
Orca mothers make ‘lifelong sacrifice’ for sons
Center for Whale ResearchBy Victoria GillScience correspondent, BBC NewsA 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. Orcas remain closely bonded to their families throughout their lives. But while young female offspring become independent in adulthood, males depend on their mothers - even demanding a share of the food that their matriarchs catch. Prof Croft described it as a "new insight into the co...