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Mon July 1, 2013
Dr. Glynnis Hood, University of Alberta – Beaver-Dependant Ecology
In today’s Academic Minute, Dr. Glynnis Hood of the University of Alberta explains the ecological importance of the beaver.
Glynnis Hood is an associate professor of environmental science at the University of Alberta where her research interests include freshwater ecology, wildlife ecology and management, and parks and protected areas. Her current research focuses on wetland ecology as it relates to wildlife habitat and how the presence of beavers affects pond morphometry, biodiversity, and water quality and quantity. She earned her Ph.D. at the University of Alberta.
Dr. Glynnis Hood – Beaver-Dependant Ecology
Imagine an animal that can dig through landscapes with two front feet the size of dessert spoons, stop flowing water to create large ponds with a mere pile of mud and sticks, and combat drought with the precision and expertise of the most skilled engineer. It can even affect the formation of ice in northern ponds. For millennia, North America has been shaped by an animal like no other – the beaver.
Often regarded as a pest, the beaver is one of the most influential species in freshwater ecosystems. A keystone species, beavers act much like the central stone in an ecological arch. Beaver ponds consistently have higher waterfowl diversity, more complex invertebrate communities, and provide critical habitats for endangered amphibians. Beavers create habitats that also provide flood mitigation and resilience to extreme drought. In Canada’s southern boreal forest, ponds with beavers had nine times more open water than those same ponds without beavers, even during extreme drought. Unlike some areas where building dams plays a key role in water management, it was digging of extensive channels away from the pond edge and on pond bottoms that allowed beavers to focus water in this landscape. Their ability to modify landscapes for their gain reflects an unprecedented feat of ecological engineering.
In many areas, beavers spend winters living in lodges while making short feeding trips under the ice. As a result, ice beside active beaver lodges melts almost 11 days sooner than ice in ponds without beavers. Early access to water is a welcome resource to many animals in an otherwise frozen landscape. Canada geese not only use these open water areas during their spring migration, they use the beaver lodges as nesting platforms that protect them from terrestrial predators. Yet another example of the diverse benefits of nature’s wetland engineer.
Production support for the Academic Minute comes from Newman’s Own, giving all profits to charity and pursuing the common good for over 30 years, and from Mount Holyoke College.