Black bear

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Black Bear Fact File

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<ul><li> 1. BLACK BEAR UNIVERSITY OF SARGODHA SARGODHA </li></ul><p> 2. CONTENTS Introduction Basic Facts About Black Bears Fast Facts Range Map Form and Function Evolution and Classification Asian Black Bear American Black Bear Black Bears Fun Fact Save Black Bears References 3. INTRODUCTION A medium-sized forest-dwelling bear with blackish fur and a paler face, found in North America and eastern Asia. Although it has a reputation for being fierce and aggressive, the bear is more often a peaceful and solitary creature. The largest of the carnivores-animals classified in an order of flesh-eating land mammals-and the least carnivorous, or flesh-eating. It is closely related to the dog and the raccoon. Black bears are North America's most familiar and common bears. They typically live in forests and are excellent tree climbers, but are also found in mountains and swamps. Despite their name, black bears can be blue-gray or blue-black, brown, cinnamon, or even (very rarely) white. Black bears are very opportunistic eaters. Most of their diet consists of grasses, roots, berries, and insects. They will also eat fish and mammalsincluding carrionand easily develop a taste for human foods and garbage. Bears that become habituated to human food at campsites, cabins, or rural homes can become dangerous and are often killed thus the frequent reminder: Please don't feed the bears! Solitary animals, black bears roam large territories, though they do not protect them from other bears. Males might wander a 15- to 80-square-mile (39- to 207-square- kilometer) home range. When winter arrives, black bears spend the season dormant in their dens, feeding on body fat they have built up by eating ravenously all summer and fall. They make their dens in caves, burrows, brush piles, or other sheltered spotssometimes even in tree holes high above the ground. Black bears den for various lengths of time governed by the diverse climates in which they live, from Canada to northern Mexico. Female black bears give birth to two or three blind, helpless cubs in mid-winter and nurse them in the den until spring, when all emerge in search of food. The cubs will stay with their very protective mother for about two years. 4. BASIC FACTS ABOUT BLACK BEARS Black bears have short, non-retractable claws that give them an excellent tree-climbing ability. Black bear fur Fur is usually a uniform color except for a brown muzzle and light markings that sometimes appear on their chests. Eastern populations are usually black in color while western populations often show brown, cinnamon, and blond coloration in addition to black. Black bears with white-bluish fur are known as Kermode (glacier) bears and these unique color phases are only found in coastal British Columbia, Canada. Diet American black bears are omnivorous: plants, fruits, nuts, insects, honey, salmon, small mammals and carrion. In northern regions, they eat spawning salmon. Black bears will also occasionally kill young deer or moose calves. Population 5. It is estimated that there are at least 600,000 black bears in North America. In the United States, there are estimated to be over 300,000 individuals. However, the Louisiana black bear (Ursus americanus luteolu) and Florida black bear (Ursus americanus floridanus) are threatened subspecies with small populations (see Legal Status/Protection). Behavior Black bears are extremely adaptable and show a great variation in habitat types, though they are primarily found in forested areas with thick ground vegetation and an abundance of fruits, nuts, and vegetation. In the northern areas, they can be found in the tundra, and they will sometimes forage in fields or meadows. Black bears tend to be solitary animals, with the exception of mothers and cubs. The bears usually forage alone, but will tolerate each other and forage in groups if there is an abundance of food in one area. Most black bears hibernate depending on local weather conditions and availability of food during the winter months. In regions where there is a consistent food supply and warmer weather throughout the winter, bears may not hibernate at all or do so for a very brief time. Females give birth and usually remain denned throughout the winter, but males and females without young may leave their dens from time to time during winter months. Reproduction Mating Season: Summer. Gestation: 63-70 days. Litter Size: 1-6 cubs; 2 cubs are most common. Cubs remain with the mother for a year and a half or more, even though they are weaned at 6-8 months of age. Females only reproduce every second year (or more). Should the young die for some reason, the female may reproduce again after only one year. 6. FAST FACTS Type: Mammal Diet: Omnivore Average life span in the wild: 20 years Size: 5 to 6 ft (1.5 to 1.8 m) long Weight: 200 to 600 lbs (90 to 270 kg) Group name: Sleuth or Sloth Did you know? Black bears are not true hibernators. During their winter dormant period, though, they do not eat, drink, urinate, or defecate, but may wake up if disturbed. Size relative to a 6-ft (2-m) man: RANGE MAP The American black bear is distributed throughout North America, from Canada to Mexico and in at least 40 states in the U.S. They historically occupied nearly all of the forested regions of North America, but in the U.S. they are now restricted to the forested areas less densely occupied by humans. 7. In Canada, black bears still inhabit most of their historic range except for the intensively farmed areas of the central plains. In Mexico, black bears were thought to have inhabited the mountainous regions of the northern states but are now limited to a few remnant populations. Form and function In most species, the male is larger than the female. Unlike cats and canids such as dogs and wolves, bears walk in plantigrade fashion (on the soles of their feet with the heels touching the ground). Each foot has five digits ending in large nonretractile claws that are sometimes adapted for digging, as in the Asian sloth bear. The claws on the front feet are usually better developed than those on the rear, and they are especially adapted for digging out small rodents or nutritious plant roots. The feet generally have hairless soles, but those of the polar bear are covered with hair, enabling the animal to walk on ice with a firm footing. Bears lack a clavicle but have a baculum (penis bone). Their lips are protrusible and mobile. All have a short stubby tail. 8. Bears have an elongate skull that is especially heavy in the back portion, and their jaws are controlled at the hinge by a powerful set of muscles. The teeth of the omnivorous bears are unspecialized. The first three premolars are usually either missing or extremely small. Except for variability as to the presence of premolars, the ursid dental formula is that of the Carnivora generally, but the sloth bear lacks one pair of upper incisors. The shearing teeth (carnassials) are poorly developed, and the molars have broad, flat crowns. Evolution and classification The bear family is the most recently evolved lineage of carnivores. Studies of mitochondrial DNA (mtDNA) performed during the early 21st century showed that black bears, brown bears, and polar bears diverged from one another some 45 million years ago, early in the Pliocene Epoch (5.3 million to 2.6 million years ago). There has been much disagreement over the classification of giant pandas. Mammalogists have placed giant pandas with bears (family Ursidae), with raccoons (Procyonidae), or with the red, or lesser, panda (Ailurus fulgens) in Ailuridae. However, molecular analyses performed during the 1990s have revealed a close evolutionary relationship between giant pandas and bears. Kingdom Animalia Phylum Chordata Class Mammalia Order Carnivora Family Ursidae (bears) 8 species in 5 genera found in North America, South America, Europe, and Asia, not including 1 African species (Ursus crowtheri) of the Atlas Mountains, driven to extinction in the 19th century. Genus Ursus (American black bear, Asiatic black bear, polar bear, and brown bear, including the grizzly bear) 4 species of North America, Asia, and Europe. Genus Ailuropoda (giant panda) 1 species of central China. Genus Helarctos (sun bear) 1 species of Southeast Asia. Genus Melursus (sloth bear) 1 species of the Indian subcontinent. 9. Genus Tremarctos (spectacled bear) 1 species of the Andes Mountains of South America. There are two species of black bears belonging to genus ursus .i.e. Asiatic Black Bear and American Black Bear. Asiatic black bear: bear with a black coat living in central and eastern Asia. American black bear: brown to black North American bear; smaller and less ferocious than the brown bear. Asian black bear (Ursus thibetanus) The Asian black bear (Ursus thibetanus), also known as the moon bear or white-chested bear, is a medium-sized species of bear, largely adapted for arboreal life, seen across much of the Himalayas and the northern parts of the Indian Subcontinent, Korea, northeastern China, the Russian far east and the Honsh and Shikoku islands of Japan. It is classed by the IUCN as a vulnerable species, mostly due to deforestation and active hunting for its body parts. The species is morphologically very similar to some prehistoric bears, and is thought by some scientists to be the ancestor of other extant bear species. Though largely herbivorous, Asian black bears can be very aggressive toward humans, and have frequently attacked people without provocation. The species was described by Rudyard Kipling as "the most bizarre of the ursine species." .and made by Quinton Tarlton. Ancestral and sister taxa Biologically and morphologically, Asian black bears represent the beginning of the arboreal specialisations attained by sloth bears and sun bears. Asian black bears have karotypes nearly identical to those of the five other ursine bears, and, as is typical in the genus, they have 74 chromosomes. From an evolutionary perspective, Asian black bears are the least changed of Old World bears, with certain scientists arguing that it is likely that all other lineages of ursine bear stem from this species. Asian black bears are close relatives to American black bears, with which they share a European common ancestor; the two species are thought to have diverged 3 million years ago, though genetic evidence is inconclusive. Both American and Asiatic species are considered sister taxa, 10. and are more closely related to each other than other species of bear. The earliest American black bear fossils, which were located in Port Kennedy, Pennsylvania, greatly resemble the Asiatic species. The first mtDNA study undertaken on Asian black bears suggested that the species arose after the American black bears, while a second study could not statistically resolve the branching order of sloth bears and the two black species, suggesting that these three species underwent a rapid radiation event. A third study suggested that American black bears and Asian black bears diverged as sister taxa after the sloth bear lineage and before the sun bear lineage. Further investigations on the entire mitochondrial cytochrome b sequence indicate that the divergence of continental and Japanese black bear populations might have occurred when bears crossed the land bridge between the Korean peninsula and Japan 500,000 years ago, which is consistent with paleontological evidence. Until the Late Pleistocene, two further subspecies ranged across Europe and western Asia. These are Ursus thibetanus mediterraneus in western Europe and the Caucasus and Ursus thibetanus permjak from eastern Europe, especially the Ural Mountains. Hybrids Asian black bears are reproductively compatible with several other bear species, and have on occasion 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, and Scherren's Some notes on hybrid bears published in 1907 mentioned a successful mating between an Asian black bear and a sloth bear. In 1975, within Venezuela's "Las Delicias" Zoo, a female black bear shared its enclosure with a spectacled bear, and produced several hybrid descendants. In 2005, a possible black bear/sun bear hybrid cub was captured in the Mekong River watershed of eastern Cambodia. An Asian black bear/brown bear hybrid, taken from a bile farm, is housed at the Animals Asia Foundation's China Moon Bear Rescue as of 2010. DESCRIPTION Asian black bears are similar in general appearance to brown bears, but are more lightly built and are more slender limbed. The skulls of Asian black bears are relatively small, but massive, particularly in the lower jaw. Adult males have skulls measuring 311.7328 mm (12.313 in) long and 199.5228 mm (7.99 in) wide, while females have skulls measuring 291.6315 mm (11.512.4 in) long and 163173 mm (6.46.8 in) wide. Compared to other bears of the genus Ursus, the projections of the skull are weakly developed; the sagittal crest is low and short, even in old specimens, and does not exceed more than 1920% of the total length of the skull, unlike in brown bears, which have sagittal crests comprising up to 41% of the skull's length. 11. Although mostly herbivorous, the jaw structure of Asian black bears is not as specialised for plant eating as that of pandas: Asian black bears have much narrower zygomatic arches, and the weight ratio of the two pterygoid muscles is also much smaller in Asian black bears. However, the lateral slips of the temporal muscles are thicker and stronger in black bears. In contrast to polar bears, Asian black bears have powerful upper bodies for climbing trees, and relatively weak hind legs, which are shorter than those in brown bears and American black bears. A black bear with broken hind legs can still climb effectively. They are the most bipedal of all bears, and have been known to walk upright for over a quarter mile. The heel pads on the forefeet are larger than those of most other bear species. Their claws, which are primarily used for climbing and digging, are slightly longer on the fore foot (3045 mm) than the back (1836 mm), and are larger and more hooked than those of the American black bear. The ears, which are bell shaped, are proportionately longer than those of other bears, and stick out sideways from the head. The lips and nose are larger and more mobile than those of brown bears. On average, adult black bears are slightly smaller than American black bears, though large males can exceed the size of several other bear species. They measure 70100 cm (2840 in) at the shoulder, and 120195 cm (4777 in) in length. The tail is 11 cm (4.4 inches) long. Mature males typically weigh between 100200 kg (220-440 lbs), with an average weight of about 135 kg (about 300 lbs). Females weigh about 6590 kg (143198 lbs), with large ones up to 14...</p>

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