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BEAR UPDATE: How adaptable is the Whistler black bear? By Michael Allen Black Bear Researcher On May 19, after 199 days, Hali, a brown phase three-year-old female black bear tunnelled out of a 65-cm diameter sub- alpine fir cavity and up through 300 cm of snow, 24 metres from a ski trail on Whistler Mountain. Hali's response to a period of cold temperatures, high snowfall, and no natural food was to sleep for 6 1/2 months. The scraps of human food she found at the Roundhouse Lodge last October topped off the 40 days of summer berry feeding before the remaining fall berries (depleted due to drought in mid-September) provided her with sufficient reserves to survive a longer than usual winter sleep. This year, Hali is faced again with a summer-fall berry crop failure. She will graze the already-one-month-late green-up of grasses and clover into late summer due to the huge snowpack that is covering Vaccinium (huckleberry) shrubs above mid-mountain. The only sugar-rich berries available to her this summer will be on the lower slopes outside her newly established territory and in scattered patches on mid-higher slopes within her territory during late fall. These increasingly unbalanced trends in weather are causing annual berry crop failures which may force Hali and other ski area bears, over time, to shift foraging behaviours toward the search for human foods as supplements during shortages of natural food. On May 20 Susie, an adult female black bear with three 15-month-old yearlings, moved away from the Whistler landfill where she had unrestricted access (two holes under the fence) to high caloric human food and into the Whistler Interpretive Forest to feed on natural foods. Susie arrived at the landfill on May 1 and fed daily on edible construction dump garbage until the gate was closed on May 4. She then fed on natural foods throughout landfill habitats until May 14 when she dug a hole beneath the electric fence to access the high-fat human food inside the household dump site. Her strategy to consume human foods did not dominate her urge to avoid Heidi, another resident mother black bear with three 15-month-old yearlings visiting the landfill. Susie’s strategies to exploit human foods when possible, avoid conflicts with other bears, and revert back to natural food foraging are what yield her high reproductive fitness. However, Susie’s downfall is that she teaches her offspring to utilize human food, which ultimately yields a higher probability of mortality, especially with 2-4 year old bears. Can Susie survive without human food supplements and only on natural foods? Yes, but she will produce fewer cubs in her litters, which is probably more efficient in the long term. The only management option that will prevent Susie from consuming human food is the closure of the landfill because it is doubtful that an electric fence will ever restrict her and other bear families’ access. On May 22 Katie, an adult female black bear with two, 2-year-olds, grazed nervously along the first snow-melt ski trails 500 metres above Whistler village. Katie, unlike any other resident ski area mothers and through some unknown experience, is extremely intolerant of human activity, including ski area operations as much as 200 metres away. Even though she resides in productive habitat, Katie experiences habitat loss daily. She is constantly disturbed and forced from high quality feeding areas due to the intrusion of humans and/or other bears. Most mothers in the Whistler Ecosystem have become habituated or extremely tolerant of human activity (but not other bears) with the net result being the daily consumption of high quality foods required for the rearing of their cubs. Katie's intolerance toward human activity may be the reason for her keeping yearlings for a second year, allowing more time for habitat utilization and altered behaviour of her offspring (getting used to people). Fall berry crop failures, due to extreme weather changes; availability of edible human garbage, which alters bear behaviour and biology especially the ecology of cubs; and influences of human activity, including new development in the ski area, are the primary forces of rapid change in the Whistler black bear environment. The Whistler Ecosystem yields some of the most productive black bear habitat in North America, but the human population expansion and continued habitat fragmentation may reduce long-term bear numbers. Environmental selection pressures will likely shape highly adaptable black bears, but there will be fewer bears. Anyone with questions about black bears or information of a bear family sighting in the Whistler-D’Arcy corridor may contact me at 935-1176. Whistler black bear education programs are sponsored in part by Whistler-Blackcomb Mountains, Whistler Museum and Archives and Pique Newsmagazine.

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