Eurasian beaver
| Eurasian beaver | |
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| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Rodentia |
| Family: | Castoridae |
| Genus: | Castor |
| Species: | C. fiber |
| Binomial name | |
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Castor fiber Linnaeus, 1758 |
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| Approximate current range of the Eurasian beaver | |
The Eurasian beaver or European beaver (Castor fiber) is a species of beaver which was once widespread in Eurasia. It was hunted to near-extinction for both its fur and castoreum; and by 1900, only 1200 beavers survived in eight relict populations in Europe and Asia. Reintroduced through much of its former range, it now occurs from Great Britain to China and Mongolia, although it is absent from Italy, Portugal, the southern Balkans, and the Middle East.
The fur color of Eurasian beavers varies geographically. Light, chestnut-rust is the dominant colour in Belarus. In Russia, the beavers of the Sozh River basin are predominantly blackish brown, while beavers in the Voronezh Reserve are equally distributed between brown and blackish-brown.
Eurasian beavers are one of the largest living species of rodents and are the largest rodent native to Eurasia. They weigh around 11–30 kg (24–66 lb), with an average of 18 kg (40 lb). While the largest specimen confirmed on record weighed 31.7 kg (70 lb), the Smithsonian has reported that this species can exceptionally exceed 40 kg (88 lb). Typically, the head-and-body length is 80–100 cm (31–39 in) and the tail length is 25–50 cm (9.8–19.7 in).
Although the Eurasian beaver appears superficially similar to the North American beaver, there are several important differences: the Eurasian beaver has a larger, less rounded head; a longer, narrower muzzle; a narrower, less oval-shaped tail; and shorter shin bones, making it less capable of bipedal locomotion than the North American species. The Eurasian beaver also has longer nasal bones, with the widest point being at the end of the snout; in the case of the North American beaver, the widest point is at the middle of the snout. The Eurasian beaver has a triangular nasal opening, unlike those of the North American beavers, which are square. Furthermore, the foramen magnum is rounded in the Eurasian beaver, but triangular in the North American beaver. The anal glands of the Eurasian beaver are larger, and thin-walled, with a large internal volume, relative to that of the North American beaver. The guard hairs of the Eurasian beaver have longer hollow medullae at their tips. Also, a difference in fur colour exists: overall, 66% of Eurasian beavers have beige or pale brown fur, 20% have reddish brown, nearly 8% are brown, and only 4% have blackish coats; in North American beavers, 50% have pale brown fur, 25% are reddish brown, 20% are brown, and 6% are blackish.
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Wikipedia