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The bear-salmon equation Add to ...

The importance of salmon to bears has been the focus of numerous studies, and biologists are unanimous in agreeing on the vital importance of the link. Some facts:

Bears eat an average of 1.6 kg from each salmon carcass, focusing on brains, ovaries and dorsal musculature, while rejecting viscera, testes and bony jaws.

In one study on the Queen Charlotte Islands, black bears were seen to be eating about 12 salmon a day during a 45-day period in the fall.

Coastal bear populations with access to abundant, spawning salmon are larger, more densely populated and have greater reproductive success than bears in the B.C. Interior.

A study in Alaska found salmon-eating bear populations on the coast had densities 55 times higher than those of the more vegetarian inland populations.

Reproductive rates of bears is one of the lowest of any terrestrial mammal, and reproductive success is directly related to body mass in the fall.

'Digestible-energy content' of foods eaten by bears ranges from a low of 30 per cent for vegetation and berries to over 90 per cent for meat. Salmon is the largest source of meat for the largest bears and for the most productive populations.

Bears transfer huge numbers of salmon carcasses from the water to land. In the process, they cycle salmon-derived nutrients into the broader ecosystem.

Widespread collapses of salmon population over time, scientists say, will translate into broader declines elsewhere in the ecosystem.

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