Killer whales and humans are among the only animals known to experience menopause.

Female orcas go through two main stages of life: a fertile phase and, in their many post-reproductive years, a leadership phase. By studying these whales, scientists are starting to shed light on the natural history of menopause — why it emerged and how it benefits a species.

This is an area of research that can't be done with captive whales. The older females in the wild are leading large pods in the act of hunting. Captive whales can't form pods or hunt.