28 Jun 2011

Offshore islands yield a seabird surprise

By BirdLife Australia
Last summer, when members of the Australasian Seabird Group (a Birds Australia’s [BirdLife Partner] special interest group) ventured onto the Broughton Islands offshore from Port Stephens on the NSW coast, they had little idea of what treasures they would uncover. They surveyed three outer islets off the main island that had not been visited by ornithologists since the early 1970s. With landing treacherous even in the calmest of conditions, it was easy to understand why they had not been visited since then. The undoubted highlight was the discovery of a population of (Vulnerable) Gould’s Petrel breeding at three separate sites on Little Broughton Island. One of Australia’s rarest seabirds, with populations formerly in serious decline and listed as Endangered under the EPBC Act, the species had also been discovered during the previous summer breeding on Broughton Island itself. Before that, the birds had only been recorded nesting on Cabbage Tree Island and Boondelbah Island, about 12 km to the south-west. The discovery of extra breeding islands is a boon for the conservation of the species—in the space of a year, the number of known breeding islands has doubled. Sharing the island group with the petrels were 100,000 pairs of Wedge-tailed Shearwater, as well as nesting Short-tailed Shearwater and White-faced Storm-Petrel, Crested Tern and Silver Gull. More good news from Little Broughton Island was the discovery of a thriving population of Blue-tongued Lizard, which gives a clear indication that rodents have been successfully eradicated from the island group. Gould’s Petrel have benefitted from a number of conservation interventions on their breeding islands in recent years, and their success raises the hope that petrels will be able to colonise other rat-free islands in the group. “Unfortunately, the picture from these surveys is not all good,” said Nicholas Carlile, Secretary of the ASG. “Both Broughton and Little Broughton Islands were known as breeding sites of Sooty Shearwaters in the 1970s, but this species was absent from the latest survey”. The seabirds of two of the smaller islets of the Broughton group are yet to be surveyed, and members of the ASG hope to do so in 2011. With their recent track record, who knows what treasures they might find?