All about the Beaver

Photo courtesy of David Parkyn Cornwall Wildlife Trust

Beavers could be returning to Ealing after an absence of some 400 years. In a joint project between Ealing Wildlife Group (EWG), Ealing Council, Citizen Zoo and Friends of Horsenden Hill, supported by experts at the Beaver Trust, the intention is to apply for a license from Natural England to reintroduce Eurasian beavers to Ealing in a controlled enclosure trial at Paradise Fields in North Greenford.

Beavers are native to Britain but were wiped out in the 16th century, mainly due to hunting. They were hunted for their luxurious fur and for the castoreum they secrete which has been widely used in perfumes over the years, mainly for its ‘leathery’ notes.   

Beavers live in lodges that they build with sticks and mud; the entrance is underwater. They build dams primarily as protection against predators, and as a way to provide easy access to food during the winter.

The dams can modify the natural environment in such a way that the surrounding ecosystem builds upon the change, making beavers a keystone species. They work at night, carrying mud and stones with their fore-paws and timber between their teeth, and are prolific builders. Beavers can close their mouths behind their teeth allowing them to swim with sticks in their mouths.

What impact do beavers have on the environment?

Beavers modify the habitats and landscapes in which they live, these changes can markedly alter the appearance of the local environment but research indicates a positive overall ecological functioning of catchments and river systems.

Beaver adaptations can bring enormous benefits to other species, including otters, water shrews, water voles, birds, invertebrates especially dragonflies, and breeding fish. Beavers naturally create and maintain diverse habitats providing catchment resilience and climate change adaptation. Their leaky dams can hold water in periods of drought and can regulate flooding by slowing water flow. They can also improve water quality by holding silt behind dams and catching acidic and agricultural run-off. 

Beavers forage close to water with activity usually concentrated within 20m of the water’s edge. Beavers fell primarily broad-leafed trees and bushes, in order to eat the cambium (a thin layer between the bark and wood) during the winter and to construct their lodges and dams. Most coppiced trees will regenerate, diversifying the surrounding habitat structure.

In some locations and circumstances, beavers require direct management intervention by people. A range of mitigation and management techniques are available such as installing overflow piping on dams to alter pool height and wrapping trees in wire mesh to prevent gnawing. Beavers rarely eat conifers, although they can be felled by beavers as an emergency forage in rare instances. Immature animals may attempt gnawing before quickly learning that they are unpalatable and unsuitable,  due to the tannins and sap present. Beavers generally do not live in water entirely surrounded by conifers. 

Do beavers eat fish?

No. Beavers are herbivores. They eat woody plants and cambium from trees, aquatic plants, grasses and shrubs

What impact do the beavers have on water quality and hydrology?

Research suggests that ponds and water pools created from beaver dams can have marked benefits on local water quality. The ponds can help to neutralise acidic run-off, act as sinks for pollutants and increase the self- purification of a watercourse. They can form considerable sediment traps, reducing very strongly erosive run-off and particulate loads in downstream water.

Beaver Reintroduction in the UK

Humans evolved alongside beavers and they are part of the British natural fauna.  The Berne Convention on Species places an obligation on us to reintroduce them.  Over the last few years there have been numerous reintroductions across the UK, including the Forest of Dean, the river Otter in Devon, Ham in Kent and Lowther Castle in Cumbria.  

In 2020, two adult beavers, a male and female, were released into a 27-acre enclosure at Lowther Estate near Penrith, for a five-year scientific trial. The aim is to obtain data on the impact of beavers in an upland environment, in particular on a stream in a farmed landscape.

The female, Dragonfly, was trapped and relocated from the River Tay catchment in Scotland, under licence from NatureScot, the public body responsible for Scotland’s natural heritage. The male, Glen, was rescued from the outflow of a hydroelectric plant in Perthshire by the Scottish Society for Prevention of Cruelty to Animals (SSPCA).

 It’s thought that Glen became trapped while moving between areas, trying to establish his own territory.

Heather Devey introduces the Lowther Beavers

Now we hope it’s the turn of Ealing. Find out more on the EWG website; Ealing Beaver Reintroduction Project: statement of intention. – Ealing Wildlife Group