Bearly making it: grizzly bears face an uphill struggle in the lower 48 states

Animals, Summer, 2002 by Deborah Knight

This condition of compulsive eating is called hyperphagia and is essential to a grizzly's survival. The bears must lay on inches of fat before the cold and snow sweep in and another physiological switch goes off, prompting the animal to slow down and crawl into the den it has dug. While its heart rate drops to 8-10 beats a minute, its temperature will dip no more than 10 degrees. For the next five to six months, the grizzly will achieve a kind of scientific miracle: it will not eat, drink, urinate or defecate, yet its metabolism will continue at a near normal rate. Any other animal would quickly die as toxic byproducts accumulated in the body, but the grizzly reabsorbs them and converts them into usable proteins.

In this state of drowsiness, the pregnant female gives birth to cubs the size of chipmunks. The newborns are blind and toothless and can neither hear nor smell, but find their mother's nipples and suckle on milk that is 30 percent fat. Come April or May, at 15-20 pounds, they will bounce out of the den with their still lethargic mother, who has lost up to 40 percent of her body weight.

Thus does food rule the life of the grizzly. It is no wonder that the greatest cause of human-grizzly conflict arises from bears learning to find food among humans.

Kerry Gunther's title at Yellowstone National Park is bear management specialist, but the job consists largely of managing people. Grizzlies are regularly visible from the roads, and drivers simply veer over and stop when a grizzly is in sight. In summer, there may be two rangers trying to manage five or six "bearjams" at a time. Rangers also patrol the campgrounds daily to make sure all food, coolers, and cooking items are kept locked up in a car or bearproof container. With a sense of smell up to 5,000 times more sensitive than a human's, a grizzly doesn't need more than one lesson to find a food source. People often take a good deal more time to learn that they must make food unavailable to bears.

As grizzlies have spread outside the park boundaries, reducing human-grizzly conflicts has come to require more and more public education and cooperation with residents, hunters, and private landowners. Grizzlies will eat livestock, beehives, gut piles left by hunters, fruit from orchards, vegetables from gardens, pet food, bird food, and of course garbage. Bears that are first-time offenders may be candidates for relocation, although grizzlies are great travelers and have an uncanny ability to make their way back from distant locations. Bears that are serious or repeat offenders are candidates for "removal"--euthanasia or a zoo.

Chuck Schwartz heads the Interagency Grizzly Bear Study Team, a group of scientists at the U.S. Geological Survey that conducts research on grizzly bears in and around Yellowstone. If an adult grizzly dies there, Schwartz says, chances are 9 out of 10 that it was at the hand of a human. By contrast, grizzly attacks on people are rare, and the danger can be minimized by taking precautions such as hiking with others, making noise, taking care with food, and carrying pepper spray. The normal response of grizzlies is to avoid humans.