Bears can be found throughout the world. They are generally large animals, and are characterized by a plantigrade walk (on their heels, like humans), a large body, short legs, a stub of a tail, small, round ears, and forward facing eyes.
All bears are classified as carnivores, with each species having a variable degree of herbivorous tendency. The panda, for example, is almost exclusively a plant eater. The polar bear is almost entirely a carnivore.
The black bear has managed to be quite prolific and successful as bears go. The eighteen known subspecies can be found throughout the United States and Canada. Estimates of the number of black bears in North America vary, with 750,000 being the most often suggested. In the state of Pennsylvania there are believed to be more than 7000 of the animals scattered across the state.
Despite their name, black bears can actually appear in a variety of colors. There are brown black bears, white black bears, and even the blue glacier bear.
Expert estimates of the weights of the bears also seem to vary widely. Conservative measurements put the average weight of the animals is around 300 pounds. However, the degree of sexual dimorphism exhibited by the species makes accurate accounts difficult. The largest black bear recorded was a male shot in Wisconsin in 1885. The bear was 802 pounds, far heavier than would be expected.
They have a wide an varied diet. They can and will eat nearly anything. Typical of bears, they are fond of honey, and are responsible for thousands of dollars worth of damage to aphiaries each year.
The black bear has claws which are shorter and more curved than those of the grizzly bear. This allows it to have a great agility in climbing trees. Often, a sow will encourage her cubs to tree themselves while there is danger. Black bears have a characteristic way of climbing and descending trees. They mostly use their front claws for climbing and keeping a hold.
The Brown Bear has captured the human consciousness like nearly no other animal can. It presents an image so like ourselves that we often get caught up in the “cuteness” and forget that it is a wild animal that we are dealing with. The brown bear is often seen as the cuddly buffoon of animation, and the “Teddy” bear of children and collectors alike. In reality, the brown bear is a complex and fascinating animal deserving of great respect.
The brown bear distinguishes itself from the other ursines by virtue of its shoulder hump, which is caused by muscles which are used for digging. The color of the animal varies from a light creamy color through to black. It has a dished facial profile and very long claws on the front paws. In addition, has a wider distribution than any of the other bears, and can be found throuhout the world. The animal has been found in such diverse places as Europe, Japan, North Asia, the western Canadian provinces, and the states of Washington, Idaho, Montana, Wyoming, and Alaska. This diversity does not limit itself to purely geographical happenings, as the bear is also found in a great number of different habitats as well. Brown bears can be found on the plains, in the forests, the tundra, and in subalpine mountain areas. At one time, the brown bear could be found throughout the North American continent. However, excessive hunting and destruction of the animal’s habitat have all but wiped out this majestic creature.
This animal’s weight varies widely throughout the course of the year. Some can even double their weigh between emerging from their dens in the Spring and returning in the Fall. The males can weigh anywhere from 300 to 860 pounds, with the females coming in somewhere between 205 and 455 pounds. The average size of these bears is difficult to pinpoint, because it seems to depend greatly on the food sources available. The island grizzlies of Alaska (Kodiak and Admiralty) are considered the largest land carnivores in the world, and live on a diet of fish and other rich food. The inland animals are smaller by some 30%.
Of the browns, people tend to be more familiar with the grizzly bear. This animal is well known for it’s aggressive nature, and it is for this reason that many folks believe it gets its name. Not so! The name “grizzly” comes from the “grizzling” of its fur, which gives it a lighter color at the tips of hairs.
Brown bears reach sexual maturity somewhere between their 4 1/2 to 7th years. Females and males mature at approximately the same time, but males often do not become successful breeders until they are 8-10 years old due to competition with older, stronger males. Mating between browns takes place from early May to mid-July Implantation of the egg in the uterus, however, does not occur until sometime in Oct.-Nov. 1-4 cubs are born during winter hibernation of the female, with 2 being most common, sometime between January and March. The cubs will stay with the sow up to 2 1/2 years, meaning that the female may only breed about once every 3 years or so. Given that bears generally live only until they are 20-25 years of age, this does not give very many opportunities to reproduce.
Like most other bears, the brown bears are longers; with the notable exception of females with cubs. During the mating season, males and females may pair up and mate frequently for up to two weeks. The females require the stimulation of frequent mating before they will ovulate. While fertile, she may mate with several males, leading to cubs in a litter which may not all have the same father. This is one of the factors that makes research into bears more difficult, since paternity is often hard to determine.
The home ranges of bears often overlap. The ranges of males will often intersect those of several females. Bears will not generally attack other bears which wander in to their territories. They will even congregate peacefully in places where food is plentiful such as garbage dumps and salmon streams. In such places, the big, dominant males will usually get the choice fishing areas.
Brown bears are technically carnivores, but in practice most of their diet consists of plant matter such as sedges, grasses, bulbs, seeds, berries, and roots. They will also eat insects, fish, and small mammals. Some of these bears have even developed predatory practices on large animals, including moose, caribou, and elk.
The polar bear is a mighty hunter of seals. The most carnivorous of the bears, it is also the most patient. They will sit near a seal blow-hole for hours, waiting, until the animal surfaces. When it does, it is all over for the seal. One powerful blow from a forepaw brings a swift meal for the bear and a swifter death for the seal.
The conditions of the polar north are harsh, with temperatures well below freezing almost constantly. In order to survive, the polar bear has to be an expert survivalist, able to cope with the grueling conditions of his environment. Like a giant solar panel, the skin of the bear is black to draw every bit of possible heat from the sunlight. The hairs if the pelt appear to be white, but are actually transluscent and transmit the light down to the skin. Below these hairs are “underhairs” of orange or yellow.
Like those of other bears, the ears of the polar bear are round. They are, however, smaller and closer to the head. This, along with the overall shape of the animal help to make it a formidable swimmer. The paws are large, and slightly webbed, which also contribute to the bear’s abilities as a swimmer.
There is a great degree of sexual dimorphism among the bears as well. The males are huge, the heaviest of them weighing as much as 1300 pounds. The females are smaller, the largest of them being only about 600 pounds.
The boars do not generally hibernate, but remain active for most of the year. The pregnant females are the exception to this, however. They go through a denning and hibernation period, just like that of the black, brown, and other bears.
Polar bears are more aggressive than other bears. Even in captivity.
The asiatic black bear has many similarities to its American cousin. Both are medium sized, and black. The ears of the asiatic bear are large and seem inappropriately sized to the rest of its head and those of other bears. These bears have a white patch of fur on their chest, which is often shaped like a V, with some varying amount of white on their chin as well. Occasionally, they can be found in a brown color phase.
The asiatic black bears are not as widely studied as the other bears, so very little information is available about their relative size and other statistics. Generally, they have been found to be 50-75 inches in length. The males usually weigh from 220-440 pounds, and the females from 110-275 pounds.
These bears can be found throughout Southern Asia. They are known in Afghanistan, Pakistan, Nepal, Sikkim, Northern India, Bhutan, and into Burma. They can also be found in Northeast China, and Southeast Russia, Taiwan, and the Japaneese islands of Honshu and Shikoku. Mostly, these bears live in forested areas, especially hilly and mountainous places. The preferred elevations change seasonally. In summer, asiatic black bears have been spotted at over 9,900 feet–moving to lower elevations as the cold of winter comes on. In the northern parts of their range, they den for winter. Current thinking is that the bears in the southern reaches do not hibernate.
The diet of the asiatic black bear is quite diverse. They eat carrion, bee’s nests, insects, invertebrates, small vertibrates, and fruit. They have been known to kill domestic livestock, but to what degree they exhibit this predation is not known. They are also known to make daybeds and feeding platforms in nut-bearing trees.
The sloth bear is relatively small, with long hair and shaggy coat. The bear is often black, but reddish animals have been seen. The nostrils of the muzzle can be closed at will, possibly as an adaptation to the defenses of the termites which make up a large portion of their diet. Their dark fur is often interspersed with whitish or greyish strands, and they display a noticeable whiteish or cream-colored U shaped patch on their chest. Behind their heads, they have a mane, a ruff of fur that covers their neck and part of their shoulders. Their belly and underlegs are nearly bare. The sloth bear’s ears are large and floppy; they have very good hearing. The claws of the sloth bear are sickle-shaped, and deeply curved.
The sloth bear is unique among bears as it has only 40 adult teeth. The cubs have 42 while nursing. The two middle, upper incisors do not grow in with the rest of the permanent teeth. The dirt that the bears ingest with their food often leads to bad teeth, as it grinds away the enamel. When feeding, the bears make loud, sucking sounds which can be heard for many miles.
Sloth bear adults can weigh anywhere from 120-310 pounds and measure anywhere from 60-75 inches in length. The males are larger than the females.
Sloth bears are found in the forested areas and grasslands of India and Sri Lanka. However, the bears have also been witnessed in Nepal, Bangladesh, and Bhutan.
Sloth bears live a solitary existence, except when raising young or mating. The bears have a number of vocalizations, but their purpose is not understood.
Reproduction for the sloth bears is a fairly standard affar. The animals breed in late Spring/early Summer, with the cubs being born six to seven months later. Like other bears, the litters are small, consisting of only a cub or two. Very rarely, sloth bears have been reported as having three. The cubs stay in their mother’s earth den for the first two to three months, they will continue to stay with their mother through their adolescence, which lasts approximately 2 years.
The spectacled bear gets its name from the distinctive circular bands which ring its eyes. The markings vary slightly from bear to bear, but the general look is the same. The markings are a creamy-yellowish color while the rest of the fur on the animal could be anywhere from brown to black. The spectacled bear is a small animal as bears go, the males generally weighing from 220 to 340 pounds, and the females 140 to 180 pounds. The animals are generally from 60-72 inches in length, with the females being about 30% smaller, on average, than the males.
The females are generally mature somewhere between their 4th and 7th years. After maturity, the animals will mate between May and June, with the litters of up to 3 being born during the Nov-Feb period. The cubs weigh a mere 10-11 1/2 ounces at birth. During the mating months, the bears will pair up and stay together for up to two weeks, copulating frequently. Like most other bears, the female requires this stimulation to ovulate.
Apart from basic mating and other minor habits, we have no information on the social life of these animals in the wild. The bears that have been studied in captivity have shed some light on their society. Females and cubs communicate with vocalizations, of which somewhere between two and five calls have been identified (depending on which source you check with).
The sun bear is a rather small member of the bear family which makes its home in the lowland tropical rainforests of Southeast Asia. It is covered with a black coat made of sleek, short hairs. It has a white or yellowish patch on its chest shaped like a half-moon. It has a muzzle which is both yellower and shorter than that of a black bear. Sometimes the light color extends up over the eyes. The long, pointed claws are curved with hairless soles, likely as an adaptive measure to help in climbing trees. The ears of the sun bear are smaller and rounder than those of other bears. The teeth of the sun bear are flatter than those of other bears and the canines are long enough to protrude between the lips.
The omnivorous sun bear lives on a diet consisting mostly of termites, birds, small mammals, and even bits of oil palms, and other commercial crops.
Sun bears are the smallest of all the bears. The adults only weigh up to 145 pounds, and measure at the longest 60 inches.
This bear can be found in Laos, Vietnam, Cambodia, Thailand, Burma, Bangledesh, and many other countries in the Southeastern portions of Asia. However, poaching and deforestration have been slowly eroding the available population and habitat.
As for reproductive habits, there is little available information. Captive breeding has produced such wildly different gestation periods that scientists are not even sure if the sun bear has a mechanism of delayed implantation.
The Giant Panda is one of the most misunderstood animals on the planet. For many years, it was believed to be a type of racoon, like the similarly named red panda. However, genetics testing and observation have revealed that the panda is in fact, a bear. It has several adaptations that make it unusual. First is the fact that it has six digits on the front paws, giving it an opposable thumb ideal for holding onto the stalks of bamboo which it consumes in great amounts. The genitalia of the male are rear-pointing and small which is also decidedly unbearish, and much more like those of the red panda. It has only been since 1995 that the Panda has been officially considered a bear.
Typical pandas have a large head, and distinct white and black coloration which contrasts sharply with the deep green of their natural habitat. Pandas can only be found in six tiny regions in southwest China. These places are along the Tibetan plateau in Sichuan, Gansu, and Shaanzi provinces. Combined, these areas are less than 5,400 square miles of very high altitude (4,000-11,500 ft.) mountain forests grown thick with patches of more than 30 species of bamboo. The bears themselves have home ranges from 1.8 to 3.3 square miles. The territories of the males often overlap those of a number of females.
Newborn pandas weigh between 3 and 5 ounces. Males grow to 190-275 pounds and 64-76 inches in length, with females being slightly smaller and lighter at 155-220 pounds. They reach sexual maturity between ages 4 1/2 to 6 1/2 years and mate once during the spring months of March, April, and May. The females are in estrus for anywhere from 1 to 3 weeks, but are only really receptive for a few days of that time. During August and September, pregnant females give birth to anywhere from one to three cubs, with one being the more common. The cubs are weaned at nine months, but often stay with their mothers for more than two years.
Like most bears, pandas are solitary animals. Females with cubs being the only exception. They mark their territories by scratching trees and by rubbing a musky anogenital gland against rocks and trees. Additionally, they communicate with different vocalizations. Scientists have identified 11 distince calls, but cannot identify the exact function of all of them.
Pandas are quite vegitarian, making bamboo 99% of their diet. Adults can eat anywhere between 26 and 33 pounds of it in a day, and with soft new shoots up to 84 pounds! Incredibly, that’s almost 40% of their body weight! Ocassionally they consume meat and some other plants.