Health Editor’s Note: So Orca females go into menopause at about the age of 50, and while the male orcas are dying at that age, these girls go on to become leaders of the pods and live another 40 or so years. In nature, the value of the female seems to be that of reproduction of the species, and after the time of no longer being able to produce young, that female will usually die. Humans have long and productive lives after they can no longer become pregnant due to menopause (decrease or absence of female reproductive hormones that occurs naturally with aging) and now we find out that orcas have the same type of existence. I wonder if there are other species who match the criteria of having females move into other roles after they are no longer able to reproduce young?…..Carol
After Menopause, Killer Whale Moms Become Pod Leaders
by Ben Miren Smithsonian.com
As one of only a handful of animals on the planet to live many years after menopause, killer whales have just provided new insight into the benefits of this seemingly strange reproductive strategy. Females that are past their child-bearing years go on to become group leaders with valuable survival skills, scientists report today in the journal Current Biology.
Theoretically, menopause should not exist. If the purpose of survival is reproduction, then there is no reason for an animal to stay alive when it can no longer have offspring. For killer whales, females stop reproducing at around 50 years old, which is also the age when most male killer whales are nearing the ends of their lives. Typically, though, post-menopausal females still have another 40 years to go.
Scientists from the University of Exeter, the University of York and the Center for Whale Research examined 35 years’ worth of observational data from an endangered population of southern resident killer whales in the Pacific Northwest. They poured over decades’ worth of photographs capturing whales on the move and noticed a pattern: Post-menopausal females, the oldest in the group, typically swam at the front and directed their pods’ movements in a variety of scenarios.