Beaked whales may evade killer whales by silently diving in sync
Beaked whales have a killer whale problem. More formidable whales, of the sperm or pilot variety, have the size and muscle to flee or defend against a killer whale, an ocean superpredator. Smaller prey, like dolphins, can find safety by swimming in large pods. Certain toothed whales even communicate in pitches killer whales can’t hear. But elephant-sized beaked whales, named for their pointy snouts, have none of these advantages. These extreme divers swim in small groups, are too slow to outswim a killer whale, and rely on audible clicks to echolocate food deep in the ocean. Killer whales (Orcinus orca) should be able to hear them hunting below and easily pick them off as they ascend. But beaked whales have evolved a sneaky trick. An unusual, highly synchronized style of diving helps them silently slip past killer whales when surfacing to breathe, researchers describe February 6 in Scientific Reports. Predation from killer whales has shaped that strange behavior, the scientists say, and also might explain why naval sonar...