31 March 2011

NZ fur seal population boom could spell doom for Kangaroo Island's little penguins

New Zealand fur seals on Kangaroo
Island. Photo by Mike Lehmann.
Some rights reserved.
AUSTRALIA - What is good news for Kangaroo Island's New Zealand fur seals is bad news for its little penguins. The fur seal population in South Australia is exploding, and it could spell the end of large penguin colonies on the island.

New Zealand fur seals were nearly wiped out by early colonial sealing, Simon Goldsworthy, associate professor at Flinders University's School of Biological Sciences, told The Australian, when more than 100,000 fur seals were taken from Kangaroo Island.

Since commercial sealing stopped, however, the fur seal population has been increasing for at least the last 30 years according to the IUCN Red List.

Bill Haddrill, Kangaroo Island's conservation program manager with the Department for Environment and Heritage, told The Australian there are currently about 25,000 fur seals in Kangaroo Island waters, with the population expanding at a compound rate of 10-12% a year.

South Australia's wildlife authorities see this rebuilding of the fur seal population as a natural phenomenon, and say it would be futile to intervene.

However, Simone Somerfield feels somewhat differently about what she described as the "wholesale slaughter" by these furry predators of the little penguins who nest at her Penneshaw Penguin Centre on Kangaroo Island.

Three years ago, the penguin population at the centre was 200 birds. Today it is less than half a dozen.

Ms Somerfield has seen the predatory powers of the fur seals first-hand and said she didn't know how the penguins would survive on Kangaroo Island because of the way they were being attacked.

She told The Australian that at first she saw the penguins being taken one at a time and would say, "That's amazing, it's like David Attenborough."

"But then it was more and more and more, and then mass kills in which the seals were not even eating them. It was happening within 100m and you have a complete view, it was like watching a horror movie," she said.

But Mr Haddrill said that it was likely penguin numbers and distributions on Kangaroo Island were returning to historical norms.

"It is not clear if there has been a decline in the overall population or in the distribution along the shore line," he said. Kingscote, on the northern side of the island, now had a steady population of 700 to 800 breeding birds and, although the number of penguins on Penneshaw's main beach had significantly reduced, there were higher numbers at the nearby North Shore.

According to Professor Goldsworthy, there will always be little penguin colonies breeding on Kangaroo Island, but large colonies may be a thing of the past now the fur seal population is recovering.

Sources
Fate of island penguins appears sealed as hunted become hunters by Graham Lloyd, 26 March 2011, The Australian

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