Jump to content

Eurasian beaver

From Tilcayo Cats, the lean encyclopaedia by Tilcayo Knowledge Systems

The Eurasian beaver (Castor fiber) is a large rodent that lives in and beside rivers, streams and lakes in Europe and Asia.[1][2] It is the largest rodent in Britain.[3] A century ago, hunting had reduced it to about 1,200 animals in scattered places from France to Mongolia, but it has since recovered to a minimum of about 1.5 million.[2][4] On the global IUCN Red List it is assessed as Least Concern, in an assessment published in 2016.[5][6] In Great Britain, where it was hunted out and later brought back, it is listed as Endangered on the British regional Red List.[7][8]

Description

Adults measure 74–90 cm long, not counting the broad, flat tail, which is 28.5–35 cm long. They usually weigh between 12.5 and 38 kg.[9] Their front teeth are bright orange, because the enamel is strengthened with iron.[10] The hairless tail works as a rudder when swimming and as a warning signal.[11] Beavers are slow on land but are excellent swimmers and can hold their breath for up to 15 minutes.[12]

Behaviour and diet

Beavers live in small family groups, usually a breeding pair with their young.[13] They eat plants: in summer they feed on rhizomes, pondweed, ferns and grasses, and in winter they switch to wood and tree bark.[14] Their average lifespan is 8 years, but they can live up to 25.[15]

Beavers build dams only where the water is too shallow or fast-flowing; they also dig burrows in riverbanks or build lodges for shelter.[16] Lodges are surrounded by water and entered from underwater, which protects the beavers from predators.[17]

Effects on the environment

Beavers are often called "ecosystem engineers" because they change the places where they live, most famously by building dams.[18] By felling trees they coppice woodland, letting smaller plants grow underneath.[19] Their dams stop eroded soil being washed out to sea and can improve water quality downstream by trapping sediment.[20] The Mammal Society notes that beavers can also cause conflict with people when new wetlands spread onto farmland.[21]

Distribution and recovery

According to a 2021 review by Halley, Saveljev and Rosell, about half of the world's Eurasian beavers live in Russia.[22] The species has been re-established in every country of its former European range except Portugal, Italy and the southern Balkans.[23]

Great Britain

The Mammal Society states that the beaver was hunted to extinction in the UK by the end of the 18th century, and that the first official reintroduction, into an enclosure in Kent, took place in 2003.[7] Wild populations are now known on the rivers Avon, Frome and Otter in south-west England, and at Knapdale and on the River Tay in Scotland.[24]

On the 2020 regional Red List for Great Britain, the beaver is classed as Endangered in Great Britain and in Scotland, and "Critical" in England; the Mammal Society gives no category for Wales.[6][8] These categories apply to Britain only; worldwide, the species is assessed as Least Concern.[6]

In England the beaver became a legally protected species on 1 October 2022, when the Beavers (England) Order 2022 added it to the list of European Protected Species.[25][26]

References

  1. ↑ "Eurasian beaver". The Mammal Society. Retrieved 18 October 2026. Riparian, usually associated with broad-leaved woodland.
  2. ↑ 2.0 2.1 Halley, Duncan J.; Saveljev, Alexander P.; Rosell, Frank (2021). "Population and distribution of beavers Castor fiber and Castor canadensis in Eurasia". Mammal Review. 51 (1). doi:10.1111/mam.12216. A century ago, overhunting had reduced Eurasian beaver Castor fiber populations to c. 1200 animals in scattered refugia from France to Mongolia. {{cite journal}}: |access-date= requires |url= (help)
  3. ↑ "Eurasian beaver". The Mammal Society. Retrieved 18 October 2026. The Eurasian beaver is the largest rodent in Britain.
  4. ↑ Halley, Duncan J.; Saveljev, Alexander P.; Rosell, Frank (2021). "Population and distribution of beavers Castor fiber and Castor canadensis in Eurasia". Mammal Review. 51 (1). doi:10.1111/mam.12216. Population has more than tripled since the first modern estimate in 1998; the minimum estimate is now c. 1.5 million. {{cite journal}}: |access-date= requires |url= (help)
  5. ↑ "Castor fiber". IUCN Red List of Threatened Species. IUCN. 10 September 2016. Retrieved 18 October 2026. Castor fiber: Batbold, J, Batsaikhan, N., Shar, S., Hutterer, R., Kryštufek, B., Yigit, N., Mitsain, G. & Palomo, L.
  6. ↑ 6.0 6.1 6.2 "Eurasian beaver". The Mammal Society. Retrieved 18 October 2026. Conservation status: UK Red List GB: Endangered England: Critical Scotland: Endangered Wales: N/A Global: Least Concern
  7. ↑ 7.0 7.1 "Eurasian beaver". The Mammal Society. Retrieved 18 October 2026. Hunted to extinction in the UK by the end of the 18th century, the first official Eurasian beaver reintroduction into an enclosure took place on an enclosed wetland site in Kent in 2003.
  8. ↑ 8.0 8.1 Briggs, Helen (30 July 2020). "Wildcat and red squirrel among mammals at risk of extinction in Britain". BBC News. Retrieved 18 October 2026. Endangered: Beaver, red squirrel, water vole, grey long-eared bat
  9. ↑ "Eurasian beaver". The Mammal Society. Retrieved 18 October 2026. Between 74-90cm in length, excluding the broad, flat tail which measures between 28.5-35cm long. Weight is variable, typically anywhere between 12.5-38kg.
  10. ↑ "Eurasian beaver". The Mammal Society. Retrieved 18 October 2026. Their teeth are bright orange, due to their enamel being reinforced with iron
  11. ↑ "Eurasian beaver". The Mammal Society. Retrieved 18 October 2026. The tail is broad, flat and hairless, functioning as both a rudder for swimming and as a warning signal
  12. ↑ "Eurasian beaver". The Mammal Society. Retrieved 18 October 2026. Although slow on land, beavers spend a lot of time in the water and are excellent swimmers, able to hold their breath for up to 15 minutes.
  13. ↑ "Eurasian beaver". The Mammal Society. Retrieved 18 October 2026. They live in small family groups, usually consisting of a monogamous breeding pair and the young of that year, sometimes accompanied by the previous year's young.
  14. ↑ "Eurasian beaver". The Mammal Society. Retrieved 18 October 2026. In the summer, beavers will eat vegetation such as rhizomes, pondweed, ferns and grasses, switching to wood and tree bark in the winter months.
  15. ↑ "Eurasian beaver". The Mammal Society. Retrieved 18 October 2026. Average lifespan is 8 years, but they can live up to 25.
  16. ↑ "Eurasian beaver". The Mammal Society. Retrieved 18 October 2026. Beavers only dam rivers where the water is too shallow or fast-flowing, but they will also burrow into riverbanks or build lodges for shelter.
  17. ↑ "Eurasian beaver". The Mammal Society. Retrieved 18 October 2026. These lodges offer protection from predators as they are surrounded by water and accessed from underwater.
  18. ↑ "Eurasian beaver". The Mammal Society. Retrieved 18 October 2026. As ecosystem engineers, these large rodents modify the environment around them, most famously by building their distinctive dams.
  19. ↑ "Eurasian beaver". The Mammal Society. Retrieved 18 October 2026. By felling trees, they coppice woodland, allowing understorey plants to grow
  20. ↑ "Eurasian beaver". The Mammal Society. Retrieved 18 October 2026. Their dams prevent eroded soil being washed to sea, and improve water quality downstream by blocking sediment and filtering water.
  21. ↑ "Eurasian beaver". The Mammal Society. Retrieved 18 October 2026. they hold potential for human-wildlife conflict if they colonise and cause new wetland areas that encroach on productive farmland
  22. ↑ Halley, Duncan J.; Saveljev, Alexander P.; Rosell, Frank (2021). "Population and distribution of beavers Castor fiber and Castor canadensis in Eurasia". Mammal Review. 51 (1). doi:10.1111/mam.12216. About half of the world population lives in Russia. {{cite journal}}: |access-date= requires |url= (help)
  23. ↑ Halley, Duncan J.; Saveljev, Alexander P.; Rosell, Frank (2021). "Population and distribution of beavers Castor fiber and Castor canadensis in Eurasia". Mammal Review. 51 (1). doi:10.1111/mam.12216. Beavers are now re‐established in all countries of their former European range except for Portugal, Italy, and the southern Balkans {{cite journal}}: |access-date= requires |url= (help)
  24. ↑ "Eurasian beaver". The Mammal Society. Retrieved 18 October 2026. Currently, wild beaver populations are known to be present on the rivers Avon, Frome and Otter in south-west England, and in Knapdale and the river Tay from Scotland.
  25. ↑ "The Beavers (England) Order 2022 (SI 2022/858)". legislation.gov.uk. Retrieved 18 October 2026. In Schedule 2 (European Protected Species of animals) to the Conservation of Habitats and Species Regulations 2017, after the entry for "Bats, Typical (all species)" insert— "Beaver, Eurasian Castor fiber"
  26. ↑ "The Beavers (England) Order 2022 (SI 2022/858)". legislation.gov.uk. Retrieved 18 October 2026. Made 21st July 2022 Laid before Parliament 22nd July 2022 Coming into force 1st October 2022
Retrieved from "https://tilcayo.cat/w/index.php?title=Eurasian_beaver&oldid=175558"