Recent research has shed some light on whether family relationships play a role in beachings of otherwise healthy whales. Investigators used genetic data to describe the kinship of individual long-finned pilot whales involved in mass strandings. The study found that stranded groups are not necessarily members of one extended family, contradicting the hypothesis that stranding groups all descend from a single ancestral mother. Further, many stranded calves were found with no mother in evidence.

Source: Mass strandings of pilot whales may not be driven by kinship, DNA profiles show