Long claws make for excellent clam-digging.

Every year when coastal brown bears emerge from their winter lairs, groggy from a long hibernation, they go questing for a good dinner. They’re opportunistic feeders, eating vegetation, intertidal invertebrates, berries, and salmon.

Bears are unbelievably effective clammers: during a study watching bears go clamming for 233 days over 3 years, the researchers found bears find and eat a clam every minute. Clams are only exposed for a brief time: a few hours at extreme low tides about 15 days a month. Yet in that extremely brief time, bears manage to eat 50 to 100 clams in a single session. It’s not enough to build up fat supplies like salmon does, but it’s a far more energy-dense supply than purely grazing.

A coastal brown bear and her cub walk along the beach at Silver Salmon Creek in Lake Clark National Park. Image credit: National Parks Service/K. Jalone

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Interestingly, most bears you see clamming are sows, and usually have cubs in-tow. Researchers theorize that it’s too much effort for larger bears to go digging for such a small amount of food. This subsequently means that it’s an open space with no big bears, so sows can go foraging without fearing for their cubs.

Bears can be right and left pawed, or even ambidextrous while digging for dinner. Along the Alaskan coast, brown bears adore munching on Pacific razor clams, soft shell clams, a few molluscs, and any tube worms they happen to sniff out.

[Cunningham Outdoors; Dynamics of Intertidal Foraging by Coastal Brown Bears in Southwestern Alaska]

Top image: A costal brown bear and her cubs dig for clams on the shore of Lake Clark. Credit: National Parks Service/K. Jalone


Contact the author at mika.mckinnon@io9.com or follow her at @MikaMcKinnon.