City Bears Live Large

Humans, it turns out, aren't the only animals that become "couch potatoes."

• Laura Tangley
• Apr 01, 2004

Humans, it turns out, aren’t the only animals that become "couch potatoes." A study of black bears in the Lake Tahoe region of California and Nevada found that bears living in or near urban areas weigh up to 30 percent more than their brethren residing in wilder locales. The explanation, notes a report published in the Journal of Zoology, is that city bears are more sedentary than country bears.

To study the animals’ feeding habits, biologists from the Bronx Zoo-based Wildlife Conservation Society outfitted 59 black bears with radio collars and tracked them. Rather than hunting prey or foraging for berries and nuts (the species’ natural fare), bears living near people scrounged most of their food from dumpsters behind suburban homes, shopping centers and fast-food restaurants—activities that burn considerably fewer calories than chasing down food in the wild. The biologists discovered other behavioral oddities, too: To avoid running into people during mealtimes, urban bears had become more nocturnal, eating at night and sleeping during the day. And because human garbage is readily available all year long—unlike much of the food wild bears eat—city bears spent an average of 42 fewer days in their winter dens.