Killer whales also experience menopause and they stop breeding after their 30s. This results in better health for the whales, keeps them more active and increases their life span, says a study.
Killer whales , humans and pilot whales are the only three species who remain alive for an extended period even after they stop reproducing. The enhanced life span helps them take care of their off springs in turn leading to a longer life for their young. The findings are based on the study led by the researchers from Exeter University in U.K. and New York University.
These researchers studied more than 30,00,0 Killer whales over the last 30 years. They found that Killer whales also go through menopause. However, they could not specify how and why it happens and said that it needed further research.
"Our main aim is to understand why these Killer whales have a menopause strategy that's so similar to humans. Female killer whales stop reproducing in their 30s or 40s but live until they are 90," said Dr Darren Croft of Exeter University, one of the researchers, reports The Guardian.
According to the study, the human tendency observed among the killer whales is due to their typical social structure. The male Killer whales stay with their mothers lifelong. The female whales act like typical mothers and look after the needs of their off springs.
The male Killer whales do not stay with their partner after mating and the female ones give birth and rear their children within the pod. This habit among the male Killer whales is a consequence of excessive dependency on their mothers. "Our analysis shows that male killer whales are pretty much mommy's boys and struggle to survive without their mother's help. The need for mothers to care for their sons into adulthood explains why killer whales have evolved the longest post-reproductive lifespan of any non-human animal," said Dr Dan Franks, at the New York University, according to a recent post on Science Daily. On the other hand, the female orcas are not that dependent on their mothers.
The study also reveals that if a male Killer whale is aged below 30 at the time of his mother's death, chances of his survival reduces by three times. If the Killer whale is aged above 30 the chances of his survival cut down by eight times in the next year.
