Beavers: Keystone Species and Builders

Beavers build dams and lodges using tree branches, vegetation, rocks and mud; they

chew down trees for building material. Dams restrict water flow, forming ponds,

and lodges (usually built in ponds) serve as shelters. Their infrastructure creates wetlands

used by many other species, and because of their effect on other organisms in the

ecosystem, beavers are considered a keystone species. Adult males and females live in

monogamous pairs with their offspring. After their first year, the young help their

parents repair dams and lodges; older siblings may also help raise newly born offspring.

Beavers hold territories and mark them using scent mounds made of mud, debris,