Radio Collars Are Debunking Myths About Grizzlies

Since 1981, biologist John Schoen has fastened radio collars on the necks of more than 100 grizzly bears, tracing their lives by the radio blips he hears during survey flights.

Besides producing population counts and maps, Schoen’s work for the Alaska Department of Fish and Game sheds light on the many myths about bears.

While hiking into the alpine tundra and rain forests where southeastern Alaska grizzlies live, Schoen found bear caves high above the snow line.

“Some cave dens are rubbed smooth like marble, so we assume the bears have been using them for centuries,” he said.

Grizzlies rarely choose caves for dens in other parts of the country. The wide use in southeastern Alaska is an oddity no one had documented before, Schoen says.

He also found Alaska grizzlies are light sleepers. Collared bears moved around in their dens when disturbed by the noise of overflying airplanes, and frequent flights prompted at least one bear to dig out in mid-winter and move to another, presumably quieter, resting place.

The tracking project also punctured the popular assumption that all southeastern Alaska bears feed on fish. It’s true most bears move to streams near salt water each year to gorge on spawning salmon, but Schoen has tracked a small population of grizzlies that never go to the coast.

They apparently find all their food in the rain forest and alpine meadows, maintaining their massive bodies--up to 500 pounds for females and double that for males--on diets of berries, small game and perhaps an occasional deer.

Schoen says old-timers had told him of such highland bears, but until the radio study was done, no one had been able to prove the tales.