Issue link: http://digital.canadawide.com/i/170490
The Flathead region has the highest recorded density of grizzly bears, 53 per 1,000 square kilometres, for a population of 175 bears. FALL TrAnSiTiOn The potential lack of available dens worries biologists. less is known about Interior black bear dens and provincewide researchers have only recorded 250 grizzly bear dens at most. The good news, at least for coastal black bears, is that research from the Haida First Nation suggests dens can be created for black bears by culturally modifying trees—their preferred hibernation habitat—with chainsaws. As long it's dry and safe, bears will snooze. it's October and Marsha is trudging up a trail. Mountain hemlock trees thicken the landscape as she climbs higher, a sign that snow, not rain, falls on this coastal habitat. She pauses before a knot of trees, then like a quarterback hiking a ball, starts hurling dirt between her legs, her powerful claws carving out space under a mass of tree roots. The cubs join her. They do little to help, their gazes following a spider or beetle scurrying across the dirt, then they pounce. Marsha smooths the entrance, ducks inside, then backs out, rolling a boulder the size of an exercise ball. She shoves the rock out of the way, lumbering back inside to finish the family den. it's shorter than the length of a Smart car, a cozy winter home for the mother to settle in with her year-old cubs as company. • right: A female grizzly bear and her cubs head into hibernation high in the Rocky Mountains, near elk lakes Provincial Park. JoHN E MArrIoTT /WIlDErNESSPrINTS.CoM With dens dug and meals scarce, bears go into a reverse walking hibernation around the beginning of october. They stray only about a kilometre from dens to snack and sleep in day beds. Interior bears typically forage in cutblocks and sleep in the forest. By Halloween most bears have retreated from the outside world, though northern bears snuggle in a couple weeks earlier. In places like Kingcome Inlet or Squamish, a December salmon run may keep coastal bears out. But usually only a hungry, desperate bear lingers outside in winter. Den size depends on family size. roomier coastal dens reflect the higher birth rates of coastal bears that are able to fatten up on salmon. They average over two cubs while Interior bears average just over one cub. geography determines architecture, too. Mountain grizzlies crawl into rocky crevices while Plateau bears look for tree cavities or dig into a slope above a creek. In Prince george, Ciarniello studied black bears in the urban landscape, documenting long chambers at bizarre angles leading to dens, possibly a defence against domestic dogs. "Cubs of the year can be very noisy, making suckling sounds, crying, and moving around in the bed," she says. grizzlies prefer mostly unfurnished pads, while black bears strip trees, collect boughs, and gather enough moss to fill a large garbage bag to create an intricate bed resembling a giant bird's nest, often inside older yellow or red cedar trees. large ones average almost 1.5 metres in diameter. "The classic coastal den is a 'Pooh bear' den," Hamilton says. "And we think there is evidence for legacy dens." That's right, bears could be inheriting the family digs. Epilogue: Hamilton lost contact with Marsha when her radio collar dropped off in 1989. She would have had more adventures before her death, probably in the mid-1990s if she lived the expected lifespan of most bears, about 25 years. INFO • visit the Smithsonian Institute website for a brief field guide, photos, and range maps of grizzly and black bears (mnh.si. edu/mna/image_info. cfm?species_id=416; mnh. si.edu/mna/image_info. cfm?species_id=415). Watch a short video of a University of Alaska study bear (youtube.com/ watch?v=8rtcC738Ftw). • • Camp responsibly. Cache your food (pc.gc.ca/pn-np/ bc/gwaiihaanas/activ/activ1/ activ1a.aspx). Stay safe. Learn how to be "bear aware" (bearaware.bc.ca). • WeB exTRAS bcmag.ca Bonus video: Writer Jude Isabella follows bear biologists into the field. B r IT ISH C o lU M B IA M AgA Z IN E • FA l l 2 0 1 3 31