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Cane toads may have halved some freshwater crocodile
populations in the space of a year.
Image: iStockphoto

Research by a leading animal ecologist has found that numbers of freshwater crocodiles have more than halved in some Northern Territory waterways due to the westerly advance of the toxic cane toad.

Zoology theme leader with Charles Darwin University’s School of Environmental and Life Sciences, Professor Keith Christian said he believed the biggest threat to freshwater crocodiles came from cane toads.

"A recent survey on the Victoria River (west of Katherine) showed that in a one-year period as many as 77 per cent of the crocodiles have died as a result of eating cane toads, with second-year data also showing evidence of high mortality,” he said.

"Populations can't really withstand that year after year of high mortality, particularly in these really long-lived species that take a long time to mature before they are reproductive."

Professor Christian has been awarded $35,000 from the NT Government to start a monitoring project, and he said he hoped the Commonwealth would contribute an extra $400,000.

He said the funding would enable much-needed research into the new challenges freshwater crocodiles faced.

“Our team of researchers will investigate the effects of cane toads, climate change and demands for water resources on the fresh water crocodiles,” Professor Christian said.

“Increasing demands on freshwater resources are a threat to the freshwater crocodile population, as is global warming which could affect nesting.”