Orca moms baby their adult sons. That favoritism pays off — eventually

Salmon-hunting Pacific females feed their sons for years, boosting chances of grandwhales

Two orca whales breaching.

Exceptional family records on some Pacific killer whales (from the population where these two live) show that a young orca mother’s annual chance of weaning another calf drops by about half after she has a son. Yet there’s a big genetic bonanza.

David K. Ellifrit/©Center for Whale Research (research permit number: NMFS 21238)

Among some killer whale moms, lifelong feeding for adult sons but not daughters could be a long-term investment play.