Grey petrels making a comeback on Macquarie Island

GREY petrels have been making a resurgence on Macquarie Island since the eradication of feral cats, which had prevented the birds from breeding on the island until 2000.

Grey petrel and chick in nest at Macquarie Island. Picture: RICHARD DAKIN

GREY petrels have been making a comeback on Macquarie Island since the eradication of feral cats, which had prevented the birds from breeding on the island until 2000.

And this year Tasmanian researchers have been amazed to discover how far the threatened species flies from the island to gather food.

During winter, Parks and Wildlife Service ranger Marcus Salton counted as many as 94 breeding pairs in burrows on the island and attached matchbox-sized satellite transmitters to the bodies of 10 adults.

Mr Salton said the Department of Primary Industries, Parks, Water and Environment had been studying birds on the island since 2000. They weigh about 1kg and their dimensions and nesting habits resemble those of the unrelated short-tailed shearwaters in Tasmania.

The petrels are unique because they breed as well as forage during winter.

“Until now we knew nothing about their at sea foraging behaviour and habitat use,” Mr Salton said.

“The results were astounding, showing the birds foraged over a very broad area.

“Some flew as far as 3000km east of Macquarie Island past New Zealand, while other birds foraged several thousand kilometres north-west near to Australia.”

He said the revelations could force a rethink of the conservation management plans for the species, including extensions into Australian and NZ territorial waters where the potential for interactions with humans, particularly on fishing vessels, could be greater than first thought.

Mr Salton said continued deployment of the transmitters, which tracked the birds’ movements for more than 100 days before falling off, could eventually build a picture of the birds’ favoured feeding grounds and possible overlaps with fisheries.

The research is a part of the Australian Antarctic Science Program and a joint initiative of DPIPWE and the Marine Conservation Program’s albatross and petrel program.

Mr Salton said there were signs the petrel, which had disappeared from the main part of Macquarie Island in the early 1900s, was also benefiting from the rabbit and rat eradication that ended in 2014.

Originally published as Grey petrels making a comeback on Macquarie Island