Some people believe beavers are harmful to the natural world. They are, in fact, essential for the health and wellbeing of the ecosystem. Here are some common misconceptions, myths, exploded.

If you have a question that is not answered below, please do not hesitate to get in touch

Beavers eat fish

No. Beavers are herbivores, feeding exclusively on bark, leaves and roots

Beavers have a bad effect on fish

On the contrary, beavers have been reintroduced into American rivers such as the Elk Creek of the South Umpqua River to return Coho salmon after the river was ruined by logging.  The coarse woody debris that beavers put in the river provides food and habitat for young fish. Because of the evidence, there are projects currently running along the River Calder in order to ‘re-naturalise’ the area and provide important habitat and shelter for returning breeding salmon and salmonids, by simply uprooting trees and placing them in the river.

Beaver dams rarely restrict access to migrating fish and this usually only occurs in periods of drought. Beaver dams are completely different from man-made structures. They are organic structures and designed to leak, compared to their concrete based man-made counterparts.

The decline of salmonids  is likely to be partly related to the decline in beaver populations. A study of small streams in Sweden found that brown trout were larger in beaver ponds compared with those in fast flowing sections, and that beaver ponds provide habitat for larger trout in small streams during periods of drought.

On balance the benefits outweigh any temporary negative impacts for migratory fish. In exceptional situations dams can be modified or removed.

Now beavers are protected it is not possible to legally manage them

SWBG recognises that various forms of management are needed for beavers and that the need will increase as the population increases. However, we feel strongly opposed to a free-for-all approach to beaver culling. Beaver mitigation is a vastly studied and ‘tried-and-tested’ topic across North America and Europe. It is clear that mitigation can take place to remove most obstacles that occur due to beaver habitation in an area, and lethal control should only be used as a very last resort. However, mitigation such as the installation of ‘beaver-deceivers’ or tree rapping should be tried first, in order for beavers and humans to live in harmony within the same landscape. Where good habitat exists other beavers will move in if the first family are removed.

Managing beavers is expensive and not worth the money

Beavers bring benefits of great economic value: they strip agricultural pollutants out of water, mitigate both floods and droughts and vastly increase biodiversity (including economically important species).  The cost of local mitigation is minor compared to this.

Beavers dam big rivers

No. Beavers can’t dam fast flowing water.  Their dams are built on small streams and ditches.  Their impact on big rivers is minimal.

Beavers kill lots of valuable trees

Beavers do cut down native trees near the water’s edge, but most of these trees coppice abundantly or sucker from the roots (they evolved with beavers). Whilst visiting beaver inhabited areas you will see there are often numerous examples of regrowth. Sometimes beavers do flood small areas of woodland and drown some trees, but  wet woodlands are a rare and important ecosystem for many species, and dams can always be altered or removed if this is a problem.

Beaver coppice has been demonstrated to help stabilise river banks, by turning taller trees (whose roots may take bank with them if they blow down) into short bushy growth less vulnerable to wind blow. Beaver coppice does not affect the root system of the trees, but does increase the diversity of age classes, which has positive affects on species diversity.

Beavers very rarely cut conifers in valuable plantations. However, if  valuable conifers are flooded by a beaver dam, measures can be taken to reduce the height of the dam.


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