Grey seals observed communicating by clapping underwater

Feb. 3 (UPI) -- For the first time, grey seals have been observed clapping underwater to communicate.

Like whales and dolphins, seals typically use a variety of calls to communicate with one another. But during breeding season, researchers discovered grey seals using claps to demonstrate their strength to would be competitors and potential mates.

"The discovery of 'clapping seals' might not seem that surprising, after all, they're famous for clapping in zoos and aquariums," lead research David Hocking, a biologist at Monash University in Australia, said in a news release. "But where zoo animals are often trained to clap for our entertainment -- these grey seals are doing it in the wild of their own accord."

The new study, published in the journal Marine Mammal Science, was made possible by the recording efforts of Ben Burville, a visiting researcher with Newcastle University in Britain.

Burville, who has been diving with seals for 17 years, captured footage of a male seal slapping its flippers together to make a loud, piercing crack. The clap recalls the sound made by a beaver's tail slapping the surface of a pond.

"The clap was incredibly loud and at first I found it hard to believe what I had seen," Burville said. "How could a seal make such a loud clap underwater with no air to compress between its flippers?"

Analysis of the footage captured by Burville suggests the high frequency sound waves created by the clap can penetrate background noise, ensuring the clapping seal is clearly heard.

"Depending on the context, the claps may help to ward off competitors and/or attract potential mates," Hocking said. "Think of a chest-beating male gorilla, for example. Like seal claps, those chest beats carry two messages: I am strong, stay away; and I am strong, my genes are good."

Just as noise from loud boat engines and sonar from sea vessels can disrupt the communication abilities of whales, human-caused noise pollution could interfere with the high frequency sounds made by clapping grey seals.

"If we do not know a behavior exists, we cannot easily act to protect it," Hocking said.