Southern long-finned pilot whales are marine mammals with a lot to say—and they may use vocalizations (发声) to outsmart a deadly enemy. 

Cetaceans (鲸类动物) such as whales and dolphins communicate through sound to find food and mates, to navigate and to interact socially. Their vocalizations 1 between species and within communities. The animals can mimic (模仿) artificial noise such as sonar, but nobody had previously recorded them 2 other cetaceans' sounds. A new study, however, found overlap in the cetacean sound book.

Researchers listened to 2, 028 vocalizations of long-finned pilot whales off the coast of Australia, the first time sounds from the species in this region have been 3 described. They were surprised to hear 19 instances of vocalizations that resembled those of orcas—the whales' oceanic 4 . " We found some calls that are, to the human ear, 5 to the killer whale calls in the same area, " says Christine Erbe, an expert in Marine Science and Technology.

Pilot whales and orcas, the two largest species of cetaceans, are often seen in the same 6  and are similar sizes, and both live in social groups. Orcas compete for food with long-finned pilot whales and are 7  their predators (猎食者) . 

 8  from orca stomachs shows they do occasionally eat pilot whales. But pilot whales can mob and chase orcas away, the only cetaceans seen 9  themselves from their predator in this way. 

Mimicry could serve as an 10 defense: " One theory is that if they use similar sounds, they may not be recognized as prey, " Erbe says. Pilot whales hunting or eating orcas' food remainders might go 11 if they use orca-like calls. " This is all underwater, where light travels really poorly, " she adds. " So these animals 12 sound for detecting their prey and predators and for navigating. " Long-finned pilot whales have shown an ability to 13 between orca calls with different meanings.

Additional work would 14 whether mimicry is actually occurring. Researchers could pair their listening data with direct observations of the animals' interactions in the wild or perhaps even play orca sounds and watch the whales' 15 .