Tooth-marked orca fins hint cannibalism shapes tight-knit pods
Live Science reports two washed-up orca dorsal fins from southern resident orcas found on Russia’s Bering Island, each bearing distinctive killer-whale tooth marks. Genetic testing links the fins to southern residents, while researchers say mammal-eating Bigg’s killer whales may have preyed on them, suggesting occasional cannibalism. The study posits that predation pressure by Bigg’s could help explain why resident, fish-eating orcas form large, protective family groups, though some scientists urge caution and note scavenging or other explanations could account for the marks.
