Easy prey:Big Alaska bears rely on small streams to fatten up on salmon

摘要

It's a familiar scene to anyone who's watched footage of brown bears catching sockeye salmon in Alaska: They're standing knee-deep in a rushing river, usually near a waterfall, and grabbing passing fish with their paws or jaws.But a new study published in the journal Conservation Letters reveals a different picture of how and when bears eat salmon. Most of these bears, also known as grizzlies, are dipping into small streams to capture their iconic prey.Using a foraging model based on the Wood River basin in Southwest Alaska, a study team led by Oregon State University determined that while small-stream habitats have only about 20 percent of the available salmon in the watershed, they provide 50 percent of bear consumption of salmon.