简体中文
A wild grey seal has been filmed clapping its flippers underwater for the first time.
The underwater footage, filmed near the Farne Islands off the coast of Northumberland, shows the male seal repeatedly clapping its flippers to create a loud gunshot-like noise.
The video is part of an international study led by Monash University, Australia, and has been published in the journal Marine Mammal Science.
Image:Seals make the noise during breeding season. Pic: Ben Burville
Dr Ben Burville, a researcher at Newcastle University, has described the moment he captured the phenomenon.
"I've heard the distinctive shotgun-like cracks many times over the years and I felt sure this clapping behaviour was the source, but filming the seals in action has eluded me for 17 years," he said.
"Then one day I had heard a couple of claps in the distance, I just hit the record button and eureka! I got it!
"The clap was incredibly loud and at first I found it hard to believe what I had seen. How could a seal make such a loud clap underwater with no air to compress between its flippers?"
He added: "Diving with seals is my passion and I have spent more time underwater with grey seals than anyone in the world.
"And yet they still amaze me every time and capturing this previously unseen behaviour just makes me realise how much there still is to learn about these incredible creatures."
Image:Dr Ben Burville says diving with seals is his 'passion'. Pic: Ben Burville
While humans clap to applaud or express approval, in the case of wild grey seals (Halichoerus grypus), this gesture signifies quite the opposite.
Scientists believe male seals clap to demonstrate their strength, as part of an attempt to ward off competitors and attract potential mates.
The action produces a "loud high-frequency noise", sending out "a clear signal" to other males in the area.
In the video, the male seal can be seen swimming close to a female, with other males lurking nearby, before it starts clapping.
Lead author Dr David Hocking, from Monash University, said: "The discovery of 'clapping seals' might not seem that surprising, after all, they're famous for clapping in zoos and aquaria.
"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 researchers say understanding more about grey seals and other marine life could help protect the species against the harmful effects of pollution.
Dr Hocking added: "Clapping appears to be an important social behaviour for grey seals, so anything that disturbed it could impact breeding success and survival for this species.
"Human noise pollution is known to interfere with other forms of marine mammal communication, including whale song.
"But if we do not know a behaviour exists, we cannot easily act to protect it."
