BEAR UPDATE: 183 days inside a tree den: status of sleeping bears By Michael Allen Black Bear Researcher Large snowflakes mixed with small granular snowballs whirl and crackle against my Gore-Tex jacket. I lean out of the wind and sit with my back up against a snag tree. Peering through the sub-alpine fir forest to the ski trail edge 24 metres away, I hear the swoosh of skis. "Last call for ski patrol — sweep!" The time was 16:50 and the ratta-tat-tat of the gondola and the distant hum of a snowcat were dying as blizzard-like conditions settled in. It is May 3, 1999. Approximately 400 cm beneath me, through the snow, and inside the hollow dead tree I was leaning against, lay a dormant three-year-old female black bear. After six months and three days, Hali has yet to emerge from this winter den. Born to Whistler Mountain resident mother Hazel in 1996, Hali entered her den on Nov. 2, 1998 after being forced to search for man-made food at the Roundhouse Lodge following an abrupt drop in September huckleberries due to extended high temperatures. I sit with my back against the tree den because it's the only method I know to detect bear activity beneath the snow. I can't here bear movement through the snow pack but when the bear shifts position or scratches against the inside of the hollowed tree, vibrations can be felt and claws can be heard up through the cavity of the tree. When I do begin to hear sounds of activity from inside the tree and I think it's near a potential emergence period I retreat to 15-20 metres to observe. I slump back and close my eyes trying to visualize Hali inside. On Jan. 25-26, 1999, BBC camerman Jeff Turner and I were successful in filming a dormant bear inside another tree den on Whistler Mountain. Our first attempts were with Hali's den, which involved hand drilling a 1/4 inch hole into the snag's cavity to insert a "lipstick" camera. The camera could not be inserted because the hollow cavity did not extend high enough and we kept finding small isolated pockets of rotten wood which did not provide a clear view to the sleeping bear. We attempted another den where I knew the entrance was slightly exposed and I could see the bear after removing only handfuls of snow. We lowered the camera, taped to a bamboo pole, through the entrance without waking the sleeping bear and managed to record two hours of footage, of which some will appear in the BBC documentary next winter. This winter a minimum of six black bears are denned (four in trees, two in ground dens) within the ski area boundary on Whistler Mountain. All but one of the denning bears remain dormant inside their dens. One adult bear emerged during the last week of March. There are likely more than six bears denning in the ski area because bears often remain active into early November grazing clover and foraging scattered berries amongst the mid-elevation ski trails prior to the first heavy snow falls. The ski area benefits the bears by providing pre-denning foods and nearby secure den sites so bears can avoid travelling many kilometres outside the ski area through deeper snows. This gives the bears an advantage to feed later and still find a den nearby. Dens may be found in clusters. Ten dens may be found in 500 metres of sub-alpine fir or mountain hemlock forests. These clusters of den use reveal the importance and quality of available dens to bears in the ski area. But usually half of the dens are abandoned due to natural deterioration, leaving 3-5 solid active den sites for bears. Bears don't reuse the same den site every winter but will look for a den in that same area, sometimes denning as close as 100 metres to their previous den. Physical characteristics of 96 den sites and their bear use in the Whistler Ecosystem will identify variables to describe denning ecology in Whistler. So far, Whistler-Blackcomb winter ski resort operations have had no significant negative impact on the black bear's natural dormancy period. Bear Family Information - Since 1996 many people have provided information about bear family sightings throughout the Whistler, Pemberton, Birken, and D’Arcy corridors. I verified many of these sightings and am currently constructing a database on the reproductive fitness of adult female black bears from these different ecosystems. Each yields different food resources for adult females which dictate cub production and survival. Natural foods vital to bears along the corridor are skunk cabbage, clover, berries, and salmon. Salmon is not available to bears in Whistler. Anthropogenic (man-made) food sources which enhance adult female black bear reproductive fitness (increased size and frequency of litters) are edible human garbage in Whistler and agricultural crops in Pemberton through D’Arcy. Anyone with questions about black bears or with information of a bear family sighting (mother with cubs or yearlings) in the Whistler-D’Arcy corridor may contact me at 935-1176. Black bear education programs in Whistler are sponsored in part by Whistler-Blackcomb, Whistler Museum and Archives, and Pique Newsmagazine.
