Known as Bear No. 56, the female American black bear was first captured and radio-collared in July 1981 by DNR scientists during the first summer of a long-term research project on bear population ecology. The bear was 7 years old at the time and was accompanied by three female cubs.
Bear No. 56 became a significant animal in the DNR research project. During a 32-year study period, she and her many offspring provided an almost uninterrupted record of reproduction, survival, movements and, eventually, senescence (aging), within a single matriarchal lineage. Data from this bear and her offspring have contributed significantly to the scientific literature on black bear biology.
From 1981-95, Bear No. 56 produced eight litters of cubs and successfully reared a remarkable 21 of the 22 cubs to 1.5 years of age. In 1997, at age 23, she uncharacteristically lost two of her three cubs before weaning. In 1999, at age 25, she bore and raised her last cub. In 2001, when she was next expected to give birth, researchers found her healthy in her den and producing milk but without cubs.
Bear No. 56 outlived all of the 360 other radio-collared black bears that DNR researchers have followed since 1981 by an astounding 19 years. She also outlived any radio-collared bear of any species in the world. Only a very few individual study bears have been reported to reach age 30. The second-oldest was a brown bear that lived to 34.
Researchers suspect Bear No. 56's longevity probably is best attributed to a combination of factors, including the location of her home range in a forested area with few people or major roads; a more reticent nature than that of many bears, in terms of her avoidance of people; and luck.