On the sea-salted slopes of Broughton Island, a team of volunteers is capturing more knowledge about the local land birds in a monumental five-year study.
Members of the Hunter Bird Observers Club have recently spent three days on the island, north-east of Port Stephens, catching and releasing dozens of birds in a delicate operation.
“We believe no one has studied land birds on a mainland Australian island before,” said team leader Alan Stuart. “On Broughton Island, most attention has been on the seabirds.”
By way of preparation, club members had been travelling to the island from 2012 to 2016 to conduct surveys. They estimated there were 30 species, including 13 land birds, that they believed were either resident or regular visitors to the island.
“From that we’ve established there are birds that are here all the time, but now we’ve got to prove that,” Mr Stuart said
Since winter 2017, club members have been on the island each season to catch birds and put a band on their legs.
The hope is to later recapture a banded bird, to learn more about their growth, their patterns, and to prove they live on the island.
“As time goes by, we’ll build up information about the birds that are here all the time, and get a better idea of the bird population,” Mr Stuart said.
But first the birds have to be captured. On the summer field trip, team members unfurled nine fine-mesh nets in areas where birds flew through. The researchers said the nets didn’t cause harm.
“The birds’ welfare always comes first to us,” said Rob Kyte, as he straightened a net in a clearing in the scrub.
Within a couple of hours, the team of 11 had caught a silvereye and a tawny grassbird. The birds were examined at a makeshift research station at the National Parks and Wildlife Service hut on the shores of Esmeralda Bay.
Club member Judy Little placed a small metal identification band on each bird’s leg. While Mrs Little gently held the creature, Rob Kyte took measurements and weighed the bird. Once the information was recorded, the bird was released.
“We’re building local knowledge and national knowledge, because what we collect goes into a national database,” Mr Stuart said.
In the course of the three-day trip, 51 birds were caught, banded and released, including three elusive brown quails.
“Wherever you walk, you can hear them,” said Greg Little in the field on the first day.
The team had to improvise to catch the quails, using ground traps and Weet-Bix as bait.
One team member, Fred van Gessel, also captured sounds. His specialty is recording bird calls, and he has collected about 40,000. Mr van Gessel estimated this was his 10th visit to Broughton Island since 1972.
“I still love it here,” he said. “It’s a place to constantly explore, and you can always find something here.”
The island, which is part of Myall Lakes National Park, has been undergoing rapid change since the eradication of rats and rabbits in 2009. National Parks and Wildlife Service ranger Susanne Callaghan said the bird studies were vital to charting that change and the impact that had on the island’s wildlife.
“We hope to learn more about what’s happening since the pest eradication, because the changes in vegetation trigger changes in the land birds,” Ms Callaghan explained. “As the researchers find out more, it is a benefit to us for the management of the island.”
After three field trips, club members have now placed bands on about 150 birds. The team will return to the island in autumn.
“We’ll keep plodding away,” said Alan Stuart. “We’ll keep assembling the jigsaw.”