Bear Update: Visiting a bear den 

By Michael Allen,

Whistler Black Bear Project

I crouch on a worn pair of Tubbs snowshoes. Pale grey and cracking, these extra-large bundles of aluminum and plastic have provided me with winter mobility to over 1,000 bear dens during the last decade.

At nearly 1700-metres elevation on Whistler Mountain’s North Slope, I shift my weight as I hunch back on creaking bindings and glance through a small opening to a clump of trees – fir and hemlocks huddled against sub-alpine fury. Snow crystals launch through -17 C winds from airstrips off stunted, frozen conifer boughs. I breathe onto my bare finger tips and remove a pair of binoculars. Twenty metres side-slope a shadow stares at me from the clump of trees. I stare back.

Within that shadow is a lethargic blackness I have marvelled at for the last 18 winters. The search for hibernating bears in secret winter dens is the jewel of my research, but not without its physical and mental demands. Standing to force the ache and numbness from my legs, I am nearly thigh-deep in powder.

I snowshoe down-slope of the tree clump away from the dead tree then back up, stopping just three meters side-slope and in full view of the black hole. I stop, listen, eyes fixed into darkness. I glide my large snowshoes quietly through dry powder up to the black hole in the dead tree.

Tree cavity dens are the norm for denning bears in Whistler. Basal cavities within dead (or dying) standing snags provide dry, secure shelter from winter weather and outside intrusion of animal or human kind.

I switch on a LED lamp and quietly peer in through an 18-cm wide crack. This is not the entrance but an old knot given way to falling out and cracking. Tips of black hair coat the jagged edge of the opening. I carefully and quietly collect about 10 shafts and place them into an empty film canister.

Bears usually stand or climb inside tree cavities snagging hair at knots or cracks besides the den entrance and denning bed substrate.

Doubtful that follicles are present, good samples of shafts still may hold DNA. I don’t know the identity of this particular bear but now with the tool of genetic profiling from hair DNA I can match this sample’s profile with known bear profiles from my population database.

Most of the time I know the ID of bears that I snow-trail to dens in November and December. Although not knowing, is interesting too – to the sound of three new-born cubs on a few den visits in March. New-born cubs can be detected by vocalizations during March and April.


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