Parents, at least the human sort, know the benefits of having a grandmother close by: the extra help with child care, the reassuring advice borne from years of experience. In evolutionary biology, scientists call this the “grandmother effect,” and have hypothesized it’s one of the reasons humans live so long.

Now, a new study suggests that the effect isn’t limited to humans, and that killer whales also benefit from having grandmothers around. The study, published Monday in the Proceedings of the National Academy of Sciences, found that grandmother killer whales helped improve their grandcalves’ chances of survival, particularly when food was scarce.

The findings may shed light on an enduring mystery: why some whale species live for years after they go through menopause and stop reproducing. The study showed that, by stopping reproduction, grandmother killer whales avoided conflict with their reproducing offspring and helped their grandcalves find enough to eat when salmon stocks dwindled.

“Having a living grandmother improves your survival; you’re less likely to die when she’s alive than in the years following her death,” Stuart Nattrass, the study’s lead author, and a researcher at the University of Hull, in Britain, wrote in an email.