow) and studying the behaviour and activities of the beavers. We will be making comparisons to the baseline data gathered before they arrived to see how beavers can improve the habitat they occupy and the wider benefits they can potentially bring to the environment in terms of biodiversity, water quality and beneficial effects on river catchments.

The site is a locked site with no parking or public access and will be accessible for accompanied visitors by invitation only. We are sharing footage and photographs of the beavers in our blog and on social media so you can stay up to date with how they are doing.

• Beavers are vegetarians. They do not eat fish. In fact, they are known to co-exist well with them, boosting fish populations. Beavers snack on riverside plants, grasses, as well as tree bark and shoots.
• Beavers feel safest in still, deep water (around 70cm). They are very unlikely to stray far from it and will create dams if the water levels aren’t what they would like them to be.
• Where beavers go – more wildlife will follow. Beavers create diverse wetland habitats that can provide a home for a wide range of wildlife such as amphibians, water voles, dragonflies, birds and even plants.

• Beaver dams vary in size and structure. In many cases they are small temporary structures made of twigs, which gradually break down as water levels rise. In others, they can be larger stable structures that create big ponds. Both water and fish are able to move through and around them and they are not the huge dam structures made by the North American beaver.

• Beavers can reduce flooding. Beaver dams slow the flow of water; in storms more water is stored; in droughts more water is available. The potential for beavers to reduce flooding and maintain baseflows downstream is significant.

• Beavers can improve water quality. Impoundment of water behind dams can positively affect the quality of water by diffusing pollutants being transported downstream. Their dams act as sediment traps cleaning our waters.