Motion sensor cameras have revealed the confronting spread of cane toads across Western Australia’s eastern Kimberley region.
Supported by the World Wide Fund for Nature-Australia, the Nyaliga Rangers deployed cameras at 141 locations between August 2020 and October 2022.
The devices were left out for two months at a time, spread through the vast Nyaliga country spanning almost 640,000 hectares across the former Durack River and Karunjie cattle stations.
Cane toads were detected 256 times across 20 sites, while feral cats were picked up on 52 occasions between 34 sites.
Cattle were detected 145 times across 15 sites.
The western chestnut mouse was the only native animal found in greater abundance in the results of the extensive wildlife survey, which is said to be the first of its kind undertaken across Nyaliga country.
Only two goannas were detected across three years of surveillance.
“When the cane toads came through, definitely the goanna population declined heaps,” ranger Silas Purcell said.
“I think they will come back in time, once they learn they can’t eat toads. I’m starting to see lots of little goannas.”
Northern nail-tail wallabies, short-eared rock wallabies, dunnarts, echidnas and various reptiles and birds were among the native species detected by the cameras.
A surprise inclusion was the Ningbing false antechinus, a carnivorous marsupial weighing about 15 grams.
“They are a secretive and elusive species never before recorded in Nyaliga Country,” WWF-Australia conservation field officer Nick Weigner said.
“We found the Ningbing in a remote gorge area in the north, it’s very rocky terrain which might have helped it persist despite the presence of feral species.”
It is hoped the survey results will help the rangers identify high-value conservation areas for future protection.
They are being supported by the Wilinggin and Nyaliga Aboriginal corporations to manage pest species, destock cattle and conduct cultural fire management.
Cane toads first crossed into WA from the Northern Territory about 15 years ago and have slowly spread their way through the Kimberley.
On nearby Bunuba country, local rangers have been attempting to stop the freshwater crocodiles residing in Danggu Gorge from being poisoned by the pests.
Working with researchers, they inject nausea-inducing chemicals into cane toad corpses which are presented as baits, conditioning the crocs not to eat the introduced pests.