SYDNEY, Nov. 7 (Xinhua) -- Juvenile leopard seals are increasingly flocking to Australian shores, an expert has found.
Sam Thalmann, a marine biologist with 20 years of experience based in Tasmania, said that in a typical year there were three to five leopard seals spotted in the island state.
"This year we've seen more than 10 individuals just over the last three and a half to four months," Thalmann told the Australian Broadcasting Corporation (ABC) on Tuesday.
The seals that have been spotted in Tasmania were usually not yet of breeding size, Thalmann found.
He said that the spike tended to happen once every seven years or so.
"In their young years, as they discover their range, they can disperse a lot further than the adults do," Thalmann said.
"There is a little bit of a driver potentially due to different sea-ice levels in Antarctica."
"The cycle that we see may well be related to environmental cycles within Antarctica, but we don't think this is anything to be alarmed by."
Tasmania's Department of Environment has used the opportunity to study the Antarctic predators and monitor their diets.
"We've documented about six separate individuals that are foraging on different kinds of seabirds, from kelp gulls to sea gulls, penguins, cormorants and even fur seals," Thalmann said.
"And these are all diet items that are typical within leopard seals foraging within the Antarctic, and the sub-Antarctic and around Tasmania.
"We do expect them sooner or later to head back down to Antarctic waters where they'll start to look to moving into their adult lifestyle and start to breed."
Researchers on Macquarie Island, a sub-Antarctic Australian territory, and in New South Wales (NSW) have also observed a record number of the seals.