American black bear

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American black bear
Temporal range: Late Pliocene-Early Pleistocene to recent
At Lake Louise, Alberta
Conservation status
Scientific classification
Kingdom:Animalia
Phylum:Chordata
Class:Mammalia
Order:Carnivora
Family:Ursidae
Genus:Ursus
Species:U. americanus
Binomial name
Ursus americanus
(Pallas, 1780)
Subspecies[2]

16, see text

Synonyms

Euarctos americanus

 
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American black bear
Temporal range: Late Pliocene-Early Pleistocene to recent
At Lake Louise, Alberta
Conservation status
Scientific classification
Kingdom:Animalia
Phylum:Chordata
Class:Mammalia
Order:Carnivora
Family:Ursidae
Genus:Ursus
Species:U. americanus
Binomial name
Ursus americanus
(Pallas, 1780)
Subspecies[2]

16, see text

Synonyms

Euarctos americanus

The American black bear (Ursus americanus) is a medium-sized bear native to North America. It is the continent's smallest and most widely distributed bear species. Black bears are omnivores with their diets varying greatly depending on season and location. They typically live in largely forested areas, but do leave forests in search of food. Sometimes they become attracted to human communities because of the immediate availability of food. The American black bear is the world's most common bear species. It is listed by the IUCN as Least Concern, due to the species' widespread distribution and a large global population estimated to be twice that of all other bear species combined. Along with the brown bear, it is one of only two of the eight modern bear species not considered globally threatened with extinction by the IUCN. 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]

Contents

Taxonomy and evolution

Detail of head – taken at the Cincinnati Zoo
Cinnamon-coloured Black bear eating dandelions in Waterton Lakes National Park

Although they all live 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.[3] Both American and Asiatic black bears are considered sister taxa, and are more closely related to each other than to other species of bear.[3][4] Reportedly, 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 Asiatic 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 Asiatic species,[10] though later specimens grew to sizes comparable to grizzlies.[11] From the Holocene to 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 short-faced bears (Arctodus simus and A. pristinus) and the Florida spectacled bear (Tremarctos floridanus). These Tremarctine bears evolved from bears that had emigrated from Asia to North America 7–8 ma.[12] The 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 black bear's generalist behavior allowed it to exploit a wider variety of foods and has been given as a reason why of these 3 genera, it alone survived climate and vegetative changes through and last ice age while the other more specialized North American predators went extinct. However, both Arctodus and Tremarctos had survived several other ice ages. After these prehistoric Ursids went extinct during the last glacial period 10,000 years ago, black bears were probably the only bear present in much of North America until the arrival of brown bears to the rest of the continent.[11]

Subspecies

Listed alphabetically.[14]

American black bear sub-species
Sub-species nameCommon nameDistributionDescription
Ursus americanus altifrontalisOlympic black bearPacific Northwest coast from central British Columbia through northern California and inland to the tip of northern Idaho and British Columbia
Ursus americanus amblycepsNew Mexico black bearnative to Colorado, New Mexico, west Texas, the eastern half of Arizona into northern Mexico, southeastern Utah
Ursus americanus americanusEastern black beareastern Montana to the Atlantic coast, from Alaska south and east through Canada to the Atlantic and south to Texas. Thought to be increasing in some regions. It is amongst the largest-bodied subspecies and almost all specimens are black.
Ursus americanus californiensisCalifornia black bearmountain ranges of southern California, north through the Central Valley to southern Oregon
Ursus americanus carlottaeHaida Gwaii black bear, Queen Charlotte black bearHaida Gwaii/Queen Charlotte Islands and AlaskaGenerally larger than its mainland counterparts with a huge skull and molars, and is found only as a black color phase[15]
Ursus americanus cinnamomumCinnamon bearIdaho, western Montana, and Wyoming, eastern Washington and Oregon, northeastern UtahHas brown or red-brown fur, reminiscent of cinnamon
Ursus americanus emmonsiiGlacier bearSoutheast Alaska. Stable.Distinguished by the fur of its flanks being silvery gray with a blue lustre[16]
Ursus americanus eremicusMexican black bearnortheastern Mexico. Endangered.
Ursus americanus floridanusFlorida black bearFlorida, southern Georgia, and Alabama.Has a light brown nose and shiny black fur. A white chest patch is also common. An average male weighs 136 kg (300 lb).
Ursus americanus hamiltoniNewfoundland black bearNewfoundlandGenerally bigger than its mainland relatives, ranging in size from 90 to 270 kg (200 to 600 lb) and averaging 135 kg (300 lb). It also has one of the longest hibernation periods of any bear in North America.[17]
Ursus americanus kermodeiKermode bear, Spirit bearCentral coast of British ColumbiaApproximately 10% of the population of this subspecies has white or cream-colored coats due to recessive genes and are called Kermodes or spirit bears. The other 90% are normal-colored black bears.[18]
Ursus americanus luteolusLouisiana black bearEastern Texas, Louisiana, southern Mississippi. Threatened (federal list).Has relatively long, narrow, and flat skull, and proportionately large molar teeth[19]
Ursus americanus machetesWest Mexico black bearNorth-central Mexico
Ursus americanus pernigerKenai black bearKenai Peninsula, Alaska
Ursus americanus pugnaxDall black bearAlexander Archipelago, Alaska
Ursus americanus vancouveriVancouver Island black bearVancouver Island, British Columbia

Native names

The word baribal is used as a name for the black bear in Spanish, French, Italian and German. Although the root word is popularly written as being from an unspecified Native American language, there is no evidence for this.[25]

Hybrids

American black bears are reproductively compatible with several other bear species, and have occasionally produced 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 an American black bear.[26] In 1859, a black bear and a Eurasian brown bear were bred together in the London Zoological Gardens, but the three cubs did not reach 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),...[27]

A black bear shot in autumn 1986 in Michigan was thought by some to be a black bear/grizzly bear hybrid, due to its unusually large size and its proportionately larger braincase and skull. DNA testing was unable to determine whether it was a black bear or grizzly.[28]

Current range and population

Historically, black bears occupied the majority of North America's forested regions. Today, they are primarily limited to sparsely settled, forested areas.[29]

Black bears currently inhabit much of their original Canadian range, though they do not occur in the southern farmlands of Alberta, Saskatchewan, and Manitoba. They have been extinct in Prince Edward Island since 1937. The total Canadian black bear population is between 396,000 and 476,000,[30] based on surveys taken in the mid-1990s in seven Canadian provinces, though this estimate excludes black bear populations in New Brunswick, Northwest Territories, Nova Scotia, and Saskatchewan. All provinces indicated stable populations of black bears over the last decade.[29]

The current range of black bears in the United States is constant throughout most of the northeast (down in the Appalachian Mountains almost continuously to Virginia and West Virginia), the northern midwest, the Rocky mountain region, the west coast and Alaska. However it becomes increasingly fragmented or absent in other regions. Despite this, black bears in those areas seems to have expanded their range during the last decade. Surveys taken from 35 states in the early 1990s indicate that black bears are either stable or increasing, excepting Idaho and New Mexico. The overall population of black bears in the United States has been estimated to range between 339,000 and 465,000,[31] though this excludes populations from Alaska, Idaho, South Dakota, Texas, and Wyoming, whose population sizes are unknown.[29]

As of 1993, known Mexican black bear populations existed in four areas, though knowledge on the distributions of populations outside those areas have not been updated since 1959. Mexico is the only country where the black bear is classed as endangered.[29]

Habitat

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 black bear having evolved alongside larger, more aggressive bear species, such as the extinct short-faced bear and the still living brown bear, that monopolized more open habitats.[32] Although found in the largest numbers in wild, undisturbed areas and rural regions, black bears can adapt to surviving in some numbers in peri-urban regions as long as they contain easily assessible foods and some vegetative coverage.[5] In most of the contiguous United States, black bears today are usually found in heavily vegetated mountainous areas, from 400 to 3,000 m (1,300 to 9,800 ft). For bears living 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 Southeast United States. 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 or Louisiana), bears inhabit a mixture of flatwoods, bays, and swampy hardwood sites. In the northeast part of the range (United States and Canada), prime habitat consists of a forest canopy of hardwoods such as beech, maple, and 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 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 black bear in the Rockies. Important nonforested 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.[32] In parts of northeastern Canada, especially Labrador, black bears have adapted exclusively to semi-open areas which are more typical habitat in North America for brown bears (likely due to the absence here of brown and polar bears as well as other large carnivore species).[5]

Physical description

American black bears can be distinguished from brown bears by their smaller size, their less concave profiles, their shorter claws and the lack of a shoulder hump

Build

Some specimens may develop a white “crescent moon” mark on the chest. This white mark, which is constant in Asiatic black bears, occurs in only 25% of American black bears[33]

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).[32] Across its range, greatest skull length for the species has been reportedly measured from 23.5 to 35 cm (9.3 to 14 in).[5] Females tend to have more slender and 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 sizeable, with a rear foot length of 13.7 to 22.5 cm (5.4 to 8.9 in), being proportionly 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 Asiatic black bears. The vestigal tail is usually 4.8 inches (12 cm) long. The ears are small and rounded, and are set well back on the head.

Black bears are highly dexterous, being capable of opening screw-top jars and manipulating door latches. They also have great physical strength. Even bear cubs have been known to turn over flat-shaped rocks weighing 310 to 325 pounds (140 to 147 kg) by flipping them over with a single foreleg.[34] They move in a rhythmic, surefooted way and can run at speeds of 25–30 mph (40–50 km/h).[35] Black bears have good eyesight, and have been proven experimentally to be able to learn visual discrimination tasks based on color faster than chimpanzees and as fast as dogs. They are also capable of rapidly learning to distinguish different shapes, such as small triangles, circles and squares.[36]

Size

Cinnamon-colored black bear in Yellowstone National Park

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. Black bears on the East Coast tend to be heavier on average than those on the West Coast, although 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 (130–550 lb), while females weigh 33% less at 41–170 kg (90–370 lb).[5][37] In the state of California, studies have indicated that the average mass is 86 kg (190 lb) in adult males and 58 kg (130 lb) in adult females.[32] Adult 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 southeast Alaska (where nutritious salmon are readily available) adult bears averaged an estimated 115 kg (250 lb).[38][39] In Great Smoky Mountains National Park, adult males averaged 112 kg (250 lb) and adult females averaged 47 kg (100 lb) per one study.[40] In Yellowstone National Park, a population study found that adult males averaged 119 kg (260 lb) and adult females averaged 67 kg (150 lb).[41] In New York state, the two sexes reportedly average 135 kg (300 lb) and 74 kg (160 lb), respectively.[42] 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.[34][43][44][45] Although they are the smallest species in North America, large males exceed the size of other bear species except the brown and polar bears.[34] The biggest wild American black bear ever recorded was a male from New Brunswick, shot in November 1972, that weighed 409 kg (900 lb) after it had been dressed, meaning it weighed an estimated 500 kg (1,100 lb) in life, and measured 2.41 m (7.9 ft) long.[46] Another notably outsized wild black bear, weighing in at 408 kg (900 lb) in total, was the cattle-killer shot in December 1921 on the Moqui Reservation in Arizona.[46] The record-sized bear from New Jersey was shot in Morris County December 2011 and scaled 376.5 kg (830 lb).[47] Even larger, the most massive black bear recorded in Pennsylvania (one of six weighing over 363 kg (800 lb) shot in the in the last 15 years in the state) weighed in at 399 kg (880 lb) and was shot in November 2010 in Pike County.[48] The North American Bear Center, located in Ely, Minnesota, is home to the world's largest captive male and female black bears. Ted, the male, weighed 431–453.5 kg (950–1,000 lb) in the fall of 2006.[49] Honey, the female, weighed 219.6 kg (484 lb) in the fall of 2007.[50]

Pelage

A white-furred Kermode black bear

The fur is soft, with dense underfur and long, coarse, thick guard hairs.[34] The fur is not as shaggy or coarse as that of brown bears.[46] American black bear skins can be distinguished from those of Asiatic black bears by the lack of a white mark on the chin and hairier footpads.[51] Despite their name, black bears show a great deal of color variation. Individual coat colors can range from white, blond, cinnamon, or light brown to dark chocolate brown or to jet black, with many intermediate variations existing. Bluish tinged black bears occur along a portion of coastal Alaska and British Columbia. White to cream colored black bears occur in coastal islands and the adjacent mainland of south-western British Columbia. Albino specimens have also been recorded.[52] Black coats tend to predominate in moist areas such as New England, New York, Tennessee, Michigan and western Washington. Approximately 70% of all black bears are black, though only 50% of black bears in the Rocky Mountains are black.[34] Many black bears in Northwestern North America are cinnamon, blond 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.[53]

In his book The Great Bear Almanac, Gary Brown summarized the predominance of black or brown/blond specimens by location:[34]

Color variations of black bears by location
LocationColor breakdown
Michigan100% black
Minnesota94% black, 6% brown
New England100% black
New York100% black
Tennessee100% black
Washington (coastal)99% black, 1% brown or blonde
Washington (inland)21% black, 79% brown or blonde
Yosemite National Park9% black, 91% brown or blonde

Behavior

In his Great Bear Almanac, Gary Brown lists 20 different sounds in eight different contexts. Sounds expressing aggression include growls, woofs, snorts, bellows and roars. Sounds expressing contentment include mumbles, squeaks and pants.[35] American black bears tend to be territorial and non-gregarious in nature. However, at abundant food sources (i.e. spawning salmon or garbage dumps) black bears may congregate and dominance hierarchies form, with the largest, most powerful males dominating the most fruitful feeding spots.[54] They mark their territories by rubbing their bodies against trees and clawing at the bark. Annual ranges held by mature male black bears tend to be very large but 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 males bears travelling as much as 4,349 sq mi (11,260 km2) in times of food shortages.[5][54] Black bears are excellent and strong swimmers, doing so for pleasure and to feed (largely on fish). Black bears climb regularly to feed, escape enemies or to hibernate. They are one of the half bear species that 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.[35] Black bears may be active at any time of the day or night, although mainly forage by night. Bears living near human habitations tend to be more extensively nocturnal and bears living near brown bears tend to be more extensively diurnal.[5][32]

Newborn black bear cubs

Reproduction and development

Sows usually produce their first litter at the age of 3–5 years.[35] Sows living in more developed areas tend to get pregnant at younger ages.[55] 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 2–3 weeks. 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.[32] Sows tend to be short tempered with their mates after copulating. The fertilised 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. Litters usually consist of two cubs, though litters of 6 have been recorded. 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, downlike 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 six weeks, they attain 900 g (2.0 lb), by 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 three years, and attain their full growth at 5 years.[35]

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Female with cubs in Parc Omega, Quebec

Longevity and Mortality

The average lifespan in the wild is 18 years, though it is quite possible for wild specimens to survive for more than 23 years.[53] The record age of a wild specimen was 31 years, while that in captivity was 44 years.[34] Average annual survival rates for adult bears is variable, ranging from 86% in Florida to 73% in Virginia and North Carolina.[32] In Minnesota, 99% of wintering adult bears were able to survive the hibernation cycle in one study.[32] Remarkably, a study of 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.[32] Across the range, the estimated amount of cubs who survive past their first year is 60%.[5]

With the exception of the rare confrontation with an adult brown bear or gray wolf pack, adult black bears are not usually subject to natural predation.[32] Black bear cubs tend to be more vulnerable to predation than adults. Known predators of bear cubs have included bobcats, coyotes, cougars, wolves, brown bears and other bears of their own species.[5][32] Many of these will steathly 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.[32] Even cougars will reportedly be displaced by an angry mother bear if they are discovered stalking the cubs.[56] Flooding of dens after birth may also occasionally kill newborn cubs. However, in current times, American black bears fatalities are overwhelming attributable to human activities. Seasonally, tens of thousands of black bears are hunting legally across North America, with many more being illegally poached or trapped. Auto-collisions also may claim many black bear lives annually.[5][32]

Hibernation

Mother black bear and cubs, hibernating

Black bears were once not considered true or "deep" hibernators, but because of discoveries about the metabolic changes that allow 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". Black bears are now considered highly efficient hibernators.[57][58]

Black bears enter their dens in October and November. Prior to that time, they can put on up to 30 pounds of body fat to get them through the seven months during which they fast. Hibernation in black bears typically lasts 3–5 months.[15] During this time, their heart rate drops from 40–50 beats per minute to 8 beats per minute. They spend their time in hollowed-out dens in tree cavities, under logs or rocks, in banks, caves, or culverts, and in shallow depressions. Females, however, have been shown to be pickier in their choice of dens, in comparison to males.[59] Although naturally-made dens are occasionally used, most dens are dug out by the bear itself.[53] A special hormone, leptin is released into the black bear's systems, to suppress appetite. Because they do not urinate or defecate during dormancy, the nitrogen waste from the bear's body is biochemically recycled back into their proteins. This also serves the purpose of preventing muscle loss, as the process uses the waste products to build muscle during the long periods of inactivity. In comparison to true hibernators, their body temperature does not drop significantly (staying around 35 degrees Celsius) 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.[60] During winter, black bears consume 25–40% of their body weight.[61] The footpads peel off while they sleep, making room for new tissue. In the most southernly areas (i.e. Florida, Mexico, the Southeastern United States) of the black bear's distribution only pregnant females and mothers with yearling cubs will enter hibernation.[5] 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. Black bears use dense cover for hiding and thermal protection, as well as for bedding.

Dietary habits

Black bear feeding on a bush
Black bear taking a dead chum salmon near Hyder, Alaska

Generally, American black bears are largely crepuscular in foraging active, though may actively feed at any time.[54] Up to 85% of the black bear's diet consists of vegetation,[35] though they tend to dig less than brown bears, eating far fewer roots, bulbs, corms and tubers than the latter species.[52] When initially emerging from hibernation, they will seek to feed on carrion from winter-killed animals and newborn ungulates. As the spring temperature warms, black bears seek new shoots of many plant species, especially new grasses, wetland plants and forbs.[61] Young shoots and buds from trees and shrubs during the spring period are also especially important to 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.[62] During summer, the diet is comprised largely by fruits, especially berries and soft masts such as buds and drupes. During the autumn hyperphagia, feeding becomes pretty much the full-time task of black bears. Hard masts become the most important part of the black bear's diet in autumn and may even partially dictate the species distribution. Favored masts such as hazlenuts, oak acorns and whitebark pine nuts may be consumed by the hundreds each day by a single black bear during fall.[5][32] During the fall period, American black bears may also habitually raid the nut caches of tree squirrels.[61] Also extremely important in fall are berries such as huckleberries and buffalo berries.[5] 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.[53]

The majority of the black bear's animal diet consists of insects such as bees, yellow jackets, ants and their larvae.[61] Black bears are also fond of honey, and will gnaw through trees if hives are too deeply set into the trunks for them to reach them with their paws. Once the hive is breached, black bears will scrape the honeycombs together with their paws and eat them, regardless of stings from the bees.[46] 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. However, the white furred black bears of the islands of western Canada have a 30% greater success rate in catching salmon than their black furred counterparts.[63] Other fish including suckers, trout and catfish are readily caught when possible.[64] Although black bears do not often engage in active predation of other large animals for much of the year, the species will also regularly prey on mule and white-tailed deer fawns in spring given the opportunity.[65][66][67] In addition they have been recorded similarly preying on elk calves in Idaho[68] and moose calves in Alaska.[69]

Black bear with pink salmon.

Black bear predation on adult deer is rare but has been recorded.[70][71][72] They may even hunt prey up to the size of adult moose, which are considerably larger than themselves, by ambushing them.[73] In Labrador, black bears are exceptionally carnivorous, living largely off of caribou, usually sickly, young or dead specimens, and rodents such as voles. This is believed to be is 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).[53] Like brown bears, black bears try to use surprise to ambush their prey and target the sickly animals in herds. Once a deer fawn is captured, it is frequently torn apart alive while feeding.[66] If able to capture a mother deer in spring, the bear frequently begins feeding on the udder of lactating females, but generally prefer meat from the viscera. 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 wolves and coyotes, black bears rarely scatter the remains of their kills. Vegetation around the carcass is usually matted down by black bears and their droppings are frequently found nearby. 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.[74] They will readily consume eggs and nestlings of various birds and can easily access many tree nests, even the huge nest of the bald eagle.[35] Black bears have been reported stealing deer and other animals from human hunters.

Interspecific predatory relationships

Over much of their range, black bears are assured scavengers who, using their large size and considerable strength, can intimidate and, if necessary, dominate other predators in confrontations over carcasses. In occasions where they encounter the brown bear, however, the larger brown species dominates them. 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 black bears have been recorded in Yellowstone National Park.[75][76]

Black bears may 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 carcasses.[77][78] Fights between the two species are rare, though they can be violent. Cremony, in his Life among the Apaches, describes an incident in which a cougar killed a black bear.[79] Several accounts, almost entirely told ancedotedly from the 18th and 19th centuries, detail confrontations in which cougars and black bears have engaged in protacted combat and end with both competitors fatally wounded.[80][81][82]

Black bear interactions with wolves are much rarer than with brown bears, due to differences in habitat preferences. The majority of black bear encounters with wolves occur in the species' northern range, with no interactions being recorded in Mexico. Despite the 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, black bears frequently lose against wolves in disputes over kills.[83] Wolf packs typically kill black bears when the large animals are in their hibernation cycle.[37]

There is at least one record of a black bear killing a wolverine in a dispute over food in Yellowstone National Park.[84] Black bears may sometimes habitually predate American alligator nests. Sometimes, they are fought off by the female alligator but will also occasionally wound or even kill an adult alligator, though neither species are likely to confront a large adult of the other directly.[85] Ancedotal cases of alligator predation on bears have been reported, though such cases may involve assaults on cubs.[86]

Relationships with humans

In folklore, mythology and culture

Harry Colebourn and Winnie, the bear from which Winnie the Pooh derives his name

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 was created by the Evil Spirit.[87] In the mythology of the Haida, Tlingit, Tsimshian people of the Northwest Coast, mankind first learned to respect bears when a girl married the son of black bear Chieftain.[88] In Kwakiutl mythology, 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 own cubs.[89] 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.[90]

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 a black bear cub trapped up a tree.[91] Winnie the Pooh was named after Winnipeg, a female black bear cub that lived at London Zoo from 1915 until her death in 1934.[92] A 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.[93]

The American black bear is the mascot of Baylor University; the university houses two live black bears on campus.

Sleeping Bear Dunes is named after a Native American legend, where a female bear and her cub swam across Lake Michigan. Exhausted from their journey, the bears rested on the shoreline and fell sound asleep. Over the years, the sand covered them up, creating a huge sand dune.

Attacks on humans

Although an adult bear is quite capable of killing a human, American black bears typically avoid confronting humans when possible. 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. Black bears rarely attack when confronted by humans, and usually limit themselves to making mock charges, emitting blowing noises and swatting the ground with their forepaws. However, according to Stephen Herrero in his Bear Attacks: Their Causes and Avoidance, 23 people were killed by black bears from 1900 to 1980. The number of black bear attacks on humans is higher than those of the brown bear in North America, though this is largely because the black species considerably outnumbers the brown rather than greater aggressiveness.

The incidence of bear attacks in parks and campgrounds declined after the introduction of bear-resistant garbage cans and other reforms

Compared to brown bear attacks, aggressive encounters with black bears rarely lead to serious injury. However, the majority of 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 grizzlies, female black bears do not display the same level of protectiveness to their cubs, and seldom attack humans in their vicinity.[52] However, occasionally, attacks by protective mothers do occur.[32] The worst recorded fatality incident occurred in May 1978, in which a black bear killed three teenagers who were fishing in Algonquin Park in Canada.[94] Another exceptional, spree-like attack occurred in July 1998 in Liard River Hot Springs Provincial Park in Canada, when an emaciated black bear attacked a child and mother, killing the latter as well as an adult man who tried to intervene. This bear was shot while mauling a fourth victim.[95][96]

The majority of attacks happened in national parks, usually near campgrounds, where the bears had become habituated to human contact and food.[52] 1,028 incidences of black bears acting aggressively toward people, 107 of which resulted in injury, were recorded from 1964 to 1976 in the Great Smoky Mountains National Park, and occurred mainly in tourist hotspots where people regularly fed the bears handouts.[94] In almost every case where open dumps or handouts that had previously attracted black bears were ceased, the amount of aggressive encounters with bears have decreased precipitously over time.[32] However, in the afforementioned case of the spree attack in Liard River Hot Springs, the attacking bear was believed to have been previously almost fully dependent on a local garbage dump that had closed and was starving as a result of the loss of that food source.[95] Attempts to relocate bears are typically unsuccessful, as black bears seem to be able to return to their home range even without familiar landscape cues.[32]

Livestock and crop predation

A limitation of food sources in early spring and wild berry and nut crop failures during summer months are probably major contributing factors to black bears regularly feeding from commercial human-based food sources. Crops are frequently eaten by these bears, especially during autumn hyperphagia when natural foods are scarce. Favored crops may include apples, oats and corns.[5] Black bears can do extensive damage in some areas of the northwestern United States by stripping the bark from trees and feeding on the cambium. Livestock depredations by black bears occur mostly in spring. Though black bears have the capacity to (and occasionally do) hunt adult cattle and horses, they seem to prefer smaller, more easily overwhelmed prey such as sheep, goats, calves, and pigs. They normally kill by biting the neck and shoulders, though they may break the neck or back of prey with blows from the paws. Evidence of a bear attack includes claw marks and is frequently found on the neck, back, and shoulders of larger animals. Surplus killing of sheep and goats are common. 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.[74] Occasionally, pets, especially dogs which are most prone to harass a bear, are killed by black bears.[97] It is not recommended to use unleashed dogs as a deterrent from bear attacks. Although large, aggressive dogs sometimes cause a bear to run, if pressed, angry bears frequently turn the tables end up chasing the dog in return. A bear in pursuit of a pet dog has the potential to threaten both canid and human lives.[98][99]

Hunting and exploitation

Hunting

Historically, black bears were hunted by both Native Americans and European settlers. Some Native American tribes, in admiration for the 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, and would compliment the animal for its courage.[46] The Kutchin typically hunted black bears during their hibernation cycle. Unlike the hunting of hibernating grizzlies, which was wrought with danger, black bears took longer to awaken, and was thus safer and easier.[22] During the European colonisation of eastern North America, thousands of black bears were hunted for their meat, fat and fur.[4] Theodore Roosevelt wrote extensively on 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". He wrote that black bears were difficult to hunt by stalking, due to their habitat preferences, though were easy to trap. Roosevelt described how in the Southern States, planters regularly hunted black bears on horseback with hounds. General Wade Hampton was known to have been present at 500 successful black bear hunts, two thirds of which he killed personally. He killed thirty or forty 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.[73] Unless well trained, horses were often useless in black bear hunts, as they often bolted when the bears stood their ground.[46] In 1799, 192,000 black bear skins were exported from Quebec. In 1822, 3,000 skins were exported from the Hudson's Bay Company.[100] In 1992, untanned, fleshed and salted black bear hides were sold for an average of $165.[101]

In Canada, black bears are considered as both a big game and furbearer species in all provinces save for New Brunswick and Northwest Territories, where they are only classed as a big game species. There are currently 80,822 licensed 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 yearling specimens.[29]

Currently, 28 of the USA's states have 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 black bears. Overall over 481,500 black bear hunting licences 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 of a six-day bear-hunting season in early December 2010 to slow the growth of the black bear population. Bear-hunting had been banned in New Jersey for five years.[102] A Fairleigh Dickinson University PublicMind poll found that 53% of New Jersey voters approved of the new season if scientists concluded black bears were leaving their usual habitats and destroying private property.[103] 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.[103] In the western states, where there are large black populations, there are spring and year-round seasons. Approximately 18,845 black bears were killed annually in the USA between 1988–1992. Within this period, annual kills ranged from six bears in South Carolina to 2,232 in Maine.[29]

According to Dwight Schuh in his Bowhunter's Encyclopedia, black bears are the third most popular quarry of bowhunters, behind deer and elk.[104]

Meat and organs

Black bear meat
Nutritional value per 100 g (3.5 oz)
Energy649 kJ (155 kcal)
Carbohydrates0.00 g
Fat8.30 g
Protein20.10 g
Water71.20 g
Vitamin A equiv.78 μg (10%)
Thiamine (vit. B1)0.160 mg (14%)
Riboflavin (vit. B2)0.680 mg (57%)
Niacin (vit. B3)3.200 mg (21%)
Iron7.20 mg (55%)
Phosphorus162 mg (23%)
Percentages are relative to
US recommendations for adults.
Source: USDA Nutrient Database

Black bear meat had historically been held in high esteem among North America's indigenous people and colonists.[46] Black bears were the only bear species the Kutchin hunted for their meat, though this constituted only a small part of their diet.[22] 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 black bears to that of pork, and not as coarse or flavourless as the meat of grizzlies.[105] The most favoured cuts of the black bear's meat are concentrated in the legs and loins. Meat from the neck, front legs and shoulders is usually ground into mincemeat or used for stews and casseroles. Keeping the fat tends to give the meat a strong flavour. As black bears can have trichinellosis, cooking temperatures need to be high in order to kill the parasites.[106]

Black bear fat was once valued as a cosmetic article which promoted hair growth and gloss. The fat most favoured 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.[46] However animal rights activism over the last decade has slowed the harvest of these animals; therefore the lard from black bear has not been used in recent years for the purpose of cosmetics.

See also

References

  1. ^ a b Garshelis, D.L., Crider, D. & van Manen, F. (2008). Ursus americanus. In: IUCN 2008. IUCN Red List of Threatened Species. Retrieved 27 January 2009.
  2. ^ Ursus americanus, Mammal Species of the World, 3rd ed.
  3. ^ a b c d e Krause, J.; Unger, T.; Noçon, A.; Malaspinas, A.; Kolokotronis, S.; Stiller, M.; Soibelzon, L.; Spriggs, H.; Dear, P. H.; Briggs, A. W.; Bray, S. C. E.; O'Brien, S. J.; Rabeder, G.; Matheus, P.; Cooper, A.; Slatkin, M.; Pääbo, S.; Hofreiter, M. (2008). "Mitochondrial genomes reveal an explosive radiation of extinct and extant bears near the Miocene-Pliocene boundary". BMC Evolutionary Biology 8 (220): 220. doi:10.1186/1471-2148-8-220. PMC 2518930. PMID 18662376. //www.ncbi.nlm.nih.gov/pmc/articles/PMC2518930/.
  4. ^ a b Bears of the World by Lance Craighead, Publisher: Voyageur Press, 2003, ISBN 0-89658-008-3
  5. ^ a b c d e f g h i j k l m n o p q r Carnivores of the World by Dr. Luke Hunter. Princeton University Press (2011), ISBN 9780691152288
  6. ^ Michael O. Woodburne (2004). Late Cretaceous and Cenozoic Mammals of North America: Biostratigraphy and Geochronology. Columbia University Press. pp. 178, 252. ISBN 978-0-231-13040-0. http://books.google.com/books?id=73ZaLf_LL9cC&pg=PA252. Retrieved 25 June 2012.
  7. ^ a b Kurten, B., and E. Anderson. 1980. Pleistocene mammals of North America. Columbia University Press, New York.
  8. ^ a b Wolverton, S., and R. L. Lyman (1998). "Measuring late Quaternary Ursid diminution in the Midwest". Quaternary Research 49 (3): 322–329. doi:10.1006/qres.1998.1964.
  9. ^ Lisette Waits, David Paetkau, and Curtis Strobeck, "Overview" from Genetics of the Bears of the World chapter 3 of Bears: Status Survey and Conservation Action Plan, compiled by Christopher Servheen, Stephen Herrero and Bernard Peyton, IUCN/SSC Bear Specialist Group
  10. ^ Herrero, Stephen. "Aspects of Evolution and Adaptation in American Black Bears (Ursus americanus Pallas) and Brown and Grizzly Bears (U. arctos Linne.) of North America" (PDF). Environmental Sciences Centre (Kananaskis). http://www.bearbiology.com/fileadmin/tpl/Downloads/URSUS/Vol_2/Herrero.pdf. Retrieved 2011-02-21.
  11. ^ a b "The American Black Bear". Grizzlybear.org. http://www.grizzlybear.org/bearbook/american_black_bear.htm. Retrieved 2011-02-21.
  12. ^ Qiu, Z. (2003). "Dispersals of Neogene Carnivorans between Asia and North America". Bulletin American Museum of Natural History 279: 18–31. doi:10.1206/0003-0090(2003)279<0018:C>2.0.CO;2. http://www.catsg.org/catsglib/recordetail.php?recordid=5322.
  13. ^ Schubert, B. W.; Hulbert, Jr.; MacFadden, B. J.; Searle, M.; Searle, S. (2010). "Giant short-faced bears (Arctodus simus) in Pleistocene Florida USA, a substantial range expansion". Journal of Paleontology 84: 79–87. doi:10.1666/09-113.1.
  14. ^ Black Bear Subspecies, CoveBear
  15. ^ a b "Haida Gwaii Black Bear (Ursus Americanus Carlottae Subspecies)" (PDF). http://www.llbc.leg.bc.ca/public/PubDocs/bcdocs/373436/Chapter%202.8.pdf. Retrieved 2011-02-21.
  16. ^ "SPECIES VARIATION – Editorial Comment". Wildlife1.wildlifeinformation.org. http://wildlife1.wildlifeinformation.org/S/0MCarnivor/ursidae/ursus/Ursus_americanus/19Ursus_americanusSpecVar.html. Retrieved 2011-02-21.
  17. ^ Black Bear, Parks Canada
  18. ^ "Spirit Bear Facts". Province of British Columbia. Archived from the original on 17 December 2009. http://www.corporate.gov.bc.ca/bcspiritbear/more_about_spirit_bear.htm. Retrieved 2009-12-03.
  19. ^ ''Louisiana Black Bear''. (PDF) . Retrieved on 2011-09-15.
  20. ^ "Abnaki-Penobscot Animal Words". Native-languages.org. http://www.native-languages.org/abenaki_animals.htm. Retrieved 2011-02-21.
  21. ^ "Algonquin Animal Words". Native-languages.org. http://www.native-languages.org/algonquin_animals.htm. Retrieved 2011-02-21.
  22. ^ a b c Nelson, Richard K. Hunters of the northern forest: designs for survival among the Alaskan Kutchin, University of Chicago Press, 1986, ISBN 0-226-57181-5
  23. ^ "English-Tlingit Dictionary". Alaskool.org. http://www.alaskool.org/LANGUAGE/dictionaries/akn/tlingit/information/Index_TND.html. Retrieved 2011-02-21.
  24. ^ English/Cherokee Dictionary wehali.com
  25. ^ Diebold, A. Richard, Jr. (1982). "Alleged American Indian "Baribal" 'American Black Bear': A Query". International Journal of American Linguistics 48 (1): 89–91. doi:10.1086/465718. JSTOR 1264753.
  26. ^ Hybrid Bears. messybeast.com
  27. ^ Darwin, Charles (1868). The Variation of Animals and Plants under Domestication. Volume 2 (1st ed.). London: John Murray. p. 151. ISBN 1-4068-4250-8. http://darwin-online.org.uk/EditorialIntroductions/Freeman_VariationunderDomestication.html.
  28. ^ Richard P. Smith, "Hybrid Black Bear" in Black Bear Hunting, Stackpole Books, 2007, ISBN 0-8117-0269-3
  29. ^ a b c d e f Michael R. Pelton, Alex B. Coley, Thomas H. Eason, Diana L. Doan Martinez, Joel A. Pederson, Frank T. van Manen, and Keith M. Weaver. "Chapter 8. American Black Bear Conservation Action Plan" (PDF). Archived from the original on 2011-07-23. http://web.archive.org/web/20110723235737/http://wildlife1.wildlifeinformation.org/000ADOBES/Bears/Bears_IUCN_ActionPlan/bearsAP_chapter8.pdf. Retrieved 2011-02-21.
  30. ^ "Canadian Population". World Wildlife Fund. http://wwf.ca/newsroom/?1058. Retrieved 2011-08-31.
  31. ^ "United States Population". World Wildlife Fund. http://wwf.ca/newsroom/?1058. Retrieved 2011-08-31.
  32. ^ a b c d e f g h i j k l m n o p q Lariviere, S. (2001). "Ursus americanus". Mammalian Species 647: 1–11. doi:10.1644/1545-1410(2001)647<0001:UA>2.0.CO;2. http://www.science.smith.edu/departments/Biology/VHAYSSEN/msi/default.html.
  33. ^ "Bears of the World". Americanbear.org. http://www.americanbear.org/otherbears.htm. Retrieved 2011-02-21.
  34. ^ a b c d e f g Brown 1993, Ch. "Bear Anatomy and Physiology".
  35. ^ a b c d e f g Brown 1993, Ch. "Behaviour and Activities".
  36. ^ "Learning and Color Discrimination in the American Black Bear" (PDF). http://www.bearbiology.com/fileadmin/tpl/Downloads/URSUS/Vol_3/Bacon_Burghardt_B_Vol_3.pdf. Retrieved 2011-02-21.
  37. ^ a b Scorzafava, Dick (2007). Radical Bear Hunter. Stackpole Books. ISBN 978-0-8117-3418-9.
  38. ^ Bertram, M.R.; Vivion M. T. (2002). "Black bear monitoring in eastern interior Alaska". Ursus 13 (69–77). http://alaska.fws.gov/nwr/yukonflats/pdf/black_bear_monitoring_ursus.pdf.
  39. ^ Peacock, Elizabeth (2004). Population, Genetic and Behavioral Studies of Black Bears Ursus americanus in Southeast Alaska. PhD Thesis, University of Nevada, Reno
  40. ^ Ursus americanus (Pallas); Black Bear. Discoverlife.org. Retrieved on 2012-12-20.
  41. ^ Barnes, V.G., and O.E. Bray. 1967. Population characteristics and activities of black bears in Yellowstone National Park. Final rep., Colorado Wildl. Res. Unit, Colorado State Univ., Fort Collins; cited in Characteristics of Black Bears and Grizzly Bears in YNP. nps.gov
  42. ^ BLACK BEARS IN NEW YORK: Natural History, Range, and Interactions with People. Bureau of Wildlife – Black Bear Management Team, 2003; Second Edition: 2007
  43. ^ Audubon Field Guide. Audubonguides.com. Retrieved on 2011-09-15.
  44. ^ Kronk, C. (2007). Ursus americanus. Animal Diversity Web. Retrieved on 2011-09-15.
  45. ^ American black bear videos, photos and facts – Ursus americanus. ARKive. Retrieved on 2011-09-15.
  46. ^ a b c d e f g h Wood, Gerald (1983). The Guinness Book of Animal Facts & Feats. Sterling Publishing Co. ISBN 978-0-85112-235-9.
  47. ^ [1]
  48. ^ [2]
  49. ^ Rogers, Lyn. "North American Bear Center — Meet Our Bears > Ted's Page". Bear.org. http://www.bear.org/website/the-nabc/meet-our-bears/teds-page.html. Retrieved 11 February 2011.
  50. ^ "North American Bear Center — Meet Our Bears > Honey's Page". Bear.org. http://www.bear.org/website/the-nabc/meet-our-bears/honeys-page.html. Retrieved 11 February 2011.
  51. ^ Ursus thibetanus (G. Cuvier, 1823)[dead link]
  52. ^ a b c d Stephen Herrero (2002). Bear Attacks: Their Causes and Avoidance. Globe Pequot. ISBN 978-1-58574-557-9. http://books.google.com/books?id=gFlz6UKGqrcC. Retrieved 16 May 2012.
  53. ^ a b c d e Macdonald, D.W. (2006) The Encyclopedia of Mammals. Oxford University Press, Oxford ISBN 0199567999.
  54. ^ a b c Nowak, R.M. (1991) Walker's Mammals of the World. The Johns Hopkins University Press, Baltimore and London.
  55. ^ "''Urban Black Bears "Live Fast, Die Young"'', ScienceDaily (Oct. 1, 2008)". Sciencedaily.com. 2008-10-01. http://www.sciencedaily.com/releases/2008/09/080930135301.htm. Retrieved 2011-02-21.
  56. ^ Man Says Bear Saved Him From Mountain Lion Attack In Butte County « CBS Sacramento. Sacramento.cbslocal.com (2012-03-29). Retrieved on 2012-12-21.
  57. ^ "Hibernation". Bear.org. 2004-07-19. http://www.bear.org/website/bear-pages/black-bear/black-bear-facts/hibernation.html. Retrieved 2011-02-19.
  58. ^ "Yellowstone National Park – Denning and Hibernation Behavior (U.S. National Park Service)". Nps.gov. 2008-04-15. http://www.nps.gov/yell/naturescience/denning.htm. Retrieved 2011-02-19.
  59. ^ Goals, Ben. "American Black Bear Teaching Guide". Cornell. http://www.entomology.cornell.edu/public/IthacaCampus/ExtOutreach/Outreach/Resources/pageBodySections/05/pageBodySections/00/text_files/file7/Golas_TeacherResourceGuide.pdf. Retrieved 22 November 2009.
  60. ^ Bennett, Bobby (Spring 2006). "Hibernation of the Black and Brown Bear". Mountain Research Station. http://culter.colorado.edu:1030/~kittel/WEcol_Projects06/BearsHiberntn_BBennett.ppt. Retrieved 22 November 2009.
  61. ^ a b c d Becker, Jim (1993). "The Black Bear". Spanning the Gap – The newsletter of Delaware Water Gap National Recreation Area. http://www.nps.gov/dewa/naturescience/upload/cmsstgBEAR.pdf. Retrieved 2011-02-21.
  62. ^ American Black Bear Fact Sheet – National Zoo| FONZ. Nationalzoo.si.edu. Retrieved on 2011-09-15.
  63. ^ Bourton, Jody (2009-11-06). "Spirit bears become 'invisible' by Jody Bourton, Earth News reporter". BBC News. http://news.bbc.co.uk/earth/hi/earth_news/newsid_8344000/8344367.stm. Retrieved 2011-02-21.
  64. ^ black bear. Pvci.org. Retrieved on 2012-12-20.
  65. ^ Smith, R. 1983. Mule deer reproduction and survival in the LaSal Mountains of Utah, 1983. M.S. thesis, Utah State University, Logan.
  66. ^ a b Mathews, N. E.; Porter, W. F (1988). "Black bear predation on white-tailed deer neonates in the central Adirondacks". Canadian Journal of Zoology 66 (5): 1241–1242. doi:10.1139/z88-179.
  67. ^ Ozoga, J. J., and Clute, R.K. (1988). "Mortality rates of marked and unmarked fawns". Journal of Wildlife Management 52 (3): 549–551. doi:10.2307/3801608. JSTOR 10.2307/3801608.
  68. ^ Schlegal, M. (1976). "Factor affecting calf elk survival in north central Idaho". Western Association of State Game and Fish Commission 56: 342–355.
  69. ^ Franzmann, Albert W.; Schwartz, Charles C.; Peterson, Rolf O. (1980). "Moose calf mortality in summer at Kenai Peninsula, Alaska". Journal of Wildlife Management 44 (3): 764–768. doi:10.2307/3808038. JSTOR 10.2307/3808038.
  70. ^ Behrend, D.F.; Sage, R.W.; Jr (1974). "Unusual feeding behavior by black bears". Journal of Wildlife Management 38 (3): 570. doi:10.2307/3800894.
  71. ^ Svoboda, Nathan J.; Belant, Jerrold L., Beyer, Dean E., Duquette, Jared F., Stricker, Heather K., Albright, Craig A. (2011). "American black bear predation of an adult white-tailed deer". Ursus 22 (1): 91–94.. doi:10.2192/URSUS-D-10-00024.1.
  72. ^ Austin, M. A., Obbard, M. E. and Kolenosky, G. B. (1994). "Evidence for a black bear, Ursus americanus, killing an adult moose, Alces alces". The Canadian Field Naturalist 108: 236–238.
  73. ^ a b Roosevelt, Theodore (2007). Hunting the Grisly and Other Sketches. ReadHowYouWant.com. pp. 33–. ISBN 978-1-4250-7306-0. http://books.google.com/books?id=rXzr9PaITD4C&pg=PT33. Retrieved 25 June 2012.
  74. ^ a b "Bear Predation — Description". Texnat.tamu.edu. Archived from the original on 2006-10-17. http://web.archive.org/web/20061017112052/http://texnat.tamu.edu/ranchref/predator/bears/t-bears.htm. Retrieved 2008-11-24.
  75. ^ Kerry A. Gunther and Mark J. Biel. "Evidence of grizzly bear predation on a black bear in Hayden Valley" (PDF). http://www.greateryellowstonescience.org/files/pdf/ys5-gunther.pdf. Retrieved 2011-02-21.
  76. ^ "Probable Grizzly Bear Predation On An American Black Bear In Yellowstone National Park" (PDF). http://www.nps.gov/yell/naturescience/upload/predation.pdf. Retrieved 2011-02-21.
  77. ^ COSEWIC. Canadian Wildlife Service (2002) (PDF). Assessment and Update Status Report on the Grizzly Bear (Ursus arctos). Environment Canada. http://dsp-psd.pwgsc.gc.ca/Collection/CW69-14-166-2002E.pdf. Retrieved 2007-04-08.
  78. ^ Murphy, Kerry M.; Felzien, Gregory S.; Hornocker, Maurice G. and Ruth, Toni K. (1998). "Encounter Competition between Bears and Cougars: Some Ecological Implications". Ursus 10: 55. JSTOR 3873109.
  79. ^ Cremony, Life Among the Apaches, 1951, 225–26, a reprint of the 1868 edition ISBN 1434408361
  80. ^ Turnbo, S. C. A Fight to a Finish Between a Bear and Panther. Thelibrary.org. Retrieved on 2012-12-19.
  81. ^ Stone 1975, pp. 137–39
  82. ^ Bradley 1940, p. 116
  83. ^ Mech, L. David and Boitani, Luigi (2001). Wolves: Behaviour, Ecology and Conservation. Chicago: University of Chicago Press. p. 448. ISBN 0-226-51696-2.
  84. ^ "''In Yellowstone, It's a Carnivore Competition'', Washington Post, May 19, 2003". Ecoearth.info. 2003-05-19. http://www.ecoearth.info/shared/reader/welcome.aspx?linkid=22714&keybold=predator%20AND%20%20coyote. Retrieved 2011-02-21.
  85. ^ Crocodiles: Proceedings of the 6th Working Meeting of the Crocodile Specialist Group of the Species Survival Commission of the International Union for Conservation of Nature and Natural Resources (IUCN publication. New series). IUCN (1986), ISBN 2880329051.
  86. ^ Key West Florida Attractions | Alligator Exhibit. Key West Aquarium (2012-11-30). Retrieved on 2012-12-20.
  87. ^ Lippincott, Joshua B. Folklore and Legends of the North American Indian, Abela Publishing Ltd, 2009, ISBN 0-9560584-6-9
  88. ^ Bastian, Dawn Elaine and Mitchell, Judy K.. Handbook of Native American mythology, ABC-CLIO, 2004, ISBN 1-85109-533-0
  89. ^ Averkieva, Julia and Sherman, Mark, Kwakiutl String Figures, UBC Press, 1992, ISBN 0-7748-0432-7
  90. ^ Clark, LaVerne Harrell. They sang for horses: the impact of the horse on Navajo & Apache folklore, University Press of Colorado, 2001, ISBN 0-87081-496-6
  91. ^ "Teddy Bears". Library Of Congress. Archived from the original on 17 December 2007. http://www.americaslibrary.gov/cgi-bin/page.cgi/aa/presidents/roosevelt/bears_1. Retrieved 2007-12-10.
  92. ^ A Bear Named Winnie CBC.ca TV (2004)
  93. ^ "Zoogoer Nov/Dec 2002 Sidebar: Smokey Comes to Washington by Alex Hawes". Nationalzoo.si.edu. http://nationalzoo.si.edu/Publications/ZooGoer/2002/6/smokey.cfm. Retrieved 2011-02-21.
  94. ^ a b Kruuk, Hans. Hunter and hunted: relationships between carnivores and people, Cambridge University Press, 2002, ISBN 0-521-89109-4
  95. ^ a b Shockey, Jim (April 1, 1999). "Black Bears—Simple Fools or Cunning Killers". Outdoor Life. http://www.outdoorlife.com/article/Hunting/Black-Bears--Simple-Fools-or-Cunning-Killers. Retrieved 2008-10-20.
  96. ^ "Black Bear Kills Texas Woman, Canadian Man". Los Angeles Times. 17 August 1997. http://articles.latimes.com/1997/aug/17/news/mn-23311. Retrieved 25 December 2010.
  97. ^ Black Bear Attacks Dog. Wjhg.com. Retrieved on 2012-12-21.
  98. ^ Frequently Asked Questions Regarding Bears – Denali National Park & Preserve. Nps.gov. Retrieved on 2012-12-21.
  99. ^ Encountering Black Bears in Arkansas. University of Arkansas uaex.edu
  100. ^ Partington, Charles Frederick (1835) The British Cyclopædia of Natural History: Combining a Scientific Classification of Animals, Plants, and Minerals, Charles Frederick Partington, Vol. 1, Orr & Smith.
  101. ^ Brown 1993, Ch. "Use of Bears and Bear Parts".
  102. ^ Sciarrino, Robert (2010-07-21). "Black bear hunt gets final approval from Department of Environmental Protection head". NJ.com. http://www.nj.com/news/index.ssf/2010/07/nj_environmental_comissioner_g.html. Retrieved 2011-02-19.
  103. ^ a b "Bear Necessity? Public Approves of Bear Hunt". Publicmind.fdu.edu. http://publicmind.fdu.edu/1011bears/. Retrieved 2011-02-19.
  104. ^ Schuh, Dwight R. Bowhunter's Encyclopedia, Stackpole Books, 1992, ISBN 0-8117-2412-3
  105. ^ Roosevelt, Theodore. Hunting Trips of a Ranchman: Hunting Trips on the Prairie and in the Mountains, Adamant Media Corporation, ISBN 1-4212-6647-4
  106. ^ Smith, Richard P. Black Bear Hunting, Stackpole Books, 2007 ISBN 0-8117-0269-3

Bibliography

Brown, Gary (1993). The great bear almanac. Lyons & Burford. ISBN 978-1-55821-210-7. http://books.google.com/books?id=L0ggAQAAIAAJ.

Further reading

External links