Spring Coming-out Season for Bears
By J. Ann Eldridge

March means that New Hampshire's black bears will soon be waking from a long winter nap. Their autumn goal was to eat five times their summer intake, trying for a five-inch layer of fat. As the weather cooled down, so did their appetites, and they sought winter lodging.

Biologists have learned that appetite in bears is controlled by leptin, a hormone secreted by fat cells. As bears fatten, leptin travels through the bloodstream, signaling the brain to suppress the appetite. As the weather warms their hunger returns slowly. Bears in good condition still have some fat remaining in spring and they feel no hungrier on arising than when they hunkered down. This arrangement with the hormone leptin is essential. It could prove fatal for a bear to spend a lot of energy in late fall and early spring searching for scarce food.

Bears aren't true hibernators; their metabolic rate slows only moderately and their body temperature drops only a few degrees. In his book Winter World, Bernd Heinrich describes winter bears as "the ultimate couch potato." For five inactive months they suffer no thirst, require no bathroom facilities, and show no change in muscle fiber and only negligible loss of muscle mass. Despite lack of exercise, they lose no bone density.

After burning fat for fuel, bears' cholesterol levels are double their summer readings and double those of humans, yet even an old bear has supple arteries and no gallstones. They don't get bedsores, and the sows continue napping after giving birth to their non-hibernating offspring. How bears accomplish all these metabolic feats is poorly understood.

Most of us think of bears simply as large, potentially hazardous beasts randomly roaming the deeper woods and occasionally galloping across the roads. Largely due to our comparatively weak senses of smell and hearing, we rarely imagine them as having vibrant and complex social lives. Ben Kilham, who has been raising orphaned bears in the woods since 1992, describes bears' social play, their varied repertoire of vocalizations, and their advanced methods of teaching by demonstration.

Bears, Mr. Kilham notes, are also capable of remorse, empathy, and deception, qualities, which indicate a highly developed sense of self-awareness and awareness of the minds of others. Mr. Kilham has recorded what appears to be altruistic behavior, suggesting that bears occupy the same level of intelligence as the larger primates.

After reading Mr. Kilham's book, Among the Bears, I came away with a vision of the forest as a dynamic place full of complex visual and olfactory animal messaging systems. Bears are repelled by and attracted to each other across the landscape. Although highly social, they rarely come into actual physical contact because bears' large food requirements usually keep them widely spaced. When food sources are abundant, however, bears set up food allocation systems within their territories, allowing even non-related bears to benefit.

Which brings us to the seasonal drama of bears at bird feeders. At 160 calories per ounce, bird food is a powerful attraction. Although bears would prefer not to approach human artifacts, some do, and they appear to be able to map out routes for themselves and their friends. The bears that go to feeders are usually young males, hard-pressed between their mother's territory, from which they've been ousted, and the holdings of dominant male bears. They'll get by any way they can on the margins until they grow large enough to claim a place for themselves or emigrate.

People have a compulsion to lure wildlife nearer with food. Often we convince ourselves we're helping, or connecting with nature. It's certainly easier to see wildlife in your backyard than in the woods. People who intentionally feed wildlife have all the positive results of watching "their" deer, turkeys, and more, but claim none of the responsibility when things go awry.

The New Hampshire Fish and Game Department has been trying to educate people about the long-term ill effects of winter feeding that Good Samaritans typically overlook. Some of the ill effects they cite: increased predation, disease, and disruption of social and feeding patterns. Wild animals habituated to humans often break our rules by destroying gardens, breaking and entering for food, and rearranging backyards. So, if you care about and want to support bears, remove bird feeders in spring–the birds don't need them. Frighten bears away if they appear in your yard. Many feeder-raiding bears end up being shot–not by Fish and Game officials, who generally try to relocate them, but by landowners.

And if you want to connect with bears, perhaps even see signs of bears and other wildlife, visit their native habitat. Spend more time in the woods.

-- J. Ann Eldridge, Wildlife Coverts Cooperator, UNH Cooperative Extension


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