Half the platypus population at Tidbinbilla Nature Reserve have had to be rescued from their disappearing ponds as the drought takes its toll on the ACT’s popular animal sanctuary.
Seven platypus – two males and five females – are now recovering at Taronga Zoo in Sydney after their life-saving rescue late last month when it was feared the water bodies would be completely dry within weeks, with the dire situation compounded by severe fire conditions.
Researchers from Taronga Conservation Society Australia and the UNSW Sydney’s Centre for Ecosystem Science teamed up with officers from ACT Parks and Conservation to rescue the unique animals on 27 December when there was a small window to access Tidbinbilla safely.
Taronga’s Manager of Conservation and Recovery Programs Andrew Elphinstone said it was feared the platypus would have perished in the worsening conditions.
“With an ever-decreasing water body comes the reduction in resources including food. It was feared there were not enough prey items to support the platypus population,” he said.
ACT Parks and Conservation Service regional manager Pete Cotsell said platypus were quite a fragile species and once stressed it was not long before they died.
“That’s why we took ours out so early because once they are distressed it is not far till mortality,” he said.
Mr Cotsell said the drought meant there was no water in the system to fill the drying ponds, and there were no escape routes as Tidbinbilla is a sanctuary designed to keep out predators.
About six or seven platypus were left in the top pond which remains full, and leading researchers had advised that was the right carrying capacity.
“If that gets worse and starts drying up we’ve got capacity to move them to Taronga, too,” he said.
Recent rainfall had hardly touched the surface at Tidbinbilla and there had been nothing for the actual wetland complex.
The rescued platypus would return home when the ponds hopefully filled up by autumn/winter.
Mr Cotsell said Tidbinbilla had a long working relationship with Taronga Park and other animals had previously been removed to Sydney when sick or conditions at the Reserve deteriorated.
The Zoo was one of Tidbinbilla’s primary stakeholders and the Reserve relied on it for advice and assistance.
Mr Cotsell said the platypus were very happy at Taronga and feeding, a primary indicator of how they were settling in.
“If stressed they’ll stop eating and their fur condition will deteriorate. We’ve had good advice from Taronga and our vets have been up there monitoring them,” he said.
Rescue team member Dr Sarah May from ACT Parks and Conservation said the platypus had nowhere to go and would have almost certainly perished.
“I can’t thank Taronga and Dr Richard Kingsford’s team from UNSW enough for helping us save these animals. We will return them when conditions improve, but given how extreme conditions are currently, I fully expect that it will be many months before we see enough rain to replenish this wetland and warrant their return,” she said.
Platypus were once considered widespread across the eastern Australian mainland and Tasmania, although not a lot is known about them because of their secretive and nocturnal nature.
A new study, led by UNSW and supported by Taronga Conservation Society Australia, has for the first time examined the risks of extinction for platypus.
The study estimated that under current climate conditions and due to land clearing and habitat fragmentation by dams, platypus numbers had almost halved since European colonisation, leading to the extinction of local populations across about 40 per cent of the species’ range.
As a result of predicted climate change conditions, the losses forecast in the study were far greater because of increases in extreme drought frequencies and duration, such as the current dry spell.
According to Professor Richard Kingsford, the Director of the Centre for Ecosystem Science at UNSW, platypus waterholes in some NSW rivers are drying up and stranding animals, as a result of the drought and exacerbated by river management.
“Our research has indicated that these incidences will likely increase in an increasingly dry future,” he said
The platypus is currently listed as ‘near threatened’ by the International Union for Conservation of Nature (IUCN). Experts have recommended that this be downgraded to ‘vulnerable’.
Mr Cotsell said that while platypus populations in the Murrumbidgee River were not actively monitored, he believed continuous environmental flows out of the Cotter Dam were helping to maintain habitat and food sources.
“No deaths have been reported recently, so no news is good news,” he said.
The rescue team included Dr May and colleague veterinarian Dr Arianne Lowe, Taronga’s Wildlife Conservation Officer Dr Phoebe Meagher and platypus keeper Rob Dockerill, and researchers from UNSW led by Tahneal Hawke.