Platypuses have been removed from drying waterways in Tidbinbilla and taken to Taronga Zoo

Seven platypuses, estimated to be more than half of the population at Tidbinbilla, have been taken from disappearing ponds at the reserve and transported to the Taronga Zoo in Sydney.

Director of Namadgi, Tidbinbilla and Murrumbidgee River Corridor Peter Cotsell said the platypuses would have perished if they were to remain at the ponds.

"About two months ago we noticed the wetlands were drying up and there was no inflows from Tidbinbilla River," he said.

"It's a semi-wild area that does not have access to open rivers right now so we realised we had to move them out ... they were facing mortality if we didn't."

Mr Cotsell said they used their network of experts around the country to determine if a translocation was manageable, which it was.

There was a small window between Christmas and New Year where a team had safe access to Tidbinbilla Nature Reserve to rescue the mammals.

A team that consisted of members from ACT Parks and Conservation, Taronga Zoo and University of NSW researchers staged the rescue on the evening of December 27.

The platypuses were trapped by the team using netting and taken to Taronga Zoo the next morning. Mr Cotsell said the low water levels meant the process was not stressful.

He said they were confident the remaining platypuses could be sustained.

"We looked at the carrying capacity of the wetlands complex as a whole and we determined we could keep seven in the top pond which still has a fair amount of water," Mr Cotsell said.

"We believe we have enough food to keep them going through the summer, if that starts drying out a bit more than we have more capacity to move them to Taronga Zoo."

They plan to return the relocated platypuses 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," Dr Sarah May of ACT Parks and Conservation said.

The platypuses are said to be doing well at their new home in Taronga Zoo.

Platypuses are listed as being "near threatened" by CSIRO and the International Union for Conservation of Nature.

A recent study by the UNSW and the Taronga Conservation Society Australia found that platypus numbers have almost halved since European colonisation.