Beavers leave a trail as they head into the Arctic and reshape the landscape

A study has provided new evidence of beavers' expansion into the Canadian Arctic by dating the changes they have made to the tundra landscape as they spread northward. Published in the journal Ecosphere, the research combines tree-ring analysis, or dendrochronology, with satellite imagery of surface water to pinpoint the spread of the North American beaver (Castor canadensis) in a remote part of Canada's Northwest Territories.