American Black Bear

The American Black Bear (***Ursus americanus***) Also known as The Black Bear is a species of bear endemic to North America. The American black bear is an omnivore, with its diet varying greatly depending on season and location. It lives in largely forest areas, but will leave forests in search of food.

Behavior and life history

American black bears have eyesight and hearing. Their sense is their sense of smell, which is about seven times more sensitive than a domestic dog's. American black bears are excellent and strong swimmers, swimming and to feed on fish. They climb trees to feed, escape enemies and hibernate. Four of the eight modern bear species are habitually arboreal (the most arboreal species, the American and Asian black bears and the sun bear.) They may be active at any time of the day or night, although they mainly forage by night.

American black bears may communicate with vocal and non-vocal sounds. Tongue-clicking and grunting are the most common sounds and are made in cordial situations to conspecifics, offspring and occasionally humans. 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. 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

Hibernation

The bears enter their dens in October and November, only pregnant females and mothers with cubs will enter hibernation. Hibernation in American black bears typically lasts 3–8 months, depending on regional climate.

Hibernating American black bears spend their time in hollowed-out dens in tree cavities, under logs or rocks, in banks, caves, or culverts and in shallow depressions.

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

The time that American black bears emerge from hibernation. 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. Bears at lower altitudes tend to emerge earlier. Finally, mature males tend to come out earliest, followed by immature males and females, and lastly mothers with cubs. Mothers with cubs are seen before those with newborns.

Diet

When 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 also important to American black bears emerging from hibernation. During summer, the diet largely comprises fruits, especially berries and soft masts such as buds and drupes. During the autumn hyperphagia, feeding becomes virtually the full-time task of American black bears. Hard masts become the most important part of the American black bear's diet in autumn and may even partially dictate the species' distribution. Favored masts such as hazelnuts, oak acorns and whitebark pine nuts may be consumed by the hundreds each day by a single American black bear during the fall.[*page needed*] During the fall period, American black 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 American black bear's animal diet consists of insects, such as bees, yellow jackets, ants, beetles and their larvae. They are also fond of Honey and will gnaw on trees to find the hives. Once the hive is breached, the bears will scrape the honeycomb with their paws and eat them, regardless of stings from the bees. American black 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. Other fish, including suckers, trout and catfish, are readily caught whenever possible. The species will prey on mule and white-tailed deer fawns in spring, given the opportunity. Bears may catch fawns when foraging for something else and then sniff them out and pounce on them. As the fawns reach 10 days of age, they can outmaneuver the bears and their scent is soon ignored until the next year. American black bears have also been recorded similarly preying on elk calves in Idaho and moose calves in Alaska.

Predator Relationships

American black bears are scavengers that can intimidate, using their large size and considerable strength, and if necessary dominate other predators in confrontations over carcasses. However, on occasions where they encounter Grizzly bears, the larger brown subspecie dominate them. American black bears tend to escape competition from brown bears by being more active in the daytime and living in more densely forest areas. Violent interactions, resulting in the deaths of American black bears, have been recorded in Yellowstone National Park.

American black bears do compete with cougars over carcasses. Like brown bears, they will sometimes steal kills from cougars.

American black bear interactions with gray wolves are much rarer than with brown bears. Despite the American black bear being more powerful on a one-to-one basis, packs of wolves have been recorded to kill black bears without eating them. Unlike brown bears, American black bears lose against wolves in disputes over kills. Wolf packs kill American black bears when the larger animals are in their hibernation cycle.

There is at least one record of an American black bear killing a wolverine in a dispute over food in Yellowstone National Park. Alligator predation on American black bears have been reported.

At least one jaguar has been recorded to have attacked and eaten a black bear