Black Bears

Overview

American Black Bear - Photo by: Alan Bauer

Figure 1: Photo Credit - Alan Bauer

American black bears (Ursus americanus, Fig. 1) are the most common and widely distributed bears in North America. In Maine, black bears live in a diverse array of forested habitats, from coastal blueberry barrens to central oak-maple-beech forests to the spruce-fir woodlands of the north. In general, black bears are strongly associated with forest cover, but they do occasionally use relatively open country, such as clear cuts, agricultural fields, and the fringes of other open habitat.

The statewide black bear population in Maine numbers at least 30,000 animals. As human populations encroach on bear habitat, the chances of encounters increase. Bears usually avoid people, but when they do come into close proximity, the bear's strength and surprising speed make it potentially dangerous. Although confrontations with black bears are rare, most are the result of a surprise encounter at close range. All bears should be viewed from distance, given plenty of respect and room to retreat.

Facts about Maine's Black Bears

Food and Feeding Behavior

Black Bears Are Notorious For Taking Advantage Of Human Irresponsibility With Food - Photo by: Alan Bauer

Figure 2: Photo Credit - Alan Bauer

  • Black bears are omnivores, meaning that they eat both plants and animals. Their diet, however, consists mostly of vegetation. They move in response to the seasonal availability of food, roaming constantly throughout their home range.
  • In the spring, black bears feed primarily on herbaceous plants, from emerging grasses, tree buds and sedges to horsetail and various flowering plants.
  • In summer, bears typically add ants, bees, grubs, early berry crops, and a host of later emerging plants to their diets.
  • During late summer and fall, bears typically shift their diets toward tree fruits, berries, acorns and beech nuts, but they still may consume a variety of plants.
  • Fall is a critical season for black bears and they commonly acquire most of their annual fat accumulation at this time. Bears may forage up to 20 hours a day during fall, increasing their body weight by 35 percent in preparation for winter.
  • A small proportion of the black bear's annual diet is made up of animal matter, including insects, mice, voles, deer fawns, moose calves, eggs and fish. An occasional bear may take livestock.
  • Black bears have adequate senses of sight and hearing, but their keen sense of smell and innate curiosity make them skilled scavengers. They consume carrion (animal carcasses) when they can find it, and are notorious for taking advantage of foods sources such as bird seed, trash, grills and pet food. Bears will eat anything that smells appealing and that could prepare them for their long winter sleep.
  • Black bears are notorious for taking advantage of human irresponsibility with food (Fig. 2).
Black Bear Cubs Resting - Oregon Department of Fish and Wildlife

Figure 3: Drawing Credit - BCI

Dens and Resting Sites

  • Black bears den during the winter months, typically from mid-late October into April. when food is scarce and the weather is harsh.
  • Denning black bears enter a state of torpor, a modified form of hibernation. This drowsy condition allows bears to defend themselves and their cubs more effectively should a predator visit the den.
  • Bears do not urinate or defecate during denning. Instead, they recycle their waste into proteins and other nutrients. By not defecating, bears keep their dens essentially scent-free, protecting them from potential predators.
  • Black bears can take up residence in small dens, some scarcely bigger than a garbage can. Den sites include rock or tree cavities, hollow logs, and areas beneath brush piles, dense vegetation, large tree roots, stumps, logs, and rural buildings. They'll occasionally excavate a den in the side of a hill near shrubs or other cover.
  • Summer beds are merely concealed places scratched in the ground in dense vegetation, by a rock, or under the branches of a fallen tree. Young bears rest in trees for safety (Fig. 3).

Reproduction and Family Structure

  • In Maine, female black bears breed for the first time at three and a half to five and a half years of age.
  • Males compete for the right to breed, and breeding fights between males may be intense. Older males frequently have extensive scars on their heads and necks from fights in previous breeding seasons.
  • Mating takes place in early June to mid-July. Bears have a reproductive pattern known as delayed implantation. Following fertilization, a bear's embryo goes dormant, free-floating in the uterus. After the female dens in late fall, the embryo implants in the uterine wall and the fetus develops rapidly. Although the total gestation time is approximately seven months, the actual developmental period for the fetus is less than three months.
  • Females normally give birth to one to three cubs in the winter den during January or February, and they provide all care for the young. Females have one litter every other year.
  • At six months, cubs are able to locate food, but generally remain with their mother for more than a year, usually denning with her during their second winter.

Longevity and Mortality

  • Female black bears have the potential to live into their mid-twenties. Male black bears do not typically live as long, rarely attaining 20 years of age.
  • In Maine, hunters harvest between 2,500 and 3,500 bears each year.
  • Other than humans, black bears have few predators. If given the opportunity, bobcats, coyotes, and male bears may attack and kill cubs.
  • Bears are occasionally struck by vehicles.

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Viewing Black Bears and Bear Signs

Except for females with cubs, black bears are usually solitary animals. Depending on their food supply, they move about during the day or night. In late summer and fall, feeding keeps them active throughout the day so they can gain the weight needed for winter. When bears find a human food source, their schedule may change. If they are receiving handouts they can be most active at midday; if they are feeding at dumps or trash cans, they become more active at night.

Black bears should be treated with respect and safely observed from a distance of at least a hundred yards. This is especially important with females accompanied by offspring, as mother bears are very protective of their young. Never hand feed a bear, especially a cub.

Tracks

Black Bear Print - Courtesy of: Virtual Dirt Time

Figure 4: Photo Credit - VDT

Black bear prints usually show five digits (Fig. 4). When claw marks show – and they often do not – they are about half an inch in front of the toes. The toes form a rough semicircle in front of each foot, with the middle toe being the longest.

Front foot prints have small foot pads, whereas hind foot prints characteristically show an extended pad, thus resembling a human foot.

The hind feet of an adult black bear average seven to nine inches long and three to five inches wide; the front feet are four to five inches long and nearly the same width. (Courtesy of Virtual Dirt Time)

Black Bear Droppings - Photos by: Alan Bauer

Figure 5a: Photo Credit: Alan Bauer

Black Bear Droppings - Photos by: Alan Bauer

Figure 5b: Photo Credit: Alan Bauer

Droppings

When plants, insects, and animal carcasses make up most of a bear's diet, the droppings are cylindrical and typically deposited in a coiled form, sometimes in individual segments. Segments are two to three inches long and one and a quarter to one and a half inches in diameter (Fig. 5a). Bits of hair, fur, bone, insect parts, and plant fibers distinguish these droppings from human feces, as does the large size of the deposit. Color ranges from dark brown to black; when bears are eating grasses heavily, droppings are often green. When fruits and berries are in season, droppings assume a moist, "cowpie" form and seeds are visible (Fig. 5b).

The consistency of droppings changes depending on what bears have been eating. When fruits and berries are in season, droppings assume a moist, "cowpie" form with visible seeds.

Bear Trees

Black bears commonly leave a variety of marks on trees:

Because bears often climb, trees with smooth bark such as beech and aspen often show telltale claw marks and hairs.

On young conifers, bears may rip strips of bark off with their teeth to reach insects or the sweet-tasting sap found inside (Fig. 6). Their teeth leave long vertical grooves in the sapwood; large strips of bark lie at the base of peeled trees. Bears typically make these marks from April to July, but the results remain all year. This foraging activity is more common in large stands of even-aged trees of a single species.

Black Bear Markings - Courtesy of: Virtual Dirt Time

Figure 6: Photo Credit VDT

A bear may rub its back against a tree – particularly a rough-barked tree – or other object to relieve the torment of parasites and loosen thick, matted winter coat. Rubbing is a favorite summer pastime, and bears may use good rubbing trees repeatedly. These trees are easy to identify, as they have broken branches and tops with a lot of long, black or brown fur caught in the bark and sap.

Bears also make tooth and claw marks that have prompted debate about whether they are marking trees to convey social information akin to territorial marking in other carnivores. These marks are most easily seen on smooth-barked species such poplar, beech, birch, and white pine, but any live or dead standing tree may be heavily chewed with branches and tree tops broken.

Bears may also chew human structures such as utility poles, footbridges, and even outbuildings.

Black bear marks vary from claw marks left when they climb to peeling and bite marks produced when larger bears (generally females) feed on insects and sap found under the bark. (Courtesy of Virtual Dirt Time)

Feeding Areas

Bears commonly turn over and tear apart rotting logs and stumps to get at fat and protein-rich grubs, ants, worms, and spiders. A bear will knock off the top of an ant hill or beehive to get to the insects.

Black bears may break off entire limbs of fruiting trees, such as apple and chokecherry, to reach the fruit. Huckleberries and other fruiting shrubs may show signs of being crushed underfoot.

Bears may also dig to reach starchy roots, excavate squirrel or mouse seed caches, or capture mice and voles. Evidence of digging ranges from well-defined holes to large areas that appear to have been rototilled.

In the summer, berry patches are popular feeding areas for black bears. In the fall, when nut crops are plentiful, bears frequent hardwood ridges.

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Preventing Conflicts

State wildlife offices receive hundreds of black bear complaints each year. The most common conflicts are the result of improper storage, especially of bird seed and garbage. Most bear conflicts can be avoided by removing or properly storing potential attractants, including bird feeders, grills, pet and livestock food, and garbage. Bears can become conditioned to human food or waste when these items are consistently available. In years when natural foods are scarce, bears may seek food in areas where they ordinarily would not, causing an increase in conflicts between bears and people. In addition, because adult bears do not tolerate young bears – especially young males – these animals may wander into areas occupied by humans.

If you live where black bears are common, use these strategies to prevent conflicts:

Do not feed bears.

Never hand feed a bear. Do not leave food out for bears so you can take pictures or show them to visiting friends. When bears directly associate food with humans, they lose their fear of people. When bears seem at home around humans, people often hand-feed them. The sad reality is that these habituated bears will likely die when someone protects their property or life, or a wildlife manager removes it as potentially dangerous animal.

Manage your garbage.

Bears will expend a great amount of time and energy digging under, breaking down, or crawling over barriers to get food, including garbage. If you have a pickup service, put garbage out shortly before the truck arrives rather than the night before. If you are leaving several days before pickup, haul it to a transfer station or ask your neighbor to put it out for you.

Keep garbage cans with tight-fitting lids in a shed, garage, or fenced area.

Spray garbage cans and dumpsters regularly with a disinfectant to reduce odors. Keep fish parts and meat waste in your freezer until they can be disposed of properly. If bears are common in your area, consider investing in a commercial bear-proof garbage container or dumpster. Ask a local disposal company about availability or search the Internet for vendors.

Remove other attractants:

  • Place only plant material in compost bins.
  • From late March to early November, remove bird feeders (suet and seed feeders), and residual seed that has built up on the ground. If bear are common in your area, consider planting bird-friendly shrubs rather than using bird feeders.
  • Bring in hummingbird feeders at night.
  • Harvest orchard fruit from trees regularly, as rotting fruit left on the ground is a powerful bear attractant.
  • Do not feed pets or store pet food outside.
  • Clean barbecue grills after each use. Wash the grill or burn off smells, food residue, and grease; store the equipment in a shed or garage and keep the door closed. If you can smell your barbecue then it is not clean enough.
  • Avoid the use of outdoor refrigerators, which will attract bears.
  • Check with neighbors. Usually a nuisance bear in an area or neighborhood is the product of someone feeding or being careless with garbage or other bear attractants. Encourage your neighbors to remove or secure attractants.

Protect livestock and bees.

Place livestock pens and beehives at least 150 feet away from wooded areas and protective cover. Confine livestock in buildings and pens, especially during lambing or calving seasons. Store livestock food in a secure barn or shed behind closed doors; if bears are allowed access to livestock food, they may learn to feed on livestock. Immediately bury any carcasses or remove them from the site.

Black Bear Control Using Fences - Drawing by: Jenifer Rees

Figure 7: Drawing Credit - Jenifer Rees

Install fences and other barriers.

Electric fencing can be used where raids on orchards, livestock, beehives, and other areas are frequent (Fig. 7). Electric fencing works best if it is in place and operating before conflicts occur, as bears that are food-conditioned will go right through electric fencing. Bears can be lured into licking or sniffing the electrified wire by applying molasses, bacon grease, or peanut butter packets (commercially available or a packet made from aluminum foil) on the fence. Check voltage regular. (See "Preventing Conflicts" in Deer for additional information on electric fences)

An electric fence designed to keep bears out of an area (Fig 7). This five-wire electric fence has been effective at keeping adult bears and their cubs out. If necessary, a two-foot wide underground apron of chain-link fencing or steel mesh can be staked down and attached to the fence to keep bears from digging under the fence. If wood or other heavy-duty corner stakes are not used, the corner posts will need to be carefully braced.

Traditional wire fencing can also be used as a barrier. Use heavy chain-link or woven-wire fencing at least six feet high. Install 24-inch long wood or metal bar extensions at an outward angle to the top of the fence with two strands of barbed wire running on top. If necessary, a two-foot wide underground apron of chain-link fencing or steel mesh can be staked down and attached to the fence to keep bears from digging under the fence.

Use temporary scare tactics.

Bears can be temporarily frightened from a building, livestock corral, orchard, and similar places by a night light or strobe light hooked up to a motion detector on a tripod, loud music, or exploder cannons. Change the location of frightening devices every other day. Even so, over a period of time, bears will become accustomed to these tactics and will not be scared away; human safety can become a concern.

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Bear Encounters

Bears tend to avoid humans, but prolonged exposure can cause some human-habituated bears to lose their natural fear and wariness. Human food-conditioned bears are those that associate people with food. Such bears can become aggressive in their pursuit of a meal.

Prevention is the best advice, so when you are recreating in bear country, do everything you can to avoid an encounter with a bear:

When Hiking

  • Travel with someone else (never alone).
  • Because children often run ahead, keep small children near you at all times.
  • Be observant of your surroundings.
  • Never approach a bear.
  • Make your presence known to avoid surprising a bear. Simply talking will do the trick.
  • Most experts recommend carrying pepper spray when in areas of high bear density. A pepper spray that has a pepper content between one and a third and two percent can be an effective deterrent to an aggressive bear if it is sprayed within six to 10 feet directly into the bear's face.

When Camping:

  • Keep your campsite clean of food and food odors.
  • Store food and garbage away from your camp site.
  • Clean fish and game away from your sleeping area.
  • Burn food off your grill.
  • Never hand feed bears.
  • Report any bears observed in campground or site.

If You Encounter a Bear

  • Stop, remain calm, and assess the situation. If the bear seems unaware of you, back away quietly when it is not looking in your direction. Continue to observe the animal as you retreat, watching for changes in behavior.
  • If the bear walks toward you, identify yourself as a human by standing up, waving your hands above your head, and talking to the bear in a low voice.
  • Don't throw anything at the bear.
  • Avoid direct eye contact, which the bear could interpret as a threat or a challenge.
  • If you cannot safely move away from the bear or if the bear continues toward you, scare it away by clapping your hands, stomping your feet, yelling, and staring the animal in the eyes. If you are in a group, stand shoulder-to-shoulder, raising and waving your arms to appear intimidating. The more the animal persists, the more aggressive your response should be. If you have pepper spray, use it.
  • A bear can run 35 mph, so don't run unless safety is very near and you are absolutely certain you can reach it.
  • Black bears are adept climbers, so do not climb a tree to escape. The bear may follow you.
  • Report all aggressive bear encounters.

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Bear Attacks

In the unlikely event a black bear attacks you and makes actual contact, fight back aggressively, aiming for the eyes and using your hands, feet, legs, and any object you can reach. If you have pepper spray, aim for the face.

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Professional Assistance

The most effective long-term solution to conflicts between people and bears is removing, securing, and properly storing attractants such as bird-feeders, garbage, grills, pet and livestock foods, livestock, and bee hives. Wildlife offices throughout Maine can provide assistance with securing or removing attractants.

Wildlife offices throughout Maine respond to bear sightings only when there is a threat to public safety or property. A sighting or the presence of a bear does not constitute a threat to property or public safety. Typically, no attempt will be made by wildlife agency staff to remove, relocate, or destroy the animal.

Although problem bears can be live trapped by specially trained wildlife professionals and moved to more remote areas, removal is expensive, time consuming, and seldom effective. Once a bear has tasted human food or garbage, it will remember the source and return again and again. Bears have been known to cover more than a hundred miles after relocation to return to a human food source. In addition, using tranquilizing drugs on bears to facilitate removal is not without risks to bears and humans.

When other methods have failed or the bear poses a threat to public safety, lethal removal of problem animals may be the only alternative. You can help prevent lethal removal by following the recommendations presented above.

Contact your regional wildlife office for additional information and, in the case of an immediate emergency, call 911 or the state police.

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Public Health Concerns

Bears are not considered a significant source of infectious diseases that can be transmitted to humans or domestic animals. Humans can, however, become infected with trichinosis by eating undercooked bear meat.

To view information on preparing bear meat, go to the Center for Disease Control & Prevention website.

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Legal Status

The black bear is classified as a big game animal. A hunting and/or trapping license and bear permit (with the exception of resident deer-hunters during the November firearm season on deer) are required to hunt black bears during a 13-week fall season that opens the last Monday in August and closes the last Saturday in November.

If a bear is causing damage or is a nuisance, consult Maine's laws on this subject: See all sections, particularly Subsection #1: Bears, which applies to the taking or killing of a bear found doing damage.

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Additional Information

Books

New England Wildlife, Habitat, Natural History, and Distribution
Written by: Richard DeGraff, and Mariko Yamasaki
University Press of New England, 2001.
(Available from: www.upne.com)

Internet Resources

Adapted from: "Living with Wildlife in the Pacific Northwest"
(see Washington Department of Fish and Wildlife)
Written by: Russell Link, Wildlife Biologist, with assistance from WDFW Biologists Rich Beausoleil and Rocky Spencer

Design and layout: Peggy Ushakoff, ITT2

Illustrations: As credited

Copyright 2007 by the Washington Department of Fish and Wildlife

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