One of those hypotheses — that family bonds play into the stranding phenomenon — is now subject to question, based on genetic analysis of hundreds of beached whales in New Zealand and Australia. The mothers of beached calves, for instance, often were missing entirely from the beach, says cetacean researcher Scott Baker, associate director of the Marine Mammal Institute at Oregon State. Given whales’ strong kinship bonds, this familial separation could signal some disruption prior to the stranding — a disruption that could, in fact, play a role in triggering the event.
“Rescue efforts aimed at ‘refloating’ stranded whales often focus on placing stranded calves with the nearest mature female” on the assumption she’s the mother, Baker says. “Our results suggest that rescuers should be cautious when making difficult welfare decisions … based on this assumption alone.”