Beaver Management and Beaver Dam Analogs

Beavers are large, semiaquatic, herbivorous rodents that reside in the Northern Hemisphere. Only one species of beaver, the North American beaver (Castor canadensis), lives in the United States, covering most of the contiguous states (except for Florida, small patches of the Midwest, and the arid Southwest) and southern Alaska (USFS n.d.). Beavers are prominent ecosystem engineers because of their dam-building prowess. Beaver dams alter the hydrology of streams and small rivers, generating a multitude of benefits including filtering pollution, creating wetlands, storing groundwater, preventing floods, and sequestering carbon (Goldfarb 2018). In the pre-Columbian era, there were an estimated 250 million beavers in North America, a number that declined to 100,000 in the early 1900s as a result of intensive trapping (Ortiz and Dello Russo 2021; Goldfarb 2018). Since then, trapping regulations and beaver reintroductions have resulted in an estimated 10 to 15 million beavers living in North America today (Ortiz and Dello Russo 2021; Bardeen 2022). Beaver management refers to a strategy of increasing beaver populations through beaver reintroductions, enhancing beaver habitat, and promoting human–beaver coexistence (Jordan and Fairfax 2022). If an area wants to reap the benefits of beaver dams but does not have any beavers, beaver dam analogs (BDAs) can be built. BDAs are human built structures meant to mimic the design and function of beaver dams (Anabranch Solutions n.d.).