Chewed-up orca fins on Russian beach point to cannibalism, and scientists say it may explain why some pods are so tight-knit Live ScienceCannibal killer whales a sign of evolution in action Oceanographic MagazineRussian killer whales locked in bloody clan wars turning to cannibalism to survive Daily StarSevered Fin Reveals Rare Killer Whale Cannibalism and Questions the Differences in Orca Species Discover MagazineCannibalism may explain why some orcas stay in family groups New Scientist