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
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.
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
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 )
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
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.
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
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
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
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 ; tactile ; acoustic ; chemical
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:
Anti-predator Adaptations: cryptic
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); sexual ; 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
See Denning and Preferred Habitat.
Home range and density: Home range size, distribution within home ranges, and density of American black bears are determined by sex, habitat quality, population density, distribution of food, breeding season, and topography [9,64,76,113,130,149,187,201,208,211]. Adult males have the largest home ranges, followed by adult females, yearling males, and yearling females [9,104,130,132,149,250].
Home ranges may or may not overlap between sexes and age classes depending on intraspecific relationships and habitat quality [9,104,114,130,149,187,208]. Females that are related usually have overlapping home ranges [9,106,114,148,187,187,213,223]; however, Schenk and others [223] found that home range overlap in Chapleau Crown Game Preserve, Ontario, was not a consequence of natal philopatric tendencies. Usually, subadult males and subadult females are allowed to stay on their mothers' home ranges for their first year of independence before dispersing (see Dispersal) [132]. After female yearlings separate from their mothers (16-17 months of age), they live alone within their natal home range. As they get older, some expand their ranges, some leave to establish territories in adjacent areas, and some disperse several kilometers away. Mothers may shift their territories away from their daughters, probably to avoid crowding [208]. Home ranges of adult males and females may overlap. In the Pisgah Bear Sanctuary, home ranges of males and females overlapped at home range peripheries and in core areas. Overlap increased during summer and decreased during autumn [106].
Home ranges may be smaller and have more overlap in mild climates and productive habitats [9,104,106,114,132,148,187,188,201,223]. In boreal forests, home ranges do not usually overlap, and territoriality between adult females is common [106,114,208,213]. This may be a consequence of low habitat productivity [106]. In ponderosa pine-mixed conifer forests in north-central Arizona, home range size was 5 times larger in fragmented forest areas than nonfragmented areas [178].
Home range size is largest during the breeding season and smallest before entry into dens in fall and emergence from dens in spring. Home range size of adult females and cubs peaks when foods are most abundant, from September to October [76]. During the breeding season in Superior National Forest, Minnesota, home ranges of males overlapped each other. Each breeding range included the territories of 7 to 15 female territories, and no males had exclusive access to any one female. After the breeding season, males migrated up to 124 miles (200 km) to forage. Foraging occurred between females' territories or on the outer 0.2 mile (0.4 km) of them. All subadult males (n=20) dispersed a mean of 38 miles (61 km; range= 8-136 miles (13-219 km)). Most males established their home ranges by 4 years old and used the home range for mating for at least 1 year after [208].
Topography may determine home range size, access to food resources, and/or potential mates. In Pisgah Bear Sanctuary, topography constrained size and shape of home ranges. The perimeter of home ranges aligned with ridges and valleys and home ranges were oriented on topographic features such as basins and watersheds. Steep slopes were utilized because they contained high densities of berries. American black bears avoided crossing over ridgetops to slopes on the other side probably due to high energetic costs and to avoid humans hiking along ridgelines [201].
Habitat use within home ranges is dictated by seasonal food production and breeding season, but a "core" use area may remain essentially unchanged throughout the year [114,149,187]. In Superior National Forest, foraging becomes the dominant activity after the breeding season ends, coinciding with the ripening of soft and hard mast. Between 40% and 69% of males and females, including females with cubs, foraged >4 miles (7 km) outside of their home ranges during late summer to access areas containing abundant food [208].
The table below shows mean annual home range sizes for American black bears in various geographic regions of the United States:
Mean annual home range sizes for American black bears (km²) LocationGender
Male Female Okanogan National Forest, Washington 289.7 (n=26) 37.1 (n=11) [75] Long Island, Washington 5.1 (n=10) 2.4 (n=13) [148] Weiser River, Idaho 112.1 (n=2) 48.9 (n=7) [9] Whitefish Range, Montana 30.1 (n=16) 5.2 (n=31) [114] Upper Peninsula of Michigan 75.6 (n=3) 48.1 (n=12) [104] Big Bend National Park, Texas 97.7 (n=7) 32.1 (n=7) [188] White River National Wildlife Refuge, Arkansas not available 4.9 (n=16) [187] Eglin Air Force Base, Florida 351.0 (n=6) 88 (n=3) [250]Habitat quality and size limit American black bear density. Density of American black bears may be greater in areas with abundant food resources [25,113,114,132,148,208]. On the Neuse-Pamlico Peninsula, densities and home ranges of adult female American black bears were higher in areas dominated by pocosins, marshes, and clearcuts compared to areas dominated by large loblolly pine plantations due to superior cover and food resources. Annual home range size for females was 6.6 km² (95% harmonic mean, n=8), and density was 1.35 American black bear/ km² in pocosins, marshes, and clearcuts. Annual home range size was 11.6 km² (n=5), and density was 0.53 American black bear/km² in loblolly pine plantations [113].
The estimated density of American black bears in west-central Idaho and the Shasta-Trinity National Forest, California, was 1 American black bear/0.5 mile² (1.3 km²) [25,198]. Density in the Whitefish Range of Montana ranged from 1 American black bear/0.8 mi² to 1 American black bear/1.7 mi² [114]. On the Superior National Forest, density was 1 American black bear/4.5 km² [208]. Density of American black bears in Coahuila, Mexico, was 0.35 American black bear/km² [63]. In the Ozark and Ouachita Mountains in Arkansas, density was 7.5 American black bears/100 km² [44].
American black bears are omnivorous and opportunistic [78,96,105,192,264,268]. Food habits are influenced by season, food abundance and accessibility, human activities near American black bear habitat, and reproductive status [268]. In general, grasses and forbs are preferred during spring; soft mast (typically berries) and insects are preferred during summer; and hard mast such as acorns and other nuts dominates the fall diet [76,96,96,101,110,132,157,160,162,192,242,252,272].
Grasses and herbaceous plants: Due to a poor ability to digest cellulose in mature plants, American black bears consume young, green vegetation, primarily during spring [208]. In Yukon, Canada [157] and the Yukon-Tanana uplands of interior Alaska, horsetail (Equisetum spp.) is important during spring and summer, comprising up to 86% of American black bear diets [96]. Apical meristems of saw-palmetto are an important part of Florida black bear diets [161], and cabbage palmetto (Sabal palmetto) dominates the spring diet [160].
Insects: Insects obtained from coarse woody debris are important food items, primarily during summer [18,37,100,160,168,199,268]. In northeastern Oregon, Bull and others [37] reported higher frequencies of insect consumption than elsewhere in the United States. High consumption of insects may have been related to a shortage of other foods. Total frequency of insect occurrence in 621 American black bear scats collected between April and October over 2 years was 70%. During July of one year, total frequency of occurrence was 98%. Insects eaten included carpenter ants (Camponotus spp.), forest ants (Formica spp.), other ants (Lasius spp., Tapinoma spp., and Aphaenogaster spp.), and yellowjackets (Vespula spp. and Dolichovespula spp.) [37]. In the Greater Yellowstone ecosystem, army cutworm moths (Euxoa auxiliaris) are eaten during summer months. Feeding sites are located on scree slopes at high elevations (x=11,010 feet (3,356 m)), with alpine tundra-covered benches and plateaus above and below feeding sites [168].
Soft mast: The most common soft mast eaten by American black bears are berries produced by shrubs. Some of the more important masting species include blueberries (Vaccinium spp.) [21,32], huckleberries (Vaccinium spp.), blackberries (Rubus spp.), serviceberries (Amelanchier spp.), strawberries (Fragaria spp.), autumn-olive (Elaeagnus umbellata) [5], and russet buffaloberry (Shepherdia canadensis) [86,87]. Saw-palmetto fruits are an important year-round food item for Florida black bears [160,162,250]. For a list of native fleshy fruits eaten by American black bears across their range, see Wilson [274].
Hard mast: Hard mast is important for American black bears in all geographic regions except the Pacific Northwest [264] and is generally more abundant in eastern portions of the American black bear's range [209]. American black bears may travel long distances during fall looking for hard mast [114] and may climb up to 98 feet (30 m) in trees to forage [192]. Hard mast eaten by American black bears may include acorns [71,91,98,114,192,198,258,264,268], hickory (Carya spp.) nuts [113], beechnuts (Fagus spp.) [192], whitebark pine (Pinus albicaulis) seeds [123,124,125,140,169,170,196], limber pine (P. flexilis) seeds [171], and pinyon (Pinus spp.) seeds [139]. Acorns preferred by American black bears include those of Gambel oak in ponderosa pine habitat in the Rocky Mountains [258], red oak and white oak in central hardwood forests [98,247,264], and Oregon white oak in the northwestern United States and southwestern Canada [71,144]. Production of acorns is often episodic and synchronous, so acorns may not be a reliable food source [43].
Whitebark pine seeds are a high-quality food for American black bears due to their high digestibility, relatively large size, and high fat content. Consumption of whitebark pine seeds occurs primarily south of the western US-Canada border [123,124,125]. Use is greater in continental climates (18.7%) in the northern and central Rockies than in maritime climates (2.7%) in the northwestern United States [123,125,169]. Within the Greater Yellowstone Area, American black bear consumption of whitebark pine seeds is greatest in mature stands (>100 years old) [123,125,169]. Whitebark pine seeds are eaten primarily during fall. American black bears may also raid red squirrel (Tamiasciurus hudsonicus) whitebark pine seed caches during spring [123,124,125,140,169,196]. Whitebark pine cone production may vary widely based on site, individual trees, years, and white pine blister-rust infection. In Yellowstone National Park, large cone crops usually occur every 4 to 9 years. Seed consumption may vary considerably among years, depending on crop size. Heavy consumption of whitebark pine seeds occurs when crops average >13 to 23 cones/tree [170]. American black bears may eat seeds up to 1 year after crop production [170].
In the Rocky Mountains, limber pine seeds may be an important food for American black bears when other foods are limited [171], and pinyon seeds are eaten in the Great Basin and southwestern United States [139].
Vertebrates: American black bears are more likely to eat carrion than to capture live prey [208]; however, they are capable of killing vertebrates. Vertebrate carrion or prey items include woodland caribou (Rangifer tarandus caribou) [41,42,238,277,280], elk (Cervis canadensis) [37,229,278], white-tailed deer (Odocoileus virginianus) [12], mule deer (O. hemionus) [37,207,278], and moose (Alces alces) [41,135,197,226]. Other vertebrates eaten by American black bears include Mount Graham red squirrels (Tamiasciurus hudsonicus grahamensis) [70], sooty grouse (Dendragapus fuliginosus) [127], bird eggs [23,57,205,220,265], and salmon (Oncorhynus spp.) [198,275]. Florida black bears may eat nine-banded armadillos (Dasypus novemcinctus) and feral pigs (Sus scrofa) [160].
Other: Stems and leaves of quaking aspen [26,132], poplar (Populus spp.) catkins, and black cottonwood buds are eaten during spring [133]. When wild foods are scarce, American black bears may occasionally prey on domestic sheep, goats, pigs, and young cattle. They may also eat garbage, agricultural crops, and orchard fruits [67,115,167,167,213,285].
For information on forage preferences and palatability ratings of American black bears in various phases within the grand fir/Rocky Mountain maple (Acer glabrum) habitat type and the Douglas-fir/white spirea (Spiraea betulifolia) habitat types in Idaho, see Steele and Geier-Hayes [244,245]. For a list of foods eaten by American black bears by season in lodgepole pine (P. contorta) and mixed deciduous-coniferous forest in Kananaskis Country, Alberta, see Holcroft and Herrero [105].
Habitat modification by fire has a greater effect on American black bears than direct mortality [80,259]. HABITAT RELATED FIRE EFFECTS depend on habitat type, habitat condition, fire severity, and pattern of fire across a landscape [153,155,199]. American black bears require a mosaic of successional stages for foraging, cover, and denning, so fires that create patches of burned and unburned habitat are most beneficial [7,27,52,121,133,144,153,156,199,221,222,243,251,268].
Fire may negatively impact American black bears in the short term by reducing food resources, cover, and potential den sites [31,53,69,88,136,152,194,216,250]. As production of early-seral vegetation increases, more food and cover become available [10,10,14,51,51,61,68,86,87,88,99,99,136,154,230,259]. Increased food resources in early- and midseral habitat may increase reproductive success [50,52,122,225,226] see Impacts on reproductive success). As the canopy closes in later stages of succession, availability of some foods may decrease; however, cover and potential den sites increase [121,126] (see Timing of food production and Impacts on den sites and cover).
Impacts on food production: Many plant species that American black bears consume benefit from fire [10,16,64,68,85,86,87,91,99,136]. They include grasses, forbs, fruit-producing shrubs, and some tree species [10,51,61,68,86,87,99,136]. Fire may also provide a medium for invasion of insects that American black bears eat (see Food Habits) [37]. Immediately following a severe wildfire, American black bears may benefit from availability of carcasses of elk and deer killed by fire [30,69,80,114,235,236] and displaced small mammals along firelines [121].
Fire is important in the maintenance and regeneration of whitebark pine [13]. Following low-, medium-, and high-severity fires, whitebark pine often establishes from seeds cached by the Clark's nutcracker (Nucifraga columbiana) [254,269]. Infrequent stand-replacement fires are an important component of whitebark pine's fire ecology [13,119]; however, large, stand-replacement prescribed burns are not recommended in areas where whitebark pine is in severe decline (for example, northern Idaho and northwestern Montana). Small-scale prescribed burning is recommended, especially where whitebark pine is seral; otherwise, regeneration may be extremely slow [179,180,181,240,256]. For more information about fire and whitebark pine, see the FEIS review of whitebark pine.
Frequent surface fires perpetuate oak growth in some areas by removing mid- and understory strata and reducing shading [2,22,107]. To mimic a natural disturbance pattern in mature mixed oak stands, Healy [98] suggests enhancing oak regeneration by conducting a shelterwood cut followed by a prescribed fire. Quaking aspen often sprouts after fire, providing a food source for the American black bear [82,267].
Fire exclusion may have adverse impacts on American black bear foraging habitat in some areas [261]. Once-productive, seral berry fields in Oregon and Washington have been invaded by conifers. Because plants growing under a closed canopy generally produce few berries, fruit production has been steadily declining [174]. Logging treatments that include severe soil scarification or slash burns may also reduce berry yields. Even where timber harvest favors berry production, lack of cover in early postfire years may limit American black bear use [283]. Huckleberries and blueberries are more productive on recently burned sites compared to unburned sites. However, severe, duff-consuming fires can destroy shallow rhizomes [15,33,45,85,163,217].
Timing of food production: Availability of forage may decrease in the "short term" after fire [10,14,51,51,61,68,87,88,99,99,136,154,230,259], but may begin to increase 1 year following fire. Potter and Kessell [200] modeled potential feeding and reproductive habitat utilization for large mammals in any homogenous forest community. The model examined wildlife use of an unburned habitat and habitats at 0, 10, and 25 postfire years. American black bears showed the lowest preference for foraging in unburned communities and the highest preference for foraging in the postfire year 10 community [200].
Depending on fire severity and habitat type, soft mast production may begin to increase 1 year following fire, and abundant fruit crops may be produced for up to 20 years after fire [10,51,61,68,86,87,99,136]. Blueberry (Vaccinium spp.) and blackberry (Rubus spp.) produce the most fruit "several years" after fire [136]. In boreal forests in the Great Lakes-St Lawrence region, blueberries, red raspberries (R. idaeus), serviceberries (Amelanchier spp.), and cherries (Prunus spp.) were most abundant 2 to 20 years after fire or logging [99,136]. In Minnesota, blueberry production increased 1 year after fire, attracting American black bears [32]. Near Farewell, Alaska, American black bears were seen eating blueberries in late August and early September on a 5-year-old burn in habitat formerly dominated by black spruce and white spruce, ericaceous (Ericaceae) and dwarf birch shrublands, and sedge (Cyperaceae) tussock plant communities. Sightings of American black bears were incidental, and systematic wildlife inventories were not conducted [92].
In general, fruit production of most western huckleberry species is delayed for at least 5 years following fire. On some sites, fruit production may be reduced for 20 to 30 years or longer [15,33,45,163,217]. Refer to the FEIS reviews of evergreen huckleberry, big huckleberry, and other huckleberry species for more information about fire effects.
Russet buffaloberry is resistant to fire, surviving by root crowns and dormant buds located on the taproot [185]. Stand-replacing prescribed burns on southern aspects led to the greatest production of russet buffaloberries at least 5 years after fire in a seral lodgepole pine and hybrid white spruce à Engelmann spruce forest in the Front Ranges of Banff National Park and the Ghost River Wilderness Area in Alberta. Fruit production began to decrease in 25-year-old burns where trees had restocked successfully. Fruit production on sites >50 years old varied depending on the site and fire characteristics. In areas that remained forest-free due to environmental factors, russet buffaloberry fruit production remained high. Two or more prescribed burns may be required to achieve the desired reduction in tree crown cover in habitat containing russet buffaloberry [86,87]. For more information about fire and russet buffaloberry, see the FEIS review of russet buffaloberry.
Three years after a wildfire in Seney National Wildlife Refuge in Michigan's Upper Peninsula, American black bears were commonly seen foraging in burned areas. Habitat use was greatest during postfire year 4, when soft mast production peaked. The 260 km² wildfire occurred in quaking aspen-paper birch habitat. Wooded wetlands, marshy grasslands, and open lakes were also common. The fire burned in a patchy pattern with varying intensities and severities, from light surface fires to severe crown fires where upper organic layers were ashed and all vegetation was consumed. Observations of American black bears in the area were incidental, and quantitative data on postfire habitat use were not collected [10].
In the northern Kenai Peninsula lowlands of Alaska, foods eaten by American black bears were similar between a recent burn (13-18 years old) and an old burn (35-40 years old). Major exceptions were that American black bears ate 4 times more moose calves in the recent burn, and more mountain cranberries (V. vitis-idaea) in the old burn. The 2 wildfires were located in northern coniferous forest dominated by white spruce, black spruce, balsam poplar, quaking aspen, and paper birch. The recent burn lasted 3 weeks and burned 86,490 acres (35,000 ha). Within the study area, 67% of the habitat was burned. The fire creating the old burn lasted 6 weeks and burned 308,900 acres (125,000 ha). Within the study area, 42% of the habitat was burned. Due to fuel loading, topography, and changes in fire severity, numerous "islands" of mature forest were left unburned, creating a mosaic effect with large amounts of edge. Abundant postfire vegetative growth occurred in the recent burn, increasing the moose population and providing abundant prey for American black bears during spring. Approximately 6.2 moose calves/American black bear were killed and eaten during spring in the recent burn compared to 1.2 moose calves/American black bear in the old burn. During spring and fall, mountain cranberries were eaten more frequently in the old burn because mountain cranberry had not yet recovered from the recent burn. More invertebrates were available in the old burn because the burned wood had rotted. Devil's club (Oplopanax horridus) and claspedleaf twistedstalk (Streptopus amplexifolius) were the most common foods eaten in unburned patches of the recent burn. Horsetails and bluejoint reedgrass (Calamagrostis canadensis) were available in the old and recent burns and were the only 2 plant groups consumed as green vegetation. During summer, most American black bears from both burns left their traditional use areas to forage on devil's club [226].
Following a severe fire within chaparral and Madrean evergreen forest in the southern Mazatzal Mountains, Arizona, American black bears extensively used unburned patches of vegetation within postfire habitats, illustrating the importance of managing a mosaic of burned and unburned habitat. Presence of shrubs in proximity to large coniferous trees was considered optimal postfire foraging and bedding habitat [52]. According to Cunningham and others [52], shrub live oak-pointleaf manzanita (Quercus turbinella-Arctostaphylos pungens) chaparral reestablishment begins approximately 11 years after fire. As the density of chaparral increases, American black bears use burned areas more often. To reduce fire severity and potential negative impacts on American black bear, the authors recommend periodically removing litter via prescribed fire [52].
Impacts on dens and cover: Quantitative data on fire's impacts on dens and American black bear cover are scarce. Depending on fire severity, den sites and cover may or may not be negatively affected by fire. Low- to medium-severity fire may increase the density of snags and downed wood used by American black bears [39]. A severe fire that removes large amounts of snags, coarse woody debris, and vegetative cover would most likely negatively affect American black bears [36,54,54,84,114,186,199,250].
Impacts on reproductive success: Reproductive success may increase several years following fire due to increased vegetative growth within early-successional habitat [50,52,122,225,226].
On the northern Kenai Peninsula lowlands of Alaska, density of moose was greater on a recent burn (13-18 years old) than an old burn (35-40 years old), resulting in significantly (P<0.05) greater reproductive success, cub survival, and body size of American black bears on the recent burn. In the recent burn, excellent early-successional habitat was available for moose forage, resulting in a moose population twice that of the old burn. Consumption of moose calves by American black bears was 4 times greater in the recent burn compared to the old burn. Density and litter size of American black bears were similar between recent and old burns; however, females in the recent burn bred at a younger age and had shorter reproductive intervals than females in the old burn. Survival of cubs was higher in the recent burn, but survival of subadult and adult females and males was lower. Hunting was the main cause of death for all age classes except cubs [225,226]:
Population dynamics of moose and American black bears in a recent and old burn in the northern Kenai Peninsula lowlands of Alaska [225,226] Recent burnMoose
Density (moose/km² 3.3 to 3.7 1.3 to 0.3 ---* Population trend during study peaked down --- Population peak (yrs.) postfire years 15-16 postfire years 13-14 --- Twinning rate (%) 70 22 ---American black bears
Density 258 205 not significant Age of 1st reproduction (years) 4.6 5.8 P<0.05 Interval between successful weanings of yearlings (years) 2.0 2.4 P<0.05 Cub survival 0.91 0.74 P<0.05 Subadult male survival 0.38 0.70 --- Subadult female survival 0.66 0.93 --- Adult male survival 0.77 0.90 --- Adult female survival 0.85 0.89 --- Body size greater smaller (kg not given) P<0.05 Number of moose calves consumed by 1 American black bear/season 6.2 1.2 --- *No data.Density of American black bears, adult survival rates, and cub production were similar between burned and unburned areas in 2 desert sky-island habitats in the southern Mazatzal Mountains, Arizona. The largest impact of the fire was lack of recruitment of cubs to the yearling age class. Elevations in both study areas ranged from 2,300 to 7,500 feet (700-2,300 m), with many slopes >45%. Habitat at low elevations (<2,900 feet (900 m)) was semidesert grassland and Arizona Sonoran desert scrub. At moderate elevations (2,900-6,100 feet (900-1,800 m)), habitat type was interior shrub live oak-pointleaf manzanita chaparral. At high elevations (>6,070 feet), habitat types were pure ponderosa pine forest and Madrean evergreen forest consisting of ponderosa pine mixed with Gambel oak, Emory oak (Q. emoryi), and other chaparral species [50,52].
A severe wildfire killed >90% of vegetation within the 237 km² burned study area. Within the burned Madrean evergreen forest, 2 patches of unburned vegetation remained (16 km² and 10.2 km²), and American black bears used them more than expected based on their availability. Within burned areas, most vegetation used for American black bear cover was removed. Trunks and large tree branches were charred but intact. Daytime cover was not available until postfire year 4, and forage was not available until postfire year 2 [50,52].
From 1997 to 2000, the number of cubs produced per female was similar between burned and unburned sites (1.3 cubs/female). In the burned area, 16 cubs were produced, and 0 survived to 1 year of age. Females with cubs had to share small, unburned patches within burned areas with adult males. Death of cubs was caused either by adult males or from malnutrition. In the unburned habitat, 13 cubs were produced, and 36% survived to 1 year of age [50,52]:
Production and survival of American black bear cubs in the Mazatzal Mountains, Arizona from 1997 to 2000 [50,52] Study area No. breeding females % of females producing cubs No. cubs produced % of cubs surviving to 1 year of ageBurn (1996)
1997 4 100.0 9 0.0 1998 5 40.0 5 0.0 1999 3 33.3 2 0.0 Total 12 16 0.0Unburned
1997 4 75.0 6 16.6 1998 3 66.6 5 60.0 1999 3 33.3 2 no data Total 10 no data 13 36.4Prescribed fire: Prescribed fire combined with other silvicultural treatments creates and maintains suitable conditions for the American black bear by increasing food availability [82,268]. Large-scale prescribed burns are not recommended because American black bears may be displaced by lack of food, cover, and den sites. Frequent, low-severity surface fires on a small scale are recommended in most habitats because they create a variety of successional stages [34,86,111,144] and do not destroy large coarse woody debris [34,84,88,144,256,262,267].
To maximize soft mast production in open slash pine (Pinus elliottii) forests in southeastern Georgia, Johnson and Landers [111] suggest conducting low-severity prescribed burns at 3-year intervals. To encourage hard mast production, some longer intervals (>5 years) are encouraged [111].
Low-severity prescribed burns conducted at 5-year intervals benefit production of Oregon white oak. In areas with Douglas-fir encroachment, Larsen and Morgan [144] suggest burning every 3 to 5 years, and in areas where oak sapling growth success is critical or fuel loading is not a problem, burning every 5 to 10 years [144]. For more recommendations on Oregon white oak restoration and enhancement for wildlife, see Larsen and Morgan [144].
High-severity stand-replacing prescribed burns may lead to productive russet buffaloberry feeding habitat for American black bears ≥5 years after fire. Due to potential hazards of conducting stand-replacing prescribed burns, 2 or more burns may be necessary to simulate a high-severity burn. Prescribed burning on south-facing slopes results in successful regeneration of buffaloberry [86].
In forests located in the southeastern US and the southern Appalachians, extensive laurel (Kalmia spp.) and rhododendron (Rhododendron spp.) thickets provide dense cover for American black bears, and prescribed fire should be used carefully in these areas [88]. Hamilton [88] does not recommend prescribed fire in areas used for denning or cover by American black bears. Instead, it should be applied to heath or grass balds to stimulate growth of grasses, forbs, and fruit-producing shrubs. Low-severity burning should be conducted during winter because summer burning may reduce American black bear's food supply. Prescribed fire should also be applied with caution along the periphery of Carolina bays, and fire should be excluded from Coastal Plain hardwood swamps, sand ridges dominated by oaks, and from mountainous terrain due to potential detrimental effects on mast production and hardwood regeneration [88].
Small-scale prescribed burns are recommended for renewing seral whitebark pine communities at high-elevations areas where whitebark pine is badly damaged by mountain pine beetles (Dendroctonus ponderosae) and white pine blister rust [256]. In quaking aspen habitat, prescribed burning during spring is beneficial for regeneration of quaking aspen. In older stands where fuel is lacking, prescribed burns may not be possible. A good substitute for prescribed fire in quaking aspen habitat is dormant season logging, which promotes sprout regeneration [82].
A late winter/early spring prescribed burn in grassland habitat in Craig Mountain Wildlife Management Area in west-central Idaho improved habitat quality for mule deer, elk, and bighorn sheep (Ovis canadensis). The effects of the prescribed fire were not examined for American black bears; however, American black bears occupied the area may have benefited from improved forage of grasses during spring. Grasslands were composed of perennial bunchgrasses. The 3 grassland types burned were: bluebunch wheatgrass (Pseudoroegneria spicata)/plains prickly-pear (Opuntia polyacantha), bluebunch wheatgrass/Sandberg bluegrass (Poa secunda), and Idaho fescue (Festuca idahoensis)-bluebunch wheatgrass. Elevation ranged from 800 to 3,600 feet (200-1,100 m), and slopes ranged from 20% to 80%. Three-thousand acres (1,214 ha) were burned in late February and mid-March. The fire created a mosaic pattern, burning 30% to 65% of the area. Prior to fire exclusion, fires occurred in the area every 10 to 25 years. The fire was an effective tool for maintaining, rejuvenating, and improving big game winter ranges [112].
Evidence suggests that most oaks are favored by relatively frequent fires [1,11,17,151,218,262,279]. A series of low-severity prescribed fires prior to timber harvest can promote advanced regeneration of white oak. In the southern Appalachians, biennial summer fires are often most effective in promoting advance regeneration [262,266]. In upland habitat of the southeastern coastal plain of Florida, Stratman [250] recommends prescribed fire intervals of 7 to 10 years to promote oak regeneration and mast production. In stands dominated by oak, advance regeneration in the understory is a prerequisite for reestablishment subsequent to timber harvest [34,262]. To favor oak reproduction and establishment, Brose and Van Lear [34] recommend prescribed fires at intervals of 3 to 5 years following shelterwood cuts in upland stands with advance oak regeneration [34]. Refer to the FEIS reviews of northern red oak, white oak, Oregon white oak, and other oak species used by American black bears for more information about fire effects to oaks.
In sand pine (P. clausa)-scrub habitat in Ocala National Forest, Florida, full recovery of vegetation occurred 16 months following a prescribed stand-replacement fire. Three months after the fire, Florida black bears ate apical meristems from 50% of saw-palmetto and scrub palmetto (Sabal etonia) sprouts [81]. A mosaic of recent burns and relatively fire-free pine and saw-palmetto habitat is most beneficial for Florida black bears, and regular production of saw-palmetto fruits cannot be expected with frequent prescribed burning [159]. Maehr and others [161] recommend maintaining saw-palmetto in several stages of postfire recovery. Patches of saw-palmetto should be maintained at 1- to 20-postfire-year intervals to provide food, cover, and den sites [161].
Florida black bears showed the highest annual use of 2-year-old and 6-year-old prescribed burns in longleaf pine-Beyrech threeawn sandhills and pine (Pinus spp.) habitat in northern Florida. Burns <1 year old did not provide American black bears with adequate food resources or escape cover. High use of 2-year-old and 6-year-old burns was probably attributed to peak production of mast species and proximity to riparian areas used for cover. During fall, 2-year-old and 5-year-old burns resulting form low-severity fire were used most often. The low-severity of fall burns probably allowed high survival of oaks. In upland habitat, low-severity prescribed fire intervals of 3 to 5 years benefits Florida black bears by stimulating mast production of plants such as huckleberry, ground blueberry (V. myrsinites), sweet gallberry (Ilex coriacea), bitter gallberry (I. glabra), and greenbrier (Smilax spp.). A fire cycle >5 years stimulates mast production of highbush blueberry (V. corymbosum), sparkleberry (V. arboreum), black tupelo (Nyssa sylvatica), and common persimmon (Diospyros virginiana). Winter fire exclusion prevents disturbance of denning Florida black bears [250].
Hall [84] and Weaver [268] recommend protecting snags and coarse woody debris during prescribed burning. Before conducting a prescribed burn, potential den trees and large (>20 inches (50 cm)), hollow logs should be protected from fire by removing combustible material from the immediate areas [84,268].
The following table provides fire regime information on vegetation communities in which American black bear may occur, based on the habitat characteristics and species composition of communities American black bear are known to occupy. There is not conclusive evidence that American black bear occur in all the habitat types listed, and some community types, especially those used rarely, may have been omitted. Find further fire regime information for the plant communities in which this species may occur by entering the species name in the FEIS home page under "Find FIRE REGIMES".
Fire regime information on vegetation communities in which American black bear may occur. For each community, fire regime characteristics are taken from the LANDFIRE Rapid Assessment Vegetation Models [138]. These vegetation models were developed by local experts using available literature, local data, and/or expert opinion as documented in the PDF file linked from each Potential Natural Vegetation Group listed below. Cells are blank where information is not available in the Rapid Assessment Vegetation Model. Pacific Northwest California Southwest Great Basin Northern Rockies Northern Great Plains Great Lakes Northeast South-central US Southern Appalachians Southeast Pacific Northwest Vegetation Community (Potential Natural Vegetation Group) Fire severity* Fire regime characteristics Percent of fires Mean intervalManagement options for optimizing American black bear habitat may include the following: maintaining a mosaic of successional stages, maintaining riparian habitat for foraging and traveling, maintaining den sites, decreasing tree damage, and minimizing conflicts with humans [7,156,211,261,263].
Silviculture: American black bears are habitat generalists that require a mosaic of habitat types and may have diverse responses to forest management [177]. Effects of forest management on the American black bear vary depending on habitat type, landscape, and past management activities [177]. Logging and prescribed burning may maintain a diversity of vegetation, increase cover, and increase the productivity of some important plants eaten by American black bears [7,110,113,114,173,177,208,261,263,268]. The benefits of logging and prescribed burning on shrub growth decrease once the canopy closes [177]. Logging and prescribed burning may decrease the availability of den sites, cover, travel corridors, and trees that produce hard mast [56,193]. Disturbance of American black bears during timber harvesting may also create negative effects. Female adults with cubs often remain in their dens during timber harvest but may eventually abandon the site. Newborn cubs may die if forced to abandon dens in early spring [54]. Despite food abundance in some logged areas, American black bears may avoid the centers of logged areas due to lack of cover and potential heat stress [114].
Rogers and Allen [209] suggest that timber management provides a diversity of vegetational age classes in close proximity to each other. Ideally, 5% to 25% of an area should be managed as an unforested cover type [209]. Season of harvest should be considered to avoid disturbance of denning sites and foraging areas. Logging should not occur in riparian areas, seeps, or wetlands because they provide important seasonal food resources. According to Weaver [268], management treatments in a central hardwood landscape should maintain a diversity of hard mast species, high mast yields, and perpetuate desired hard mast-producing species in future hardwood stands.
On the Bridger-Teton National Forest in Wyoming, Irwin and Hammond [110] recommend providing a mosaic of successional stages by clearcutting in patches <25 acres (10 ha) on north- and east-facing slopes; planting fruit-producing shrubs in clearcuts; protecting old-growth stands of whitebark pine to provide American black bear food when berry production is low; maintaining low-elevation Douglas-fir forest on south-facing slopes; and cutting or burning quaking aspen to stimulate growth [110].
In southeastern Alaska, food resources for American black bears are abundant for 15 to 20 years following logging [173]. In a 1974 report, Meehan [173] suggests that small patch cuts or clearcut strips with blocks or strips of timber left between are ideal for maximum wildlife production. Logged areas that are <20 years old should be available at all times, as well as mature timber and edges [173].
If maximizing the preharvest mammalian community is a management goal in North American boreal forests, the rate of successional convergence to predisturbance, old-growth forest may be increased by doing the following: 1) leave "moderate" amounts of coarse woody debris in harvested areas; 2) leave snags and dead wood in close proximity to live trees to form clumps; and 3) leave >30% of mature trees as clumped residuals in harvested areas [68].
In Maryland, Fecske and others [67] recommend maintaining mature mixed forest and wetland habitats. Plant conifers if necessary, and help to increase growth of rhododendron (Rhododendron spp.) thickets and other native shrubs for cover in maturing deciduous forest [67]. On the Atlantic Coastal Plain, landscape-scale American black bear management is necessary to maintain large blocks of habitat relatively free from human activities. Pocosins and other wetlands types are important high-quality habitats for American black bear, and Jones and Pelton [113] state that these habitats should be maintained or restored. In seasonally-flooded forested wetlands, large trees (≥33 inches (84 cm) DBH) should be protected for Louisiana black bear denning sites [186].
Fragmentation of American black bear habitat from logging may make it difficult for American black bears to move between remaining habitat and may increase their vulnerability to predators. In ponderosa pine-mixed conifer habitat in north central Arizona, forest fragmentation influenced home range size, movement between usable habitat, and movement to important seasonal use areas. In fragmented habitat, American black bears were concentrated into smaller areas and became more vulnerable when moving between suitable habitat patches. Road systems created by logging also increased access by hunters. According to Mollohan and LeCount [178], American black bears must be managed carefully in fragmented habitat and further fragmentation should be avoided. Travel corridors should be provided between usable habitats [178].
Impacts of salvage logging depend on the number and condition of fire-killed trees that are retained in salvage cuts. Salvage logging may have negative impacts on wildlife by eliminating foraging and denning sites [182].
An American black bear habitat suitability model was created by Rogers and Allen [209] for northeast Minnesota, northern Wisconsin, and Michigan's Upper Peninsula and the upper half of the Lower Peninsula. The model has 3 major components: 1) variables that estimate the abundance and quality of seasonal foods in specific cover types; 2) variables used to estimate the cover type composition within an area; and 3) a variable that is used to estimate the influence of human disturbance on the habitat quality of American black bear [209].
Snags and coarse woody debris: Large-diameter hollow trees and coarse woody debris are important for hiding, denning, and foraging on insects [35,36,54,56,59,98,144,189,249] (see Denning and Food Habits). Cavity tree management includes maintaining existing cavity trees and snags, creating snags if they are absent [59,98,129,193,209], and leaving slash after logging for potential den sites [7,36,39,79,268]. Preserving large trees and snags is particularly important in areas with high human use, marginal habitat, and areas where flooding may occur [209]. Potential den sites should be retained in various aspects and elevations [54].
In Alaska, Alberta, British Columbia, the Pacific Northwest, California, the northern Rocky Mountains, and the northern Great Basin, Bunnell and others [38,39] offer the following recommendations for the distribution of dead wood in a managed forest occupied by American black bears and other wildlife: maintain 2 to 3 large snags (>20 inches (50 cm) DBH in coastal habitat and >12 inches (30 cm) DBH in less productive habitat)) per hectare; maintain 10 to 20 smaller snags (size not given) per hectare; leave scattered logs 20 to 39 inches (50-100 cm DBH)) in 2 to 7 acre (1-3 ha) patches [38,39].
To manage for snags and coarse woody debris in the Pacific Northwest, the following management is recommended: 1) ensure sustained provision of dead and dying wood; 2) retain trees and snags of hardwoods and favored conifer species such as western larch, Douglas-fir, and ponderosa pine; 3) retain a range of size and age classes of dead wood; 4) meet dead wood requirements for large mammal species; and 5) limit salvage logging after fires [36,39]. For more information about recommended size, species, and number of logs to retain in the Columbia River Basin, see Bull and others [36]. See Naylor [183] for guidelines on retaining cavity trees in eastern white pine and red pine forests in the Great Lakes-St Lawrence forest of central Ontario. See Davis [54] for recommendations on management of American black bear dens in western British Columbia.
To provide maximum use of slash piles for wildlife, Allen [7] suggest that slash piles be 100 ÃÂ 25 feet (30 ÃÂ 8 m) in size and adjacent to forested cover if possible [7]. To provide sites for ground dens, Weaver [268] suggests piling felled tops of trees and promoting thick regeneration [268]. White and others [273] recommend minimizing logging debris at low elevations (≤148.0 feet (45.1 m)) to reduce the probability of Louisiana black bears choosing flood-prone areas to den [273].
Retention of coarse woody debris is encouraged to provide insects for American black bear consumption [18,37,100,160,168,199,268] (see Food Habits). As logs decay, insect activity on the exterior and interior of the wood increases, enhancing the value for American black bears [35,37,60,100,199]. Bull and others [37] suggest retaining coarse woody debris in a variety of sizes and decay stages to enhance ant diversity.
Hard and soft mast management: Hard mast and soft mast are important seasonal foods for the American black bear [76,97,120,169,208,209,214,232] (see Food Habits). Management that promotes the establishment, diversification, proliferation, and perpetuation of soft mast-producing species is encouraged [268]. In some locations, the temporary paucity of hard mast may be offset by the availability of soft mast, so ideally, both should be managed [117,118].
Oak regeneration is hampered by consumption of acorns by animals, insect damage of acorns, and competition by shade-tolerant vegetation [91]. Recommendations to promote oak acorn production in eastern North America include 1) periodic thinning to promote rapid growth and vigorous crowns [97,232]; 2) managing for a diversity of mast-producing species, especially white oak and red oak; and 3) maintaining half of the management unit as mast-producing stands (40 to 80+ years old) [232].
Whitebark pine habitat needs to be secure for American black bears during fall and potentially during late spring and summer [170]. According to Romme and Turner [214], whitebark pine habitat is projected to decrease in the future due to climate change and white pine blister rust. They advise caution when harvesting whitebark pine, especially at low elevations, and advise restricting human facilities in the whitebark pine zone [169].
In the absence of white pine blister rust, whitebark pines >100 years old provide productive seed crops. Good seeds crops may be produced for 200 to 300 years thereafter [169]. In areas where American black bear management is a high priority, Mattson and Reinhart [169] recommend that timber be harvested in 300-year stand rotations, and landscape-wide harvest should be approximately 3%/decade. Thinning of subalpine fir is required to encourage growth of whitebark pine. Planting areas with rust-resistant whitebark pine seedlings may also promote whitebark pine [256]. Because American black bears raid red squirrel caches for whitebark pine seeds, low red squirrel densities limit American black bear use of whitebark pine seeds. Several authors suggest favoring red squirrels in habitat with whitebark pine [123,124,125,140,169,196]. For whitebark pine restoration techniques, see the FEIS review of whitebark pine.
Costello and others [48] suggest that in areas where hard mast is a primary fall food for American black bears, annual mast production should be documented to forecast changes in reproductive output.
Conversion of mast-producing flatwood and hardwood communities to slash pine plantations and winter burning to control understory growth may have negative impacts on food resources for the Florida black bear [160]. Because mast production of saw-palmetto is unpredictable in Florida black bear habitats, Stratman [250] suggests promoting production of acorns in upland hardwood stands with oak on the southeastern coastal plain. The size of oak stands should optimally range from 7 to 12 acres (3-5 ha), and the stands should be adjacent to riparian and swamp habitat [250].
Clearcutting: By opening the canopy, clearcutting increases production of early seral vegetation, providing forage and cover, benefiting American black bears. Negative consequences of clearcutting include loss of hard mast production, loss of potential den sites [54,95,149,177,209], and loss of understory trees, which may not reach suitable sizes for den use in future cutting rotations [54]. As harvested stands age and logging slash decomposes, many resources made available by clearcutting decline [177].
Use of clearcuts by American black bears is determined by age, size, shape, and distribution of cutting units, as well as proximity of logging roads to American black bear habitat [209,263]. Recent clearcuts (<8 years old) are seldom used by American black bears in Montana, Idaho, and Washington [114,149,261] except to travel through [114]. On Long Island, Washington, American black bears avoided 9- to 14-year-old clearcuts but used 18- to 25-year-old clearcuts [149]. In the Whitefish Range in northwestern Montana, American black bears used 10-year-old clearcuts but did not use newer cuts [114]. For more information on habitat use by American black bears in clearcut areas, see Preferred Habitat.
Clearcutting on a large scale radically alters American black bear habitat because it involves large tracts of land and extensive road systems. The negative impacts of clearcutting on American black bears could be minimized by harvesting small, irregular-shaped areas adjacent to cut areas >20 years old [281]. The size of clearcuts relative to shape is important when determining value to wildlife. Clearcuts that are highly sinuous and follow natural contours and soil types have the smallest negative impacts [95]. Rogers and Allen [209] recommend providing irregular boundaries, islands of standing timber, and travel corridors along drainages and ridgelines to offset potential negative impacts of clearcutting [209].Vander Heyden and Meslow [263] and Young and Beecham [281] suggest that within American black bear habitat, clearcutting either be minimized or clearcuts be small in size. To maximize food and cover for American black bears, place clearcuts adjacent to mature timber and open-canopy pole stands [263,281]. Rogers and Allen [209] suggest that clearcuts ideally be ≤20 acres (8 ha), and the farthest distance from forested escape cover from a clearcut be ≤820 feet (250 m).
Regeneration activities associated with clearcutting include burning slash, planting trees, and controlling weeds, shrubs, and animals that hinder tree reproduction [195]. Clearcutting that involves posttreatment practices that involve bulldozer piling of slash, burning, and soil scarification may damage roots of berry-producing plants and be detrimental to American black bear habitat. Arno and others [15] and Hungerford [108] recommend either broadcast burning slash or leaving it untreated to protect future mast production [15,108]. Aerial application of herbicides to enhance conifer regeneration may reduce soft mast production for several years [149,208].
Tree damage: American black bears may cause damage to trees, especially in the Pacific Northwest [46,62,77,284]. During spring and early summer, American black bears may strip bark to eat new sapwood [65,145,176,176,184,253]. This typically 3.3 to 4.9 feet (1.0 to 1.5 m) from the ground [184], but upper boles of trees may also be stripped [65]. American black bears do not forage on all tree species or age classes equally [62]. Trees of any age are vulnerable to damage by American black bear [128,184,253] but pole-sized trees are most vulnerable [65,128]. In the Pacific Northwest, American black bears may damage Douglas-fir, ponderosa pine [29,62], grand fir, western redcedar [128], or second-growth redwood (Sequoia sempervirens) trees [77]. In the northern Rocky Mountains, American black bears may damage western larch [233].
Tree damage typically occurs in thinned stands [166]. In northwestern Montana, American black bears damaged trees 5 times more often in thinned stands compared to adjacent unthinned stands of western larch, lodgepole pine, and Engelmann spruce. Small western larch trees (4-13 inches (10-33 cm)) DBH suffered the greatest damage (63% of all trees damaged and 92% of the trees killed) [166]. In northwestern California, American black bears damaged dense stands of pole-sized (4-20 inches (10-50 cm DBH)) redwood trees located in regenerating stands more than trees in other size classes. Density of damage was negatively correlated with distance from the edge in old-growth stands (P<0.001, t= -4.702). American black bears may benefit dense regenerating redwood stands by thinning trees. Therefore, culling American black bears to prevent tree mortality may be counterproductive and increase the need for future tree thinning [219].
Options for reducing tree damage and mortality include specific silviculture treatments during precommercial thinning, creating physical barriers, using American black bear repellents, supplemental feeding during the time of year when most tree damage occurs, capturing and relocating American black bears, or killing them [46,184,202]. On private lands in the Pacific Northwest, supplemental feeding programs have been successful in reducing American black bear damage [284]. For detailed suggestions on tree damage management, see Nolte and others [184].
Livestock grazing: American black bears have been eliminated from much of their range by the livestock industry [40]. Domestic livestock may compete directly with American black bears in some habitats [40,285]. According to Irwin and Hammond [110], Rogers and Allen [209], and Debyle [55], grazing should be curtailed or eliminated on low-elevation south slopes, riparian areas, quaking aspen stands, and high-elevation avalanche chutes to avoid competition for food resources between American black bears and livestock.
Roads: The impacts of roads on American black bears are determined by location, road structure, amount of traffic, and timing of road use. In the northern Cascade Range of Washington, roads consistently had a negative impact on habitat used by female American black bear [75]. Roads may not be problematic for American black bears if they are gated to reduce vehicular traffic and maintained as linear wildlife openings [75,149,156,208,209,268]. Highways may reduce viability of American black bear populations by acting as barriers to intraterritorial movement, increasing mortality from motor vehicle collisions, and increasing human disturbance [237]. Wildlife underpasses or overpasses may be constructed to provide travel corridors for American black bears under or across high-speed highways [67,94].
Hunting: Overharvest of American black bears creates a younger age structure. As populations become younger, fewer females reach puberty, reducing per capita recruitment. The age structure of the female population is then forced to an even younger average age. Full effects of overharvest do not occur until 5 to 10 years after harvest. One way to manage the sex composition of American black bear harvest is to schedule hunting seasons based on denning chronology (see Denning). Because pregnant females enter dens before males, the fall hunting season could begin after females have entered their dens. In spring, hunting of males could occur before females and young emerge from dens [76]. According to Lee and Vaughan [146], managers should monitor sex ratio of harvest to ensure that females are not overharvested.
To reduce cub mortality and increase subsequent American black bear recruitment, Cunningham and others [50,52] suggest reducing hunting of females following severe fire and hunting males during spring.
Climate: During La Niña, drought may decrease food supply for American black bears and increase encounters with humans [282].
Other: Migration corridors are critical for linking habitat between American black bear populations [25,143,146].
According to Willson and others [275], areas used by American black bears for salmon foraging should be protected from human disturbance and development.
American black bears may be important long-distance dispersers of some fruit seeds. Fruit seeds are dispersed when American black bears swallow them whole and defecate them intact. Germination rates of some plants may be increased by chemical or mechanical scarification that occurs in the American black bear's gut [3,18,27,85,134,210,230,257]. American black bears are unlikely to defecate intact acorns, hickory nuts, beechnuts [270], or pine seeds [109,141].The American black bear requires a mosaic of vegetation associations rather than one plant community, so habitat diversity is important. American black bears prefer mesic over xeric sites and forests over open areas [261], but wet meadows, swamps, high tidelands, burned areas, and avalanche chutes may be used [191]. In general, a combination of adjacent forest, riparian borders, edge habitats, and forest openings spread over large, relatively remote areas provide good habitat for American black bears [7,65,88,114,133,156,209,221,222,243,251,268].
Habitat use is dictated by seasonal food production [9,96,114,208]. In general, meadows are preferred for foraging on grasses and forbs during spring [76,114,248,261]. Riparian habitat, avalanche chutes, and early-successional habitat created by logging or fire are preferred for foraging during summer [72,86,92], and mature forest containing hard mast is preferred during fall [64,150,208,208,221,222,264,268] (see Food Habits). For denning and cover, mature or old-growth forest containing coarse woody debris, snags, and adequate cover are typically preferred [35,54,193,204,261] (see Stand- and landscape-level habitat and Snags and coarse woody debris).
Stand- and landscape-level habitat:
Canada—On the coast of British Columbia, American black bears prefer midelevation habitat, late-successional forest, and forest patches with high structural complexity and coarse woody debris. In the Nimpkish Valley of Vancouver Island, American black bears denned exclusively in structures of wood on slopes >15%. Of 67 American black bear dens, large-diameter (x= 56 inches (143 cm) DBH)) hollow trees were used most often, followed by root boles, stumps, logs, and under trees. Western redcedar (Thuja plicata) and Alaska-cedar (Chamaecyparis nootkatensis) were used most often (28% and 30% of dens, respectively), because they tend to decay in the heartwood but retain a hard outer shell, providing good thermal and security cover. Some dens were located 52 feet (16 m) above ground, and those that required entrance from the tops of hollow trees provided the most security. The following table shows tree species and diameters of den types used by the American black bear [54]:
Of 185 visual observations of American black bears on the northeastern coast of Labrador, "forested" habitat was used most often (53.8% of observations). "Forested" habitat consisted of 3-foot (1 m)- tall spruce/fir; black spruce (Picea mariana)/lichen; birch (Betula spp.) thickets; dwarf shrubs; and tuckamore (spruce trees stunted from coastal salt spray). Barren grounds, which consisted of any nonwetland area with <5% canopy cover, were used nearly as much as forest (40.4% of observations). Of 18 den sites found, 7 were located in forest, 6 were in barren grounds, and 5 were in shrub thickets. Because large, hollow trees were uncommon in the area, all dens were excavated and den roofs were supported by root systems of woody vegetation [41].
In British Columbia, American black bears use Oregon white oak (Q. garryana) for foraging, thermal, and security cover [71].
Alaska—In the Yukon-Tanana uplands of interior Alaska, preferred spring forage areas were riverbottoms containing brush ≥2.5 feet (0.8 m) tall and paper birch (Betula papyrifera), quaking aspen (Populus tremuloides), and black cottonwood (P. balsamifera ssp. trichocarpa). Riverbottoms contained new green leaves and abundant horsetail (Equisetum spp.), which composed 86% of their spring diet. During summer, American black bears preferred foraging for bog blueberries (Vaccinium uliginosum) in "old" burns (age not given) dominated by willow (Salix spp.), alder (Alnus spp.), and dwarf birch (B. nana) [96].
Den site selection and den type were related to topography and climatic conditions in south-central Alaska. On the Kenai Peninsula, American black bears denned in 2 major vegetation types: "regrowth" boreal upland forest (67% of dens, "regrowth" not defined ) and "mature" boreal upland forest (31% of dens, "mature" not defined). At high elevations of the Kenai Peninsula and the Susitna River Basin, caves and excavated dens under large boulders and rockpiles were used most often because few trees attained large diameters. In virgin coastal rain forest at low elevations of the Kenai Peninsula, large-diameter western hemlock, white spruce (Picea glauca), and black spruce were preferred for denning. At low elevations in the Susitna River Basin, American black bears preferred denning in alder draws with spruce or paper birch. In Prince William Sound, excavated dens at low elevations were more prone to flooding at low altitudes and were not used as often as tree dens or rock caves [228].
In southeastern Alaska, American black bears preferred den sites located in windstorm-protected forest (58%) over windstorm-prone forest (6%). In windstorm-protected forest, large, hollow trees (>35 inches (88 cm)) were least prone to wind damage. Density of large trees was twice that of the windstorm-prone forest and the forest was in later successional stages [56].
Pacific Northwest—On Long Island, Washington, yearling and adult male and female American black bears selected habitat within home ranges disproportionately to availability, preferring recently logged areas over older logged areas. Preference was probably related to availability of berries and cover. Habitat consisted of forest formerly dominated by Sitka spruce. In recently logged areas (7 to 14 years old), shrub cover was 56%. Dominant shrubs were salal (Gaultheria shallon), red huckleberry (Vaccinium parvifolium), and evergreen huckleberry (V. ovatum). Berry-producing shrubs were 7 to 8 times more abundant in the recently logged areas than in older areas. Young western hemlock was the most dominant tree species, and cover was 7%. In intermediate-aged logged areas (14 to 20 years old), shrub cover was 21%. Young western hemlock occurred in small, dense stands, and cover was 58%. These areas provided adequate cover and food for American black bear, but not as much food as recently logged habitat. In the oldest logged areas (≥37 years old) and in alder stands, shrub cover was 7% to 8%. These areas were dominated by western hemlock and used least often. Mature timber (age not given) stands were dominated by western redcedar and covered 346 acres (140 ha) of the island. Shrub cover was 45%. Tidelands were associated principally with slough systems and contained various sedges (Carex spp.), rushes (Scirpus spp.), and halophytic forbs. Edges (115 feet (35 m)) between 2 vegetation types) occurred between areas used for foraging and for cover and were often used in all ages of habitat [148].
American black bear use of habitat on Long Island, Washington [149] Habitat % cover on island % cover on American black bear home ranges % American black bear locations in habitat types (n=1,973 locations) % locations on edges 7- to 14-year-old logged 28 36 26 23 14- to 20-year-old logged 22 22 35 16 ≥37-year-old logged 33 27 33 57 Alder 5 1 0.2 no data Mature timber 7 8 3 54 Tidelands 6 6 3 100On the Willamette National Forest, Oregon, female American black bears preferred early-successional habitat for foraging and late-successional habitat for cover and denning. Adjacency of early-successional stages (shrub and sapling-pole) to mature forest was also preferred. Habitat was dominated by Douglas-fir on dry, low-elevation sites; western hemlock on moist, low elevation sites; and Pacific silver fir, Douglas-fir, western hemlock, and mountain hemlock on high-elevation sites. Open-canopy sapling/pole habitat (canopy closure <60%; shrub understory common) was preferred for foraging during summer. Open-canopy mature timber (canopy closure <80%; average tree DBH >21 inches (53 cm); understory of shrubs and small trees common) and closed-canopy mature timber (canopy closure 80% to 100%; average tree DBH >21 inches; some ground vegetation) were preferred for cover and denning. During fall, open- and closed-canopy mature stands with steep slopes and southeastern exposures at low-elevations were preferred for foraging and hiding from hunters. American black bears were negatively associated with roads and positively associated with riparian habitat [263].
In the Blue Mountains of northeastern Oregon, American black bears used large-diameter (>40 inches (102 cm)) hollow western larch (Larix occidentalis) and grand fir (Abies grandis) trees located within old-growth forest for denning. Of 59 American black bear den locations, 41% occurred inside hollow trees that were either standing or lying on the ground. American black bears entered 42% of standing hollow trees from the tops or near the tops of trees, which offered the best protection from predators. These trees averaged 45 inches (114 cm) DBH (range 36-63 inches (91-160 cm)) and 62 feet (19 m) tall (range 26-98 feet (8-30 m)). Den entrances averaged 43 feet (13 m) above the ground [35]. Other trees used by American black bears in the Columbia River Basin region for denning and resting include white fir (A. concolor) [189], western redcedar, and subalpine fir (A. lasiocarpa) [133].
Due to the dry climate in the northeastern Cascade Range, American black bears prefer riparian and deciduous forest for foraging. In the Okanogan National Forest, Washington, American black bears preferred the following habitats for home ranges (in decreasing order): deciduous forest, Douglas-fir forest, riparian forest, meadow, subalpine fir forest, shrubfield, mosaic (mixture of trees, shrubs, forbs, and bare ground), mosaic-harvest, bare, ponderosa pine (Pinus ponderosa) forest, other conifer forest, shrub-steppe, postfire meadow, and western hemlock forest. Within home ranges, American black bears selected for a mosaic of food resources and cover in forested habitat classes. Preferred home range habitat was (in decreasing order): riparian forest, ponderosa pine forest equal to Douglas-fir forest, meadow, hemlock forest equal to subalpine fir forest, other conifers, shrubfield equal to mosaic, mosaic-harvest, shrub-steppe, and meadow-fire areas [156].
California—In forests dominated by Douglas-fir on the Six Rivers, Klamath, and Shasta-Trinity National Forests, mean relative abundance of American black bears was greatest in late-successional stages and lowest in intermediate successional stages [204]:
Mean relative abundance of American black bears among successional stages in Douglas-fir forest [204] Successional stage American black bears captured (n) Early (trees <10 years old) 20 Sapling (10-20 years old) 25 Pole (20-50 years old) 5 Sawtimber (50-150 years old) 42 Mature (150-250 years old) 45 Old growth (>250 years old) 48 Total number captured in all habitats 196Southwest—During spring in southwestern Colorado, American black bears prefer foraging in mixed-shrub and Gambel oak (Q. gambelii) habitats. During summer, late-seral Gambel oak, mixed shrub, ponderosa pine-Gambel oak, quaking aspen, and riparian habitats containing abundant berry-producing plants are preferred. During fall, American black bears move to low elevations seeking hard mast such as acorns and Colorado pinyon (P. edulis) seeds [76,248].
Northern and central Rocky Mountains—In the Whitefish Range in northwestern Montana, American black bears occupied 2 major habitats. Permanent home range habitat was located in low-elevation Engelmann spruce (Picea engelmannii)-subalpine fir/Oregon boxwood (Paxistima myrsinites) forest containing various seral stages. Most home range habitat had previously burned (age of burn not given), and all seral stages were used equally by American black bears except clearcuts <8 years old. Avoidance of recent clearcuts suggested that American black bears would probably not use recent burns either. Home range habitat was used for foraging during spring, for cover, and for denning. Dens were located within home range habitat and occurred most often at the bases of hollow trees (species not given), followed by rock caves, excavated underground dens, and under fallen logs. The second type of habitat used by American black bears was located outside of home ranges in sparsely forested, high-elevation (6,000 feet (1,829 m)) areas that were free of snow only during summer and fall. American black bears congregated in these areas to forage on abundant soft mast during summer and hard mast during fall [114].
On the Middle Fork of the Weiser River in west-central Idaho, habitat use by American black bears differed significantly (P<0.01) between seasons. Habitat was dominated by big sagebrush (Artemisia tridentata), grasses, and forbs at low elevations and ponderosa pine, Douglas-fir, and grand fir at high elevations. During spring, selection cut-open forest was preferred for foraging on grasses and forbs. During summer and fall, American black bears preferred open forest-shrubfield, shrubfield, riparian, and selection cut-forest (10 to 35 years old) because these habitats supported the densest stands of berries. Uncut forest was preferred for nightly bedding (56.9%, n=281). Clearcuts (<8 years old) were seldom used (2 of 640 American black bear locations), and rock-talus and big sagebrush-grass habitats were avoided [261]:
Availability and use (%) of cover types by season and activity categories for 10 female American black bears over 2 years on the Middle Fork of the Weiser River, Idaho [261] Cover type Random availability (n=489) Spring use (n=151) Summer and fall use (n=483) Foraging (n=123) Bedding (n=281) Uncut forest 13.9 43.6+* 37.9+ 12.3 56.9+ Open forest 10.6 12.8 5.0-* 5.7 5.0- Open forest-shrubfield 7.4 8.3 13.9+ 15.6 11.4 Riparian 0.4 1.3 2.5+ 1.6 0.4 Quaking aspen 0.8 1.3 3.3+ 3.3 3.2 Shrubfield 4.7 0.6- 7.9 14.8+ 5.0 Meadow 6.7 3.2 0.0- 3.3 0.0- Rock-talus 1.6 0.0- 0.0- 0.0- 0.0- Sagebrush-grass 17.8 3.2- 0.6- 2.5- 0.0- Roads 3.5 1.3 0.4- 0.8 0.0- Clearcut 2.7 0.6 0.2- 0.8 0.4- Selection cut-shrubfield 5.7 7.1 8.9 16.4+ 3.6 Selection cut-open forest 20.2 15.4 16.6 21.3 10.3- Selection cut-forest 3.9 1.3 2.9 1.6 3.9 * "+" indicates use >availability, "-" indicates use <availability (P<0.10).Great Lakes—In Minnesota, Wisconsin, and Michigan, American black bears prefer foraging in the following general habitats: riparian areas and alder and ash swamps with adjacent refuge trees during spring; forest openings and stands of black cherry (Prunus serotina) during summer; and mature oak stands during fall. For refuge, large eastern white pine (Pinus strobus) or eastern hemlock (Tsuga canadensis) occurring at 1 tree/6 acres are commonly used. During April and May, mothers and cubs spend >95% of their time within 300 feet (90 m) of eastern white pines or eastern hemlocks that are >8 inches (20 cm) DBH [209,212]. Quaking aspen forests of various ages are also used by American black bears in the Great Lakes region [4].
Northeast—For foraging and cover, 5 adult female American black bears (n=641 radio-telemetry locations) in Garrett County, Maryland, preferred wetlands and second-growth (70-90 years old) mixed forest with high stream densities over second-growth hardwood forest. Mixed forest contained conifers, which provided more escape, concealment, and thermal cover than hardwood forest. Habitats containing commercial, industrial, and residential activities were not included in any of the American black bear home ranges; however, residential and agricultural areas provided food during fall when natural food sources were scarce. Primary highways limited American black bear movements, but margins of logging roads and other roads with light traffic (<100 vehicles/day) were readily used for traveling and foraging. Wetland habitat is decreasing in Maryland, and American black bears have shown increased use of riparian habitat to compensate or substitute for wetlands [67].
South-central US—Within a montane desert sky island in Big Bend National Park, Texas, female American black bears preferred Mexican pinyon (P. cembroides)-oak-juniper/talus/meadow habitat for home ranges. Males preferred lower-elevation areas within smooth-leaf sotol-yucca-lechuguilla (Dasylirion leiophyllum-Yucca spp.-Agave lechuguilla)/grass; creosotebush (Larrea tridentata)-lechuguilla-mesquite (Prosopis spp.)/prickly-pear (Opuntia spp.)-grass; or oak-ponderosa pine-cypress (Cupressus spp.) habitats [175,188]. Den sites were located most often in rock outcrops and canyon walls (slopes >70%). South-facing slopes at high elevations (>5,906 feet (1,800 m)) in the southern Chisos Mountains are considered optimal denning habitat within Big Bend National Park [175].
In bottomland hardwood habitat in the lower Mississippi Valley, oak trees are preferred for denning [187]. On the White River National Wildlife Refuge in Arkansas, most dens (90.2%, n=51) were located in elevated tree cavities, with openings located in the top or middle of the main trunk. Overcup oak (Q. lyrata) with a mean DBH of 39.5 inches (100.3 cm) was used most often (77.8%, n=36). Other tree species used for denning included baldcypress (Taxodium distichum) and sycamore (Platanus occidentalis). Five of 51 dens (9.8%) were located under fallen leaves on the ground. Timing and intensity of flooding influenced denning chronology and use of multiple dens. Most American black bears (55.6%, n=27) used 1 den/season, but some females used up to 4 different dens/season. Emergence from dens was delayed during a longer flooding season [186].
Southern Appalachians—Den sites in central hardwood forests are typically located in live trees, >35 inches (90 cm) DBH and >150 years old. Potential denning trees include eastern white pine, eastern hemlock, northern red oak (Q. rubra), chestnut oak (Q. prinus), yellow-poplar (Liriodendron tulipifera), yellow birch (Betula alleghaniensis), red maple (Acer rubrum), and white oak (Q. alba) [129,268].
In Shenandoah National Park, Virginia, 84% of pregnant American black bears denned in live tree cavities. The most common tree species used was northern red oak. Mean DBH of den trees was 38.1 inches (96.8 cm) (n=38). Mean height was 76.8 feet (23.4 m) (n=39), and mean height of cavity entrances was 32.5 feet (9.9 m) (n=39). Other trees used for denning included (in decreasing importance): white oak, yellow-poplar, snags (species not given), and white ash (Fraxinus americana) [117].
In Great Smoky Mountains National Park, Tennessee and North Carolina, large (38.2 inches (97.1 cm) DBH)) eastern hemlock, red maple, and northern red oak trees were preferred by American black bears for denning. Of 12 dens found, 7 were located at a mean height of 43.6 feet (13.3 m) (range 20.0-57.1 feet (6.1-17.4 m)) above ground. Two dens were located inside the bases of trees with their entrances high above the ground, 2 were beneath root networks of large trees or beneath stumps, and 1 was in the sheltered base of a red maple [193].
In the Pisgah Bear Sanctuary, recently logged areas (<10 years old) had mixed effects on American black bear habitat. Major forest types were eastern hemlock, cove hardwoods (yellow-poplar, magnolias (Magnolia spp.), and birches (Betula spp.)), oak-hickory, pine, and pine-hardwood mix. Early seral stages provided abundant food for American black bears, but denning habitat was poor. Increased productivity of soft mast-producing plants would last only as long as the canopy remained open [177].
Southeast—American black bears on the Neuse-Pamlico Peninsula in eastern North Carolina preferred marshes, clearcuts (age not given), and pocosins over large loblolly pine (Pinus taeda) plantations due to availability of superior food and cover [113].
On the Southeastern Coastal Plain of the United States, American black bears prefer ground nests for denning [89,101,164]. Dens located in hollow trees are sometimes used; however, few large trees are available due to intense land use practices [101,273].
Habitat use by Florida black bears probably does not change seasonally because many habitats produce food throughout the year [160]. Riparian areas and swamps are 2 of the most important habitats for Florida black bears on the southeastern coastal plain [250,251]. At Eglin Air Force Base in northern Florida, riparian areas were preferred seasonally and annually over swamps, longleaf pine-Beyrech threeawn (P. palustris-Aristida beyrichiana) sandhills, pine (Pinus spp.), and open habitats. The closed canopy and dense understory of riparian areas provided food, denning habitat, and escape cover. Swamps ranked second in overall use and were used most often for denning. Open areas ranked lowest in preference due to lack of forested cover. During summer, pine habitat was used most often due to availability of soft mast species provided by 3- to 5-year-interval prescribed burns. During fall, sandhills habitat was used most often due to abundance of acorns [250].
In southern Florida, understory conditions are more important to the Florida black bear than species composition or understory height. Uplands dominated by saw-palmetto (Serenoa repens) are preferred by Florida black bears for food and cover [161,162]. A mature overstory of south Florida slash pine (P. elliottii var. densa) is not required for a saw-palmetto patch to have value to Florida black bears [161].
Availability of suitable den sites is not a limiting factor for Louisiana black bears. Louisiana black bears used ground nests most often in small bottomland hardwood stands, baldcypress-water tupelo (Nyssa aquatica) swamps, and coastal marshes in the Atchafalaya River Basin, Louisiana. Louisiana black bears inhabiting logged bottomland hardwood forest within a floodway used trees with elevated entrances most often. Den trees are not required for successful reproduction, but Hightower and others [102] recommend protecting den trees >36 inches (91 cm) DBH in areas prone to flooding. Tree species used for dens include oaks, American elm (Ulmus americana), sweetgum (Liquidambar styraciflua), and water hickory (Carya aquatica) [102].
LIFE HISTORY:
Diet and nutrition influence most aspects of the American black bear life history including reproduction, development, survival, timing of denning, and seasonal movements [264].
Mating: American black bears have low reproductive rates [76,114]. Mating occurs from late May to August and peaks in June [76,114,132,208,272]. Females typically mate for the first time at 3 years old [64,272] but may not mate until 8 years old in northern portions of their range [41,114,131]. Females that have borne young usually breed every other year [76,114,131]. If females abandon their cubs after den emergence in spring, they may breed again in early summer of the same year [66].
Reproductive success: Female reproductive success may be determined by diet and nutrition. During years of high mast production, good nutritional condition of American black bears resulted in earlier maturation, larger litter sizes, shorter breeding intervals, and higher survival rates [25,43,48,64,76,114,131,208,209,213,226]. For example, over a 6-year study period, 26 of 28 female American black bears in western Massachusetts produced cubs when they had consumed a high fat and high carbohydrate diet of hard and soft mast. During years of low mast production, 10 of 10 females produced no cubs [64]. In some studies, variability in food supply did not solely explain fluctuations in reproduction [44,118,172].
Gestation period and litter size: Due to delayed implantation, embryos are not implanted and cubs are not born until the winter denning period [76,78,272]. Litter size ranges from 1 to 5 cubs [76,132,272], depending on the age and nutritional condition of the female before the denning period [272]. Litters typically consist of twins or triplets [272]. Subadult (1.5-3 years old) females produce the smallest litters (typically 1 cub) their first time breeding [272], and older females produce intermediate-sized litters [76,132]. Mean litter size was 1.6 cubs in the Shasta-Trinity National Forest, California (n=6 adult females) [198], Sequoia National Park, California (n=9 adult females) [78], and the Whitefish Range in northwestern Montana (n=45 adult females) [114]. Mean litter sizes were 2.25 (n=20) and 1.41 (n=17) in the Ouachita Mountains and Ozark Mountains of Arkansas, respectively [44]. Mean litter size in northeastern Minnesota was 2.38 cubs (n=52 adult females) [208]. In northern Coahuila, Mexico, mean litter size was 2.75 cubs (n=12 adult females) [63]. Sex ratio of cubs may be determined by maternal condition. In La Mauricie National Park, Quebec, females gave birth to more males when maternal weight was heavier [221].
Development: A mother's milk supply depends on the quality of nutrients obtained the year before she gives birth [213]. Large, well-nourished females produce healthier cubs than malnourished females [132]. American black bears in eastern deciduous forests generally experience higher growth rates than those in western North America due to a larger variety of foods, including oak (Quercus spp.) acorns [132]. After leaving the den, cubs gain weight quickly if abundant food is available [213]. Young are weaned approximately 7 months after birth, between July and September [76,114]. In northern portions of the American black bear's range, where summers are shorter and food is less abundant, females may wean at a later date [114]. Young remain with their mothers until they are approximately 1.5 years old, and/or when their mothers enter estrus [76,114,149,208,208,227].
Social organization: American black bears are generally solitary. Exceptions occur during the breeding season, the first 1.5 years of a cub's life [78,114,132,208,272], and areas where American black bears congregate to forage on seasonally abundant foods [132,208,213].
Habits: American black bears are diurnal [9,41,74,142,149] but may be nocturnal in areas containing human food sources such as garbage dumps, agricultural areas [142], or in habitat cooccupied with grizzly bears (Ursus arctos horribilis) [158]. During early spring and late fall, females are more nocturnal than males. They forage nocturnally to improve physical condition needed for breeding, denning, and lactation [9].
Mortality: Starvation is the most significant cause of natural mortality [76,114,213,221], especially in northern latitudes where foraging periods are shorter [114]. Mortality rates may range from 5% when food is abundant to 70% when food is scarce [76]. Natural mortality is high between birth and 2 years of age and depends primarily on food availability [76,213,221], physical condition of the mother, litter size, and/or experience of the mother [64]. Mortality is also high for subadult males (>2 years old) during dispersal from natal areas because subadult males may be forced into less preferred habitat by older American black bears [132]. After home ranges are established, mortality for males and females is 5% to 10%/year [76]. Other causes of natural mortality include disease, predation, injuries from other American black bears, and cannibalism [76,114].
Human-related mortality for American black bears is caused by hunting, collisions with vehicles, and poaching. Hunting-related mortality for subadult males is greatest during dispersal from natal areas [64,114,146,227]. Mortality from humans is greater during seasons or years when natural food resources are low and American black bears enter human-inhabited areas looking for food [169,213,221,255].
Survival rates: In the Ouachita Mountains, Arkansas, mean annual survival rates of males and females over a 2-year period was 94% for American black bears >1 year old and 88% for cubs. In the Ozark Mountains, Arkansas, mean annual survival rates were 0.87 for males and females >1 year old, and 0.25 for cubs [44]. In northeastern Minnesota, the cub survival rate ranged from 59% to 88%, depending on food supply during year of conception and year of birth [208]. In the Pisgah Bear Sanctuary in North Carolina, the mean annual survival rate of male and female American black bears trapped 251 times over a 15-year period was 76% (SD= 0.04, n=151) [241].
Dispersal: Natal dispersal occurs in the subadult age class and is male-biased [64,114,146,208,223,227]. Typically, >95% of subadult females establish home ranges within their mothers' home ranges [64,146,227] (see Home range and density). In areas of high American black bear densities or limited food resources, adult females may prompt subadult females to disperse [25,114]. Dispersal distance of 18 subadult males in northeastern Minnesota ranged from 8 to 136 miles (13-219 km) and averaged 38 miles (61 km) [208]. Dispersal distance for 57 yearling to 3-year-old males in western Virginia ranged from 0.6 to 49.7 miles (0.9-80.0 km) and averaged 8 miles (13 km) [146].
Denning: American black bears den to conserve energy during winter months [148,224]. The denning period depends on length of winter [132,148,228] but typically occurs from October to May [9,41,73,148]. In southern latitudes, American black bears typically den for 3 months (January or February to March or April), but not all American black bears den [63,89,102,175,186].
Onset of denning may be related to sex, reproductive status, food availability [73,114,117,224], and/or weather [114,148,224,228]. Females typically enter dens earlier and leave dens later than males [54,73,148]. In the northeastern Cascade Range of Washington, females entered dens approximately 1 week earlier in the fall and left dens 1 week later in the spring than males [73]. Pregnant females den longer than nonpregnant females or males [54,148,208,224,228]. A pregnant female in south-central Alaska spent 247 days in her den [228]. In southern portions of the American black bear's range, subadult and adult males and nonpregnant females may not hibernate [89]. In Coahuila, Mexico, all pregnant females (n=13) denned, 2 of 5 females with yearlings denned, and 0 males (n=10) denned [63].
American black bears may enter dens early and emerge from dens late when food is scarce [117,132]. Otherwise, a negative energy balance may occur if they continue to forage as food becomes less abundant [224]. Acorn crop failure may influence denning behavior. During a gypsy moth infestation that destroyed the acorn crop in Shenandoah National Park, Virginia, pregnant American black bears entered dens an average of 1 week earlier and emerged from dens 1 week later than other females [117].
Secure den sites ensure survival [54,101,186]. Den selection may be influenced by factors including availability of dens, climate, reproductive status, age of the American black bear, energetic efficiency of the den, and/or safety from predators [54,56,73,76,186,224]. Den type varies geographically; however, dens located in dead- and live-tree cavities are preferred across the American black bear's range [35,36,114,133,189,234]. In northern latitudes, den sites may be located in hollow trees and logs, under fallen logs or piles of man-made debris, under tree roots, in trees with hollow chambers at their bases [36,54], or in rock crevices [59]. In southern portions of the American black bear range, dens may consist of open nests of leaves and grass, shallow depressions on the ground [89,132], or may be elevated in hollow trees, especially in areas where seasonal flooding may occur [186,273]. In second-growth forests that lack large tree cavities, caves, slash piles, rock crevices, or nests on the ground surface may be used for den sites [114,208]. Dens with large chambers may be an important factor in den selection for pregnant females and for old, large American black bears [54,129]. In western Virginia, American black bears >10 years old used rock cavities more often than trees, probably because they could not find big enough tree cavities [129]. American black bears on Vancouver Island denned close to spring forage areas to decrease long movements and encounters with other American black bears [54]. Dens may or may not be reused [24,54,114,117,129,208,228]. Den reuse may be related to the longevity of den structures [54] or availability of suitable den sites [228]. For detailed information about habitat used for denning in various geographic locations, see Preferred Habitat.
The American black bear (Ursus americanus), also known as the black bear is a species of medium-sized bear endemic to North America. It is the continent's smallest and most widely distributed bear species. The American black bear is an omnivore, with its diet varying greatly depending on season and location. It typically lives in largely forested areas, but will leave forests in search of food, and is sometimes attracted to human communities due to the immediate availability of food.
The International Union for Conservation of Nature (IUCN) lists the American black bear as a least-concern species, due to its widespread distribution and a large population estimated to be twice that of all other bear species combined. Along with the brown bear (Ursus arctos), it is one of only two modern bear species not considered by the IUCN to be globally threatened with extinction.
Despite living in North America, American black bears are not closely related to brown bears and polar bears; genetic studies reveal that they split from a common ancestor 5.05 million years ago (mya).[3] American and Asian black bears are considered sister taxa and are more closely related to each other than to the other modern species of bears.[3][4] According to recent studies, the sun bear is also a relatively recent split from this lineage.[5]
A small primitive bear called Ursus abstrusus is the oldest known North American fossil member of the genus Ursus, dated to 4.95 mya.[6] This suggests that U. abstrusus may be the direct ancestor of the American black bear, which evolved in North America.[3][7] Although Wolverton and Lyman still consider U. vitabilis an "apparent precursor to modern black bears",[8] it has also been placed within U. americanus.[7]
The ancestors of American black bears and Asian black bears diverged from sun bears 4.58 mya. The American black bear then split from the Asian black bear 4.08 mya.[3][9] The earliest American black bear fossils, which were located in Port Kennedy, Pennsylvania, greatly resemble the Asian species,[10] though later specimens grew to sizes comparable to grizzly bears.[11] From the Holocene to the present, American black bears seem to have shrunk in size,[3] but this has been disputed because of problems with dating these fossil specimens.[8]
The American black bear lived during the same period as the giant and lesser short-faced bears (Arctodus simus and A. pristinus, respectively) and the Florida spectacled bear (Tremarctos floridanus). These tremarctine bears evolved from bears that had emigrated from Asia to the Americas 7–8 mya.[12] The giant and lesser short-faced bears are thought to have been heavily carnivorous and the Florida spectacled bear more herbivorous,[13] while the American black bears remained arboreal omnivores, like their Asian ancestors. The American black bear's generalist behavior allowed it to exploit a wider variety of foods and has been given as a reason why, of these three genera, it alone survived climate and vegetative changes through the last Ice Age while the other, more specialized North American predators became extinct. However, both Arctodus and Tremarctos had survived several other, previous ice ages. After these prehistoric ursids became extinct during the last glacial period 10,000 years ago, American black bears were probably the only bear present in much of North America until the migration of brown bears to the rest of the continent.[11]
American black bears are reproductively compatible with several other bear species and occasionally produce hybrid offspring. According to Jack Hanna's Monkeys on the Interstate, a bear captured in Sanford, Florida was thought to have been the offspring of an escaped female Asian black bear and a male American black bear.[14] In 1859, an American black bear and a Eurasian brown bear were bred together in the London Zoological Gardens, but the three cubs that were born died before they reached maturity. In The Variation of Animals and Plants Under Domestication, Charles Darwin noted:
In the nine-year Report it is stated that the bears had been seen in the zoological gardens to couple freely, but previously to 1848 most had rarely conceived. In the reports published since this date three species have produced young (hybrids in one case), ...[15]
A bear shot in autumn 1986 in Michigan was thought by some to be an American black bear/grizzly bear hybrid, due to its unusually large size and its proportionately larger brain case and skull. DNA testing was unable to determine whether it was a large American black bear or a grizzly bear.[16]
Sixteen subspecies are traditionally recognized; however, a recent genetic study does not support designating some of these, such as the Florida black bear, as distinct subspecies.[17] Listed alphabetically according to subspecific name:[18][19]
Historically, American black bears occupied the majority of North America's forested regions. Today, they are primarily limited to sparsely settled, forested areas.[26] American black bears currently inhabit much of their original Canadian range, though they seldom occur in the southern farmlands of Alberta, Saskatchewan and Manitoba; they have been extirpated on Prince Edward Island since 1937.[27] The total Canadian black bear population is between 396,000 and 476,000,[28] based on surveys taken in the mid-1990s in seven Canadian provinces, though this estimate excludes American black bear populations in New Brunswick, the Northwest Territories, Nova Scotia and Saskatchewan. All provinces indicated stable populations of American black bears over the last decade.[26]
The current range of American black bears in the United States is constant throughout most of the Northeast and within the Appalachian Mountains almost continuously from Maine to northern Georgia, the northern Midwest, the Rocky Mountain region, the West Coast and Alaska.[27] However, it becomes increasingly fragmented or absent in other regions. Despite this, American black bears in those areas seem to have expanded their range during the last decade, such as with recent sightings in Ohio,[27] Illinois,[29] and southern Indiana.[30] Sightings of itinerant American black bears in the Driftless Area of southeastern Minnesota, northeastern Iowa, and southwestern Wisconsin are common.[31][32] In the spring of 2019, biologists with the Iowa Department of Natural Resources confirmed documentation of an American black bear living year-round in woodlands near the town of Decorah in northeastern Iowa, believed to be the first instance of a resident black bear in Iowa since the 1880s.[33][34]
Surveys taken from 35 states in the early 1990s indicate that American black bears are either stable or increasing, except in Idaho and New Mexico. The overall population of American black bears in the United States has been estimated to range between 339,000 and 465,000,[35] though this excludes populations from Alaska, Idaho, South Dakota, Texas and Wyoming, whose population sizes are unknown.[26] In the state of California, there are an estimated 25,000-35,000 American black bears, making it the largest population of the species in the contiguous United States.[36][37]
As of 1993, known Mexican black bear populations existed in four areas, though knowledge on the distribution of populations outside those areas has not been updated since 1959. Mexico is the only country where the American black bear is classified as "endangered".[26]
There have been several sightings quite far away from where the American black bear is normally found, such as western Nebraska.[38]
There are about 1,500 bears in Great Smoky Mountains National Park. The population density is about two per square mile. They inhabit all elevations in the area.[39]
Throughout their range, habitats preferred by American black bears have a few shared characteristics. They are often found in areas with relatively inaccessible terrain, thick understory vegetation and large quantities of edible material (especially masts). The adaptation to woodlands and thick vegetation in this species may have originally been due to the American black bear having evolved alongside larger, more aggressive bear species, such as the extinct giant short-faced bear and the still-living grizzly bear, that monopolized more open habitats[40] and the historic presence of larger predators, such as Smilodon and the American lion, that could have preyed on American black bears. Although found in the largest numbers in wild, undisturbed areas and rural regions, American black bears can adapt to surviving in some numbers in peri-urban regions, as long as they contain easily accessible foods and some vegetative coverage.[5]
In most of the contiguous United States, American black bears today are usually found in heavily vegetated mountainous areas, from 400 to 3,000 m (1,300 to 9,800 ft) in elevation. For American black bears living in the American Southwest and Mexico, habitat usually consists of stands of chaparral and pinyon juniper woods. In this region, bears occasionally move to more open areas to feed on prickly pear cactus. At least two distinct, prime habitat types are inhabited in the Southeastern United States. American black bears in the southern Appalachian Mountains survive in predominantly oak-hickory and mixed mesophytic forests. In the coastal areas of the Southeast (such as Florida, the Carolinas and Louisiana), bears inhabit a mixture of flatwoods, bays and swampy hardwood sites.
In the northeastern part of the range (the United States and Canada), prime habitat consists of a forest canopy of hardwoods such as beech, maple, birch and coniferous species. 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 largely in stands of white cedar. Along the Pacific coast, redwood, Sitka spruce and hemlocks predominate as overstory cover. Within these northern forest types are early successional areas important for American black bears, such as fields of brush, 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 American black bear in the Rockies. Important non-forested areas here are wet meadows, riparian areas, avalanche chutes, roadsides, burns, sidehill parks and subalpine ridgetops.
In areas where human development is relatively low, such as stretches of Canada and Alaska, American black bears tend to be found more regularly in lowland regions.[40] In parts of northeastern Canada, especially Labrador, American black bears have adapted exclusively to semi-open areas that are more typical habitat in North America for brown bears (likely due to the absence there of brown and polar bears, as well as other large carnivore species).[5]
The skulls of American black bears are broad, with narrow muzzles and large jaw hinges. In Virginia, the total length of adult bear skulls was found to average 262 to 317 mm (10.3 to 12.5 in).[40] Across its range, the greatest skull length for the species has been reportedly measured from 23.5 to 35 cm (9.3 to 13.8 in).[5] Females tend to have slenderer and more pointed faces than males. Their claws are typically black or grayish-brown. The claws are short and rounded, being thick at the base and tapering to a point. Claws from both hind and front legs are almost identical in length, though the foreclaws tend to be more sharply curved. The paws of the species are relatively large, with a rear foot length of 13.7 to 22.5 cm (5.4 to 8.9 in), which is proportionately larger than other medium-sized bear species, but much smaller than the paws of large adult brown, and especially polar, bears.[5] The soles of the feet are black or brownish and are naked, leathery and deeply wrinkled. The hind legs are relatively longer than those of Asian black bears. The vestigial tail is usually 4.8 inches (120 mm) long. The ears are small and rounded and are set well back on the head.
American black bears are highly dexterous, being capable of opening screw-top jars and manipulating door latches.[42] They also have great physical strength; a bear weighing 120 pounds (54 kg) was observed turning flat rocks weighing 310 to 325 pounds (141 to 147 kg) by flipping them over with a single foreleg.[43] They move in a rhythmic, sure-footed way and can run at speeds of 25 to 30 miles per hour (40 to 48 km/h).[44] American black bears have good eyesight and have been proven experimentally to be able to learn visual color discrimination tasks faster than chimpanzees and just as fast as domestic dogs. They are also capable of rapidly learning to distinguish different shapes such as small triangles, circles and squares.[45]
American black bear weight tends to vary according to age, sex, health and season. Seasonal variation in weight is very pronounced: in autumn, their pre-den weight tends to be 30% higher than in spring, when black bears emerge from their dens. American black bears on the East Coast tend to be heavier on average than those on the West Coast, although American black bears follow Bergmann's rule and bears from the Northwest are often slightly heavier than the bears from the Southeast. Adult males typically weigh between 57–250 kg (126–551 lb), while females weigh 33% less at 41–170 kg (90–375 lb).[5][46]
In the state of California, studies have indicated that the average mass is 86 kg (190 lb) in adult males and 58 kg (128 lb) in adult females.[40] Adult American black bears in Yukon Flats National Wildlife Refuge in east-central Alaska were found to average 87.3 kg (192 lb) in males and 63.4 kg (140 lb) in females, whereas on Kuiu Island in southeastern Alaska (where nutritious salmon are readily available) adult American black bears averaged an estimated 115 kg (254 lb).[47][48] In Great Smoky Mountains National Park, adult males averaged 112 kg (247 lb) and adult females averaged 47 kg (104 lb) per one study.[49] In one of the largest studies on regional body mass, bears in British Columbia averaged 73.7 kg (162 lb) in 89 females and 103.1 kg (227 lb) in 243 males.[50] In Yellowstone National Park, a population study found that adult males averaged 119 kg (262 lb) and adult females averaged 67 kg (148 lb).[51] Black bears in north-central Minnesota averaged 70 kg (150 lb) in 163 females and 125 kg (276 lb) in 77 males.[52] In New York, the two sexes reportedly average 136 kg (300 lb) for males, and 72.6 kg (160 lb) for females.[53] It was found in Nevada and the Lake Tahoe region that American black bears closer to urban regions were significantly heavier than their arid-country dwelling counterparts, with males near urban areas averaging 138 kg (304 lb) against wild-land males which averaged 115.5 kg (255 lb) whereas peri-urban females averaged 97.9 kg (216 lb) against the average of 65.2 kg (144 lb) in wild-land ones.[54] In Waterton Lakes National Park, Alberta, adults reportedly averaged 125 to 128 kg (276 to 282 lb).[55] Adults typically range from 120 to 200 cm (47 to 79 in) in head-and-body length, and 70 to 105 cm (28 to 41 in) in shoulder height. The typically small tail is 7.7–17.7 cm (3.0–7.0 in) long.[42][56][57][58] Although they are the smallest bear species in North America, large males exceed the size of other bear species, except the brown bear and the polar bear.[42]
The biggest wild American black bear ever recorded was a male from New Brunswick, shot in November 1972, that weighed 409 kg (902 lb) after it had been dressed, meaning it weighed an estimated 500 kg (1,100 lb) in life and measured 2.41 m (7 ft 11 in) long.[59] Another notably outsized wild American black bear, weighing in at 408 kg (899 lb) in total, was the cattle-killer shot in December 1921 on the Moqui Reservation in Arizona.[59] The record-sized American black bear from New Jersey was shot in Morris County December 2011 and scaled 376.5 kg (830 lb).[60] Even larger, the most massive American black bear recorded in Pennsylvania (one of six weighing over 363 kg (800 lb) shot in the last 15 years in the state) weighed in at 399 kg (880 lb) and was shot in November 2010 in Pike County.[61] The North American Bear Center, located in Ely, Minnesota, is home to the world's largest captive male and female American black bears. Ted, the male, weighed 431–453.5 kg (950–1,000 lb) in the fall of 2006.[62] Honey, the female, weighed 219.6 kg (484 lb) in the fall of 2007.[63]
The fur is soft, with dense underfur and long, coarse, thick guard hairs.[42] The fur is not as shaggy or coarse as that of brown bears.[64] American black bear skins can be distinguished from those of Asian black bears by the lack of a white blaze on the chest and hairier footpads. Despite their name, American black bears show a great deal of color variation. Individual coat colors can range from white, blonde, cinnamon, light brown or dark chocolate brown to jet black, with many intermediate variations existing. Silvery-gray American black bears with a blue luster (this is found mostly on the flanks) occur along a portion of coastal Alaska and British Columbia. White to cream-colored American black bears occur in the coastal islands and the adjacent mainland of southwestern British Columbia. Albino individuals have also been recorded.[65]: 141 Black coats tend to predominate in moist areas such as Maine, New England, New York, Tennessee, Michigan and western Washington.[66] Approximately 70% of all American black bears are black, though only 50% of American black bears in the Rocky Mountains are black.[42] Many American black bears in northwestern North America are cinnamon, blonde or light brown in color and thus may sometimes be mistaken for grizzly bears. Grizzly (and other types of brown) bears can be distinguished by their shoulder hump, larger size and broader, more concave skull.[67]
In his book The Great Bear Almanac, Gary Brown summarized the predominance of black or brown/blonde specimens by location:[42]
American black bears have eyesight and hearing comparable to that of humans. Their keenest sense is their sense of smell, which is about seven times more sensitive than a domestic dog's.[68] American black bears are excellent and strong swimmers, swimming for pleasure and to feed (largely on fish). They regularly climb trees to feed, escape enemies and hibernate. Four of the eight modern bear species are habitually arboreal (the most arboreal species, the American and Asian black bears and the sun bear, being fairly closely related).[5] Their arboreal abilities tend to decline with age.[44] They may be active at any time of the day or night, although they mainly forage by night. American black bears living near human habitations tend to be more extensively nocturnal, while those living near brown bears tend to be more often diurnal.[5][40]
American black bears tend to be territorial and non-gregarious in nature. However, at abundant food sources (e.g. spawning salmon or garbage dumps), they may congregate and dominance hierarchies form, with the largest, most powerful males dominating the most fruitful feeding spots.[69] They mark their territories by rubbing their bodies against trees and clawing at the bark. Annual ranges held by mature male American black bears tend to be very large, though there is some variation. On Long Island off the coast of Washington, ranges average 5 sq mi (13 km2), whereas on the Ungava Peninsula in Canada ranges can average up to 1,000 sq mi (2,600 km2), with some male bears traveling as far as 4,349 sq mi (11,260 km2) at times of food shortages.[5][69]
American black bears may communicate with various vocal and non-vocal sounds. Tongue-clicking and grunting are the most common sounds and are made in cordial situations to conspecifics, offspring and occasionally humans. When at ease, they produce a loud rumbling hum. During times of fear or nervousness, bears may moan, huff or blow air. Warning sounds include jaw-clicking and lip-popping. In aggressive interactions, black bears produce guttural pulsing calls that may sound like growling. Cubs squeal, bawl or scream when anxious and make a motor-like humming sound when comfortable or nursing.[70][71][72] American black bears often mark trees using their teeth and claws as a form of communication with other bears, a behavior common to many species of bears.[1]
Sows usually produce their first litter at the age of 3 to 5 years,[44] with those living in more developed areas tending to get pregnant at younger ages.[73] The breeding period usually occurs in the June–July period, though it can extend to August in the species' northern range. The breeding period lasts for two to three months. Both sexes are promiscuous. Males try to mate with several females, but large, dominant ones may violently claim a female if another mature male comes near.[40] Copulation can last 20–30 minutes.[74] Sows tend to be short-tempered with their mates after copulating. The fertilized eggs undergo delayed development and do not implant in the female's womb until November. The gestation period lasts 235 days and litters are usually born in late January to early February. Litter size is between one and six cubs, typically two or three.[75] At birth, cubs weigh 280–450 g (0.62–0.99 lb) and measure 20.5 cm (8.1 in) in length. They are born with fine, gray, down-like hair and their hind quarters are underdeveloped. They typically open their eyes after 28–40 days and begin walking after 5 weeks. Cubs are dependent on their mother's milk for 30 weeks and will reach independence at 16–18 months. At the age of 6 weeks, they attain 900 g (2.0 lb), by the age of 8 weeks they reach 2.5 kg (5.5 lb) and by the age of 6 months they weigh 18 to 27 kg (40 to 60 lb). They reach sexual maturity at the age of 3 years and attain their full growth at the age of 5 years.[44]
The average lifespan in the wild is 18 years, though it is quite possible for wild individuals to survive for more than 23 years.[67] The record age of a wild individual was 39 years,[76] while that in captivity was 44 years.[42] The average annual survival rate for adult American black bears is variable, ranging from 86% in Florida to 73% in Virginia and North Carolina.[40] In Minnesota, 99% of wintering adult bears were able to survive the hibernation cycle in one study.[40] Remarkably, a study of American black bears in Nevada found that the amount of annual mortality of a population of bears in wilderness areas was 0%, whereas in developed areas in the state this figure rose to 83%.[5] Survival in subadults is generally less assured. In Alaska, only 14–17% of subadult males and 30–48% of subadult females were found in a study to survive to adulthood.[40] Across the range, the estimated number of cubs who survive past their first year is 60%.[5]
With the exception of the rare confrontation with an adult brown bear or a gray wolf pack, adult American black bears are not usually subject to natural predation.[40] However, as evidenced by scats with fur inside of them and the recently discovered carcass of an adult sow with puncture marks in the skull, American black bears may occasionally fall prey to jaguars in the southern parts of their range. In such scenarios, the big cat would have the advantage if it ambushed the bear, killing it with a crushing bite to the back of the skull.[77] American black bear cubs tend to be more vulnerable to predation than adults. Known predators of bear cubs have included bobcats, coyotes, cougars, gray wolves, brown bears and other bears of their own species.[5][40] Many of these will stealthily snatch small cubs right from under the sleeping mother. There is a single record of a golden eagle snatching a yearling cub.[5] Once out of hibernation, mother bears may be able to fight off most potential predators.[40] Even cougars will be displaced by an angry mother bear if they are discovered stalking the cubs.[78] Flooding of dens after birth may also occasionally kill newborn cubs. However, in current times, American black bear fatalities are mainly attributable to human activities. Seasonally, thousands of American black bears are hunted legally across North America to control their numbers, while some are illegally poached or trapped unregulated. Auto collisions also may claim many American black bear lives annually.[5][40]
American black bears were once not considered true or "deep" hibernators, but because of discoveries about the metabolic changes that allow American black bears to remain dormant for months without eating, drinking, urinating or defecating, most biologists have redefined mammalian hibernation as "specialized, seasonal reduction in metabolism concurrent with scarce food and cold weather". American black bears are now considered highly efficient hibernators.[79][80] The physiology of American black bears in the wild is closely related to that of bears in captivity. Understanding the physiology of bears in the wild is vital to the bear's success in captivity.[81]
The bears enter their dens in October and November, although in the southernmost areas of their range (i.e. Florida, Mexico, the Southeastern United States), only pregnant females and mothers with yearling cubs will enter hibernation.[5] Prior to that time, they can put on up to 14 kg (30 lb) of body fat to get them through the several months during which they fast. Hibernation in American black bears typically lasts 3–8 months, depending on regional climate.[20][82]
Hibernating American black bears spend their time in hollowed-out dens in tree cavities, under logs or rocks, in banks, caves, or culverts and in shallow depressions. Although naturally made dens are occasionally used, most dens are dug out by the bear itself.[67] Females have been shown to be pickier in their choice of dens in comparison to males.
During their time in hibernation, an American black bear's heart rate drops from 40 to 50 beats per minute to 8 beats per minute and the metabolic rate can drop to a quarter of the bear's (nonhibernating) basal metabolic rate (BMR). These reductions in metabolic rate and heart rate do not appear to decrease the bear's ability to heal injuries during hibernation. Their circadian rhythm stays intact during hibernation. This allows the bear to sense the changes in the day based on the ambient temperature caused by the sun's position in the sky. It has also been shown that ambient light exposure and low disturbance levels (that is to say, wild bears in ambient light conditions) directly correlate with their activity levels.[83] The bear keeping track of the changing days allows it to awaken from hibernation at the appropriate time of year to conserve as much energy as possible.[84]
The hibernating American black bear does not display the same rate of muscle and bone atrophy relative to other nonhibernatory animals that are subject to long periods of inactivity due to ailment or old age.[85][86] A hibernating American black bear loses approximately half the muscular strength compared to that of a well-nourished, inactive human. The bear's bone mass does not change in geometry or mineral composition during hibernation, which implies that the bear's conservation of bone mass during hibernation is due to a biological mechanism.[87] During hibernation American black bears retain all excretory waste, leading to the development of a hardened mass of fecal material in the colon known as a fecal plug.[88] A special hormone, leptin, is released into the bear's systems to suppress appetite. The retention of waste during hibernation (specifically in minerals such as calcium) may play a role in the bear's resistance to atrophy.[85]
The body temperature of the American black bear does not drop significantly, like other mammalian hibernators (staying around 35 °C (95 °F)) and they remain somewhat alert and active. If the winter is mild enough, they may wake up and forage for food. Females also give birth in February and nurture their cubs until the snow melts.[89] During winter, American black bears consume 25–40% of their body weight.[90] The footpads peel off while they sleep, making room for new tissue.
Many of the physiological changes an American black bear exhibits during hibernation are retained slightly post-hibernation. Upon exiting hibernation, bears retain a reduced heart rate and basal metabolic rate. The metabolic rate of a hibernating bear will remain at a reduced level for up to 21 days after hibernation.[91] After emerging from their winter dens in spring, they wander their home ranges for two weeks so that their metabolism accustoms itself to the activity. In mountainous areas, they seek southerly slopes at lower elevations for forage and move to northerly and easterly slopes at higher elevations as summer progresses.
The time that American black bears emerge from hibernation varies. Factors affecting this include temperature, flooding, and hunger. In southern areas, they may wake up in midwinter. Further north, they may not be seen until late March, April, or even early May. Altitude also has an effect. Bears at lower altitudes tend to emerge earlier. Finally, mature males tend to come out earliest, followed by immature males and females, and lastly mothers with cubs. Mothers with yearling cubs are seen before those with newborns.[92]
Generally, American black bears are largely crepuscular in foraging activity, though they may actively feed at any time.[69] Up to 85% of the American black bear's diet consists of vegetation,[44] though they tend to dig less than brown bears, eating far fewer roots, bulbs, corms and tubers than the latter species.[65] When initially emerging from hibernation, they will seek to feed on carrion from winter-killed animals and newborn ungulates. As the spring temperature warms, American black bears seek new shoots of many plant species, especially new grasses, wetland plants and forbs.[90] Young shoots and buds from trees and shrubs during the spring period are also especially important to American black bears emerging from hibernation, as they assist in rebuilding muscle and strengthening the skeleton and are often the only digestible foods available at that time.[93] During summer, the diet largely comprises fruits, especially berries and soft masts such as buds and drupes. During the autumn hyperphagia, feeding becomes virtually the full-time task of American black bears. Hard masts become the most important part of the American black bear's diet in autumn and may even partially dictate the species' distribution. Favored masts such as hazelnuts, oak acorns and whitebark pine nuts may be consumed by the hundreds each day by a single American black bear during the fall.[5][40] During the fall period, American black bears may also habitually raid the nut caches of tree squirrels.[90] Also extremely important in fall are berries such as huckleberries and buffalo berries.[5] American black bears living in areas near human settlements or around a considerable influx of recreational human activity often come to rely on foods inadvertently provided by humans, especially during summertime. These include refuse, birdseed, agricultural products and honey from apiaries.[67]
The majority of the American black bear's animal diet consists of insects, such as bees, yellow jackets, ants, beetles and their larvae.[90][94] American black bears are also fond of honey[95] and will gnaw through trees if hives are too deeply set into the trunks for them to reach it with their paws. Once the hive is breached, the bears will scrape the honeycombs together with their paws and eat them, regardless of stings from the bees.[59] American black bears that live in northern coastal regions (especially the Pacific Coast) will fish for salmon during the night, as their black fur is easily spotted by salmon in the daytime. Other bears, such as the white-furred Kermode bears of the islands of western Canada, have a 30% greater success rate in catching salmon than their black-furred counterparts.[96] Other fish, including suckers, trout and catfish, are readily caught whenever possible. Although American black bears do not often engage in active predation of other large animals for much of the year, the species will regularly prey on mule and white-tailed deer fawns in spring, given the opportunity.[97][98][99] Bears may catch the scent of hiding fawns when foraging for something else and then sniff them out and pounce on them. As the fawns reach 10 days of age, they can outmaneuver the bears and their scent is soon ignored until the next year.[100] American black bears have also been recorded similarly preying on elk calves in Idaho[101] and moose calves in Alaska.[102]
Predation on adult deer is rare, but it has been recorded.[103][104][105] They may even hunt prey up to the size of adult female moose, which are considerably larger than themselves, by ambushing them.[106] There is at least one record of a male American black bear killing two bull elk over the course of six days by chasing them into deep snow banks, which impeded their movements. In Labrador, American black bears are exceptionally carnivorous, living largely off caribou, usually young, injured, old, sickly or dead specimens, and rodents such as voles. This is believed to be due to a paucity of edible plant life in this sub-Arctic region and a local lack of competing large carnivores (including other bear species).[67] Like brown bears, American black bears try to use surprise to ambush their prey and target the weak, injured, sickly or dying animals in the herds. Once a deer fawn is captured, it is frequently torn apart alive while feeding.[98] If it is able to capture a mother deer in spring, the bear frequently begins feeding on the udder of lactating females, but generally prefers meat from the viscera. American black bears often drag their prey to cover, preferring to feed in seclusion. The skin of large prey is stripped back and turned inside out, with the skeleton usually left largely intact. Unlike gray wolves and coyotes, American black bears rarely scatter the remains of their kills. Vegetation around the carcass is usually matted down by American black bears and their droppings are frequently found nearby. American black bears may attempt to cover remains of larger carcasses, though they do not do so with the same frequency as cougars and grizzly bears.[107] They will readily consume eggs and nestlings of various birds and can easily access many tree nests, even the huge nests of bald eagles.[44] American black bears have been reported stealing deer and other game from human hunters.
Over much of their range, American black bears are assured scavengers that can intimidate, using their large size and considerable strength, and if necessary dominate other predators in confrontations over carcasses. However, on occasions where they encounter Kodiak or grizzly bears, the larger two brown subspecies dominate them. American black bears tend to escape competition from brown bears by being more active in the daytime and living in more densely forested areas. Violent interactions, resulting in the deaths of American black bears, have been recorded in Yellowstone National Park.[108][109]
American black bears do occasionally compete with cougars over carcasses. Like brown bears, they will sometimes steal kills from cougars. One study found that both bear species visited 24% of cougar kills in Yellowstone and Glacier National Parks, usurping 10% of the carcasses.[110][111] Another study found that American black bears visited 48% of cougar kills in summer in Colorado and 77% of kills in California. As a result, the cats spend more time killing and less time feeding on each kill.[112][113]
American black bear interactions with gray wolves are much rarer than with brown bears, due to differences in habitat preferences. The majority of American black bear encounters with wolves occur in the species' northern range, with no interactions being recorded in Mexico. Despite the American black bear being more powerful on a one-to-one basis, packs of wolves have been recorded to kill black bears on numerous occasions without eating them. Unlike brown bears, American black bears frequently lose against wolves in disputes over kills.[114] Wolf packs typically kill American black bears when the larger animals are in their hibernation cycle.[46]
There is at least one record of an American black bear killing a wolverine (Gulo gulo) in a dispute over food in Yellowstone National Park.[115] Anecdotal cases of alligator predation on American black bears have been reported, though such cases may involve assaults on cubs.[116]
At least one jaguar (Panthera onca) has been recorded to have attacked and eaten a black bear: "El Jefe", the jaguar famous for being the first jaguar seen in the United States in over a century.[117]
American black bears feature prominently in the stories of some of America's indigenous peoples. One tale tells of how the black bear was a creation of the Great Spirit, while the grizzly bear was created by the Evil Spirit.[118] In the mythology of the Haida, Tlingit and Tsimshian people of the Northwest Coast, mankind first learned to respect bears when a girl married the son of a black bear chieftain.[119] In Kwakwa̱ka̱ʼwakw mythology, American black and brown bears became enemies when Grizzly Bear Woman killed Black Bear Woman for being lazy. Black Bear Woman's children, in turn, killed Grizzly Bear Woman's children.[120] The Navajo believed that the Big Black Bear was chief among the bears of the four directions surrounding Sun's house and would pray to it in order to be granted its protection during raids.[121]
Sleeping Bear Dunes in Michigan is named after a Native American legend, where a female bear and her two cubs swam across Lake Michigan to escape a fire on the Wisconsin shore. The mother bear reached the shore and waited for her cubs, but they did not make it across. Two islands mark where the cubs drowned, while the dune marks the spot where the mother bear waited.[122]
Morris Michtom, the creator of the teddy bear, was inspired to make the toy when he came across a cartoon of Theodore Roosevelt refusing to shoot an American black bear cub tied to a tree.[123] The fictional character Winnie-the-Pooh was named after Winnipeg, a female American black bear cub that lived at the London Zoo from 1915 until her death in 1934.[124] An American black bear cub, who in the spring of 1950 was caught in the Capitan Gap Fire, was made into the living representative of Smokey Bear, the mascot of the United States Forest Service.[125]
Terrible Ted was a de-toothed and de-clawed American black bear who was forced to perform as a pro wrestler and whose "career" lasted from the 1950s to the 1970s. The American black bear is the mascot of the University of Maine and Baylor University, where the university houses two live American black bears on campus.
Although an adult bear is quite capable of killing a human, American black bears typically avoid confronting humans. Unlike grizzly bears, which became a subject of fearsome legend among the European settlers of North America, black bears were rarely considered overly dangerous, even though they lived in areas where the pioneers had settled.
American black bears rarely attack when confronted by humans and usually only make mock charges, emit blowing noises and swat the ground with their forepaws. The number of attacks on humans is higher than those by brown bears in North America, but this is largely because black bears considerably outnumber brown bears. Compared to brown bear attacks, aggressive encounters with American black bears rarely lead to serious injury. Most American black bear attacks tend to be motivated by hunger rather than territoriality and thus victims have a higher probability of surviving by fighting back rather than submitting. Unlike female brown bears, female American black bears are not as protective of their cubs and rarely attack humans in the vicinity of the cubs.[65] However, occasionally such attacks do occur.[40] The worst recorded attack occurred in May 1978, in which an American black bear killed three teenagers fishing in Algonquin Park in Ontario.[126] Another exceptional attack occurred in August 1997 in Liard River Hot Springs Provincial Park in British Columbia, when an emaciated American black bear attacked a mother and child, killing the mother and a man who intervened. The bear was shot while mauling a fourth victim.[127][128]
The majority of attacks happened in national parks, usually near campgrounds, where the bears had habituated too close human proximity and food.[65] Of 1,028 incidents of aggressive acts toward humans, recorded from 1964 to 1976 in the Great Smoky Mountains National Park, 107 resulted in injury and occurred mainly in tourist hot spots where people regularly fed the bears handouts.[126] In almost every case where open garbage dumps that attracted American black bears were closed and handouts ceased, the number of aggressive encounters dropped.[40] However, in the Liard River Hot Springs case, the bear was apparently almost fully dependent on a local garbage dump that had closed and so was starving to death.[127] Attempts to relocate American black bears are typically unsuccessful, as the bears seem able to return to their home range, even without familiar landscape cues.[40]
A limitation of food sources in early spring and wild berry and nut crop failures in summer may contribute to American black bears regularly feeding from human-based food sources. These bears often eat crops, especially during autumn hyperphagia when natural foods are scarce. Favored crops include apples, oats and corn.[5] American black bears can do extensive damage in areas of the northwestern United States by stripping the bark from trees and feeding on the cambium. Livestock depredations occur mostly in spring. Although they occasionally hunt adult cattle and horses, they seem to prefer smaller prey such as sheep, goats, pigs and young calves. They usually kill by biting the neck and shoulders, though they may break the neck or back of the prey with blows with the paws. Evidence of a bear attack includes claw marks and is often found on the neck, back and shoulders of larger animals. Surplus killing of sheep and goats are common. American black bears have been known to frighten livestock herds over cliffs, causing injuries and death to many animals; whether or not this is intentional is not known.[107] Occasionally American black bears kill pets, especially domestic dogs, which are most prone to harass a bear.[129] It is not recommended to use unleashed dogs to deter bear attacks. Although large, aggressive dogs can sometimes cause a bear to run, if pressed, angry bears often turn the tables and end up chasing the dogs in return. A bear in pursuit of a pet dog can threaten both canid and human lives.[130][131]
In British Columbia, a group of American black bears were used as guard animals to protect a marijuana plantation.[132][133]
The hunting of American black bears has taken place since the initial settlement of the Americas. The first piece of evidence dates to a Clovis site at Lehner Ranch, Arizona. Partially calcined teeth of a 3-month old black bear cub came from a roasting pit, suggesting the bear cub was eaten. The surrounding charcoal was dated to the Early Holocene (10,940 BP). Black bear remains also appear to be associated with early peoples in Tlapacoya, Mexico. Native Americans increasingly utilized black bears during the Holocene, particularly in the late Holocene upper Midwest, e.g., Hopewell and Mississippian cultures.[134]
Some Native American tribes, in admiration for the American black bear's intelligence, would decorate the heads of bears they killed with trinkets and place them on blankets. Tobacco smoke would be wafted into the disembodied head's nostrils by the hunter that dealt the killing blow, who would compliment the animal for its courage.[59] The Kutchin typically hunted American black bears during their hibernation cycle. Unlike the hunting of hibernating grizzly bears, which was fraught with danger, hibernating American black bears took longer to awaken and hunting them was thus safer and easier.[135] During the European colonisation of eastern North America, thousands of American black bears were hunted for their meat, fat and fur.[4] Theodore Roosevelt wrote extensively on American black bear hunting in his Hunting the Grisly and other sketches, in which he stated,
in [a black bear] chase there is much excitement, and occasionally a slight spice of danger, just enough to render it attractive; so it has always been eagerly followed.[106]
He wrote that American black bears were difficult to hunt by stalking, due to their habitat preferences, though they were easy to trap. Roosevelt described how, in the southern states, planters regularly hunted American black bears on horseback with hounds. General Wade Hampton was known to have been present at 500 successful American black bear hunts, two-thirds of which he killed personally. He killed 30 or 40 American black bears with only a knife, which he would use to stab the bears between the shoulder blades while they were distracted by his hounds.[106] Unless well trained, horses were often useless in American black bear hunts, as they often bolted when the bears stood their ground.[59] In 1799, 192,000 American black bear skins were exported from Quebec. In 1822, 3,000 skins were exported from the Hudson's Bay Company.[136] In 1992, untanned, fleshed and salted American black bear hides were sold for an average of $165.[137]
In Canada, American black bears are considered as both a big game and furbearer species in all provinces, save for New Brunswick and the Northwest Territories, where they are only classed as a big game species. There are around 80,900 licensed American black bear hunters in all of Canada. Canadian black bear hunts take place in the fall and spring and both male and female bears can be legally taken, though some provinces prohibit the hunting of females with cubs, or yearlings.[26]
Currently, 28 of the U.S. states have American black bear hunting seasons. Nineteen states require a bear hunting license, with some also requiring a big game license. In eight states, only a big game license is required to hunt American black bears. Overall, over 481,500 American black bear hunting licenses are sold per year. The hunting methods and seasons vary greatly according to state, with some bear hunting seasons including fall only, spring and fall, or year-round. New Jersey, in November 2010, approved a six-day bear-hunting season in early December 2010 to slow the growth of the American black bear population. Bear hunting had been banned in New Jersey for five years before that time.[138] A Fairleigh Dickinson University PublicMind poll found that 53% of New Jersey voters approved of the new season if scientists concluded that American black bears were leaving their usual habitats and destroying private property.[139] Men, older voters and those living in rural areas were more likely to approve of a bear hunting season in New Jersey than women, younger voters and those living in more developed parts of the state.[139] In the western states, where there are large American black bear populations, there are spring and year-round seasons. Approximately 18,000 American black bears were killed annually in the U.S. between 1988 and 1992. Within this period, annual kills ranged from six bears in South Carolina to 2,232 in Maine.[26]
According to Dwight Schuh in his Bowhunter's Encyclopedia, American black bears are the third most popular quarry of bowhunters, behind deer and elk.[140]
American black bear meat had historically been held in high esteem among North America's indigenous people and colonists.[59] American black bears were the only bear species the Kutchin hunted for their meat, though this constituted only a small part of their diet.[135] According to the second volume of Frank Forester's Field Sports of the United States, and British Provinces, of North America:
The flesh of the [black] bear is savoury, but rather luscious, and tastes not unlike pork. It was once so common an article of food in New-York as to have given the name of Bear Market to one of the principal markets of the city.
— Frank Forester's Field Sports of the United States, and British Provinces, of North America, p. 186
Theodore Roosevelt himself likened the flesh of young American black bears to that of pork, and not as coarse or flavorless as the meat of grizzly bears.[141] The most favored cuts of the American black bear's meat are concentrated in the legs and loins. Meat from the neck, front legs and shoulders is usually ground into minced meat or used for stews and casseroles. Keeping the fat on tends to give the meat a strong flavor. As American black bears can have trichinellosis, cooking temperatures need to be high in order to kill the parasites.[142]
American black bear fat was once valued as a cosmetic article that promoted hair growth and gloss. The fat most favored for this purpose was the hard white fat found in the body's interior. As only a small portion of this fat could be harvested for this purpose, the oil was often mixed with large quantities of hog lard.[59] However, animal rights activism over the last decade has slowed the harvest of these animals; therefore the lard from American black bears has not been used in recent years for the purpose of cosmetics.
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{{cite journal}}: Cite journal requires |journal= (help) The American black bear (Ursus americanus), also known as the black bear is a species of medium-sized bear endemic to North America. It is the continent's smallest and most widely distributed bear species. The American black bear is an omnivore, with its diet varying greatly depending on season and location. It typically lives in largely forested areas, but will leave forests in search of food, and is sometimes attracted to human communities due to the immediate availability of food.
The International Union for Conservation of Nature (IUCN) lists the American black bear as a least-concern species, due to its widespread distribution and a large population estimated to be twice that of all other bear species combined. Along with the brown bear (Ursus arctos), it is one of only two modern bear species not considered by the IUCN to be globally threatened with extinction.
