Northern and Southern Giant Petrels expected to “bounce back” on Macquarie Island following losses from the Macquarie Island Pest Eradication Project

Rachael Alderman (Department of Primary Industries, Parks, Water and Environment, Hobart, Australia) writes in the latest on-line number of the Australian Antarctic Magazine on deaths from non-target poisoning, especially of ACAP-listed Northern Giant Petrels Macronectes halli, caused by the Macquarie Island Pest Eradication Project (MIPEP).

She describes “the impact of poison baiting on giant petrels, during the rabbit, rat and mouse eradication project on the island.  A 30% decline in the population of both northern and southern giant petrels has been observed, but there is optimism that populations will bounce back.”

Of a total of 2500 birds known to have died over the 2010 and 2011 bait drops, 760 were giant petrels with the ratio between Northerns and Southerns M. giganteus being 40:1.  Eighty percent of the giant petrels found dead were males, reflecting their more terrestrial feeding habits in comparison to females which feed more at sea.  The similar decline in numbers of Southern Giant Petrels, but with far fewer corpses found on the island, is suggested to be due to birds dying at sea.

Meanwhile MIPEP Manager Keith Springer reports to ACAP from Macca on the ongoing searches for any remaining rabbits and rodents on the island: “Feb[ruary] will be our last month for hunting fieldwork on Macquarie (where I am currently spending the summer) – with any luck we should be able to announce it as done at the end of March”.

Northern Giant Petrel, photographed by Marienne de Villiers

Click here to read the latest MIPEP Blog for last month on changes to Macca’s vegetation by Field Assistant Lachlan Francis.

Click on MIPEP to access 17 news stories in ACAP Latest News posted over the last three years on progress with the pest eradication project on Macquarie Island.

Reference:

Alderman, R. 2013.  Managing the cost of pest eradication.  Australian Antarctic Magazine 25: 18-19.

John Cooper, ACAP Information Officer, 25 January 2014