Black bears, estimated to number well over half a million in north America, range over a vast area, from the Arctic treeline to south of Florida and northern Mexico. Of the eight species in the continent, the American Black bear (Ursus Americanus) is the most abundant species. In the US, this black bear can be found in 40 odd states, population depending on the amount of green cover available and urbanization. Alaska alone has around 200,000 black bear population. Wisconsin, California, Washington, Oregon, Maine, Minnesota and Idaho are other states with considerably large population of the animal.
Black bears require good amount of forest cover due to their shy and solitary nature, so they mainly live in heavily covered areas. However, they are able to adapt well to diverse habitats such as mountains, swampy areas, hardwood forest, softwood forest, mixed forest, logged areas, and cornfields. They may grow to a height of 1.5 meters and can weigh upto a 100 kilos
American black bears are omnivorous, they eat a variety of plants and meat. Their food generally includes roots, berries, meat, fish, insects, larvae, grass and other succulent plants. They are able to kill adult deer, elk, moose and other hoofed animals when these are very young. They may kill livestock especially sheep. Bears are even attracted to human garbage, livestock food, or other human associated foods including fruit trees. Bears getting used to human consumption foods can quickly become habituated to them, resulting in their being killed as nuisances. This is true for bee hives too as bears are very attracted to honey.
Black bears have low reproductive rates compared to many other mammals. Females usually breed only every two to three years after attaining sexual maturity at roughly four years of age. In areas of abundant food, they may attain maturity sooner than in other areas. Where food is scarce, females might not bear their first cub until they are six or seven years old. With very rare exceptions, in most populations males don’t mature sexually until age five or six. Black bears can live upto 25 to 30 years of age, but their life-span in the wild is usually much shorter than when in captivity.
Black bears in northern states, with approaching winter, eat lots of food in order to store fat for the winter when food is harder to find. During the winter, their temperature drops and they gradually become less active and hibernate, helping them to conserve energy until food is in plenty again. While the ones in warmer climes remain active throughout the year, moving small distances to suit their feeding requirements. Females in cooler areas give birth during their long winter siesta, waking up occasionally to nurse.
Black bears of north America communicate using a strong sense of smell, facial and body expressions, sounds and by touch. Males mark their territorial boundaries by scent-marking trees, biting, scraping and stripping off bark from trees such as pine, fir, and spruce. The larger the bear, the higher the marks; warning other males of their supremacy. Often used as scratching posts, same tree may be revisited for years. Scientists observe that tree marking may also be part of their mating ritual.
Apart from the Americas, around half dozen of black bear varieties are are found in Asia too. Their numbers vary with forest cover pattern in southern and eastern Asia. In central and southern India, the sloth bear (Melursus ursinus), in southern Thailand and into Malaysia, the sun bear (Helarctos malayanus) and north and west of the Russian Far East, the brown bear (Ursus arctos), are some of the variants of black bear species here.