The black bear (Ursus americanus) is the smallest of the three bear species found in North America. It is the only bear found in Vermont.
Black bears are members of the order Carnivora, which also includes dogs, cats, weasels, and raccoons.
Vermont black bears are relatively shy animals and are seldom seen by people. This is an important factor influencing bear distribution, as Vermont bears prefer wild areas with fewer people. Therefore, bears are less likely to approach populated areas. However, during times when natural food supplies are low, bears may be attracted to bird feeders and garbage cans, and can become a nuisance or a potential danger to people.
Habitat
The best habitat for black bears in Vermont is a mixture of coniferous trees, hardwoods, wetlands, and variation in terrain. Because they need dense cover to escape danger, the wary and elusive black bears prefer rough and wooded habitats. The habitat should also have a good water supply nearby.
Coniferous trees provide concealment and protection from severe weather. Stands of beech and oak, along with wetlands, are important feeding areas for bears in Vermont.
Bears are usually silent and travel alone. Exceptions are family groups and breeding adults during the mating season. Family groups typically consist of the adult female and her cubs, which travel with her through their second spring.
Black bears climb trees to feed on ripening fruit and as a means to escape danger. Bears will sit near the trunk of a tree on a large branch and pull other branches towards them to eat the nuts. This eating place looks like a large bird's nest, with all the branches pulled toward the center. Bears climb trees with the use of their claws, and claw marks can usually be seen on the trunk.
Although bears are often thought to hibernate, they are not true hibernators. During true hibernation, body temperature, respiration, and metabolic rates are considerably decreased.
A bear's respiration and metabolic rate do decrease during the winter sleep, but its temperature remains close to normal. Thus a bear in a winter den can be easily aroused within moments, whereas in a true hibernator, it may take several hours.
Food supplies are the most critical factor determining when bears den in the fall. When foods are abundant, bears will continue eating throughout the snows of November and into December. When fall foods are scarce, most bears den by mid-November.
The den is commonly a brush pile. It may also be a pocket or cave in rocky ledges; a hollow in a large tree or a fallen log; a sheltered depression or cavity dug out at the base of a log, tree, or upturned root; or even a simple hole dug into a hillside.
Male bears den up almost anywhere. Females, however, are more particular, selecting protected sites and lining them with stripped bark, leaves, grasses, ferns, or moss.
Reproduction
Bears become mature at about three and a half years. Black bears give birth every other year. The breeding season occurs during June and July.
After mating, the fertilized egg does not become placed into the mother's uterus and grow until fall. This process is called "delayed implantation." The egg will begin to grow only if the female has attained a minimum body weight of 150 pounds.
The female's ability to produce cubs relates directly to fall food supplies. If the food supplies are poor prior to denning, the female may not have enough fat reserves to grow a cub, and so no cubs will be born.
Inadequate food supplies may also affect fetal development and cub survival. In most years, the cub mortality is around 20%, but may be as high as 50% during years of food scarcity. Well-nourished females are much more likely to produce healthier, larger cubs, and in greater numbers.
Cubs are born in late January or early February while the mother is denning. The number of cubs varies from one to five, but the average is two.
The cubs, weigh only 8 to 10 ounces at birth, and are about the size of a chipmunk. The cubs will remain with the mother until they are about 16 months old. Young females may remain close to their mother's home range, but young males must find their own territory.
Diet
Although the black bear belongs to the order Carnivora, it is a true omnivore, eating both plants and animals. Major food sources include seeds and insects, but the black bear is an opportunist and will eat just about anything that crosses its path. Early spring is the most difficult time of the year for bears. At this time, food is scarce and bears must scavenge intensively to stay alive. Because wetlands green up first, wetland grasses and green, leafy plants have been found to be the primary food of the black bear in the spring. However, these have limited nutritional value, so bears continue to draw from any remaining fat reserves.
From the time they emerge from their dens to the end of July, their activities center around forested wetlands, beaver dams, and along streams and riverbanks.
Typically, bears must wait until early to mid-summer before regaining an adequate level of nutrition. By early summer, bears have the opportunity to eat a variety of succulent plants such as the roots of the jack-in-the-pulpit and berries that are beginning to become available. Bears may also prey upon young deer and moose at this time, although bears do not actively hunt for these food sources. During this time, no single food source is available in such abundance that bears can concentrate on only one item.
As summer progresses, raspberries, blueberries, and blackberries ripen. If these crops are abundant, bears immerse themselves in a concentrated food source with high sugar content.
By late August, bears seek foods with the highest nutritional value. In an effort to store as much energy as possible, they will eat up to 24 hours a day. If beechnuts and acorns are plentiful, bears will move into productive beech and oak stands and consume high quantities of the nuts. Bears may travel many miles to reach fall food supplies and will continue to forage for beechnuts for several weeks.
Other fall foods include cherries, apples, succulent plants, and berries. Bears will also eat available crops of corn and oats, and will commonly raid bee hives.
Management
In 1941, the black bear was elevated to the status of a big game animal and received protection under Vermont's laws. The techniques of black bear harvesting were further regulated by banning trapping in 1967, controlling the use of hunting dogs, outlawing baiting, and prohibiting the shooting of bears at dumps in 1972.
Because of improvements in habitat and through management efforts, Vermont's black bears have made a strong comeback. Their numbers are higher today than they have been in 200 years.
Close monitoring and management of Vermont's black bear population is necessary to ensure it remains healthy and abundant in the future. The principle concern for their future relates to their habitat. Major concerns include development and varying production of their critical wild foods, such as acorns and beechnuts.
Vermont's black bear management program has four components:
- Educating the public,
- Protecting bear habitat,
- Regulating harvest and utilization,
- Responding to animal damage and public safety issues.
Status
By examining the sex and age from harvested bears each year, wildlife biologists are able to estimate the bear population in Vermont. Bear numbers are now believed to be higher than at any time since before European settlement.
Regulated hunting is used to align population estimates with biological data, habitat limitations, and public satisfaction data to sustain a bear population between 4,500 and 6,000 animals.
Before European settlers arrived, most of Vermont was dense forestland, providing ideal bear habitat. However, by the 1850s, almost 75% of Vermont's land area was cleared for farmland. Consequently, bears were at their lowest population level at that time.
From the 1850s to the present, land use changed drastically. The once-abundant pastures and fields slowly reverted to woodlands, and today over 80% of Vermont is once again forested. As a result, the quality of Vermont's black bear habitat has greatly improved.
The highest numbers of bears can be found in the center spine of the Green Mountains, from Massachusetts to Canada, and in the northeastern part of Vermont.