Demographic and hormonal evidence for menopause in wild chimpanzees

• Published in: Science
• Main Authors: Wood, B., Negrey, J., Brown, J., Deschner, T., Thompson, M., Gunter, S., Mitani, J., Watts, D., Langergraber, K.
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2023
• Subjects: toothed whale; toothed whales
• Online Access: http://hdl.handle.net/21.11116/0000-000D-E34F-B

Among mammals, post-reproductive life spans are currently documented only in humans and a few species of toothed whales. Here we show that a post-reproductive life span exists among wild chimpanzees in the Ngogo community of Kibale National Park, Uganda. Post-reproductive representation was 0.195, indicating that a female who reached adulthood could expect to live about one-fifth of her adult life in a post-reproductive state, around half as long as human hunter-gatherers. Post-reproductive females exhibited hormonal signatures of menopause, including sharply increasing gonadotropins after age 50. We discuss whether post-reproductive life spans in wild chimpanzees occur only rarely, as a short-term response to favorable ecological conditions, or instead are an evolved species-typical trait as well as the implications of these alternatives for our understanding of the evolution of post-reproductive life spans. Menopause occurs in all known human societies; however, it is not common to all mammals and has so far only been observed in humans and a few toothed whale species. Wood et al. looked at demographic and endocrine data in a long-studied population of chimpanzees in Uganda and found clear evidence for menopause in females living past the age of 50 (see the Perspective by Cant). Unlike the case for humans and toothed whales, however, postreproductive chimps in this population are not involved in the raising of related offspring, suggesting that a different process is driving its development. ?Sacha Vignieri Substantial postfertile survival and menopause occur among wild chimpanzees in the Ngogo community in Kibale National Park, Uganda.