1^ 



black bears are isolated, human- 

 related bear problems are less fre- 

 quent. Occasionally, says Warburton, 

 exploring young males might wander 

 into a nearby town. But even bear 

 attacks in the mountains are rare, he 

 says. In the past century, there hasn't 

 been a single human death caused by a 

 black bear in eastern United States. 



Still, the curving claws, large 

 teeth and massive bulk of the animal 

 are intimidating. Thick, long, outer 

 guard hairs, fuzzy underfur and winter 

 fat can make a black bear seem larger 

 than it is. Usually 2 to 3 feet off the 

 ground on all four legs, a black bear 

 can stand 6 to 7 feet tall on its hind 

 legs. Males can reach weights of 250, 

 450, even 600 pounds. But black bears 

 are the smallest of the three North 

 American bears (black bears, polar 

 bears and grizzlies) and the least likely 

 to attack a human. The grizzly bear, 

 which lives on open plains and 

 uplands in the West, has the muscula- 

 ture to attack. Black bears are better 

 built for climbing trees to escape. 



It's actually rare for a black bear 

 to hunt prey. Succulent plants, berries, 

 acorns, insects and some fish keep a 

 wild bear well-fed. Hungry black 

 bears may kill a fawn, small animals 

 or even a bear cub, but most lack the 

 agility to kill adult elk, deer or other 

 large animals. They're more likely to 

 be scavengers, feeding off deer or 

 birds killed by a car or another animal. 



Often it seems that bear legend 

 doesn't stand up to bear fact. Al- 

 though bears may appear slow, clumsy 

 or unintelligent, they're not. Black 

 bears have sharp senses of hearing and 

 smell and excellent memories — some 

 bears return miles to the same bushes 

 year after year because they remember 

 the sweet berries. One bear repeatedly 

 tried to open Volkswagens because it 

 remembered finding fried chicken in 

 the backseat of one. Scientists think 

 black bears have good short-range, 

 color and peripheral vision. Bears 



have been clocked running at speeds 

 of 30 mph, and their long, curved 

 claws make them some of nature's 

 best tree climbers. Black bears also 

 have a delicate touch, using their lips, 

 tongue and teeth to remove fragile 

 berries from bushes without stripping 

 the plant. 



Black bears have decidedly 

 diverse appearances, some with blunt 

 snouts and squat ears like pigs, others 

 with slender, canine ears and noses. 

 Some taxonomists believe that bears 

 and dogs have common ancestors. 



Technically, bears don't hibernate 

 as commonly believed. A true 

 hibernator's body temperature cools as 

 its respiration rate and heartbeat slow 

 to almost nothing. The black bear's 

 furnace never slows. In the fall — 

 even late summer — black bears begin 

 to eat and eat and eat. They gain up to 

 one-third of their body weight 

 preparing for their winter's rest. In the 

 den, bears burn as much as 4,000 

 calories per day, losing 15 to 30 

 percent of their bulk during the winter. 



During their rest, bears never 

 wake to eat, drink or eliminate wastes. 

 Their stomachs shrink to a tight knot, 

 and their digestive systems stop. 

 Scientists are studying the unique way 

 bears retain muscle mass during 

 hibernation by recycling calcium and 

 burning fat rather than protein. Most 

 coastal black bears den at least part of 

 the winter under roots and under- 

 growth or in hollow trees. 



Bear cubs are born during the 

 winter rest period. After the female 

 mates in the late spring or early 

 summer, an embryo develops to a 

 certain stage — called the blastocyst 

 stage — and then waits. In December 

 or January, the blastocyst connects to 

 the uterine wall to continue develop- 

 ment. Typical bear litters, which are 

 born in the winter den, contain one to 

 three cubs, and each one may have a 

 different father if the female mated 

 more than once. 



Bear cubs are born tiny and 

 hairless with closed eyes and no 

 teeth. Scientists call this birth 

 altricial, or not well-developed. In the 

 den, the mother keeps them warm and 

 nourishes them with her milk, which 

 is almost 30 percent fat. By spring, 

 cubs are ready to play, tussle and 

 scramble up trees. For the first one to 

 1 1/2 years, the mother bear does her 

 best to defend her cubs, shooing them 

 up a tree when danger threatens. But 

 when it's time for the mother to mate 

 again, the young bears are abruptly 

 sent out into the world alone. 



Until recently, we could only 

 guess how bears spent their time. 

 With radio telemetry, scientists can 

 track black bears as they grow. 

 Researchers from the University of 

 Tennessee, for example, recently 

 completed a five-year study of black 

 bears at Camp Lejeune using this 

 technology. Capturing bears and 

 sedating them, scientists tagged 

 several adult females and males with 

 radio transmitters. Scientists can 

 follow the signal, recapture the bears 

 and record their weight, health, the 

 extent of their range and other 

 biological information. 



Other researchers lower record- 

 ing devices into dens to determine 

 how many cubs have been born or 

 inject bears with an innocuous 

 radioisotope that leaves traceable 

 elements in their scat. Researchers 

 also collect scat samples to get data 

 on the bears' diet, population density 

 and seasonal movements. 



The more we know about 

 American black bears in North 

 Carolina, the better we can manage 

 their populations and the habitats 

 they need to survive. Yet even as 

 populations continue to grow, the 

 chances to see the elusive animals 

 in their natural habitat are slim. 

 "If you get that rare opportunity," 

 says Warburton, "consider yourself 

 lucky." □ 



24 JANUARY/FEBRUARY 1996 



