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When post-menopausal female orcas are present, calves in their family group have better survival rates, according to a study published Monday (December 9) in the PNAS. This “grandmother effect” has been observed in humans, and scientists have suspected it exists in orcas for some time, but the current study is the first to quantify how beneficial it is for calves to have a grandmother.
Orca pods are matriarchal, with females reaching around 90 years old, which means that after they go through menopause around age 45, they have another 45 years of life in which to pass along critical information to the rest of the pod about the location of food.
“In killer whales, what granny knows is really, really important,” Hal Whitehead of Dalhousie University who was not involved with the study, tells Science.
The team of researchers, led by Daniel Franks of the University ...
