VICTORIA — A study released today says mother-daughter conflicts over competition and co-operation are helping explain why killer whales go through menopause.
Killer whales are one of only three species, including humans, who go through menopause, often living for decades after giving birth to their final calf.
Research published today by Canadian, American and British whale experts in the journal Current Biology examines the links between menopause and the relationships between so-called grandmother whales and young females within whale pods.
The research examines more than 40 years of data collected by whale scientists in the Salish Sea near Victoria and the San Juan Islands in the United States.
British scientist Darren Croft says the research indicates older female whales go through menopause because they lose out in the reproductive competition with younger females, but continue to serve roles as wise elders who guide the pod to food sources.
He says the researchers observed a whale nicknamed Granny, who died late last year at an estimated age of 105 years.