The Whistler Black Bear Project (WBBP) will be conducting surveys to determine minimum population estimates of Whistler bears by collecting bear hair from baited, barbed-wired enclosures during peak spring (June/July) and fall (September/October) bear activity seasons.
Approximately 50, non-invasive barbed-wired enclosures are constructed at valley bottom, lower slope, and mid-mountain, likely bear use habitats to collect hair samples for DNA analysis.
A scent lure is hung out from bears reach (four metres above the ground) at each enclosure to attract bears under or over a 50-cm high single strand of barbed wire fastened around a cluster of trees. As the bear enters the enclosure, its hair is snagged (no injury to bear) along the barbs.
Bait is refreshed every seven days, followed by hair collection. Four sampling sessions are run for each spring and fall season.
All hair trap sites will have signage in four locations (north, east, south and west). It is doubtful that sites will be encountered by people because they are situated in dense forest cover away from trails and residential areas. However, if you encounter a sign and/or trap site, please leave the area at once. If you have a dog or dogs, leash them immediately and leave the area.
Bear hair samples will be submitted to Dr. David Paetkau, senior geneticist at Wildlife Genetics International Ltd. in Nelson, B.C. Hair is analyzed for individuality and gender. Analysis first determines individuality because there will be obvious repeats (the same bears hitting traps more than once) which yield an individual genetic code identifying each animal for the rest of their life, and secondly for gender (male or female).
For example, if I send in 300 hair samples from the spring survey, the lab will analyze and reply with a minimum population of 110 black bears with a sex ratio of 60 females to 50 males.
Results from DNA analysis will provide the first population estimate for the Whistler bear population. An estimate yields a baseline for population trend surveys including important questions such as: are bear numbers increasing or decreasing? Are the numbers of male bears decreasing? And are male bears surviving to mature breeding status?
During the last decade mortality has been highest amongst the male cohort. The number of reproducing females has remained stable and cub production fluctuates with berry abundance and pregnant female weight gain.
Male bears are more susceptible to mortality from bear/human conflicts, relocation (removal), vehicle/train collisions, and hunting (in outlying areas of Whistler) than females because they have greater movements and yearling males are forced from mothers territories (by the mothers) to avoid inbreeding and potential cub predation. Sub-adult males disperse into and through Whistler Valley, often tolerating human activity to avoid the prime natural feeding areas filled with dominant bears.