The new study by the universities of Exeter and York, and the Center for Whale Research adds to growing evidence that post-menopausal females boost the life chances of offspring, especially males.
Post-menopause orca mothers appear to protect their male offspring from being injured by other orcas phys.org - get the latest breaking news, showbiz & celebrity photos, sport news & rumours, viral videos and top stories from phys.org Daily Mail and Mail on Sunday newspapers.