Species of Beavers

Beavers belong to the scientific genus Castor which makes up two different species. The Eurasian and American beavers are fundamentally the same but have a few different characteristics, especially with where they are found. Both beavers are considered the largest rodent species in their respective ranges and have historically been hunted for their fur.

  1. Description

    • At a glance, both beavers look identical. They are both large, dark brown rodents with a distinctive flat, paddle-like tail. The Eurasian beaver is larger on average, growing up to 53 inches in length and 77 lbs. compared with 46 inches and 70 lbs. for the American variety. In both species the ears and nose can be closed when they dive under water, and their thick waterproof coats are double layered. Beavers have large orange ncisor teeth which are used to gnaw through wood.

    Range and Habitat

    • The American beaver lives throughout North America with the exception of the most northern regions of Canada and dry desert regions in the Southern U.S. and Mexico. The Eurasian beaver, at one time, ranged widely in Europe and Asia but hunting has restricted populations to northern Europe. Populations are now found in France, Scandinavia, Russia and Germany. Both beavers live in or around fresh water such as lakes, rivers and streams in woodland habitats with a ready supply of small trees. Beavers build homes made of mud, branches, logs and stones known as dams in the water.

    Diet and Predators

    • Beavers are herbivores and both types feed heavily on tree bark and the soft tissue beneath it. Aquatic plants, shoots and plant roots are also included in the animal's diet. The tree types favored by both species include willows, aspens and birches. Since it is a large mammal, generally only the biggest predators hunt the beaver. In Europe its main predators are brown bears, wolves and foxes. American beavers have the same predators and then some, having to contend with wolverines, lynxes and black bears as well.

    Life Cycle

    • Both types of beaver are sociable animals and live in small family groups with around eight members. Each group has a dominant breeding pair which are the only ones to produce young. Breeding takes place once a year with pregnancies lasting a few months, but generally no more than four. European beavers tend to have larger litters, with up to six pups, compared with four for American beavers. Both beavers tend to mature at similar rates with pups becoming independent at 2 years old and sexual maturity at around 3 years old. American beavers generally live longer, surviving between 10 to 20 years on average compared to 10 to 17 years for European beavers.