Quirks & Quarks

How do bears find a place to hibernate

Both grizzly and black bears are able to dig themselves burrows, rather than find caves, in order to hibernate through the Winter.
A bear emerges from its den in Russia

We tend to think of bears finding places like caves to hibernate.  But according to Dr Stephen Herrero, a professor emeritus of environmental science and a bear expert from the University of Calgary, caves make up a very small percentage of hibernation sites.  In fact in his recent work in Banff National Park, only one of over fifty grizzly bear hibernation dens was a cave.  The majority of dens are created by the bears burrowing into the side of a slope high up in the mountains.  In a similar way, black bears also dig their own dens, making use of spaces under fallen trees and rotting stumps in forests.