Ursus americanus

Most Black Bears hibernate for up to seven months, and do not eat, drink, urinate, or exercise the entire time. In the South, where plant food is available all year, not all bears hibernate—but pregnant females do. The female gives birth to 1-6 cubs (usually 2 or 3) in January, while she is deep asleep in her den. The newborn cubs snuggle next to her for warmth and nurse while she fasts. They grow from a birth weight of 200-450 g each (about 7-16 pounds) to the 2-5 kg they will weigh when the family leaves the den in the spring. Black Bears eat a little meat, and some insects, but they rely on fruit, nuts, and vegetation for the bulk of their nutritional needs. They are not all black. Most are, with brown muzzles, but in some western forests they are brown, cinnamon, or blond, and a few, in southern Alaska and British Columbia, are creamy white or bluish-gray.

Adaptation: In the Black Bear, Ursus americanus, the evolution of typically carnivorous, sharp shearing molars into the flat crushing teeth, typical of bears, is evident.

Links:
Mammal Species of the World

American black bears are found through much of Canada, the United States, and the northern half of Mexico. Although they were extirpated from large portions of their historic range because of habitat loss and (mainly intentional) overexploitation, their occupied range has been expanding in recent years (Pelton et al. 1999, Williamson 2002). The species has, nevertheless been extirpated from large parts of its former range, especially in the Midwest of the United States, and in Mexico. American black bears presently occupy all provinces and territories of Canada, except Prince Edward Island (where they were extirpated in 1937), 41 U.S. states (with occasional sightings in at least 3 others), and 8 states of northern Mexico. The species never existed outside of these three countries.

Global Range: (100-250 square km (about 40-100 square miles)) Black bears exist throughout most of North America north of central Mexico, except the desert region of the southwestern United States, from north-central Alaska across boreal Canada to Labrador and Newfoundland, and south to central California, northern Nevada, northern Nayarit and southern Tamaulipas (Mexico), and Florida (Wozencraft, in Wilson and Reeder 1993). However, the species has been eliminated from most of the Midwest by intensive agriculture and human settlement. Now it occurs primarily in remaining large forested tracts.

Black bears can be found from northern Alaska east across Canada to Labrador and Newfoundland, and south through much of Alaska, virtually all of Canada, and most of the United States into central Mexico.

Biogeographic Regions: nearctic (Native )

Black bears can be found from northern Alaska east across Canada to Labrador and Newfoundland, and south through much of Alaska, virtually all of Canada, and most of the U.S. into central Mexico (Nayarit and Tamaulipas states).

Biogeographic Regions: nearctic (Native )

occurs (regularly, as a native taxon) in multiple nations

Canada

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Historic Range:
North America

Black bears are usually black in color, particularly in eastern North America. They usually have a pale muzzle which contrasts with their darker fur and may sometimes have a white chest spot. Western populations are usually lighter in color, being more often brown, cinnamon, or blonde. Some populations in coastal British Columbia and Alaska are creamy white or bluish gray. Total body length in males ranges from 1400 to 2000 mm, and from 1200 to 1600 mm in females. Tail length ranges from 80 to 140 mm. Males weigh between 47 and 409 kg, females weigh between 39 and 236 kg.

Black bears are distinguished from grizzly or brown bears (Ursus_arctos) by their longer, less heavily furred ears, smaller shoulder humps, and a convex, rather than concave, profile.

Range mass: 39.0 to 409.0 kg.

Range length: 1200.0 to 2000.0 mm.

Other Physical Features: endothermic ; heterothermic ; homoiothermic; bilateral symmetry

Sexual Dimorphism: male larger

Black bears are usually black in color, particularly in eastern North America. They usually have a pale muzzle which contrasts with their darker fur and may sometimes have a white chest spot. Western populations are usually lighter in color, being more often brown, cinnamon, or blonde. Some populations in coastal British Columbia and Alaska are creamy white or bluish gray. Total body length in males ranges from 1400 to 2000 mm, and from 1200 to 1600 mm in females. Tail length ranges from 80 to 140 mm. Males weigh between 47 and 409 kg, females weigh between 39 and 236 kg. The distance between the canine teeth is about 4.5 to 5 cm.

Black bears are distinguished from grizzly or brown bears (Ursus arctos) by their longer, less heavily furred ears, smaller shoulder humps, and a convex, rather than concave, profile.

Range mass: 39.0 to 409.0 kg.

Range length: 1200.0 to 2000.0 mm.

Other Physical Features: endothermic ; heterothermic ; homoiothermic; bilateral symmetry

Sexual Dimorphism: male larger

Length: 160 cm

Weight: 200000 grams

Sexual Dimorphism: The largest males may be nearly twice as heavy as the heaviest females.

Length:
Range: 1,44-2,000 mm males; 1,200-1,600 mm females

Weight:
Average: 120 kg males; 80 kg females
Range: 47-409 kg males; 39-236 kg females

Differs from the grizzly bear in having the claws of the forefeet only a little longer than those on the hind feet (about twice as long in the grizzly), length of second upper molar less than 29.5 mm (in part of range where grizzly occurs), snout profile straight rather than dished, and in lacking a prominent hump at the shoulders; maximum size of black bear is less than that of the grizzly (170-280 cm head and body length) (Nowak 1991, Hall 1981).

Habitat and Ecology

Systems

• Terrestrial

Black bears are most often found in areas with abundant cover and sources of food. They are usually found in rough terrain with lots of dense forest cover, including swampy areas. They require places to den during the winter, which can be in caves or under large boulders or tree roots. The most critical aspect of the habitat required by black bears is sufficient food supplies, which is why many black bears live successfully near humans.

Habitat Regions: temperate ; terrestrial

Terrestrial Biomes: forest ; scrub forest

Other Habitat Features: riparian

Throughout their range, prime black bear habitat is characterized by relatively inaccessible terrain, thick understory vegetation, and abundant sources of food in the form of shrub or tree-borne soft or hard mast. In the southwest, prime black bear habitat is restricted to vegetated, mountainous areas ranging from 900 to 3,000 m in elevation. Habitats consist mostly of chaparral and pinyon-juniper woodland sites. Bears occasionally move out of the chaparral into more open sites and feed on prickly pear cactus. There are at least two distinct, prime habitat types in the Southeast. Black bears in the southern Appalachian Mountains survive in a predominantly oak- hickory and mixed mesophytic forest. In the coastal areas of the southeast, bears inhabit a mixture of flatwoods, bays, and swampy hardwood sites. In the northeast, prime habitat consists of a forest canopy of hardwoods such as beech, maple, and birch, and coniferous species. Swampy habitat areas are mainly white cedar. Corn crops and oak-hickory mast are also common sources of food in some sections of the northeast; small, thick swampy areas provide excellent refuge cover. Along the Pacific coast, redwood, sitka spruce, and hemlocks predominate as overstory cover. Within these forest types are early successional areas important for black bears, such as brushfields, wet and dry meadows, high tidelands, riparian areas and a variety of mast-producing hardwood species. The spruce-fir forest dominates much of the range of the black bear in the Rockies. Important nonforested areas are wet meadows, riparian areas, avalanche chutes, roadsites, burns, sidehill parks, and subalpine ridgetops.

Habitat Regions: temperate ; terrestrial

Terrestrial Biomes: forest ; scrub forest

Other Habitat Features: riparian

Comments: Black bears inhabit forests and nearby openings, including forested wetlands. When inactive, they occupy dens under fallen trees, ground-level or above-ground tree cavities or hollow logs, underground cave-like sites, or the ground surface in dense cover. Young are born in a den. A low rate of den reuse was recorded in Pennsylvania.

These bears prefer mixed deciduous-coniferous forests with a thick understory but may occur in various situations. Large hardwood swamps and pocosins are important habitats on the Atlantic Coastal Plain. In the Great Dismal Swamp, Virginia and North Carolina, preferred habitats were pocosins, gum-cypress and maple-coniferous stands, disturbed areas, and roads; females exhibited seasonal changes in habitat preference (Hellgren and Vaughan 1991). In some areas (e.g., Alaska), bears make significant use of salmon spawning streams. In southeastern wetlands, bears would benefit from maintenance and enhancement of pocosins, mature gum, oak, and disturbed habitats (Hellgren et al. 1991).

Non-Migrant: Yes. At least some populations of this species do not make significant seasonal migrations. Juvenile dispersal is not considered a migration.

Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).

Locally Migrant: No. No populations of this species make annual migrations of over 200 km.

Black bears exhibit large variations in home range, depending on location and gender(Banfield 1974, Baker 1983, Klenner 1987). Female and subadult ranges typically are much smaller than those of adult males. In Minnesota, females rarely dispersed from natal home range, males dispersed when 2-4 years old (Rogers 1987). In western North Carolina, neighboring individuals often used areas of overlap for same activities and at same time (Horner and Powell 1990). Home ranges of males averaged 505 hectares on Long Island, Washington (Lindzey and Meslow 1977), 5,200 hectares in northern Washington (Poelker and Hartwell 1973), 1,060 hectares in northwestern California (Kelleyhouse 1975) and 2,240 hectares in the San Bernardino Mountains of southern California (Novick 1979). Home ranges in Idaho ranged from 1,660 to 13,030 hectares (Armstrup and Beecham 1976).

Black bears are omnivorous. They eat plants, fruit, Insecta, seeds and nuts, flesh, and carrion. Available food types vary from season to season and between regions. Only a small portion of a bears diet consists of animal matter, and this is usually made up of colonial insects, such as Isoptera, and Coleoptera. Most vertebrate are consumed as carrion. Black bears are not active predators and hunt vertebrates only if the opportunity exists. In spring, after black bears emerge from their winter dens, is a time when food is scarce. Bears tend to lose weight during this period and continue to live off of body fat stored during the previous fall. As summer approaches, black bears begin to eat a wide variety of berry crops and the large numbers of insects that are emerging. In the fall they put on large amounts of fat in preparation for the winter sleep.

Animal Foods: carrion ; insects

Plant Foods: roots and tubers; seeds, grains, and nuts; fruit

Throughout their range in North America, black bears consume primarily grasses and forbs in spring, soft mast in the form of shrub and tree-borne fruits in summer, and a mixture of hard and soft mast in fall. However, the availability of different food types varies regionally. Only a small portion of the diet of bears consists of animal matter, and then primarily in the form of colonial insects and beetles. Most vertebrates are consumed in the form of carrion. Black bears are not active predators and feed on vertebrates only if the opportunity exists.

The diet of black bears is high in carbohydrates and low in proteins and fats. Consequently, they generally prefer foods with high protein or fat content, thus their propensity for the food and garbage of people. Bears feeding on a protein-rich food source show significant weight gains and enhanced fecundity. Spring, after black bears emerge from winter dens, is a period of relative food scarcity. Bears tend to lose weight during this period and continue to subsist partly off of body fat stored during the preceding fall. They take advantage of any succulent and protein- rich foods available; however, these are not typically in sufficient quantity to maintain body weight. As summer approaches, a variety of berry crops become available. Summer is generally a period of abundant and diverse foods for black bears, enabling them to recover from the energy deficits of winter and spring. Black bears accumulate large fat reserves during the fall, primarily from fruits, nuts, and acorns.

Animal Foods: carrion ; insects

Plant Foods: roots and tubers; seeds, grains, and nuts; fruit

Primary Diet: omnivore

Comments: Opportunistic omnivore. Variable diet of plants and animals (vertebrates and invertebrates), commonly including fruits, insects, and carrion; also garbage. There is no evidence of black bears being preferentially attracted to human menstrual odors or attacking menstruating women (Rogers et al. 1991).

Black bears are important in ecosystems because of their effects on populations of insects and fruits. They help to disperse the seeds of the plants they eat and consume large numbers of colonial insects and moth larvae. They sometimes take small and large mammals as prey, such as rabbits and deer.

Black bear cubs may be at risk of being killed by large predators, such as Canis lupus and Puma concolor. However, most black bears that are killed, both young and adults, are killed by humans.

Known Predators:

• humans (Homo_sapiens)
• wolves (Canis_lupus)
• mountain lions (Puma_concolor)

Anti-predator Adaptations: cryptic

Black bears are important in ecosystems because of their effects on populations of insects and fruits. They help to disperse the seeds of the plants they eat and consume large numbers of colonial insects and moth larvae. They sometimes take small and large mammals as prey, such as rabbits and deer.

Black bear cubs may be at risk of being killed by large predators, such as wolves and mountain lions. However, most black bears that are killed, both young and adults, are killed by humans.

Known Predators:

• humans (Homo sapiens)
• wolves (Canis lupus)
• mountain lions (Puma concolor)

Anti-predator Adaptations: cryptic

Ursus americanus is prey of:
Homo sapiens
Canis lupus
Puma concolor

This list may not be complete but is based on published studies.

Ursus americanus preys on:
Microtus xanthognathus
Cervus elaphus
Rangifer tarandus
Alces alces

This list may not be complete but is based on published studies.

Note: For many non-migratory species, occurrences are roughly equivalent to populations.

Estimated Number of Occurrences: 81 to >300

Comments: Many EOs.

10,000 to >1,000,000 individuals

Density estimates in different areas: 1 bear per 1.3-8.8 sq km. Estimated density of 0.52-0.66 bears/sq km at Great Dismal Swamp National Wildlife Refuge, is the highest known density in the southeastern U.S.

Black bears communicate with body and facial expressions, sounds, touch, and through scent marking. Scent marks advertise territory boundaries to other bears. Black bears have a keen sense of smell.

Communication Channels: visual ; tactile ; acoustic ; chemical

Perception Channels: visual ; acoustic

Black bears communicate with body and facial expressions, sounds, touch, and through scent marking. Scent marks advertise territory boundaries to other bears. Black bears have a keen sense of smell.

Communication Channels: visual ; tactile ; acoustic ; chemical

Perception Channels: visual ; acoustic

Comments: Bears are dormant (but do not truly hibernate) in winter, though winter denning by males and barren females in the southern part of the range relatively short.

Daily activity may vary seasonally.

Black bears can live to 30 years in the wild but most often live for only about 10, mostly because of encounters with humans. More than 90% of black bear deaths after the age of 18 months are the result of gunshots, trapping, motor vehicle accidents, or other interactions with humans.

Range lifespan
Status: wild: 30.0 (high) years.

Average lifespan
Status: wild: 10.0 years.

Average lifespan
Sex: female
Status: wild: 26.0 years.

Average lifespan
Status: wild: 32.0 years.

Black bears can live to 30 years in the wild but most often live for only about 10, mostly because of encounters with humans. More than 90% of black bear deaths after the age of 18 months are the result of gunshots, trapping, motor vehicle accidents, or other interactions with humans.

Range lifespan
Status: wild: 30.0 (high) years.

Average lifespan
Status: wild: 10.0 years.

Average lifespan
Sex: female
Status: wild: 26.0 years.

Average lifespan
Status: wild: 32.0 years.

Maximum longevity: 34 years (captivity) Observations: During hibernation body temperature floats around 32.5ºC. Although pregnancy in bears lasts for about 220 days, there is a delayed implantation and embryonic development only occurs in the last 10 weeks of pregnancy (Ronald Nowak 1999). In the wild, it has been suggested that they may live over 33 years (http://www.bear.org/), which is dubious. Record longevity in captivity belongs to a wild born female that was about 34 years when she died in captivity (Richard Weigl 2005).

Males and females meet temporarily for mating when females are in estrus. Male home ranges overlap with those of several females.

Mating System: polygynous

Males and females coexist briefly during the mating season, which generally peaks from June to mid-July. Females usually give birth every other year, but sometimes wait 3 or 4 years, depending on food availability. Pregnancy generally lasts about 220 days, but this includes a period of time when the egg has not started developing. The fertilized eggs remain in a suspended state until the fall, when embryonic development begins. This development lasts only 10 weeks. Births occur mainly in January and February, while the female is hibernating. The number of young per litter ranges from one to five and is usually two or three. At birth the young weigh 200 to 450 grams each, the smallest young relative to adult size of any placental mammal. They are born naked and blind.

Females reach sexual maturity at from 2 to 9 years old, and have cubs every other year after maturing. Males reach sexual maturity at 3 to 4 years old but continue to grow until they are 10 to 12 years old, at which point they are large enough to dominate younger bears without fighting.

Breeding interval: Female black bears have cubs every other year if they have enough food to support pregnancy.

Breeding season: Black bears breed in June and July.

Range number of offspring: 1.0 to 5.0.

Average gestation period: 220.0 days.

Range weaning age: 6.0 to 8.0 months.

Range age at sexual or reproductive maturity (female): 2.0 to 5.0 years.

Range age at sexual or reproductive maturity (male): 2.0 to 5.0 years.

Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); fertilization ; viviparous ; delayed implantation

Average birth mass: 277.5 g.

Average gestation period: 70 days.

Average number of offspring: 2.

Black bear cubs remain in the den with their sleeping mother and nurse throughout the winter. When the family emerges in the spring the cubs weigh between 2 and 5 kg. They are ususally weaned at around 6 to 8 months of age, but remain with the mother and den with her during their second winter of life, until they are about 17 months old. At this time the mother forces the young out of her territory. They may weigh between 7 and 49 kg at this point, depending on food supplies. Black bear mothers care for their young and teach them necessary life skills throughout the time that their cubs are with them.

Male black bears do not contribute directly to their offspring but do indirectly by preventing new males from moving into the area. This makes it less likely for the young or mother to encounter an aggressive male or have to compete with new bears for food.

Parental Investment: altricial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Female); pre-independence (Provisioning: Female, Protecting: Female); extended period of juvenile learning

Males and females meet temporarily for mating when females are in estrus. Male home ranges overlap with those of several females.

Mating System: polygynous

The sexes coexist briefly during the mating season, which generally peaks from June to mid-July. Females remain in estrus throughout the season until they mate. They usually give birth every other year, but sometimes wait 3 or 4 years. Pregnancy generally lasts about 220 days, but this includes a delayed implantation. The fertilized eggs are not implanted in the uterus until the autumn, and embryonic development occurs only in the last 10 weeks of pregnancy. Births occur mainly in January and February, commonly while the female is hibernating. The number of young per litter ranges from one to five and is usually two or three. At birth the young weigh 200 to 450 grams each, the smallest young relative to adult size of any placental mammal. They are born naked and blind. Black bear cubs remain in the den with their torpid mother and nurse throughout the winter. When the family emerges in the spring the cubs weigh between 2 and 5 kg. They are ususally weaned at around 6 to 8 months of age, but remain with the mother and den with her during their second winter of life, until they are about 17 months old. At this time the female is coming into estrus and forces the young out of her territory. They may weigh between 7 and 49 kg at this point, depending on food supplies.

Females reach sexual maturity at from 2 to 9 years old, and have cubs every other year after maturing. Males reach sexual maturity at 3 to 4 years old but continue to grow until they are 10 to 12 years old, at which point they are large enough to dominate younger bears without fighting.

Breeding interval: Female black bears have cubs every other year if they have enough food to support pregnancy.

Breeding season: Black bears breed in June and July.

Range number of offspring: 1.0 to 5.0.

Average gestation period: 220.0 days.

Range weaning age: 6.0 to 8.0 months.

Range age at sexual or reproductive maturity (female): 2.0 to 5.0 years.

Range age at sexual or reproductive maturity (male): 2.0 to 5.0 years.

Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); fertilization ; viviparous ; delayed implantation

Average birth mass: 277.5 g.

Average gestation period: 70 days.

Average number of offspring: 2.

Black bear cubs remain in the den with their sleeping mother and nurse throughout the winter. When the family emerges in the spring the cubs weigh between 2 and 5 kg. They are ususally weaned at around 6 to 8 months of age, but remain with the mother and den with her during their second winter of life, until they are about 17 months old. At this time the mother forces the young out of her territory. They may weigh between 7 and 49 kg at this point, depending on food supplies. Black bear mothers care for their young and teach them necessary life skills throughout the time that their cubs are with them.

Male black bears do not contribute directly to their offspring but do indirectly by preventing new males from moving into the area. This makes it less likely for the young or mother to encounter an aggressive male or have to compete with new bears for food.

Parental Investment: altricial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Female); pre-independence (Provisioning: Female, Protecting: Female); extended period of juvenile learning

Breeding occurs in June-July. Implantation is delayed about 4 months (also reported as 5-6 months). Gestation lasts 7-7.5 months (average 220 days). Females give birth every 2 years at most. Young are born in January-February, stay with mother until fall of second year. Litter size is 1-5 (modal number generally is 2 or 3, average is less than 2 in western North America). Females generally first give birth at 2-5 years (usually 4-5 years).

A female bear's reproductive success is dependent on her condition when she enters winter dormancy. A female that has fed well in autumn puts on much body fat and gives birth to usually 2 (rarely up to 5) cubs, whereas a female in poor condition does not produce any cubs. In the southern Appalachians, productivity and survival of young were enhanced when fall food (especially hard mast) supply was favorable (Eiler et al. 1989).

Black bears once lived throughout most of North America, but hunting and agriculture drove them into heavily forested areas. Populations surive over much of their former range in less populated wooded regions and in protected areas. They are numerous and thriving, although they continue to face threats in some areas due to habitat destruction. Black bears appear in CITES appendix II.

IUCN Red List of Threatened Species: least concern

US Federal List: no special status

CITES: appendix ii

State of Michigan List: no special status

The Louisiana black bear is threatened in the following areas: all counties of Louisiana; all counties south of or touching a line from Greenville to Meridian, Mississippi; all counties east of or touching a line from Linden, southwest to Bryan, and south-southwest to Rockport, Texas [260].

Other subspecies of American black bear within the same range as the Louisiana black bear are listed as having a "similarity of appearance to a threatened taxon". This includes all counties of Louisiana, Mississippi, and Texas, and the historic county range of the Louisiana black bear [260].

Year Assessed

Assessor/s

Reviewer/s

Contributor/s

Justification

History

• 1996
  Lower Risk/least concern

Black bears once lived throughout most of North America, but hunting and agriculture drove them into heavily forested areas. Residual populations survive over much of the range in sparsely populated wooded regions and under protection in national parks. They are numerous and thriving, but continue to face threats regionally due to habitat destruction and hunting. Black bears appear in CITES appendix II.

US Federal List: no special status

CITES: appendix ii

State of Michigan List: no special status

IUCN Red List of Threatened Species: least concern

Canada

Rounded National Status Rank: N5 - Secure

United States

Rounded National Status Rank: N5 - Secure

Rounded Global Status Rank: G5 - Secure

Reasons: Widespread in North America; stable, secure population.

Population

Population Trend

Major Threats

Degree of Threat: D : Unthreatened throughout its range, communities may be threatened in minor portions of the range or degree of variation falls within natural variation

Comments: Locally threatened by habitat loss and interference by humans. Black market value of gall bladder and paws has led to an increase in the illegal harvest of this species.

Conservation Actions

Restoration Potential: Smith and Clark (1994) discussed factors (including release of 20-40 individuals/year for eight years) contributing to the successful re-establishment of a population after extirpation in the Ozark and Ouachita mountains of Arkansas.

Management Requirements: Adults (e.g., "problem bears") must be moved at least 64 km to assure that less than 50% return to original location; no increase in natural mortality occurs in translocated bears of age 2 years or older (Rogers 1986). See also Herrero (1985), Williamson (n.d.), Darling and Archibald (1990), and Clark and Smith (1991) for management information.

Global Protection: Few to several (1-12) occurrences appropriately protected and managed

Comments: Protected in various national parks, and national wildlife refuges, and wilderness areas.

Black bears have been known to occasionally kill livestock. However, attacks on livestock are very rare. Bears can do serious damage to cornfields and honey production. Some bears have become troublesome around camps and cabins if food is left within their reach. Black bears have severely injured and sometimes even killed campers or travelers who feed them. However, the danger associated with black bears is often overstated, fewer than 36 human deaths resulted from black bear encounters in the 20th century. Black bears are generally very timid and, unlike grizzly bear females, black bear mothers with cubs are unlikely to attack people. When black bear mothers confront humans, they send their cubs up a tree and retreat or bluff.

Negative Impacts: injures humans (bites or stings); crop pest

People have intensively hunted black bears as trophies and for its hide, meat, and fat. In most of the states and provinces occupied by black bears, they are treated as a game animal, which means that regulated hunting is allowed. An estimated 30,000 black bears are killed annually in North America. Relatively few skins go to market now, as regulations sometimes forbid commerce and there is no great demand.

Medical research on the ways that black bears use to survive long period of low activity is giving researchers new insight into treatments for kidney failure, gallstones, severe burns, and other illnesses.

Positive Impacts: body parts are source of valuable material; research and education

Black bears have been known to occasionally raid livestock, though losses to bears are negligible. Bears sometimes damage cornfields, and berry and honey production. Some bears have become troublesome around camps and cabins if food is left in their reach. Black bears have severely injured and sometimes even killed campers or travelers who feed them. However, the danger associated with black bears is sometimes overstated, fewer than 36 human deaths resulted from black bear encounters in the 20th century. Black bears are generally very timid and, unlike grizzly bear females, black bear mothers with cubs are unlikely to attack people. When black bear mothers confront humans, they typically send their cubs up a tree and retreat or bluff. People who live in or visit areas with black bears should be aware of the appropriate precautions for avoiding black bear encounters.

Negative Impacts: injures humans (bites or stings); crop pest

People have intensively hunted U. americanus, for trophy value and for various products, including hides for clothes or rugs, and meat and fat for food. In most of the states and provinces occupied by black bears, they are treated as game animals, subject to regulated hunting. An estimated 30,000 individuals are killed annually in North America. Relatively few skins go to market now, as regulations sometimes forbid commerce and there is no great demand.

Medical research on the metabolic pathways that black bears use to survive long period of torpor is yielding new insight into treatments for kidney failure, gallstones, severe burns, and other illnesses.

Positive Impacts: body parts are source of valuable material; research and education

Comments: Gall bladder and paws are of great value in the Asian black market (see Boston Globe, 2 March 1992, pp. 23-24).