What Are Some Physical Characteristics of Beavers?

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The word "beaver" describes a two distinct species, the North American beaver (Castor canadensis) and Eurasian beaver (Castor fiber). Although both species of sturdy rodents are undoubtedly close on the outside, they do have some subtle physical differences. They also are incapable of reproducing together.

Size

North American beavers usually weigh roughly between 29 and 70 pounds, with lengths of 35 to 46 inches. Eurasian beavers, on the other hand, are usually between 29 and 77 pounds, with lengths from 29 to 53 inches. The latter animals are just a little bigger than the former, although not usually by much. Both species are robust animals with short limbs. Their rear legs are markedly more powerful than their front legs. North American beavers' heads are a tad more rounded than those of the Eurasian beavers.

Fur

Both species possess two separate layers of their coats. The top portion of the coat, which is coarse and thick, offers defensive benefits. Although all beavers have soft and smooth underfur, it is especially so for Eurasian beavers. North American beavers typically have brownish-black or russet fur. Their Eurasian pals usually have russet fur as well. However, Eurasian beavers in southerly locales generally exhibit lighter coats.

Facial Features

All beavers have conspicuously large heads, tiny eyes and barely noticeable ears. One of their most memorable physical traits is their teeth -- they all have sizable pairs of incisors that are vivid orange in color. Beaver teeth grow for throughout their lifetimes. Eurasian beavers usually have longer, thinner mouths and noses, too.

Tails and Feet

Beavers' tails, which are often employed for equilibrium purposes, are scaled and darkly colored. The scales that adorn their tails are nearly black. They are, for the most part, devoid of fur. Although both species have oval tails, the North American beavers' are more prominently so. North American beavers' also have broader tails. All beavers have big webbed feet in the back, while their front feet are small with big claws. Their feet have five digits.

Population Status

Both North American and Eurasian beavers are classified as "least concern" species according to the IUCN Red List of Threatened Species' 2011 and 2008 assessments, respectively. Although their populations are not in urgent jeopardy, they do have some threats. North American beavers are occasionally hunted for their furs. Eurasian beavers are frequently killed in road accidents. Illicit hunting is also a problem for populations of Eurasian beavers, particularly in Mongolia.

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