Climate change to ‘disperse’ cane toads

Climate change will aid the spread of noxious pests such as cane toads, with an expert predicting their toxic march could reach as far Perth and other parts of WA’s coast.


After years of trying to hold back the westward path of the pests, authorities captured the first toad that hopped across the NT/WA border earlier this month.

Associate Professor Grant Wardell-Johnson, from Curtin University of Technology, said their arrival should act as a warning on all introduced species.

“While the initial colonisation wave seems very scary, cane toads are only one of many species on the move,” he said on Friday.

“Climate models predict that as the weather heats up, cane toads will go in search of suitable habitats further and further afield.

“It’s inevitable that eventually we will see them in Perth and in the south-west.”

Since being introduced to Queensland in the 1930s, cane toads have spread across northern Australia.

They have already ravaged the world heritage-listed Kakadu National Park, killing everything that eats them, from crocodiles to quolls, as they moved north to Darwin.

But cane toads will not be the only pests to take advantage of a warmer Australia, said Prof Wardell-Johnson.

“More worrying is the march of other species across landscapes as a result of climate change,” he said.

“While cane toads do cause damage to local ecosystems, their environmental impact seems to be exaggerated and is far outweighed by the damage caused by other more serious threats such as Phytophthora, cats and foxes.”

He said other introduced species would react to global warming, with disastrous impacts on native wildlife and flora.

“Many species that are currently ‘sleepers’ will become much more serious pests as the effects of climate change are felt,” he said.

“Like cane toads, these species will take to the road looking for more suitable habitats and will leave a trail of destruction as they go.”

The first toad to hop into WA was a 10cm male, which authorities captured near the Great Northern Highway.

His arrival came despite the millions of dollars spent by commonwealth, state and territory governments in an effort to stop the toads’ western migration.

Prof Wardell-Johnson called on governments to strengthen quarantine services.

“This is the best way to approach the issue because once a species is established eradication is almost never an option and the costs of management skyrocket quickly,” he said.

“But the real answer lies in bringing carbon emissions under limits that will enable human society to continue to live comfortably.”

If climate change continued unabated, the professor said cane toads and other introduced species would fare better than people.