Platypus returned to wild at Tidbinbilla Nature Reserve after evacuation to Taronga Zoo during bushfires

Three platypus at the centre of an emergency evacuation during last summer's scorching bushfire season have been returned to their habitat in the ACT.

The animals were moved from Tidbinbilla Nature Reserve near Canberra to Sydney's Taronga Zoo in December, as bushfires loomed and their watery homes came close to disappearing during extreme drought.

Taronga Zoo's Dr Phoebe Meagher said researchers had to move quickly, knowing bushfires were predicted to come through the area in just a few days.

"With the help of the University of New South Wales, we got out the nets and the tinny … and we managed to save seven platypus from the drying creeks," she said.

'Fourteen yabbies a day'

Since just after Christmas, the platypuses have been cared for by staff at Taronga Zoo.

To keep the animals healthy, and to ensure they kept their natural behaviours, keepers handled the monotremes as little as possible.

Dr Meagher said the platypus were fed live food for active foraging, and were kept separate from Taronga's own animals.

"Some of them have nearly doubled in weight — they were eating up to 14 yabbies a day," Dr Meagher said.

Recent rainfall in the ACT has meant Tidbinbilla Nature Reserve is now safe for the animals to return.

"We've had lots of rain, the creeks are full, and there's lots of food available," Dr Meagher said.

She said a second group of platypus would be returned to Tidbinbilla in the coming weeks.

While it was a happy ending for all involved, scientists say such evacuations could become a regular occurrence, as more animals lose their habitats due to climate change.

Before the first group of platypus were released, they were fitted with acoustic tracking devices to help researchers understand more about the animals.

Professor Richard Kingsford from the UNSW Centre for Ecosystem Science said little was known about platypus, as the species was extremely difficult to track in the wild.

"Nothing really sticks on them — so we've been developing these acoustic tags, which are often used on fish," he said.

The tags are implanted in the animals' abdominal cavities, and each one has its own unique signature.

Listening stations are also placed throughout the animals' habitat.

"So when it swims up and down a river or around a pond … it pings them every time it goes past," Professor Kingsford said.

"Even within a day, we were able to tell the three of them were doing pretty well.

"They'd pinged various listening stations that we had there."

Animal evacuations could become more common

UNSW researchers will continue to work closely with the staff at Tidbinbilla to monitor the animals' progress.

But Professor Kingsford warned that similar evacuations may be required in the future, as climate change continues to impact platypus habitat — and the information they gather from the Tidbinbilla animals could be used to inform future rescue strategies.

"We're getting more reports of rivers drying up. The last drought for example, in north western NSW, really impacted on some rivers," he said.

"When that happens, the platypus have nowhere to go. They're very vulnerable to predation, to foxes, pigs, cats and bird of prey."

Professor Kingsford said without water, platypuses could not survive for long.

"The predictions are that our droughts are going to become even more intense," he said.

"So trying to manage rivers better is certainly something we've got some suggestion about."

Tidbinbilla Nature Reserve remains closed for public safety in response to COVID-19, and as the ACT Government works to repair damage from bushfire and floods.