Platypuses seem to be settling in nicely to their new Royal National Park home, although there are concerns about pollution from a nearby colliery.
It has been three months since the historic return of platypuses back to Royal National Park, with all 10 platypuses settling into their new home, after their disappearance several decades ago.
The National Park is now well positioned to support these platypuses as they enter their breeding season, with a reintroduction program led by a collaboration between the Platypus Conservation Initiative (UNSW Sydney), WWF-Australia, NSW National Parks Wildlife Service and Taronga Conservation Society.
Researchers have continuously tracked the six female and four male platypuses that were introduced back in May this year. After some early long-distance movements recorded, the platypuses appear to be familiarising themselves with their new home and settling into their respective home ranges. Courtship and breeding are anticipated in the coming months.
Dr Gilad Bino, a researcher at UNSW's Centre for Ecosystem Science and a leading expert on platypus conservation, leads the reintroduction project. He is very happy with the early results of the platypus reintroduction to the park.
"We've all been anxiously monitoring the platypuses since reintroduction and are delighted that they all seem to be settling nicely," he says.
"We went through a long process of investigating whether conditions in the park could support platypuses and so far, so good. We are now waiting to see how their breeding season goes."
Diverse food supply
Dr Tahneal Hawke, a platypus researcher and part of the Centre of Ecosystem Science says conditions in the park were favourable for the new population of platypuses.
"The water quality prior to release was within a favourable range, with evidence of a stable and diverse food supply for the platypus," she says.
In the lead up to the re-introduction, following overflow of fine coal material in late 2022 due to high rainfall, the team carefully tested water quality and found no evidence of poor water quality affecting the system. Recent extreme flooding events in the catchment are still a source of concern, increasing sedimentation and pollution from the local town and a coalmine. On 7 August, there was another threat following a significant rainfall event when a colliery land slip deposited a large amount of sediment into the Hacking River.
"In 2022, we did not identify significant impacts on downstream macroinvertebrate, the main food supply of platypus, however water quality and food availability need to be regularly monitored to evaluate any impacts from sedimentation on habitat quality," says Dr Hawke.
Professor Richard Kingsford, Director of the Centre for Ecosystem Science and platypus translocation team member, is cautiously optimistic about the platypuses' survival in Royal National Park.
"We are hopeful because we know platypuses are remarkably resilient animals, often occurring in urban environments. But we must be forever vigilant for the survival of this unique species and make sure these pollution events don't happen. Platypuses can be a flagship for river health."
Platypuses are facing multiple threats across their range, putting considerable strain on their ability to thrive over the longer term. They are currently listed as 'Endangered' in SA and 'Threatened' in Victoria. There is an increasing need to actively manage their conservation for the ongoing survival of their populations, including such initiatives as the reintroduction program at the Royal National Park.
About the Platypus Reintroduction Project: The Platypus Reintroduction Project is a collaborative effort between the Platypus Conservation Initiative (UNSW Sydney), WWF-Australia, NSW National Parks Wildlife Service and Taronga Conservation Society. The project is guided by a commitment to preserving the park's unique biodiversity and supporting the long-term success of the platypus population.
