With rivers drying up and platypuses becoming stranded, scientists are concerned for the future of the species.

Platypuses were once considered widespread across the eastern Australian mainland and Tasmania, although their distribution or abundance has been hard to measures because of the species’ secretive and nocturnal nature.

Now, a new study has examined the potentially devastating combination of threats to platypus populations, including water resource development, land clearing, climate change and increasingly severe periods of drought.

Alarmingly, the study estimated that under current climate conditions and due to land clearing and fragmentation by dams, platypus numbers almost halved, leading to the extinction of local populations across about 40 per cent of the species’ range, reflecting ongoing declines since European colonisation.

Under predicted climate change, the losses forecast were far greater because of increases in extreme drought frequencies and duration, such as the current dry spell.

Dr Gilad Bino, a researcher at UNSW, says action must be taken now to prevent the platypus from disappearing.

“There is an urgent need for a national risk assessment for the platypus to assess its conservation status, evaluate risks and impacts, and prioritise management in order to minimise any risk of extinction,” Dr Bino says.

The International Union for Conservation of Nature (IUCN) recently downgraded the platypus’ conservation status to “Near Threatened”, but the platypus remains unlisted in most jurisdictions in Australia – except South Australia, where it is endangered.

Study co-author Professor Richard Kingsford said platypuses often live in areas undergoing extensive human development that threatens their long-term viability.

“These include dams that stop their movements, agriculture which can destroy their burrows, fishing gear and yabby traps which can drown them and invasive foxes which can kill them,” Prof Kingsford said.

The full study is accessible here.