Bear Update: Summer Activities of Ski Area-Landfill Mother Black Bears By Michael Allen Black Bear Researcher The ratta-tat-tat of the Solar Coaster chairlift rang out through the trees. Scout looked up and seemed to acknowledge the fact that it was just that peculiar but usual noise that starts up every day on Blackcomb. He looked around briefly, satisfied everything was safe, and dove back into his mission of dissecting a small stump bite by bite. Mom was around — somewhere. In fact, mom was around about 30 metres up-slope, feeding on ripening huckleberries along the ski trail edge. Scout, her 8-month-old brown phase cub, continued to attack the stump unaware that mom was getting out of protective reach. Marisa, Scout's mother, continued to bob her head back and forth through berry shrubs, quickly but gently plucking berries from their stems with her protruding lips, unaware that Scout remained down-slope at the stump. Perhaps Marisa assumed he was in fact working his way up behind her, staying close to the trees for escape cover. As she efficiently fed on the sugar-rich berries and as he continued to be overwhelmed by the fact that he could conquer the stump, the distance between the two bears grew. As the sun rose to heat the open forests of her territory Marisa crossed onto the ski trail passing under the Solar Coaster lift and grazed in the direction of the cooler continuous forest. At the same time, Scout, realizing his mother was not close enough for his comfort, bolted up-slope through the trees adjacent to the lift line. The "bawling" cub reached Marisa as she was turning to sense his whereabouts. Scout was running so fast that he bumped into his mother's rear end. She scolded him heavily with a firm swat on the rump and the two made their way to the safety of the darker forests. Marisa has raised two cubs on Blackcomb since 1996 (one every second year) while occupying a relatively small territory ( < 3 square kilometres). She arrives in mid-May to graze the new green vegetation until late July while shifting to ripening berries at mid-station’s fragmented forests. Because Marisa consumes green vegetation for three months she does not gain weight until berry feeding in August and is at a disadvantage over feeding strategies of mother bears occupying lower elevations. As Marisa grazes Blackcomb's ski trails in June, Susie, a resident mother of the Whistler Interpretive Forest (WIF) is already beginning to feed on ripening berries in the riparian forests along the Cheakamus River. Susie also has opportunity to access the high fat human garbage in the Whistler Municipal Landfill (WML). While Susie does occupy richer habitat (earlier berries and access to edible garbage) she and her cubs are vulnerable to removal (destruction or relocation) when feeding at a garbage source. Edible human foods do enhance female black bears’ reproductive success (Susie produced six cubs in three years; Marisa produced two cubs in three years) but the long-term impact is detrimental to cub survival and bear behaviour. While Susie continues to teach her cubs to visit and feed at the WML (a process known as cultural transmission), she defeats her contribution to their survival. Meanwhile, along a shrub-field ski trail on Whistler Mountain, Jeanie and Willy (resident mother and 8-month-old black cub) exhibit similar feeding strategies as Marisa's family on Blackcomb. In June Jeanie lost the brown phase Wishbone (littermate to Willy) to unknown causes. Both coyotes and adult male black bears have been observed trying to kill cubs in the Whistler area. Jeanie will seek out ripening berries from early August through October along the mid- and upper-elevation ski trails across Whistler Mountain, eventually exploring her winter 98/99 denning range. Cub loss has also been experienced by Sadie, an older resident mother of the Cheakamus-Brandywine River area. Sadie typically visited the landfill seasonally during the last six years but has reduced her visits during 1997-1998 due, most likely, to less edible garbage and the presence of adult males. Sadie has produced four cubs in four years (1994-1998) with two of these cubs destroyed as yearlings in the landfill in 1996 and one lost this year to unknown causes. Undoubtedly, cub survival is enhanced by the length of time cubs are in protective custody of their mother. Mother black bears usually raise cubs for 15-17 months, followed by mating which initiates family break-up. Daughters typically remain in the mother’s territory and sons are forced to disperse over a 1-3 year period. Katie, a resident mother on Whistler Mountain, has been observed with her two yearlings (1997 cubs) between Olympic Station on Whistler Mountain and mid-station on Blackcomb. Katie shifts her grazing activities on Whistler to berry foraging along the hot south-west aspects of Fitzsimmons drainage where historic wildfire stimulates vigorous huckleberry production. During this study (1993-1998) no mother has ever been observed to stay with her yearlings past 17 months. Katie is the first mother observed to remain with her yearlings in their 18 month. Cassie, another resident mother to Whistler Mountain's Creekside has also been observed in late July with her yearlings. The table below lists the mean litter size (average number of cubs in litters) for black bear mothers resident to the Whistler-Blackcomb ski area and the Whistler Municipal Landfill during 1996-1998. The data is preliminary because to conclude anything significant observations must be conducted for at least 10 years or five litter intervals of a mother bear. The probability of identifying all resident mothers in each area was not equal or near equal prior to 1996, hence, the data could not be analyzed. From 1996 to 1998 14 cubs were produced by six mothers in the Whistler-Blackcomb ski area. The average number of cubs produced for that three year period were 2.3 cubs per litter. Conversely, at the WML, 10 cubs were produced by only three different mothers for an average of 3.3 cubs per litter. The most productive mother has been Susie, resident to the WML, producing six cubs: three in 1996 and three in 1998. Data on the reproductive fitness of adult female black bears will be collected from 1996 through 2005. Ski Area Whistler Landfill Mean Mean Sample Size: litter Sample Size: litter Year Cubs Moms size Cubs Moms size 1996 7 6 1.2 4 2 2.0 1997 4 6 0.7 1998 3 6 0.5 6 3 2.0 Total 14 6 2.3 10 3 3.3 Anyone with questions regarding black bears or with information of a bear family observation (mother with cubs or yearlings) in the Whistler area can contact me at 938-3816. A big thanks to those (especially ski area mountain staff) who have helped with information on bear family sightings. Black bear research and education in Whistler is sponsored together by Whistler-Blackcomb and the BBC/River Road Films Ltd. The purpose of the Bear Update columns is to increase awareness of local black bear activity for residents and visitors to Whistler with the goal of educating people on how to react in bear encounters.
