After observing 102 killer whales in the wild, British researchers have come to the conclusion that females become key leaders in their pod after they get past the menopausal age. In a study published in Current Biology on Thursday, they observed that these older females know how to find the best places where the entire lot can find salmon, their most loved food. This knowledge particularly comes handy when food gets scarce.
Lauren Brent, the lead author of the study who is an associate research fellow in animal behavior at the University of Exeter observed that whales and human women are among the few rare species found on this planet which are known to outrun their productive years.
The productive period for killer whales is between the ages of 12 and 40, though they may live to be 90 or more, which is considerable more than the average age span of a male, a few of whom make it past 50.
Brent noted that the older females are valued by the pod for their accumulated knowledge and wisdom. The evolutionary reason, Brent says, is probably similar across the species.
“The families of humans and resident killer whales are structured in a very kin-focused way,” she explains. “As humans did not develop writing for almost the entirety of our evolution, information was necessarily stored in the minds of individuals. The oldest and most experienced people were those who were most likely to know where and when to find food, especially during dangerous conditions such as drought.”
Darren Croft, a University of Exeter behavioral ecologist, who was a senior author also agreed to the same.
“This is the first study to show that these post-reproductive females play a key role in their society by storing ecological knowledge,” said Croft. “With killer whales we’re still looking at a species where information is stored in individuals — it’s not stored in the Internet or books,” he says.
Knowing that females beyond the fertile age command greater respect among killer whales might help researchers get a better insight into the forces that could have shaped the evolutionary history among humans.