Post-reproductive female killer whales act as key "repositories of ecological knowledge" to younger family members, a new study has claimed.
Menopause is a rare and mysterious phenomenon among animals on Earth. Only humans, resident killer whales and short-finned pilot whales are predisposed to outlive their reproductive years.
For example, female killer whales typically hit the menopause stage at around the age of 40, but can live into their 90s – which in turn can apparently boost the survival rate among their offspring.
Researcher Laura Brent of the University of Exeter's animal behaviour centre said:
Our results show for the first time that one way post reproductive females may boost the survival of their kin is through the transfer of ecological knowledge.
The value gained from the wisdom of elders can help explain why female killer whales and humans continue to live long after they have stopped reproducing.
Academics, who used information collected over the last 35 years and observed 102 of the mammals for the study, said that the killer whale "may provide insight into how menopause evolved in preliterate humans".
The research, results of which were published in the journal Current Biology on Thursday, claimed to have found that "postreproductively aged female killer whales are especially likely to lead group movement in years with low salmon abundance ... the ecological knowledge of elders helps explain why females of this species live long after they have stopped reproducing."
The University of Exeter's animal behaviour prof Darren Croft added:
“In humans, it has been suggested that menopause is simply an artefact of modern medicine and improved living conditions.
“However, mounting evidence suggests that menopause in humans is adaptive. In hunter-gatherers, one way that menopausal women help their relatives, and thus increase the transmission of their own genes, is by sharing food. Menopausal women may have also shared another key commodity – information." ®