Caring killer whale grandmas help calves survive
By Agence France-Presse
Doting killer whale grandmothers help their grand calves survive, particularly in times of food scarcity, scientists reported Monday in a paper that sheds new light on the evolutionary role of menopause.
Orca females stop reproducing in their thirties or forties but can continue to live for decades more, a phenomenon known only to exist in humans and four other mammal species, all of which are whales.
It has been suggested that the trait evolved because it allowed post reproductive females to help their wider kin referred to as the grandmother effect in people, but the theory had not been tested in whales until now.
This is the first non-human example of the grandmother effect in a menopausal species, senior author Daniel Franks from the University of York told AFP.
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https://www.rawstory.com/2019/12/caring-killer-whale-grandmas-help-calves-survive/