Platypus numbers decline

Research shows there is a decline of up to 30 per cent in the numbers of the iconic platypus, with localised declines and extinctions being increasingly reported. Fortunately, the Queanbeyan platypus population seems to be one of the more healthy in the state.

Geoff Williams, of the Australian Platypus Conservancy, has previously consulted with the Queanbeyan-Palerang Regional Council.

Though he flagged some concerns about further development around the river, saying any construction “over the river would have to be carefully timed,” Mr Williams was generally positive about Councils management of the species.

Mr Williams said, “Council are well aware of the parameters for such work” and “they did an excellent job in ensuring that the new Ellerton Drive Extension roadbridge was timed in such a way as to minimise any impact on platypus.”

Scientists are concerned about the loss of the platypus following almost three years of data capture. A national risk assessment was conducted by UNSW and funded by the Australian Research Council.

It used information obtained from the past two centuries on the whereabouts and population of platypus. This data was then combined with random capture surveys.

“We have great concerns about the future survival of this unique species,” project leader Professor Richard Kingsford, director of the UNSW Centre for Ecosystem Science, said.

Threats to the platypus populations include river regulation and flow disruption, increasing agricultural land use, pollution, and the capture of platypus in fishing and yabby nets.

“All of which are contributing to these declines across its range,” he said.

The national survey showed great variability in platypus numbers in eastern Australia.

UNSW researcher Dr Gilad Bino said “On degraded rivers, typically below dams and in regions of high agricultural land use, we generally see lower numbers of platypus, likely due to the impacts these threats have on bank erosion and availability of macroinvertebrate food sources,” he says.

Tahneal Hawke, a PhD candidate at UNSW said, “Previously we’ve had no information on historical platypus abundances and without this baseline reference we become misinformed about what a normal abundance is.

“This shift in our perception is particularly important for such a cryptic animal.

“Sightings are rare, people perceive sightings of a few platypuses to be indicative of the population, but historical records suggest numbers far exceeded observations.”

Iconic: Platypus numbers decline, with Queanbeyan River survivng. Photo supplied.

Iconic: Platypus numbers decline, with Queanbeyan River survivng. Photo supplied.