Adaptive prolonged postreproductive life span in killer whales

Emma A Foster, Daniel W Franks, Sonia Mazzi, Safi K Darden, Ken C Balcomb, John K B Ford, Darren P Croft

Research output: Contribution to journalArticlepeer-review


Prolonged life after reproduction is difficult to explain evolutionarily unless it arises as a physiological side effect of increased longevity or it benefits related individuals (i.e., increases inclusive fitness). There is little evidence that postreproductive life spans are adaptive in nonhuman animals. By using multigenerational records for two killer whale (Orcinus orca) populations in which females can live for decades after their final parturition, we show that postreproductive mothers increase the survival of offspring, particularly their older male offspring. This finding may explain why female killer whales have evolved the longest postreproductive life span of all nonhuman animals.
Original languageEnglish
Pages (from-to)1313
Issue number6100
Publication statusPublished - 14 Sept 2012

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