Work is underway to reduce the impact of the invasive Cane Toad on native species in the Fitzroy River valley.
Environs Kimberley (EK) is working with Gooniyandi Rangers based at Fitzroy Crossing to select sites of importance in terms of natural and cultural significance and focus on these sites to reduce the impact on native species. Funding is being provided by Rangelands NRM through the Australian Government’s National Landcare Programme.
Cane Toads are well into WA and are making their way across the Kimberley region despite widespread efforts by many to stop them. Each wet season they move further across country, holing up in the dry season in refuge sites including lagoons and creekbeds.
Dr Steve Reynolds, EK’s Project Officer for the Kimberley Nature Project said broad scale species-level approaches are required if toads are to be stopped or even slowed. However, right now they are focusing on more local-scale approaches.
“Once the sites were selected, we are providing the ecological knowledge and the Rangers are providing the all-important intimate knowledge of country such as knowing where springs are in otherwise dry areas,” he said.
“These locations will be ideal habitat for toads when they invade this part of the Kimberley, hence our selection of sites for monitoring.”
During the 2015/16 and 2016/17 wet seasons EK and the Rangers worked in the Mimbi and Ngumpan areas about 80 kilometres east of Fitzroy Crossing, an area of (Devonian reef) limestone that houses several caves.
“Most people visit the Mimbi Caves area during the day, but we visited the area at night when frogs and other nocturnal animals were active,” Dr Reynolds said.
In this area they found both the Green Tree Frog (Litoria caerulea) and the closely related but even more spectacular Splendid Tree Frog (Litoria splendida).
Ground-dwelling frog species included the beautifully patterned Ornate Burrowing Frog Platyplectrum ornatum, the Variegated Burrowing Frog Cyclorana longipes, and the Giant Burrowing Frog Cyclorana australis, a large brown frog that is often mistaken for being a cane toad.
Dr Reynolds said this is particularly a problem on roads where drivers may only gain a glimpse of the animal as it hops across.
Reptiles such as the Stimson’s Python Antaresia stimsoni, Burton’s Legless Lizard Lialis burtonis, and Northern Beaked Gecko Rhynchoedura sexapora were also discovered during the nocturnal expeditions.
To protect these animals from the cane toad invasion it is planned to remove toads from these sites.
“The aim is to reduce the initial impact of the wave of toads arriving, which seems to be the most perilous time,” Dr Reynolds said.
“If we can reduce the numbers then this may give the native animals a little bit of time to recover and maybe learn not to eat toads.”
He said evidence from elsewhere suggests that there is gradual recovery of animals after toads enter their habitat.
“Goannas are often the worst hit and because they are also traditionally hunted they are one focus of our efforts.”
Dr Reynolds said it is hard to say what will be the eventual distribution of the cane toad in northern Australia.
“Hopefully they will be stopped by the arid area of the Great Sandy Desert, but in the interim we must do what we can to try and slow their progress and prevent loss of our native species in the Kimberley”
Image: the Splendid Tree Frog is found in the Fitzroy Valley that is at risk