Conference
Members
Donate

Ursus americanus (American black bear)

The American black bear (Ursus americanus) is a large, plantigrade mammal with a broad skull, small ears, and non-retractable claws. Its pelage varies in color depending on its geographic location, and it lacks the shoulder hump seen in brown bears.

Table of Contents

Fast Facts

Body length: 75cm to 200 cm

Shoulder height: 50 to 100 cm

Average weight: 40 to 70 kg (88 to 154 lbs) for adult females; 60 to 140 kg (132 to 309 lbs) for adult males

Lifespan: >30 years in the wild; up to 40 years in captivity

Distribution: Canada, United States, and Mexico

Status: Least Concern (IUCN), Appendix II (CITES), Threatened (U.S. ESA; U. a. luteolus only)

Taxonomy

Kingdom: Animalia

Phylum: Chordata

Class: Mammalia

Order: Carnivora

Family: Ursidae

Subfamily: Ursinae

Genus: Ursus

Species: Ursus americanus Pallas, 1780

Common names

English: American black bear

French: Baribal; Ours noir américain

Spanish: Oso negro Americano

Subspecies

U. a. altifrontalis: Olympic black bear

U. a. amblyceps: New Mexico black bear

U. a. americanus: Eastern black bear

U. a. californiensis California black bear

U. a. carlottae Haida Gwaii black bear; Queen Charlotte black bear

U. a. cinnamomum: Cinnamon bear

U. a. emmonsii: Glacier bear

U. a. eremicus: Mexican black bear

U. a. floridanus: Florida black bear

U. a. hamiltoni: Newfoundland black bear

U. a. kermodei: Kermode bear; Spirit bear

U. a. luteolus: Louisiana black bear

U. a. machetes: West Mexico black bear

U. a. perniger: Kenai black bear

U. a. pugnax: Dall black bear

U. a. vancouveri: Vancouver Island black bear

[1], [2]

U. a. hunter and U. a. randii also previously identified [3]

Description

The American black bear (Ursus americanus) is a large-bodied mammal with a heavy build, broad skull, small eyes, small erect ears, thick pelage, and a short tail. Its foot posture is plantigrade (flat-soled) and its toe arrangement is pentadactyl (five toes) with non-retractable claws. Its front claws are the same length as its hind claws, which is a distinguishing feature of black bears in the parts of its range where it coexists with brown bears (U. arctos), which have longer front claws. Moreover, black bears lack the distinctive shoulder hump that is characteristic of brown bears. The pelage of black bears is uniform in color except for a brown muzzle and occasional white patch on the chest. The black bear’s pelage color differs across the its geographical range and varies from black to cinnamon, chocolate brown, bluish-gray, and cream-colored. An individual’s pelage color can change during consecutive molts [4].

American black bears are similar to other bear species in that they are sexually dimorphic; adult males are typically 15–25% longer and 10–70% heavier than adult females [5]. Average mass ranges from 40 to 70 kg (maximum >200 kg) for adult females and from 60 to 140 kg for adult males (maximum >300 kg) depending on habitat productivity [6]. Body length and height at the shoulder can range from 0.75 to 2.00 m and 0.50 to 1.00 m, respectively. Female black bears have 6 mammary glands: 4 pectoral (on the chest) and 2 inguinal (near the groin).

Black bear skulls are characterized by a large cranium, prominent sagittal crest, strong zygomatic arches, large nares, and well-developed turbinate bones within the nasal cavity [6]. The dental formula is I 3/3 C 1/1 P 4/4 M 2/3 (42 total teeth) where the first 3 upper and lower premolars are rudimentary or lacking [6]. The canines are large and well anchored. The molars are classified as bunodont, meaning they are low-crowned and rectangular with rounded cusps typical of omnivores and are designed for grinding herbaceous food materials [5].

Morphology

Total lengtha,bNeck circumferenceChest circumferenceShoulder heightHead widthHead lengthBody mass
Adultc ♂156.55586.18127.533.473.8
(17.9, 311)d(10.2. 309)(14.3, 308)(11.0, 309)(4.8, 239)(3.6, 312)(29.3, 335)
Adult ♀142.745.575.27324.830.750.1
(14.0, 339) (5.8, 335)(9.4, 336)(7.1, 340)(3.8, 273)(1.9, 341)(13.6, 352)
Subadult ♂125.44065.463.821.828.536.4
(23.0, 148)(9.4, 145)(15.1, 146)(12.9, 146)(4.5, 126)(4.1, 147)(21.5, 165)
Subadult ♀117.13660.258.919.526.727.7
(20.4, 97)(8.2, 99)(14.9, 96)(12.3, 93)(4.3, 80)(3.5, 96)(14.6, 107)

a [7], b Length measurements in cm and mass in kg, c Bears >3 years old are considered adults, d (Standard deviation, sample size)

Biology

American black bears are generalist and opportunistic omnivores generally associated with forested habitats in temperate and boreal regions throughout North America, but they also thrive in subtropical areas in the southeastern coastal plain, semi-arid montane islands of the southwestern United States and Mexico, and colder climates of the subarctic [6]. Black bears are adaptable, having the ability to exploit a wide array of foods that vary across latitude, elevation, and season. Abundant fall foods, typically in the form of hard mast (tree-borne nuts) in the East and berries in the West, are important to increase fat reserves in preparation for winter hibernation, an adaptation to cope with seasonal periods of food scarcity. Black bears are heavily built mammals with great physical strength and agility, and they can readily climb trees, swim long distances, and sprint up to 55 km/hr (35 mph). American black bears are the most widely distributed of the three bear species in North America, and they are more abundant than all other bear species combined [6, 8].

Reproduction and Lifespan
Gestation (months)Fetal development (days)Maximum litter sizeJuvenile lifespan (years)Adult lifespan (years)Maximum age (years)
7.0–8.0a60–70b62–3>338c

a [6]; b [5]; c [9]

Mating system: Promiscuous

Breeding interval: ≥2 years

Breeding season: June to September

Independence: 16 months

Population Dynamics

American black bears are long-lived animals that typically become sexually mature at 3–5 years of age, give birth to small-sized litters (average = 2), and have 2-year reproductive cycles [5, 6]. As such, black bear populations generally do not experience high rates of population growth except during periods of especially favorable conditions (e.g., abundant food resources) or in areas of recent range expansion. However, because their reproduction rates are low, black bear populations can be sensitive to sudden excessive increases in adult mortality, resulting in rapid population decline. Typically, however, annual variation in population abundance is affected more by variability in reproductive output caused by fluctuations in food resources [10, 11]. This can produce a phenomenon known as reproductive synchrony [12, 13], which can occur in response to severe food shortages, such as acorn crop failures, when all females about to give birth fail to produce litters. During the subsequent winter, the females that failed to produce cubs and the females that raised and weaned yearlings the previous year will all reproduce in synchrony. This results in the production of a large number of cubs that produces a sudden short-term increase in population size and lasting effects on age structure of the population in subsequent years as that cohort of cubs matures. The effects of such synchrony can last for several years, with females synchronously having either cubs or yearlings.

Lifespan

Black bears have been documented to live to more than 30 years of age in the wild [9] and into their mid-40s in captivity. Because females have more restricted movements within smaller home ranges and display less aggressive behavior than males, average female lifespan generally is greater [6]. Typically, lifespans are longer for populations located in remote areas with low levels of human activity. Conversely, lifespans will be shorter for bears living in populations exposed to high levels of human-caused mortality from legal harvest, human–bear conflict management actions, or incidental death such as vehicle collisions. In areas with high annual variation in food availability and shorter growing seasons, frequent starvation or prolonged periods of nutritional stress can also result in higher mortality rates and reduce average lifespan.

Reproduction

American black bears are promiscuous breeders, meaning that males will mate with multiple females and females will mate with multiple males [14]. Breeding season occurs during the summer months and peaks in late June to early July. Black bears are classified as induced ovulators because females only release an egg in response to physical contact during mating [15]. Because eggs are released and female bears may breed multiple times during a breeding season, it is not unusual for cubs in the same litter to have different fathers. Though the gestation period for black bears is 7–8 months, most fetal development occurs in the final 6–8 weeks because implantation of the embryo is delayed until late November to early December [15]. Cubs are born during late January or early February in winter dens. Newborn cubs are approximately 0.30 kg and 20 cm at birth and are born helpless, almost hairless, and with eyes closed [6]. Black bears produce among the smallest offspring relative to adult body size of any mammal, which may be a bet-hedging strategy that evolved to minimize maternal investment and maximize maternal survival in variable environments [16]. Average litter size is 2 cubs, but litters of 3 or 4 are common and litter size often increases with age and body size of the mother [5]. Females become sexually mature at 3–4 years of age, but maturity may be delayed to as late as 7 years of age in less productive habitats [6]. Offspring are dependent on the mother until about 16 months of age, after which the female breeds again. Because of this long-term investment in parental care, American black bears have a 2-year reproductive cycle. Their reproductive success is sensitive to availability of food resources causing widespread reproductive failures in years when food crops are poor. This sensitivity combined with relatively low reproductive potential can greatly affect population stability in areas where food availability greatly varies from year to year.

Hibernation

American black bears enter a state of dormancy during the winter months when food resources are scarce. Beginning in the fall when energy-rich foods such as hard mast, berries, or roe salmon are readily available, black bears exhibit hyperphagic foraging behavior during which they consume more calories per day than what is required for regular body maintenance. Caloric intake during this period can range from 15,000 to 20,000 kcal/day resulting in body mass gains of >1 kg per day [17, 18]. Weight gain primarily is in the form of fat tissue that will be used as the sole source of energy for body maintenance during dormancy when bears consume no food or water. Black bears spend much of the winter dormancy in dens excavated under uprooted trees, in hollow logs, in cavities under rocks, under brush piles, high in tree cavities, or on above-ground beds in thick cover. Timing of den entry and exit varies across black bear range and among different classes of bears. Den entry usually is earlier and exit is later in more northern latitudes. In the northern part of their geographic range, adult female black bears that will give birth to cubs are first to enter dens and do so in September or October, whereas pregnant females in southern regions enter dens from November to January [2]. Adult females with yearlings or cubs and those that are not pregnant enter dens later, followed by juvenile males and then adult males. In southern portions of their geographic range in the coastal plain and in Mexico, males, females with yearlings, and females with no offspring may only be dormant for short periods during times of poor weather but otherwise may remain active during the winter when food is available [19, 20, 21]. Physiological adaptations that enable black bears to reduce the amount of energy needed and conserve finite fat reserves include reduction of body temperature by 7–8°C, metabolism reduction of 50–60%, and heart rate decreased to 8–19 bpm [6]. In addition, black bears do not defecate or urinate during dormancy and appear to suffer very little muscle atrophy or loss of bone mass despite experiencing a greatly reduced level of activity for several months.

Behaviour

Black bears are characteristically shy and secretive, and they typically live solitary lives except when females are rearing young, during the breeding season, or in areas containing seasonally concentrated food resources. Their primary periods of activity are during dawn and dusk, but activity may shift to strictly nighttime in areas with high human activity, such as near garbage dumps and agricultural fields or in habitats shared with brown bears [5]. Timing of peak activity patterns may also be affected by seasonal breeding and foraging activities when black bears tend to be more active throughout day and evening. Because black bears are opportunistic foragers, they are susceptible to developing habitual nuisance behavior when artificial food sources are accessible.

American black bears are highly intelligent and extremely curious animals that exhibit a complex population social structure [22, 23, 24]. Along with other bear species in the Family Ursidae, black bears have one of the largest relative brain sizes compared with other families in the Order Carnivora such as Canidae, Procyonidae, Mustelidae, Viverridae, Hyaenidae, and Felidae [25]. Black bears are capable of discriminating between different numbers of objects at a level at or above that of great apes, an ability possibly evolved to discriminate between different-sized groups of prey or other food resources common in challenging environments [26]. Additionally, black bears perform at a level equivalent to great apes in their capacity to develop and retain abstract concepts and problem-solving skills such as discriminating between photographs of animals versus non-animals [27]. For bears, large brain size and concept-learning skills likely co-evolved in response to foraging challenges related to highly dispersed food resources across a geographic range that encompassed a wide variety of food resource types [25, 28].

Black bears exhibit a wide array of inter- and intra-specific behaviors. For example, confrontational interactions often result in agonistic behavior characterized by erect ear position, aggressive body posturing, jaw popping, huffing, and charging, although actual physical contact is uncommon [6]. Black bears are more prone to flee during confrontational encounters than other bear species and are believed to have developed this behavior, as opposed to more antagonistic behaviors such as actively fighting or pursuing, because they evolved in a forested environment where dense cover and trees were readily available for escape and concealment [29].

An interesting behavior exhibited by American black bears and shared by other bear species that occur in forested habitats is the marking of trees. They typically create marks by clawing or biting the tree up to 2 m above ground and rubbing their back against the tree while standing only on the hind legs. Mark trees are most often found along animal and hiking trails, ridge tops, riparian zones, and other linear landscape features along which bears frequently travel. Although the function of this behavior is not well understood, the increased frequency of it during the summer months suggests it may play a role in social structuring, mate selection, or communication of reproductive status during the breeding season [6].

Population Status

Most American black bear populations have been increasing both in numbers and in occupied range over the past quarter century. These increases likely resulted from increases in quantity and quality of suitable habitat, reductions in or tighter regulation of human-related mortality, and more effective population monitoring methods that better inform population management decisions. Recently, 60% of U.S. states and Canadian provinces and territories reported increasing populations while all other jurisdictions appeared to have stable populations [30]. Although a reliable continent-wide population estimate does not exist, a summary of regional estimates suggests the total number of bears in North America to be somewhere between 850,000 and 950,000 individuals [8].

Population Numbers
ContinentalContiguous United StatesAlaskaCanada
850,000–950,000a>300,000a100,000–200,000a450,000a

a [8]

Distribution and Range

Prehistorically, the geographic range of the American black bear has expanded and contracted in North America depending on shifts in habitat caused by glacial cycles. Genetic analysis results suggest existence of two distinct lineages within black bears that correspond to glacial refugia within North America: one along the coastal region of western North America and one in the continental region of North America [31, 32, 33]. Divergence of these two lineages dates to approximately 1.8 million years ago [31], which falls within the Pleistocene Epoch and the Quaternary glaciation. Furthermore, two separate continental refugia may have existed, based on genetic evidence supporting division of the continental lineage into two sublineages; one located in southeastern North America as far west as Texas and the other located at the southern terminus of the Rocky Mountains and northern terminus of the Sierra Madre Occidental mountain range [31]. However, recent research suggests the sublineages may be a result of recolonization along two different routes from a single continental refugium that followed opposite sides of the last ice sheet recession [34].

Prior to European settlement of North America, black bears were common throughout the forested areas of the United States, Canada, and northern Mexico. As human populations increased and expanded across the continent, overharvest and habitat loss eventually led to black bears disappearing from large portions of their historic range that were suitable for conversion to agriculture or human development and relegated only to habitats where human access was limited (e.g., mountainous areas and swamps). However, the number of bears and amount of occupied range has since increased in response to protection of vulnerable populations and the habitat on which they depend, establishment of stricter hunting regulations for populations that can sustain harvest, and conversion of human-use areas back to suitable black bear habitat. Currently, 12 Canadian provinces and territories, 40 U.S. states, and 6 Mexican states reported resident populations occupying an estimated total area of 10,500,000 km2, which represents 65% of the black bear’s historic range [35].

Map data courtesy of IUCN Redlist

Phylogeny

The American black bear is one of six members of genus Ursus, which is one of three genera in the family Ursidae. (The other two genera are Tremarctos and Ailuropoda.) Black bears and other members of the Ursidae family are understood to have evolved from a common ancestor during a relatively recent period of rapid species radiation near the Miocene-Pliocene boundary approximately 4–7 million years ago [36, 37]. Within the genus Ursus, American black bears belong to a group of three closely related species, the other two being the sun bear (Ursus malayanus) and the Asiatic black bear (Ursus thibetanus) [36, 37]. Based on mtDNA, the American black bear is most closely related to the Asiatic black bear [36, 37, 38]. Coexistence with the larger and likely more aggressive but extinct giant short-faced bear (Arctodus simus) and Florida cave bear (Tremarctos floridanus) likely constrained evolution of the American black bear toward occupying its current ecological niche, in that it is relatively secretive in nature and subordinate to brown bears where the two species’ geographic ranges currently overlap [39, 40, 41].

Home range size (km2)a
LocationFemalesMalesSource
Arkansas, USA34.789.7[50]
California, USA17.122.4[51]
Idaho, USA48.9112.1[42]
Massachusetts, USA28318[52]
Tennessee, USA6.951.2[53]
Virginia, USA27111.7[54]
Texas, USA32.197.7[55]
Alaska, USA65.8218.5[56]
Coahuila, MX26.0b–[57]
Québec, CAD65.1–[58]

a Average home range sizes of black bears derived from annual 100% minimum convex polygons in various areas, b Based on 95% minimum convex polygon

Diet

Feeding habits of American black bears vary throughout their geographic range in response to differences in available food plants among different forest types and seasonal animal-based resources (e.g., salmon, ungulates). Additionally, because different plants produce foods at different times of the year and availability of animal-based food resources varies, black bear diets also change among seasons. In general, black bears feed on grasses and herbaceous materials during the spring, on shrub- and tree-borne soft mast (berries), grasses, and herbaceous material in the summer, and a mixture of soft mast and hard mast (nuts) in the fall. In many areas, only a small portion of their diet consists of animal matter, which they primarily obtain from colonial insects and grubs. However, in some regions meat plays a larger role in black bear diets. For instance, black bears prefer anadromous salmon, elk calves, or deer fawns in areas where those food sources are seasonally plentiful and available [59, 60]. Periods of highest consumption occur during ungulate birthing seasons when bears are able to catch neonates [61, 62] and during the fall when bears scavenge on remains of animals harvested during ungulate hunting seasons [60]. Bears prefer foods high in fats and proteins, which naturally draws them to human foods and garbage [6].

Digestive efficiency of bears is directly related to the proportion of different foods in their diet. Plant matter is less digestible compared with animal matter, especially when plants are consumed later in the growing season [63]. Low digestibility of herbaceous material requires the input of large quantities of those foods; however, high passage rates compensate for such low-quality diets, allowing bears to maintain overall foraging efficiency. Bear digestive systems may also be influenced by physiological mechanisms operating differently across seasons. For example, differences in the digestibility of gross energy and crude protein observed in relation to pre- and post-denning periods may be an adaptive response to the need to increase fat stores during the winter [64].

The fall season is a critically important foraging period because this is when black bears must consume enough calories to increase the fat reserves on which they will depend while hibernating during the winter months, when food unavailability is low. In years when hard and soft mast crops fail and available food resources are low, individuals may travel great distances (>100 km) in search of patches of abundant food. Examples of important fall foods are oaks (Quercus spp.), hickories (Carya spp.), beech (Fagus grandifolia), and yellow buckeye (Aesculus flava) in the southeastern United States [6] and hazelnuts (Corylus spp.), oaks, and beeches (Fagus spp.) in the northeastern United States and eastern Canada [6]. Along the Rocky Mountains of the United States and Canada, examples of fall bear foods include blueberry (Vaccinium spp.), currants (Ribes spp.), buffaloberries (Shepherdia spp.), and bearberries (Arctostaphylos uva-ursi) [62, 65], while pinyon pines (Pinus spp.), junipers (Juniperus spp.), and oaks are important in the southwestern United States [66]. Summer diets across much of the eastern portion of the black bear’s geographic range consist of soft mast such as the fruits of huckleberry (Gaylussacia spp.), blackberry (Rubus spp.), and blueberry, whereas bears in western regions mostly forage on grasses and herbaceous materials. However, bears may utilize other regionally available foods such as yucca (Yucca spp.) and prickly pear cactus (Opuntia spp.) in arid regions of the southwest, horsetail (Equisetum sp.) in the Rocky Mountains of the western United States and Canada, or saw palmetto (Serenoa repens) in the rolling sandhills of northern Florida. The ability to utilize such a wide array of food is reflected in their widespread North American distribution.

Habitat

Black bears are adaptable and can thrive across a wide range of habitat types that offer adequate food, space, and cover. In general, black bears require habitat that provides abundant foods throughout the active season from spring through fall, thick understory vegetation that can be used for escape, cover, and resting, and concealed sites that can be used for winter denning and cub rearing. Because habitat use is primarily driven by seasonal availability of foods, prime habitat usually contains a high diversity of vegetation types that produce different foods at different times of the year. Typically, black bears prefer forested areas to open areas, although they also use swamps, wetlands, wet meadows, burned areas, avalanche chutes, and early-succession forest openings. Additionally, they may use riparian zones and other edge habitats for cover while traveling between forested areas. Because American black bear distribution extends across a wide range of latitude, elevation, and climatic conditions, occupied habitats can differ greatly in plant community composition. For example, black bears in the southeastern United States flourish in eastern deciduous forest types such as mixed mesophytic, cove hardwoods, and oak-hickory (Quercus-Carya) that occur throughout the Appalachian, Ozark, and Ouachita mountain ranges. In contrast, prime black bear habitat in the southwestern United States primarily occurs in chaparral and pinyon-juniper (Pinus-Juniperus) woodland sites located in mountainous areas between 900 and 3000 m elevation, whereas habitat in the northern Rocky Mountains of the United States and Canada is dominated by a mosaic of conifer forests, meadows, riparian areas, and avalanche chutes [6]. Other examples of plant communities used by black bears include desert grasslands and desert scrub in the southwestern United States, swamps and pocosins along coastal plains of the southeastern United States, bottomland hardwoods within the lower Mississippi River alluvial plain, and high tidelands and upland boreal forests in the Pacific Northwest.

Home Range

Annual home ranges can vary in size and shape depending on habitat quality, population density, and season. Although individuals establish and maintain relatively stable home ranges throughout their adult life, black bears are not territorial and their home ranges can overlap [42, 43, 44]. Female offspring will often establish their own home range entirely within the home range of their mother [45, 46, 47, 48]. In contrast, male offspring disperse and establish home ranges much further away [35, 46, 47, 48], a strategy that reduces the level of inbreeding and maintains genetic variability [49]. Within an individual’s home range, the intensity with which it uses some areas changes across seasons as food resources become available in different habitats at different times. Among individuals, home ranges can vary by sex, age, and reproductive status. For example, average male home range size is usually 3–8 times larger than an average female home range [6]. However, this increased mobility of males, especially during natal dispersal, can lead to increased mortality risks such as vehicle collisions when the bears are traveling through areas with high human population densities.

Home range size (km2)a
LocationFemalesMalesSource
Arkansas, USA34.789.7[50]
California, USA17.122.4[51]
Idaho, USA48.9112.1[42]
Massachusetts, USA28318[52]
Tennessee, USA6.951.2[53]
Virginia, USA27111.7[54]
Texas, USA32.197.7[55]
Alaska, USA65.8218.5[56]
Coahuila, MX26.0b–[57]
Québec, CAD65.1–[58]

a Average home range sizes of black bears derived from annual 100% minimum convex polygons in various areas, b Based on 95% minimum convex polygon

Diet

Feeding habits of American black bears vary throughout their geographic range in response to differences in available food plants among different forest types and seasonal animal-based resources (e.g., salmon, ungulates). Additionally, because different plants produce foods at different times of the year and availability of animal-based food resources varies, black bear diets also change among seasons. In general, black bears feed on grasses and herbaceous materials during the spring, on shrub- and tree-borne soft mast (berries), grasses, and herbaceous material in the summer, and a mixture of soft mast and hard mast (nuts) in the fall. In many areas, only a small portion of their diet consists of animal matter, which they primarily obtain from colonial insects and grubs. However, in some regions meat plays a larger role in black bear diets. For instance, black bears prefer anadromous salmon, elk calves, or deer fawns in areas where those food sources are seasonally plentiful and available [59, 60]. Periods of highest consumption occur during ungulate birthing seasons when bears are able to catch neonates [61, 62] and during the fall when bears scavenge on remains of animals harvested during ungulate hunting seasons [60]. Bears prefer foods high in fats and proteins, which naturally draws them to human foods and garbage [6].

Digestive efficiency of bears is directly related to the proportion of different foods in their diet. Plant matter is less digestible compared with animal matter, especially when plants are consumed later in the growing season [63]. Low digestibility of herbaceous material requires the input of large quantities of those foods; however, high passage rates compensate for such low-quality diets, allowing bears to maintain overall foraging efficiency. Bear digestive systems may also be influenced by physiological mechanisms operating differently across seasons. For example, differences in the digestibility of gross energy and crude protein observed in relation to pre- and post-denning periods may be an adaptive response to the need to increase fat stores during the winter [64].

The fall season is a critically important foraging period because this is when black bears must consume enough calories to increase the fat reserves on which they will depend while hibernating during the winter months, when food unavailability is low. In years when hard and soft mast crops fail and available food resources are low, individuals may travel great distances (>100 km) in search of patches of abundant food. Examples of important fall foods are oaks (Quercus spp.), hickories (Carya spp.), beech (Fagus grandifolia), and yellow buckeye (Aesculus flava) in the southeastern United States [6] and hazelnuts (Corylus spp.), oaks, and beeches (Fagus spp.) in the northeastern United States and eastern Canada [6]. Along the Rocky Mountains of the United States and Canada, examples of fall bear foods include blueberry (Vaccinium spp.), currants (Ribes spp.), buffaloberries (Shepherdia spp.), and bearberries (Arctostaphylos uva-ursi) [62, 65], while pinyon pines (Pinus spp.), junipers (Juniperus spp.), and oaks are important in the southwestern United States [66]. Summer diets across much of the eastern portion of the black bear’s geographic range consist of soft mast such as the fruits of huckleberry (Gaylussacia spp.), blackberry (Rubus spp.), and blueberry, whereas bears in western regions mostly forage on grasses and herbaceous materials. However, bears may utilize other regionally available foods such as yucca (Yucca spp.) and prickly pear cactus (Opuntia spp.) in arid regions of the southwest, horsetail (Equisetum sp.) in the Rocky Mountains of the western United States and Canada, or saw palmetto (Serenoa repens) in the rolling sandhills of northern Florida. The ability to utilize such a wide array of food is reflected in their widespread North American distribution.

Conservation Status

The American black bear is classified as a Species of Least Concern by the International Union for Conservation of Nature (IUCN). The IUCN classifies a species as Least Concern when “it has been evaluated against the criteria and does not qualify for Critically Endangered, Endangered, Vulnerable or Near Threatened.” [67]. In general, this status includes species that are widespread and abundant. The Convention on International Trade on Endangered Species of Wild Fauna and Flora (CITES) lists the American black bear in the Appendix II category, which consists of “(a) all species which although not necessarily now threatened with extinction may become so unless trade in specimens of such species is subject to strict regulation in order to avoid utilization incompatible with their survival; and (b) other species which must be subject to regulation in order that trade in specimens of certain species referred to in sub-paragraph (a) of this paragraph may be brought under effective control.” [68]. The latter definition applies to American black bears because of the physical similarities between commonly traded body parts of other endangered bear species and body parts of American black bears. Under the U.S. Endangered Species Act, only the Louisiana black bear (Ursus americanus luteolus) has been granted Threatened status, with loss and fragmentation of habitat listed as the primary threats [69]. Because of the similarity of appearance between the Louisiana black bear and the more common Eastern black bear (Ursus americanus americanus), all bears found within the designated historic range of the Louisiana black bear (i.e., eastern Texas, all of Louisiana, and southern Mississippi) are protected. Across much of its range, the American black bear is considered a game animal and is subject to legal harvest during hunting seasons regulated by state, provincial, or territorial wildlife management agencies. In 2003, 39 of 52 jurisdictions reported managed hunts of resident populations [70].

Threats

Adult American black bears have few natural predators other than humans. Human-caused mortality of the American black bear is primarily a result of regulated harvest as a game animal, illegal poaching, conflict and management-related incidents, and vehicle collisions. Young bears are susceptible to a greater number of potential predators including wolves (Canis lupus), coyotes (Canis latrans), bobcats (Lynx rufus), lynx (Lynx canadensis), brown bears, and other American black bears.

Compared with large populations or well-connected networks of populations, small isolated American black bear populations can be more susceptible to a variety of stochastic (randomly occurring) threats in addition to deterministic threats such as habitat loss or overexploitation. The three primary types of stochastic threats are demographic, environmental, and genetic. Demographic stochasticity pertains to random differences, due to chance, in the numbers of bears born and bears surviving from the numbers expected based on average vital rates. Such differences can be significant in small populations, which can have devastating effects as a result of accelerating population decline. Similarly, small population size can accelerate loss of genetic diversity and rapid accumulation of harmful genes due to random processes associated with breeding, which can in turn cause genetic abnormalities that further suppress population vital rates. Finally, variation in the environment can threaten small populations by increasing the frequency or severity of events such as extreme weather that lower vital rates beyond the ability of those populations to recover.

As human populations increase and expand into black bear habitat and as bear populations continue to increase, human–bear conflicts will continue to increase. If the number of conflicts rises beyond socially acceptable levels, a potential future threat to bear populations is the loss of social tolerance, which may result in a renewed view of bears as pests and subject them to greater persecution. Increased levels of human-caused mortality in areas where humans and bears co-occur have already contributed to those areas operating as ecological traps [71, 72, 73]. In regions with high densities of highways, collisions with vehicles can be a substantial source of bear mortality that negatively affects the local population and poses serious risks of injury to people. To reduce the frequency of these collisions, transportation departments are increasingly considering the incorporation of wildlife passages into transportation corridor design that allow animals to cross over or under roadways [74]. Recent research has found that wildlife passages support safe movements of bears across roadways [75, 76].

Because American black bears are extremely adaptable to different or changing landscapes, alterations in habitat composition caused by shifts in the global climate may have negligible effects on most black bear populations. However, black bears may not respond well to climate change-induced habitat fragmentation followed by latitudinal shifts in the distribution of those habitat fragments, because the restricted dispersal capability of female bears means black bears generally are poor colonizers of new areas. Furthermore, small isolated populations already at risk due to low numbers may be more susceptible to local extinction, because greater environmental fluctuations caused by climate change could lead to more severe and more frequent food crop failures, thus compounding the effects of small population size. In regions where American black bears coexist and compete with other large carnivores such as brown bears, it is possible that climate-caused changes in habitat may intensify interspecific competition and negatively affect black bears through competitive exclusion.

The use of American black bear gallbladders and other body parts for purposes such as traditional Asian medicine, trophies, jewelry or souvenirs, and religious ceremonies creates concern about the potential impact that trade of those parts may have on bear conservation. Currently, laws exist at the state, provincial, and federal levels that regulate the interstate, interprovincial, and international trade and transportation of bears and bear parts. For example, the listing of the American black bear in the CITES Appendix II strictly regulates international trade. However, stringent regulation of legal trade and transport could potentially have a negative effect on American black bears by increasing the demand for and prices of bear parts and thereby increasing motivation for illegal harvest and trade on the illegal market [77].

American Black Bears and Humans

American black bears and humans have coexisted ever since the first humans migrated from Asia to North America across the Beringia land bridge during the last glacial period. Black bears were an important resource to the indigenous peoples of North America, many of whom used bear hides for clothing and shelter, meat and fat for food, and claws and teeth for ornaments. Following European settlement of North America, black bear populations were greatly reduced through extensive loss and fragmentation of habitat and indiscriminate killing for food, fur trade, and protection of livestock and crops as the human population expanded across the continent. During the 20th century, wildlife conservationists called for the establishment of wildlife protection laws, stricter hunting regulations, and protection of remaining habitat, all of which ultimately allowed black bear populations to recover to stable or increasing levels across much of the species’ range.

Today, expanding black bear populations combined with an increasing numbers of people recreating or living in bear-occupied habitat has resulted in rising frequency of interactions between humans and bears. Human–bear interactions can range from relatively innocuous bear sightings during which a person is not compelled to take evasive action to conflicts during which a bear causes a person to take evasive action, makes physical contact with a person, or is harmed or killed by a person for reasons other than legal harvest [78]. The most common cause of conflict between humans and American black bears is when bears are attracted to and consume human garbage. Other causes of conflict in urban and rural areas include damage by bears to agricultural crops, fruit orchards, and apiaries, bears gaining access to pet or livestock feeds, and bears entering homes in search of food. In backcountry areas, conflict situations may arise due to a bear being attracted to scents associated with human foods carried by backpackers and aggressive behavior exhibited by bears in response to perceived threats posed by humans.

In general, the most effective method to reduce the likelihood of human–bear conflicts is to completely eliminate access by bears to attractants. In residential and rural areas, this includes removal of scent attractants (e.g., garbage and bird, pet, and livestock feed) and visual food cues (e.g., bird feeders, garbage cans, and food coolers) or exclusion of bears from anthropogenic food sources, such as apiaries, through the use of electrified fencing. In backcountry areas, safely storing foods and other scent attractants (e.g., scented toiletries) such that bears cannot sense or access them (e.g., stored in a locked vehicle, hanging from a tree limb, or stored in a bear-resistant container) can greatly reduce the chances of a conflict situation occurring.

Although removal of attractants is considered the most effective method of reducing most types of human–bear conflicts, residents and visitors often do not properly secure bear attractants for a variety of reasons. Those reasons may include indifference to elevated risks associated with bear access to attractants, lack of understanding of the role attractants play in human–bear conflicts, or a desire to intentionally attract bears for viewing purposes. Wildlife management agencies widely acknowledge the need for comprehensive information and outreach programs designed to educate the public about coexisting with bears, and some have already implemented such programs. These programs have experienced mixed success in changing public opinion and behavior [79, 80, 81, 82]. However, it is clear that significantly reducing human–bear conflicts related to anthropogenic sources of attractants requires the consistent and complete commitment of the public to eliminating access to those sources.

Contributor(s)

Jared S. Laufenberg, Department of Forestry, Wildlife and Fisheries, University of Tennessee, 274 Ellington Plant Sciences Building, Knoxville, TN 37996, USA

References

  1. Hall, E.R. 1981. The mammals of North America, 2nd ed. Volume II. John Wiley, New York City, New York, USA.
  2. Garshelis, D.L. 2009. Family Ursidae (Bears). Pages 448–497 in D.E. Wilson and R.A. Mittermeier, editors. Handbook of the mammals of the world. Volume 1. Carnivores. Lynx Edicions, Barcelona, Spain.
  3. Hall, E.R., and K.R. Kelson. 1959. The mammals of North America. Volume II. Ronald Press, New York, New York, USA.
  4. Rogers, L.L. 1980. Inheritance of coat color and changes in pelage coloration in black bears in Northeastern Minnesota. Journal of Mammalogy 61:324–327. doi: 10.2307/1380056
  5. Larivière, S. 2001. Ursus americanus. Mammalian Species 647:1−11. doi: 10.1644/1545-1410(2001)647<0001:UA>2.0.CO;2
  6. Pelton, M.R. 2003. Black bear. Pages 547–555 in G.A. Feldhamer, B.C. Thompson, and J.A. Chapman, editors. Wild mammals of North America. Johns Hopkins University Press, Baltimore, Maryland, USA.
  7. McLean, P.K., and M.R. Pelton. 1990. Some demographic comparisons of wild and panhandler bears in the Smoky Mountains. Pages 105–112 in Bears: Their Biology and Management. Volume 8. A Selection of Papers from the Eighth International Conference on Bear Research and Management, Victoria, British Columbia, Canada, February 1989 (1990). International Association for Bear Research and Management. doi: 10.2307/3872908.
  8. Garshelis, D.L., D. Crider, and F.T. van Manen. 2008. Ursus americanus. In IUCN 2013. IUCN Red List of Threatened Species. Version 2013.1.
  9. Garshelis, D.L., K.V. Noyce, and M.A. Ditmer. 2011. Ecology and population dynamics of black bears in Minnesota. Pages 8−22 in L. Cornicellli, M. Carstensen, M.D. Grund, M.A. Larson, and J.S. Lawrence, editors. Summaries of Wildlife Research Findings 2011. Minnesota Department of Natural Resources, St. Paul, Minnesota, USA.
  10. Mitchell, M.S., L.B. Pacifici, J.B. Grand, and R.A. Powell. 2009. Contributions of vital rates to growth of a protected population of American black bears. Ursus 20:77−84. doi: 10.2192/1537-6176-20.2.77
  11. Beston, J.A. 2011. Variation in life history and demography of the American black bear. Journal of Wildlife Management 75:1588−1596. doi: 10.1002/jwmg.195
  12. Clark, J.D., F.T. van Manen, and M.R. Pelton. 2005. Bait stations, hard mast, and black bear population growth in Great Smoky Mountains National Park. Journal of Wildlife Management 69:1633−1640. doi: 10.2193/0022-541X(2005)69[1633:BSHMAB]2.0.CO;2
  13. Bridges, A.S, M.R. Vaughan, and J.A. Fox. 2011. Reproductive ecology of American black bears in the Alleghany Mountains of Virginia, USA. Journal of Wildlife Management 75:1137−1144. doi: 10.1002/jwmg.148
  14. Schenk, A., and K.M. Kovacs. 1995. Multiple mating between black bears revealed by DNA fingerprinting. Animal Behavior 50:1483–1490. doi: 10.1016/0003-3472(95)80005-0
  15. Wimsatt, W.A. 1963. Delayed implantation in the Ursidae, with particular reference to the black bear. Pages 49−76 in A.D. Ender, editor. Delayed implantation. University of Chicago Press, Chicago, Illinois, USA.
  16. Lindström, J. 1999. Early development and fitness in birds and mammals. Trends in Ecology and Evolution 14:343–348. doi: 0.1016/S0169-5347(99)01639-0
  17. Jonkel, C.J., and I.M. Cowan. 1971. The black bear in the spruce-fir forest. Wildlife Monographs 27:1–57.
  18. Nelson, R.A., G.E. Folk, Jr., E.W. Pfeiffer, J.J. Craighead, C.J. Jonkel, and D.L. Steiger. 1983. Behavior, biochemistry, and hibernation in black, grizzly, and polar bears. Pages 284–290 in Bears: Their Biology and Management. Volume 5. A Selection of Papers from the Fifth International Conference on Bear Research and Management International Conference on Bear Research and Management, Madison, Wisconsin, USA, February 1980 (1983). International Association for Bear Research and Management. doi: 10.2307/3872551.
  19. Hamilton, R.J., and R.L. Marchinton. 1980. Denning and related activities of black bears in the coastal plain of North Carolina. Pages 121–126 in Bears: Their Biology and Management. Volume 4. A Selection of Papers from the Fourth International Conference on bear Research and Management, Kalispell, Montana, USA, February 1977 (1980). International Association for Bear Research and Management. doi: 10.2307/3872854
  20. Hellgren, E.C., and M.R. Vaughan. 1989. Denning ecology of black bears in a southeastern wetland. Journal of Wildlife Management 53:347–353. doi: 10.2307/3801136
  21. Doan-Crider, D.L., and E.C. Hellgren. 1996. Population characteristics and winter ecology of black bears in Coahuila, Mexico. Journal of Wildlife Management 60:398–407. doi: 10.2307/3802242
  22. Bacon, E.S. 1980. Curiosity of the American black bear. Pages 153–157 in Bears: Their Biology and Management. Volume 4. A Selection of Papers from the Fourth International Conference on bear Research and Management, Kalispell, Montana, USA, February 1977 (1980). International Association for Bear Research and Management. Available at: http://www.bearbiology.com/fileadmin/tpl/Downloads/URSUS/Vol_4/Bacon_Vol_4.pdf. doi: 10.2307/3872854
  23. Bacon, E.S., and G.M. Burghardt. 1974. Learning and color discrimination in the American black bear. Pages 27–36 in Bears: Their Biology and Management. Volume 3. A Selection of Papers from the Third International Conference on Bear Research and Management, Binghamton, New York, USA, and Moscow, U.S.S.R., June 1974. International Assoication for Bear Research and Management. Available at: https://portals.iucn.org/library/efiles/documents/NS-040.pdf
  24. Pruitt, C.H. 1974. Play and agonistic behavior in young captive black bears. Pages 79–86 in Bears: Their Biology and Management. Volume 3. A Selection of Papers from the Third International Conference on Bear Research and Management, Binghamton, New York, USA, and Moscow, U.S.S.R., June 1974. International Assoication for Bear Research and Management. Available at: http://www.bearbiology.com/fileadmin/tpl/Downloads/URSUS/Vol_3/Pruitt_Vol_3.pdf
  25. Gittleman, J.L. 1986. Carnivore brain size, behavioral ecology, and phylogeny. Journal of Mammology 67:23–36. doi: 10.2307/1380998
  26. Vonk, J., and M.J. Beran. 2012. Bears ‘count’ too: quantity estimation and comparison in black bears, Ursus americanus. Animal Behaviour 84:231–238. doi: 10.1016/j.anbehav.2012.05.001
  27. Vonk, J., S.E. Jett, and K.W. Mosteller. 2012. Concept formation in American black bears, Ursus americanus. Animal Behaviour 84:953–964. doi: 10.1016/j.anbehav.2012.07.020
  28. Vonk, J., and M. Galvan. 2014. What do natural categorization studies tell us about the concepts of apes and bears? Animal Behavior and Cognition 1:309–330. doi: 10.12966/abc.08.07.2014
  29. Herrero, S. 1972. Aspects of evolution and adaptation in American black bears (Ursus americanus Pallas) and brown and grizzly bears (U. arctos Linne) of North America. International Conference on Bear Research and Management 2:221−231.
  30. Garshelis, D.L., and H. Hristienko. 2006. State and provincial estimates of American black bear numbers versus assessments of population trend. Ursus 17:1−7.
  31. Wooding, S., and R. Ward. 1997. Phylogeography and Pleistocene evolution in the North American black bear. Molecular Biology and Evolution 14:1096−1105.
  32. Stone, K.D., and J.A. Cook. 2000. Phylogeography of black bears (Ursus americanus) of the Pacific Northwest. Canadian Journal of Zoology 78:1218–1223. doi: 10.1139/z00-042
  33. Byun, S.A., B.F. Koop, and T.E. Reimchen. 1997. North American black bear mtDNA phylogeography: Implications for morphology and the Haida Gwaii glacial refugium controversy. Evolution 5:1647–1653. doi: 10.2307/2411216
  34. Pelletier, A., M.E. Obbard, B.N. White, C. Doyle, and C.J. Kyle. 2011. Small-scale genetic structure of American black bears illustrates potential postglacial recolonization routes. Journal of Mammalogy 92:629–644. doi: 10.1644/10-MAMM-A-212.1
  35. Scheick, B.K., and W. McCown. 2014. Geographic distribution of American black bears in North America. Ursus 25:24–33. doi: 10.2192/URSUS-D-12-00020.1
  36. Yu, L., Y.W. Li, O.A. Ryder, and Y.P. Zhang. 2007. Analysis of complete mitochondrial genome sequences increases phylogenetic resolution of bears (Ursidae), a mammalian family that experienced rapid speciation. BMC Evolutionary Biology 7:198–208. doi: 10.1186/1471-2148-7-198
  37. Krause, J., T. Unger, A. Noco, A.S. Malaspinas, S.O. Kolokotronis, M. Stiller, L. Soibelzon, H. Spriggs, P.H. Dear, A.W. Briggs, S. C.E Bray, S.J. O’Brien, G. Rabeder, P. Matheus, A. Cooper, M. Slatkin, S. Pääbo, and M. Hofreiter. 2008. Mitochondrial genomes reveal and explosive radiation of extinct and extant bears near the Miocene-Pliocene boundary. BMC Evolutionary Biology 8:220–231. doi: 10.1186/1471-2148-8-220
  38. Yu, L., Q.W. Li, O.A. Ryder, and Y.P. Zhang. 2004. Phylogeny of the bears (Ursidae) based on nuclear and mitochondrial genes. Molecular Phylogenetics and Evolution 32:480–494. doi: 10.1016/j.ympev.2004.02.015
  39. Stirling, I., and A.E. Derocher. 1990. Factors affecting the evolution and behavioral ecology of the modern bears. International Conference on Bear Research and Management 8:189–204. doi: 10.2307/3872919
  40. McLellan, B. 1993. Competition between black and grizzly bears as a natural population regulating factor. Pages 111–116 in J.A. Keay, ed. Proceedings of the Fourth Western Black Bear Workshop. USDI Technical Report NPS/NRWR/nrtr-93/12.
  41. McLellan, B., and D.C. Reiner. 1994. A review of bear evolution. International Conference on Bear Research and Management 9:85–96. Available at: http://www.bearbiology.com/fileadmin/tpl/Downloads/URSUS/Vol_9/McLellan_Reiner_Vol_9.pdf
  42. Amstrup, S.C., and J. Beecham. 1976. Activity patterns of radio-collared black bears in Idaho. Journal of Wildlife Management 40:340–348. doi: 10.2307/3800435
  43. Horner, M.A., and R.A. Powell. 1990. Internal structure of home ranges of black bears and analyses of home-range overlap. Journal of Mammalogy 71:402–410. doi: 10.2307/1381953
  44. Samson, C., and J. Huot. 2001. Spatial and temporal interactions between female American black bears in mixed forests of eastern Canada. Canadian Journal of Zoology 79:633–641. doi: 10.1139/z01-021
  45. Elowe, K.D., and W.E. Dodge. 1989. Factors affecting black bear reproductive success and cub survival. Journal of Wildlife Management 53:962–968. doi: 10.2307/3809596
  46. Scwartz, C.C., and A.W. Franzmann. 1992. Dispersal and survival of subadult black bears from the Kenia Peninsula, Alaska. Journal of Wildlife Management 56:426–431. doi: 10.2307/3808854
  47. Costello, C.M. 2010. Estimates of dispersal and home-range fidelity in American black bears. Journal of Mammalogy 91:116–121. doi: 10.1644/09-MAMM-A-015R1.1
  48. Immell, D., D.H. Jackson, and M.C. Boulay. 2014. Home-range size and subadult dispersal of black bears in the Cascade Range of western Oregon. Western North American Naturalist 74:343–348. doi: 10.3398/064.074.0308
  49. Costello, C.M., S.R. Creel, S.T. Kalinowski, N.V. Vu, and H.B. Quigley. 2008. Sex-biased natal dispersal and inbreeding avoidance in American black bears as revealed by spatial genetic analyses. Molecular Ecology 17:4713–4723. doi: 10.1111/j.1365-294X.2008.03930.x
  50. Clark, J.D. 1991. Ecology of two black bear (Ursus americanus) populations in the interior highlands of Arkansas. Dissertation, University of Arkansas, Fayetteville, Arkansas, USA.
  51. Novick, H.J., and G.R. Stewart. 1982. Home range and habitat preferences of black bear in the San Bernardino Mountains of southern California. California Fish and Game Journal 67:21–35.
  52. Elowe, D.D. 1984. Home range, movements, and habitat preferences of black bear (Ursus americanus) in western Massachusetts. Thesis, University of Massachusetts, Amherst, Massachusetts, USA.
  53. van Manen, F.T. 1994. Black bear habitat use in Great Smoky Mountains National Park. Dissertation, University of Tennessee, Knoxville, Tennessee, USA.
  54. Hellgren, E.C., and M.R. Vaughan. 1990. Range dynamics of black bears in Great Dismal Swamp, Virginia−North Carolina. Proceedings of the Annual Converence of Southeastern Association of Fish and Wildlife Agencies 44:268–278.
  55. Onorato, D.P, E.C. Hellgren, F.S. Mitchell, and J.R Skiles. 2003. Home range and habitat use of American black bears on a desert montane island in Texas. Ursus 13:120–129.
  56. Garneau, D.E., T. Boudreau, M. Keech, and E. Post. 2008. Habitat use by black bears in relation to conspecifics and competitors. Mammalian Biology 73:48–57. doi: 10.1016/j.mambio.2006.11.004
  57. Doan-Crider, D.L. 2003. Movements and spaciotemporal variation in relation to food productivity and distribution, and population dynamics of the Mexican black bear in the Serranias del Burro, Coahuila, Mexico. Dissertation, Texas A&M University-Kingsville, Kingsville, TX, USA.
  58. Brodeur, V., J.-P. Ouellet, R. Courtois, and D. Fortin. 2008. Habitat selection by black bears in an intensively logged boreal forest. Canadian Journal of Zoology 86:1307–1316. doi:10.1139/Z08-118
  59. Fortin, J.K., C.C. Schwartz, K.A. Gunther, J.E. Teisberg, M.A. Haroldson, M.A. Evans, and C.T. Robbins. Dietary adjustability of grizzly bears and American black bears in Yellowstone National Park. Journal of Wildlife Management 77:270–281.
  60. Bull, E.L., T.R. Torgesen, and T.L. Wertz. 2001. The importance of vegetation, insects, and neonate ungulates in black bear diet in northeastern Oregon. Northwest Science 75:244–253.
  61. Murrow, J.L., J.D. Clark, and E.K. Delozier. 2009. Demographics of an experimentally released population of elk in Great Smoky Mountains National Park. Journal of Wildlife Management 73:1261–1268. doi: 10.2193/2008-573
  62. Baldwin, R.A., and L.C. Bender. 2009. Foods and nutritional components of diets of black bear in Rocky Mountain National Park, Colorado. Canadian Journal of Zoology 87:1000–1008. doi: 10.1139/Z09-088
  63. Pritchard, G.T., and C.T. Robbins. 1990. Digestive and metabolic efficiencies of grizzly and black bears. Canadian Journal of Zoology 68:1645–1651. doi: 10.1139/z90-244
  64. Brody, A.J., and M.R. Pelton. 1988. Seasonal changes in digestion in black bears. Canadian Journal of Zoology 66:1482–1484. doi: 10.1139/z88-215
  65. Raine, R.M., and J.L. Kansas. 1990. Black bear seasonal food habits and distribution by elevation in Banff National Park, Alberta. Pages 297–304 in Bears: Their Biology and Management. Volume 8. A Selection of Papers from the Eighth International Conference on Bear Research and Management, Victoria, British Columbia, Canada, February 1989 (1990). doi: 10.2307/3872932
  66. Costello, C.M., D.E. Jones, R.M. Inman, K.H. Inman, B.C. Thompson, and H.B. Quigley. 2003. Relationship of variable mast production to American black bear reproductive parameters in New Mexico. Ursus 14:1–16.
  67. IUCN. 2001. IUCN Red List Categories and Criteria: Version 3.1. IUCN Species Survival Commission. IUCN, Gland, Switzerland and Cambridge, UK.
  68. Convention on International Trade in Endangered Species of Wild Fauna and Flora Text of the Convention [https://cites.org/sites/default/files/eng/disc/CITES-Convention-EN.pdf]
  69. U.S. Fish and Wildlife Service. 1992. Endangered and threatened wildlife and plants; determination for threatened status for U. a. luteolus (Louisiana black bear). Federal Register 57:588–595.
  70. Hristienko, H., and J.E. McDonald, Jr. 2007. Going into the 21st century: a perspective on trends and controversies in the management of the American black bear. Ursus 18:72–88. Available at: http://www.bearbiology.com/fileadmin/tpl/Downloads/URSUS/Vol_18/U18_1_Hristienko_and_McDonald.pdf. doi: 10.2192/1537-6176(2007)18[72:GITSCA]2.0.CO;2
  71. Beckmann, J.P., and J. Berger. 2003. Using black bears to test ideal-free distribution models experimentally. Journal of Mammology 84:594–606. doi: 10.1644/1545-1542(2003)084<0594:UBBTTI>2.0.CO;2
  72. Hostetler, J.A., J.W. McCown, E.P. Garrison, A.M. Neils, M.A. Barrett, M.E. Sunquist, S.L. Simek, and M.K. Oli. 2009. Demographic consequences of anthropogenic influences: Florida black bears in north-central Florida. Biological Conservation 142:2456–2463. doi: 10.1016/j.biocon.2009.05.029
  73. Baruch-Mordo, S., K.R. Wilson, D.L. Lewis, J. Broderick, J.S. Mao, and S.W. Breck. 2014. Stochasticity in natural forage production affects use of urban areas by black bears: implications to management of human–bear conflicts. PLoS ONE 9:e85122. doi: 10.1371/journal.pone.0085122
  74. Beckmann, J.P., A.P. Clevenger, M.P. Huijser, and J.A. Hilty, eds. 2010. Safe passages: highways, wildlife, and habitat connectivity. Island Press, Washington, D.C., USA.
  75. van Manen, F.T., M.F. McCollister, J. M. Nicholson, L.M. Thompson, J.L. Kindall, and M.D. Jones. 2012. Short-term impacts of a 4-lane highway on American black bears in eastern North Carolina. Wildlife Monographs 181:1–35. doi: 10.1002/wmon.7
  76. Sawaya, M.A., A.P. Clevenger, and S.T. Kalinowski. 2013. Demographic connectivity for ursid populations at wildlife crossing structures in Banff National Park. Conservation Biology 27:721–730. doi: 10.1111/cobi.12075
  77. Williamson, D.F. 2002. In the black: status, management, and trade of the American black bear (Ursus americanus) in North America. TRAFFIC North America. World Wildlife Fund, Washington, D.C., USA. Available at: http://www.njfishandwildlife.com/pdf/bear/policy_lit/williamson_traffic.pdf
  78. Hopkins, J.B. III, S. Herrero, R.T. Shideler, K.A. Gunther, C.C. Schwartz, and S.T. Kalinowski. 2010. A proposed lexicon of terms and concepts for human–bear management in North America. Ursus 21:154–168. doi: 10.2192/URSUS-D-10-00005.1
  79. Gore, M.L., B.A. Knuth, C.W. Scherer, and P.D. Curtis. 2008. Evaluating a conservation investment designed to reduce human-wildlife conflict. Conservation Letters 1:136–145. doi: 10.1111/j.1755-263X.2008.00017.x
  80. Baruch-Mordo, S., S.W. Breck, K.R. Wilson, and J. Broderick. 2011. The carrot or the stick? Evaluation of education and enforcement as management tools for human-wildlife conflicts. PLos ONE 6:e15681. doi: 10.1371/journal.pone.0015681
  81. Merkle, J.A., P.R. Krausman, and M.M. Booth. 2011. Behavioral and attitudinal change of residents exposed to human–bear interactions. Ursus 22:74–83. doi: 10.2192/URSUS-D-10-00010.1
  82. Pienaar, E.F., D. Telesco, and S. Barrett. 2015. Understanding people’s willingness to implement measures to manage human–bear conflict in Florida. Journal of Wildlife Management 79:790–806. doi: 10.1002/jwmg.885

Links

State Wildlife Resource Agencies

Alabama: http://www.outdooralabama.com/alabama-black-bears

Alaska: http://www.adfg.alaska.gov/index.cfm?adfg=blackbear.main

Arizona: https://azgfdportal.az.gov/hunting/species/biggame/blackbear/

Arkansas: http://www.agfc.com/species/pages/SpeciesWildlifeDetails2.aspx?Title=Black%20Bear

California: http://www.dfg.ca.gov/wildlife/hunting/bear/biology.html

Colorado: http://cpw.state.co.us/learn/Pages/LivingwithWildlifeWildBears.aspx

Connecticut: http://www.ct.gov/deep/cwp/view.asp?a=2723&q=325930&deepNav_GID=1655

Florida: http://myfwc.com/bear

Georgia: http://georgiawildlife.com/node/1390

Idaho: http://fishandgame.idaho.gov/

Illinois: http://www.dnr.illinois.gov/news/pages/statementfromidnrdirectormarcmilleronamericanblackbearsightings.aspx

Indiana: http://www.in.gov/dnr/fishwild/files/fw-black_bear.pdf

Iowa: http://www.iowadnr.gov/Portals/idnr/uploads/education/visitors/black_bear_status.pdf

Kansas: http://ksoutdoors.com/Wildlife-Habitats/Wildlife-Sightings

Kentucky: http://fw.ky.gov/Wildlife/Pages/Black-Bears.aspx

Louisiana: http://www.wlf.louisiana.gov/american-black-bear

Maine: http://www.maine.gov/ifw/wildlife/species/mammals/bear.html

Maryland: http://dnr2.maryland.gov/wildlife/Pages/hunt_trap/BlackBear.aspx

Massachusetts: http://www.mass.gov/eea/agencies/dfg/dfw/fish-wildlife-plants/mammals/black-bear-mass.html

Michigan: http://www.michigan.gov/dnr/0,4570,7-153-10363_10856_57530—,00.html

Minnesota: http://www.dnr.state.mn.us/mammals/blackbear.html

Mississippi: https://www.mdwfp.com/wildlife-hunting/black-bear-program.aspx

Missouri: http://mdc.mo.gov/discover-nature/field-guide/black-bear

Montana: http://fwp.mt.gov/fishAndWildlife/management/blackBear/

Nebraska: http://outdoornebraska.ne.gov/wildlife/wildlife_species_guide/blackbear.asp

Nevada: http://www.ndow.org/Species/Furbearer/Black_Bear/

New Hampshire: http://www.wildlife.state.nh.us/wildlife/profiles/black-bear.html

New Jersey: http://www.state.nj.us/dep/fgw/bearfacts.htm

New Mexico: http://www.wildlife.state.nm.us/hunting/information-by-animal/big-game/bear/

New York: http://www.dec.ny.gov/animals/6960.html

North Carolina: http://www.ncwildlife.org/Learning/Species/Mammals/BlackBear.aspx#2498419-overviewbr-br-

Ohio: http://wildlife.ohiodnr.gov/species-and-habitats/nuisance-wildlife/black-bears-in-ohio

Oklahoma: http://www.wildlifedepartment.com/hunting/bear.htm

Oregon: http://www.dfw.state.or.us/wildlife/living_with/black_bears.asp

Pennsylvania: http://www.portal.state.pa.us/portal/server.pt/community/black_bear/14343

Rhode Island: http://www.dem.ri.gov/programs/bnatres/enforce/bears.htm

South Carolina: http://dnr.sc.gov/wildlife/species/bear.html

Tennessee: https://www.tn.gov/twra/bearmain.html

Texas: http://tpwd.texas.gov/huntwild/wild/species/blackbear/

Utah: http://dwrcdc.nr.utah.gov/rsgis2/Search/Display.asp?FlNm=ursuamer

Vermont: http://www.vtfishandwildlife.com/hunt/black_bear

Virginia: http://www.dgif.virginia.gov/wildlife/bear/

Washington: http://wdfw.wa.gov/living/bears.html

West Virginia: http://www.wvdnr.gov/Hunting/NuisBear.shtm

Wisconsin: http://dnr.wi.gov/topic/wildlifehabitat/bearmanagement.html

Wyoming: https://wgfd.wyo.gov/web2011/hunting-1001184.aspx

Provincial and Territorial Wildlife Resource Agencies

British Columbia: http://www.env.gov.bc.ca/wld/documents/blackbear.pdf

Manitoba: http://www.gov.mb.ca/conservation/wildlife/problem_wildlife/black_bear.html

New Brunswick: http://www2.gnb.ca/content/dam/gnb/Departments/nr-rn/pdf/en/Wildlife/BewareBlackBears.pdf

Newfoundland and Labrador: http://www.env.gov.nl.ca/env/wildlife/all_species/bear.html

North West Territories: http://www.enr.gov.nt.ca/node/7

Nova Scotia: http://novascotia.ca/natr/wildlife/living-with-wildlife/bear/

Nunavut: http://env.gov.nu.ca/sites/default/files/Black%20Bear.pdf

Ontario: http://www.ontario.ca/document/what-you-need-know-about-black-bears

Saskatchewan: http://www.environment.gov.sk.ca/Default.aspx?DN=e32884ef-2e1e-46d6-b704-7390b7012973

Donate

Terms of Service | Privacy Policy

© 2024 International Association for Bear Research and Management.

We are a registered 501(c)(3) non-profit organization.

We acknowledge the traditional custodians of the land, sea and waters, of the area that we live, work and research across the earth. We recognise their continued custodianship and connection to the land, waters and community. We respect and honor Elders past, present and emerging. Our hope is that we move forward with open minds listening and learning from their wisdom and knowledge.