Thursday, July 8, 2010

American Black Bear: Livestock and crop predation

Livestock depredations by black bears occur mostly in spring. A limitation of food sources in early spring and wild berry and nut crop failures during summer months are probably major contributing factors. Black bears can do extensive damage in some areas of the northwestern United States by stripping the bark from trees and feeding on the cambium. Though black bears will attack adult cattle and horses, they seem to prefer sheep, goats, calves, and pigs. They normally kill by biting the neck and shoulders, though they may break the neck or back of prey with blows from the paws. Evidence of a bear attack includes claw marks and is frequently being found on the neck, back, and shoulders of larger animals. Surplus killing of sheep and goats are common. Bears have been known to frighten livestock herds over cliffs, causing injuries and death to many animals; whether or not this is intentional is not known.

Sunday, July 4, 2010

American Black Bear Fur: Attacks on humans

Unlike grizzly bears, which became a subject of fearsome legend among the European settlers of North America, black bears were rarely considered overly dangerous, even though they lived in areas where the pioneers had settled. Black bears rarely attack when confronted by humans, and usually limit themselves to making mock charges, emitting blowing noises and swatting the ground with their forepaws. However, according to Stephen Herrero in his Bear Attacks: Their Causes and Avoidance, 23 people were killed by black bears from 1900 to 1980. The number of black bear attacks on humans is higher than those of brown bears, though this is largely because the black species outnumbers the brown rather than them being more aggressive. Compared to brown bear attacks, violent encounters with black bears rarely lead to serious injury. However, the majority of black bear attacks tend to be motivated by hunger rather than territoriality, and thus victims have a higher probability of surviving by fighting back rather than submitting. Unlike grizzlies, female black bears do not display the same level of protectiveness to their cubs, and seldom attack humans in their vicinity. The worst recorded fatality incident occurred in May 1978, in which a black bear killed three teenagers while fishing in Algonquin Park in Canada. The majority of attacks happened in national parks, usually near campgrounds, where the bears had become habituated to human contact and food. 1,028 incidences of black bears acting aggressively toward people, 107 of which resulted in injury, were recorded from 1964 to 1976 in the Great Smokey Mountains National Park, and occurred mainly in tourist hotspots where people regularly fed the bears handouts.