Minnesota Department of Natural Resources
The world’s oldest-known wild bear has died of old age in northern Minnesota at the age of 39½, according to the Minnesota Department of Natural Resources (DNR).
Known to DNR researchers 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 1981-1995, Bear No. 56 produced eight litters of cubs and successfully reared a remarkable 21 of the 22 cubs to 1½ 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 by 19 years all of the 360 other radio-collared black bears that DNR researchers have followed since 1981. 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.
“Getting this information about this bear has taken a lot of effort. This really attests to the value of a long-term study with a large sample of bears,” said Dave Garshelis, DNR bear project leader. “Had we not studied so many bears, we likely would not have encountered this intriguing outlier. It was not just documenting that she lived to be so old, but understanding how she was able to live to be so much older than other bears that made this incredibly interesting and useful.”
In the last few years of her life, Bear No. 56 began to visit some hunters’ baits, but hunters passed up shooting her, abiding by a DNR request that hunters not shoot collared bears.
When last handled in March 2010, Bear No. 56 was a healthy weight but her teeth showed excessive wear and her eyes were clouding. Since then, her hearing and eyesight continued to deteriorate.
Rarely observed through most of her life, Bear No. 56 had been observed by people during the past two summers with increasing frequency, foraging along trails and traveling dirt roads, likely because of the greater ease of travel than in the woods.
Sometime in July, Bear No. 56 left her normal home range, as bears often do in late summer, to explore other areas for rich food sources on which to fatten for winter. After locating her radio signal several miles from her typical home area, DNR bear researcher Karen Noyce found her decomposed body in a secluded wooded location. From all indications, she died a quiet death, with no sign of struggle at the site and no evidence of broken bones or traumatic injury.
“This is the first bear in our study to die of old age, and there is something satisfying in that,” said Noyce, who, along with Ken Soring, DNR’s current enforcement director, conducted the first capture of Bear No. 56 as a rookie biologist in 1981.
“We knew she was getting feeble,” Noyce said. “It would have been sad to find her on the side of the road somewhere, hit by a car. After following her all these years, I’m glad to know she died peacefully. It was a fitting death for a fine old bear.”