Beavers Help to Reduce Negative Effects of Droughts

American beavers (Castor canadensis) are key members of the wetland communities they inhabit, especially in times of drought. Scientists from the University of Alberta, Canada, found that when beavers and their dams are present in a habitat, that habitat was nine times more likely to contain open water than it was if no beaver or dam were present.

The study's lead investigator, Glynnis Hood, and co-investigator, Suzanne Bayley, examined wetlands in Alberta's Elk National Park over a 54-year period. They found that in times of drought, beavers and their dam-building activities helped to keep water in areas that would otherwise dry out. Hood and Bayley compared areas that had been subject to drought, with and without beavers. They found that when beavers were present in a habitat, there was 60 percent more open water than there was in that same area during previous drought periods when beavers and their dams were not present.

Many climate change models are now predicting a higher occurrence of droughts in many parts of North America. As a result, the role beavers and their dams plays in maintaining the health of wetlands through dry times is ever more critical. In describing the role of beavers and the impact of their removal from a habitat, Hood likened the disappearance of a beaver to other severe environmental disruptions:

"Removal of beaver should be considered an environmental disturbance on par with in-filling, peat mining and industrial water extraction."

Additional studies on beavers have shown that their dam building activities provides habitat for songbirds and also helps to protect amphibians.

Find out more:

• Beaver Dams Provide Habitat for Songbirds
• Beavers Help to Protect Amphibians
• Beavers Can Help Ease Drought (Eurekalert)

Photo © Glynnis Hood / University of Alberta.