Even grizzly bears, though known for being loners, have a cultural heritage that shapes their behavior and their use of resources, according to a Alaska biologist.
Since 1984, Robert Fagen, associate professor of biometry at the University of Alaska in Juneau, Alaska, has studied Alaskan brown bears that have come down from the mountains to the Alexander Archipelago to feast on spawning salmon. Though slightly different than the grizzlies of Yellowstone Park, for example, Alaskan brown bears and grizzlies are the same species.From a distance, he and tourists can see up to 30 bears on the grassy tidal flats. For their long-term study of about 20 bears, he and his co-workers have accumulated 800 hours of observations, enough to enable them to detect cultural traditions and individual differences in the bears.
In general, bears stick to tradition. For generations, perhaps millions of years, these bears have followed the same routes between the mountains and the estuary.
Mothers and their adolescent cubs tend to have the same patterns. If the mother spends 20 percent of her time on the tidal flats, her offspring do as well. "The differences that we've demonstrated for mothers point in the same directions as differences in their young," Fagen said during a lecture in Tucson.
They also fish in the same spots as she does, despite the fact that they are free to run around, said Fagen. "The rule may be that you prefer the habitat that you are brought up in, even if it is only 10 yards long."
Cultural factors - including play behavior - also affect how the bears use their environment. Even though they tend to be thought of as loners, bears can form tightly knit social groups, said Fagen. Like people, bears have different shapes, sizes, experiences, habits and social roles. These differences affect how they spend their time.
Food availability also influences the nature of play. Salmon have off years, where far fewer make it upstream to spawn, causing up to 10-fold differences in their numbers, said Fagen. "This makes a big difference to the bears."
When the bears are underfed, even minor injuries that result when playing gets out of hand can be very costly. Consequently, "The more salmon there are, the more play there is," said Fagen. - By Elizabeth Pennisi