Hair of the Bear: Fur Samples Yield Insights into Grizzlies' Salmon Dependence [Slide Show]
Researchers are checking in this summer at 72 baited hair-snagging stations located across 5,000 square kilometers of remote temperate rain forest in Heiltsuk Traditional Territory, British Columbia
![Hair of the Bear: Fur Samples Yield Insights into Grizzlies' Salmon Dependence [Slide Show]](https://www.scientificamerican.com/sciam/cache/file/E53A011E-196A-429F-8B85E65535AC61A3.jpg?w=590&h=393)
Hair of the Bear: Fur Samples Yield Insights into Grizzlies' Salmon Dependence [Slide Show]
- BIG BEAR, LITTLE HAIR: One grizzly bear hair, which was snagged on the barbed wire encircling non-reward bait, shines in the forest canopy light. From this hair, researchers are able to determine the individual, gender, diet and hormone levels of these large carnivores that weigh in the range of 90 to 135 kilograms—and heavier for some male grizzlies. Dean Azim
- STINK SAUCE ATTRACTS A GRIZZLY CUB: Sure enough, a young grizzly cub comes in to investigate the non-reward bait stink sauce. (Because bears aren't rewarded when they inspect it they aren't being trained to seek it out.) The sauce is doused over a pile of brush [foreground]. The barbed wire the cub is stepping over snags some hair, which scientists later collect to analyze. Raincoast Conservation (www.raincoast.org
- BOATING TO WORK: Each spring the researchers do three rounds of bear hair sampling across 72 baited hair-snagging stations located across 5,000 square kilometers of remote temperate rainforest in Heiltsuk Traditional Territory. Half of the remote hair-snagging stations are accessible by boat only. Anne Casselman
- SALMON ECONOMICS: Grizzly bears have one of the lowest reproductive rates of any land animal. Females will have one to three cubs every three years and the typical female will have at the very most 10 cubs over her lifetime. The more abundant the salmon, the earlier a female grizzly will reach reproductive maturity and the more offspring she'll have in her lifetime. Larry Travis/Raincoast
- COAST MOUNTAINS MEET THE SEA: The Raincoast Conservation Foundation (RCF) grizzly bear study examines how grizzly bears and other large carnivores are affected by salmon abundance or scarcity in Heiltsuk Traditional Territory along British Columbia's central coast. Raincoast Conservation (www.raincoast.org)
- MORE SALMON, MORE CUBS: The reproductive output of female grizzlies is positively correlated with salmon abundance. The bigger the fish runs in the autumn, the more likely a female grizzly will bear cubs (or in this case triplets)in the January or February. Raincoast Conservation (www.raincoast.org)
- SACKS OF SALMON: Even though the salmon runs only last for three of the six months that grizzly bears are active (they sleep during the winter), isotope analysis of their hair has shown that as much as 95 percent of their annual diet comes from salmon, the remainder is mostly berries and plants. Raincoast Conservation (www.raincoast.org)
