[citation needed] In The Variation of Animals and Plants Under Domestication, Charles Darwin noted: In the nine-year Report it is stated that the bears had been seen in the zoological gardens to couple freely, but previously to 1848 most had rarely conceived.

[17] Listed alphabetically according to subspecific name:[18][19][page needed] Historically, American black bears occupied the majority of North America's forested regions.

[26] American black bears currently inhabit much of their original Canadian range, though they seldom occur in the southern farmlands of Alberta, Saskatchewan and Manitoba; they have been extirpated on Prince Edward Island since 1937.

[5][page needed] In most of the contiguous United States, American black bears today are usually found in heavily vegetated mountainous areas, from 400 to 3,000 m (1,300 to 9,800 ft) in elevation.

In the northeastern part of the range (the United States and Canada), prime habitat consists of a forest canopy of hardwoods such as beech, maple, birch and coniferous species.

Corn crops and oak-hickory mast are also common sources of food in some sections of the northeast; small, thick swampy areas provide excellent refuge cover largely in stands of white cedar.

In areas where human development is relatively low, such as stretches of Canada and Alaska, American black bears tend to be found more regularly in lowland regions.

[48] American black bears have good eyesight and have been proven experimentally to be able to learn visual color discrimination tasks faster than chimpanzees and just as fast as domestic dogs.

[60] Another notably outsized wild American black bear, weighing in at 408 kg (899 lb), was the cattle-killer shot in December 1921 on the Moqui Reservation in Arizona.

Silvery-gray American black bears with a blue luster (this is found mostly on the flanks) occur along a portion of coastal Alaska and British Columbia.

[41] However, as evidenced by scats with fur inside of them and the recently discovered carcass of an adult sow with puncture marks in the skull, black bears may occasionally fall prey to jaguars in the southern parts of their range.

[5][page needed][41] American black bears were once not considered true or "deep" hibernators, but because of discoveries about the metabolic changes that allow black bears to remain dormant for months without eating, drinking, urinating or defecating, most biologists have redefined mammalian hibernation as "specialized, seasonal reduction in metabolism concurrent with scarce food and cold weather".

[20][83] Hibernating bears spend their time in hollowed-out dens in tree cavities, under logs or rocks, in banks, caves, or culverts, and in shallow depressions.

[85] The hibernating bear does not display the same rate of muscle and bone atrophy relative to other nonhibernatory animals that are subject to long periods of inactivity due to ailment or old age.

[70][page needed] Up to 85% of their diet consists of vegetation,[48] though they tend to dig less than brown bears, eating far fewer roots, bulbs, corms and tubers than the latter species.

[91] Young shoots and buds from trees and shrubs during the spring period are important to bears emerging from hibernation, as they assist in rebuilding muscle and strengthening the skeleton and are often the only digestible foods available at that time.

Favored masts such as hazelnuts, oak acorns and whitebark pine nuts may be consumed by the hundreds each day by a single bear during the fall.

[citation needed] Although American black bears do not often engage in active predation of other large animals for much of the year, the species will regularly prey on mule and white-tailed deer fawns in spring, given the opportunity.

[107] There is at least one record of a male American black bear killing two bull elk over the course of six days by chasing them into deep snow banks, which impeded their movements.

In Labrador, American black bears are exceptionally carnivorous, living largely off caribou, usually young, injured, old, sickly or dead specimens, and rodents such as voles.

This is believed to be due to a paucity of edible plant life in this sub-Arctic region and a local lack of competing large carnivores (including other bear species).

[99] If it is able to capture a mother deer in spring, the bear frequently begins feeding on the udder of lactating females, but generally prefers meat from the viscera.

[125] A cub, who in the spring of 1950 was caught in the Capitan Gap Fire, was made into the living representative of Smokey Bear, the mascot of the United States Forest Service.

American black bears rarely attack when confronted by humans and usually only make mock charges, emit blowing noises and swat the ground with their forepaws.

[66] Of 1,028 incidents of aggressive acts toward humans, recorded from 1964 to 1976 in the Great Smoky Mountains National Park, 107 resulted in injury and occurred mainly in tourist hot spots where people regularly fed the bears handouts.

[127][page needed] In almost every case where open garbage dumps that attracted bears were closed and handouts ceased, the number of aggressive encounters dropped.

[41] However, in the Liard River Hot Springs case, the bear was apparently dependent on a local garbage dump that had closed and so was starving to death.

[5][page needed] American black bears can do extensive damage in areas of the northwestern United States by stripping the bark from trees and feeding on the cambium.

[137] A Fairleigh Dickinson University PublicMind poll found that 53% of New Jersey voters approved of the new season if scientists concluded that bears were leaving their usual habitats and destroying private property.

[134] According to the second volume of Frank Forester's Field Sports of the United States, and British Provinces, of North America: The flesh of the [black] bear is savoury, but rather luscious, and tastes not unlike pork.