Apparent age-related bone loss among adult female Gombe chimpanzees.

Apparent age-related bone loss among adult females was observed in a skeletal sample derived from the free-ranging Gombe chimpanzee population of Tanzania. Photon absorptiometric and computed tomographic bone scans indicated that, as in humans, bone was lost from the endosteal surface, but, in contrast to humans, more bone was lost from cortical sites than from cancellous sites. The etiology of this bone loss may be related to a number of factors, including hormonal changes, nutritional inadequacy, and decreased physical activity late in life coupled with the demands of pregnancy and lactation.