1. Large semiaquatic rodent with webbed hind feet and a broad flat tail; construct complex dams and underwater lodges.
Aquatic rodent Castor fiber with webbed hind feet, a broad flat scaly tail, and thick waterproof fur. It has very large incisor teeth and fells trees to feed on the bark and to use the logs to construct the “lodge”, in which the young are reared, food is stored, and much of the winter is spent.
Beavers can construct dams on streams, and thus modify the environment considerably; beaver ponds act as traps for minerals and provide fertile living conditions for other species— zooplankton biomass may be 1,000 times greater within a beaver pond than elsewhere. Beavers once ranged across Europe, N Asia, and North America, but in Europe now only survive where they are protected, and are reduced elsewhere, partly through trapping for their fur.
2. The soft brown fur of the beaver.