#grandmotherlove Orca-grandma care proves good for grandchild survival. So far we only knew the “grandmother effect” in humans. But grandmothers are of vital importance to grandchildren as well in orcas.

The death of an orchaggrandmother is disastrous for her grandchildren. In the two years after that death, her grandchildren have four and a half times as likely to die herself compared to orcas whose grandmother is still alive. And if that dead grandmother couldn't have children herself, that chance of death is even more than six and a half times greater. This is an important proof that grandmothers in orcas are important for the survival of their grandchildren, and all postmenopausal grandmothers. For the first time in an animal species, the “grandmother effect” previously discovered in humans, a team of researchers writes in the PNAS this week. Orca women get into menopause around the age of 40, but can be 80 years old.

Grandmother love