Beavers are now living as far north as the Arctic, researchers find

North American beavers are colonizing much further north than they used to, according to the U.S. National Oceanic and Atmospheric Administration's annual Arctic Report Card. Using satellite imagery, researchers found ponds with beaver engineering in northern Alaska and Canada.

The study concluded that the number of ponds created from beavers foraging and building dams has doubled in western Alaska in the last 20 years, with over 12,000 mapped. In contrast, researchers looked at decades-old aerial photography of the region and found no beaver ponds in the area prior to 1955.

The area has seen a drastic rise in surface water, and beavers were the dominant factor in almost 66% of such cases, researchers said. In such instances, beavers' dams made rivers more shallow and created inlets. As a result, new ponds are forming and the underlying permafrost is melting, which could affect fish populations and aquatic food webs, but researchers don't have all of the answers yet.