American Black Bear Description

The American black bear (Ursus Americanus) is a medium-sized bear native North America. This is the smallest and most abundant species distributed continent bears. Black bears are omnivores and their diet is very different depending on the season and location. They usually live in forested areas most, but do leave forests in search of food. Sometimes they become attracted to human communities because of the availability of food directly. The American black bear is the most common species of bear in the world. It is listed by the IUCN as Least Concern, due to a wide distribution of species 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 bear species are not considered globally Modern threatened by the IUCN. American black bears often mark trees use their teeth and claws as a form of communication with other bears, the general behavior of many species of bears.

Although they all live in North America, 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. Second American and Asian black bears are considered sister taxa, and are more closely related to each other than other species of bear. Apparently, the Sun Bear also relatively recent split of this lineage.

A small bear called Ursus abstrusus primitive is the oldest North American fossil member of the genus Ursus, the date to 4.95 mya. This suggests that U. abstrusus probably the direct ancestor of the American black bear, which evolved in North America. Although Wolverton and Lyman still consider U. vitabilis an "apparent precursor to modern black bears", has also been placed in the U. Americanus.

Ancestors of American black bears and Asian black bears diverged from sun bears 4.58 mya. The American black bear then broke away from the Asian black bear 4.08 mya. Fossils of the earliest American black bear, which is located in Port Kennedy, Pennsylvania, much like the Asian species, though later specimens grew to sizes comparable to a bear. From the Holocene to present, American black bears seem to have decreased in size, but this has been disputed because of problems with fossil specimens dating.

The American black bear lived during the same period as short-faced bear (Arctodus simus and A. pristinus) and Florida bespectacled bear (Tremarctos floridanus). This Tremarctine bears evolved from bears that have moved from Asia to North America 7-8 ma. Short-faced bears are thought to have very carnivorous and bespectacled Florida bear more herbivorous, while the American black bears remain arboreal omnivores, like their Asian ancestors.

Behavior of black bears generalists enable it to exploit a wider variety of food and was given as the reason why these three genera, private safe climate and vegetative changes through and last ice age while the other more specialized North American predators from extinction. However, both the safe Tremarctos Arctodus and other ice age some. After Ursids prehistoric extinct during recent glacial period 10,000 years ago, black bears may bear only present in large part to the advent of the North American brown bear over the continent.

Historically, black bears occupy most of the forest areas in North America. Today, they are mainly limited to rarely settled, forested areas.

Black bears currently inhabit much of their Canadian native range, although they do not occur in agricultural land south of Alberta, Saskatchewan, and Manitoba. They have been extinct in Prince Edward Island since 1937. Total Canadian black bear population is between 396,000 and 476,000, 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 areas show stable populations of black bears during the past decade.

Current range of black bears in the United States is constant throughout most of the sea (down the Appalachian Mountains almost continuously into Virginia and West Virginia), the northern midwest, the Rocky mountain region, the west coast and Alaska. But it is becoming increasingly shattered or not in other areas. Despite this, black bears in the area seem to have expanded their coverage over the past decade. Review taken from 35 states in the early 1990s showed that black bears are good stable or increased, except Idaho and New Mexico. Overall population of black bears in the United States has been estimated range between 339,000 and 465,000, though this excludes populations from Alaska, Idaho, South Dakota, Texas, and Wyoming, whose population size is unknown.

In 1993, known Mexican black bear populations in four areas, though knowledge about the distribution of the rural areas have not been updated since 1959. Mexico is the only country where black bears are classified as endangered.

Throughout their range, habitat favored by American Black Bears have some common characteristics. They are often found in areas with a relative field is inaccessible, dense understory vegetation and a large number of edible material (especially the columns). Adaptation of forests and dense vegetation in this species may initially occur because black bears have grown with the larger, more aggressive species of bear, extinct short-faced bears, and brown bears are still alive, that the more open habitat monopolized. Although found in the largest amounts in the wild, disturbed areas and rural areas, black bears can adapt to survive in some numbers on the outskirts of the county for their food contains easily assessible and some vegetative coverage.

In most of the United States border, when black bears are usually found in mountainous areas so plants, from 400 to 3,000 m (9,800 ft to 1,300). For bears that live in the southwestern United States and Mexico, habitat usually consists of perpendicular chaparral and pinyon juniper forest. In this region, sometimes the bear moved to a more open area to feed on prickly pear cactus. At least two different major habitat types that are occupied in Southeast USA.

Black bears in the southern Appalachian Mountains took place in most of the oak-hickory and mesophytic forest mix. In southeastern coastal areas (like Florida or Louisiana), bears inhabit Flatwoods mixture, bay, and swamp wood page. In the northeastern part of the range (U.S. and Canada), the main habitat consists of hardwood forest canopy such as beech, maple, and birch, and conifer species. Corn crop and oak-hickory mast is also common food source in some parts of the northeast, small, thick swamps provide excellent protection protection especially in the perpendicular white cedar. Along the Pacific coast, redwood, fir Sitka, and hemlocks dominate the overstory cover. In the northern forest types are important for the early succession of black bears, such as field brushes, wet and dry meadows, high tides, riparian areas and various post-timber-producing species.

Pine-fir forests dominate much coverage of black bears in the Rockies. District nonforested important here is wet meadows, riparian areas, avalanches chutes, roadside, burns, sidehill parks, and subalpine ridgetops. In areas where human development is relatively low, such as stretching from Canada and Alaska, American black bears tend to be found more regularly in low-lying regions. In the northeastern part of Canada, especially Labrador, black bears have been adapted exclusively for the semi-open areas that are more typical habitat in North America for the brown bear (probably here because of the brown bear and polar as well as other large carnivore species).

American black bear skull broad, with a narrow muzzle and large jaw hinges. In Virginia, a total length of adult bear skull found on average 262-317 mm (10.3 to 12.5 in). Across the region, the greatest length of skull measured 23.5 to 35 species have been reported cm (9.3 to 14 in). Women tend to have more slender and pointed faces than males. Their claws are usually black or dun. Claws are short and rounded, thick at the base and taper to a point. Claws from the back and front foot well is almost the same length, although foreclaws tend sharper curve. The claws large enough relative species, with long hind legs 13.7 to 22.5 cm (5.4 to 8.9 in), which proportionly larger than other species of bear secondary but much smaller than the large adult brown paws and bear especially poles. Soles of the feet are black or brown, and bare, rough and very wrinkled. Relative hind legs longer than the Asian black bear. Vestigal tail is usually 4.8 inches (12 cm) long. Ears small and rounded, and well set back on the head.

Black bears are highly skilled, capable of opening screw-top jar and manipulating door hooks. They also have great physical strength. Even bear cubs have been known to deliver flat-shaped rocks weighing 310-325 pounds (140-147 kg) with their reverse singles on the front foot. They move in a way, rhythmic surefooted and can run with the speed of 25-30 mph (40-50 km / h). Black bears have good eyesight, and has been shown experimentally to be able to learn visual discrimination tasks according to color faster than chimpanzees and as fast as dogs. They can also learn quickly to distinguish various forms, such as small round, circle and squares.