Mitchell said that he is not certain of the extent to which non-urban bears are moving to the cities, and if they are what sort of an effect the re-location would have on the untamed environment.
"In principle, one has to believe that an effect exists, but defining that effect clearly and quantifying its magnitude might be very difficult to do," he said.
Regardless of the impact an exodus of bears from the wild lands to the cities might have on the environment, the researchers all agree that a population of bears relying on food from garbage cans is not a healthy situation.
There is no evidence to suggest that the garbage itself is a bad dietthough Beckmann said he can't imagine it's good, eitherbut the increase in urban bear populations has resulted in an increase in bear mortality, primarily from collisions with vehicles.
The dumpster-diving bears are also quick to learn where the food in the garbage cans comes from, and incidents of bears breaking into cars and homes when people are asleep are on the rise.
"Such conflicts rarely work out well for the bears," said Mitchell. "It is hard to imagine the development of a stable, commensal relationship between high density populations of bears and people."
As a remedy to the problem, Beckmann and Berger suggest that city planners and county commissioners require individuals and businesses to purchase and use bear-proof dumpsters.
"We know they work," said Beckmann. "Once they go into a homeowners association, the bears no longer visit."
Mitchell added: "As focused as bears are on food, and as capable as they are of finding it, the less that bears associate people with food, the better for both bears and people."
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