American Black Bear facts for kids
Quick facts for kids American Black BearTemporal range: early Pleistocene
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| American Black Bear | |
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U. americanus
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| Ursus americanus Pallas, 1780
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The American black bear (scientific name Ursus americanus) is North America's smallest and most common species of bear. Black bears are omnivores (eating both meat and plants). Black bears usually live in forested areas, but do leave forests in search of food. Sometimes they become attracted to human activity due to a lack of food. The American black bear is listed by the IUCN as Least Concern, because the species has a large global population estimated to be twice that of all other bear species combined. In the past century, only 37 people have been killed by these animals.
American black bears usually hibernate during winter. During this time, the black bear's metabolism and heart rate both decrease in relation to one another. In fact, during hibernation, an American black bear's heart can stop for twenty seconds. The body temperature of black bears also decreases to 31 °C (88 °F) during hibernation. When hibernation is over, the black bear's body temperature returns to normal.
Contents
Subspecies
Sixteen subspecies are traditionally recognized; however, a recent genetic study does not support designating some of these, such as the Florida black bear, as distinct subspecies. Listed alphabetically according to subspecific name:
| Image | Scientific name | Common name | Distribution | Description |
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Ursus americanus altifrontalis | Olympic black bear | the Pacific Northwest coast from central British Columbia through northern California and inland to the tip of northern Idaho and British Columbia | |
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Ursus americanus amblyceps | New Mexico black bear | Colorado, New Mexico, western Texas and the eastern half of Arizona into northern Mexico and southeastern Utah | |
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Ursus americanus americanus | Eastern black bear | Eastern Montana to the Atlantic coast, from Alaska south and east through Canada to Maine and south to Texas. Thought to be increasing in some regions. | Common to Eastern Canada and the eastern U.S. wherever suitable habitat is found. A large-bodied subspecies; almost all specimens have black fur. May very rarely sport a white blaze on the chest. |
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Ursus americanus californiensis | California black bear | the mountain ranges of southern California, north through the Central Valley to southern Oregon | Able to live in varied climates: found in temperate rain forest in the north and chaparral shrubland in the south. Small numbers may feature cinnamon-colored fur. |
| Ursus americanus carlottae | Haida Gwaii black bear or Queen Charlotte Islands black bear | Haida Gwaii (formerly the Queen Charlotte Islands) and Alaska | Generally larger than its mainland counterparts with a large skull and molars and found only in a black color phase. | |
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Ursus americanus cinnamomum | Cinnamon bear | Colorado, Idaho, western Montana and Wyoming, eastern Washington and Oregon and northeastern Utah | Has brown or reddish-brown fur, reminiscent of cinnamon. |
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Ursus americanus emmonsii | Glacier bear or blue bear | Southeastern Alaska | Distinguished by its fur being silvery-gray with a blue luster found mostly on its flanks. |
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Ursus americanus eremicus | East Mexican black bear | Northeastern Mexico and U.S. borderlands with Texas. | Most often found in Big Bend National Park and the desert border with Mexico. Numbers unknown in Mexico but are presumed to be very low. Critically Endangered. |
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Ursus americanus floridanus | Florida black bear | Florida, southern Georgia, Alabama and Mississippi (except the southern region) | Has a light brown nose and shiny black fur. A white blaze on the chest is common in this subspecies. An average male weighs 136 kg (300 lb). |
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Ursus americanus hamiltoni | Newfoundland black bear | Newfoundland | Generally bigger than its mainland relatives, ranging in size from 90 to 270 kg (200 to 600 lb) and averaging 135 kg (298 lb). It has one of the longest hibernation periods of any bear in North America. Known to favor foraging in fields of Vaccinium species. |
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Ursus americanus kermodei | Kermode bear or island white bear, spirit bear | the central coast of British Columbia | Approximately 10% of the population of this subspecies have white or cream-colored coats due to a recessive gene. The other 90% appear as normal-colored black bears. |
| Ursus americanus luteolus | Louisiana black bear | Eastern Texas, Louisiana and southern Mississippi. The validity of this subspecies has been repeatedly disputed. | Has relatively long, narrow and flat skull and proportionately large molars. Prefers hardwood bottom forests and bayous as habitat. | |
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Ursus americanus machetes | West Mexican black bear | north-central Mexico | |
| Ursus americanus perniger | Kenai black bear | the Kenai Peninsula, Alaska | Considered an "Apparently Secure Subspecies" by NatureServe. | |
| Ursus americanus pugnax | Dall Island black bear | Dall Island in the Alexander Archipelago, Alaska | ||
| Ursus americanus vancouveri | Vancouver Island black bear | Vancouver Island, British Columbia | Darker and slightly bigger than the other five subspecies found in British Columbia; it is most common in the north, but appears occasionally in the southern parts of Vancouver Island. |
Distribution and habitat
Historically, American black bears occupied the majority of North America's forested regions. They are often found in areas with relatively inaccessible terrain, thick understory vegetation and large quantities of edible material (especially masts).
In parts of northeastern Canada, especially Labrador, American black bears have adapted exclusively to semi-open areas that are more typical habitat in North America for brown bears (likely due to the absence there of brown and polar bears, as well as other large carnivore species).
Description
Black bears have narrow muzzles and large jaw hinges. Females tend to have slenderer and more pointed faces than males.
Their claws are typically black or grayish-brown.
The hind legs are relatively longer than those of Asian black bears. The typically small tail is 7.7–17.7 cm (3.0–7.0 in) long. The ears are small and rounded and are set well back on the head.
American black bears have great physical strength; a bear weighing 120 pounds (54 kg) was observed turning flat rocks weighing 310 to 325 pounds (141 to 147 kg) by flipping them over with a single foreleg. They move in a rhythmic, sure-footed way and can run at speeds of 25 to 30 miles per hour (40 to 48 km/h).
Size
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. Although they are the smallest bear species in North America, large males exceed the size of other bear species, except the brown bear and the polar bear.
Adult males typically weigh between 57–250 kg (126–551 lb), while females weigh 33% less at 41–170 kg (90–375 lb).
The biggest wild American black bear ever recorded was a male from New Brunswick, shot in November 1972, that weighed 409 kg (902 lb) after it had been dressed, meaning it weighed an estimated 500 kg (1,100 lb) in life and measured 2.41 m (7 ft 11 in) long. The North American Bear Center, located in Ely, Minnesota, is home to the world's largest captive male and female American black bears. Ted, the male, weighed 431–453.5 kg (950–1,000 lb) in the fall of 2006. Honey, the female, weighed 219.6 kg (484 lb) in the fall of 2007.
Pelage
The fur is soft, with dense underfur and long, coarse, thick guard hairs. The fur is not as shaggy or coarse as that of brown bears. American black bear skins can be distinguished from those of Asian black bears by the lack of a white blaze on the chest and hairier footpads.
Despite their name, black bears show a great deal of color variation. Individual coat colors can range from white, blonde, cinnamon, light brown or dark chocolate brown to jet black, with many intermediate variations existing.
Behavior
American black bears have eyesight and hearing comparable to that of humans. They are also capable of rapidly learning to distinguish different shapes such as small triangles, circles and squares.
Their keenest sense is smell, which is about seven times more sensitive than a domestic dog's. They are excellent and strong swimmers, swimming for pleasure and to feed (largely on fish). They regularly climb trees to feed, escape enemies and hibernate.
American black bears have fine motor skills, being capable of opening screw-top jars and manipulating door latches.
They may be active at any time of the day or night, although they mainly forage by night.
Sounds
Bears may communicate with various vocal and non-vocal sounds. Tongue-clicking and grunting are the most common sounds. When at ease, they produce a loud rumbling hum. During times of fear or nervousness, bears may moan, huff or blow air. Warning sounds include jaw-clicking and lip-popping. In aggressive interactions, black bears produce guttural pulsing calls that may sound like growling. Cubs squeal, bawl or scream when anxious and make a motor-like humming sound when comfortable or nursing. 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.
Reproduction and development
Females usually produce their first litter at the age of 3 to 5 years. The breeding period lasts for two to three months. Litter size is between one and six cubs, typically two or three. At birth, cubs weigh 280–450 g (0.62–0.99 lb) and measure 20.5 cm (8.1 in) in length. They are born with fine, gray, down-like hair and their hind quarters are underdeveloped. They typically open their eyes after 28–40 days and begin walking after 5 weeks. Cubs are dependent on their mother's milk for 30 weeks and will reach independence at 16–18 months. At 6 weeks, they attain 900 g (2.0 lb), by 8 weeks they reach 2.5 kg (5.5 lb) and by 6 months they weigh 18 to 27 kg (40 to 60 lb). They reach sexual maturity at 3 years and attain their full growth at 5 years.
Longevity
The average lifespan in the wild is 18 years, though it is quite possible for wild individuals to survive for more than 23 years. The record age of a wild individual was 39 years, while that in captivity was 44 years.
Predators
With the exception of the rare confrontation with an adult brown bear or a gray wolf pack, adult black bears are not usually subject to natural predation. However, as evidenced by scats with fur inside of them and the recently discovered carcass of an adult sow with puncture marks in the skull, black bears may occasionally fall prey to jaguars in the southern parts of their range. In such scenarios, the big cat would have the advantage. Cubs tend to be more vulnerable to predation than adults, with known predators including bobcats, coyotes, cougars, gray wolves, brown bears and other bears of their own species.
Hibernation
The bears enter their dens in October and November, although in the southernmost areas of their range (i.e. Florida, Mexico, the southeastern United States), only pregnant females and mothers with yearling cubs will enter hibernation. Prior to that time, they can put on up to 14 kg (30 lb) of body fat to get them through the several months during which they fast. Hibernation typically lasts 3–8 months, depending on regional climate.
Hibernating bears spend their time in hollowed-out dens in tree cavities, under logs or rocks, in banks, caves, or culverts, and in shallow depressions. Although naturally-made dens are occasionally used, most dens are dug out by the bear. During their time in hibernation, an American black bear's heart rate drops from 40 to 50 beats per minute to 8 beats per minute, and the metabolic rate can drop to a quarter of the bear's (nonhibernating) basal metabolic rate. Their circadian rhythm stays intact during hibernation. This allows the bear to sense the changes in the day based on the ambient temperature caused by the sun's position in the sky. The bear keeping track of the changing days allows it to awaken from hibernation at the appropriate time of year to conserve as much energy as possible.
The time that American black bears emerge from hibernation varies. Factors affecting this include temperature, flooding, and hunger. In southern areas, they may wake up in midwinter. Further north, they may not be seen until late March, April, or even early May. Altitude also has an effect. Bears at lower altitudes tend to emerge earlier. Mature males tend to come out earliest, followed by immature males and females, and lastly mothers with cubs. Mothers with yearling cubs are seen before those with newborns.
Dietary habits
Up to 85% of their diet consists of vegetation, though they tend to dig less than brown bears, eating far fewer roots, bulbs, corms and tubers than the latter species. When initially emerging from hibernation, they will seek to feed on carrion from winter-killed animals and newborn ungulates. As the spring temperature warms, American black bears seek new shoots of many plant species, especially new grasses, wetland plants and forbs. Young shoots and buds from trees and shrubs during the spring period are important to 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. During summer, the diet largely comprises fruits, especially berries and soft masts such as buds and drupes.
Favored masts such as hazelnuts, oak acorns and whitebark pine nuts may be consumed by the hundreds each day by a single bear during the fall. During the fall period, bears may also habitually raid the nut caches of tree squirrels. Also extremely important in fall are berries such as huckleberries and buffalo berries.
The majority of the diet consists of insects, such as bees, yellow jackets, ants, beetles and their larvae. American 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 it with their paws. Once the hive is breached, the bears will scrape the honeycombs together with their paws and eat them, regardless of stings from the bees. 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.
Although American black bears do not often engage in active predation of other large animals for much of the year, the species will regularly prey on mule and white-tailed deer fawns in spring, given the opportunity.
They will readily consume eggs and nestlings of various birds and can easily access many tree nests, even the huge nests of bald eagles. Bears have been reported stealing deer and other game from human hunters.
Images for kids
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American black bear head, Cincinnati Zoo and Botanical Garden
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A possible American black bear-grizzly bear hybrid in the Yukon Territory, Canada
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Harry Colebourn and Winnipeg, the bear from which Winnie-the-Pooh got his name
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A tame American black bear on a leash
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The incidence of bear attacks in parks and campgrounds declined after the introduction of bear-resistant garbage cans and other reforms.
See also
In Spanish: Ursus americanus para niños
