/sci/ - Science & Math

>A study of orcas in the North Pacific has revealed that mothers make a "lifelong sacrifice" for their sons.

>Rearing a son significantly reduced a female killer whale's chance of reproducing in the future.

>The energy they need to feed sons appears to compromise their health, leaving them less able to reproduce and raise other young.

>"Mothers sacrifice their own food and their own energy," said Prof Darren Croft from the University of Exeter.

>From their years of studying killer whale interactions, scientists already knew that mothers and sons "hung out" together well into the male's adulthood.

>"They'll even feed their sons salmon they catch," explained Prof Croft, whereas adult female offspring will hunt independently.

>This could, the researchers think, be a kind of evolutionary "bet-hedging", driven by the fact that the biggest, oldest males go on to father many offspring.

>"If a mother can get their son to become that big male in the population, then he's the one that will sire [much of the next generation]," explained Prof Croft.

>It may seem paradoxical that such powerful, intelligent animals remain dependent on their mothers through their lives, but it appears that males simply don't have to become independent, because their mother remains by their side.

>"If my mother cooked my dinner for me every night, perhaps I just wouldn't learn to cook my own dinner," joked Prof Croft.

>"But, indirectly, it does seem to be in a mother's interest."