Marine mammals like whales and seals usually communicate vocally using calls and
whistles.
But
now a Monash University-led international study has discovered that wild grey
seals can also clap their flippers underwater during the breeding season, as a
show of strength that warns off competitors and advertises to potential mates.
This
is the first time a seal has been seen clapping completely underwater using its
front flippers.
"The
discovery of 'clapping seals' might not seem that surprising, after all, they're
famous for clapping in zoos and aquaria," said lead study author Dr David
Hocking from Monash University's School of Biological Sciences.
"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
research, published today in the journal Marine Mammal Science, is based on
video footage collected by naturalist Dr Ben Burville, a Visiting Researcher
with Newcastle University, UK.
The
footage -- which took Dr Burville 17 years of diving to catch on film -- shows a
male grey seal clapping its paw-like flippers to produce a gunshot-like 'crack!'
sound.
"The
clap was incredibly loud and at first I found it hard to believe what I had
seen," Dr Burville said.
"How
could a seal make such a loud clap underwater with no air to compress between
its flippers?"
"Other marine mammal species can produce similar types of percussive sound by
slapping the water with their body or tail," said Associate Professor Alistair
Evans from Monash University, who was also involved in the study.
The
loud high-frequency noise produced by clapping cuts through background noise,
sending out a clear signal to any other seals in the area.
"Depending on the context, the claps may help to ward off competitors and/or
attract potential mates," Dr 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."
Dr
Hocking said clapping seals demonstrates just how much there still is to learn
about the animals living around us.
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," Dr Hocking said.
"But
if we do not know a behaviour exists, we cannot easily act to protect it."
Understanding the animals around us better may just help us to protect them, and
their way of life.
Via Science Daily