One Very Old Bear

摘要

It is rare in bear studies to get the opportunity to follow a bear into old age. In hunted populations of American black bears, Ursus americanus, (which most populations are) few bears live to be 20, and fewer still live into their mid- to late 20's. Among the more than 550 black bears that we have radio-collared in various studies around Minnesota, USA, since 1981, however, one female has defied the odds. Bear #56, radio-collared at 7 years old in July, 1981, the first summer of our studies, turned 36 years old this winter, outliving any other bear we have encountered in our work by 13 years. Moreover, since the year of bear #56’s birth, we have collected and aged 55,000 teeth from hunter-killed bears – only three (0.005%) lived past 30, the oldest being 33.