Yellow crazy ant infestation could spread to Queensland's wet tropics, conservationists warn
One of the world’s worst invasive species could spread into Queensland’s wet tropics world heritage area unless there is urgent intervention from the state and federal governments, conservationists have warned.
Yellow crazy ants, which spit formic acid and can form supercolonies that overwhelm native species, have long been an issue in the country’s north, including in Cairns where they have encroached on the world heritage area.
Now a taskforce working for the Invasive Species Council has discovered a new infestation near Alligator Creek in Townsville, less than 5km from protected parklands known for species not found anywhere else.
The organisation wrote to the federal environment minister, Sussan Ley, and Queensland’s agriculture minister, Mark Furner, last month, asking them to jointly fund a program to manage or eradicate the pest from the coastal city.
Its chief executive, Andrew Cox, wrote that significant conservation areas were at risk due to complacency from governments and a lack of adequate resourcing to manage the problem and stop ant colonies from spreading.
“It’s getting more urgent,” Cox said. “We need movement controls in place but they don’t have any in Townsville because they don’t have the resources.”
The new infestation is the fifth to be found in Townsville. Cox said one, near the residential area of Nome, was under control, but three others were expanding with little management over the past year.
The new site near Alligator Creek is 4.5km from the Mount Elliot section of the Bowling Green Bay national park, which Cox said was an area with “exceptional species endemism and is a critical climate refuge”.
He said the park was habitat for unique frogs and lizards, as well as a slug that is only found near the summit of Mount Elliot.
One of the other infestations is at Black River, about 8km from the southern extent of the wet tropics world heritage area and close to the Clemant state forest, the only known location of the critically endangered Gulbaru gecko.
Yellow crazy ants typically prey on small insects and lizards but are dangerous to many animals including birds and household pets, which can be blinded in an attack.
The invasive species gets into vegetation and gardens and can easily spread via activities such as earth moving or the transporting or dumping of garden waste.
Genetic analysis of two new infestations discovered in 2019 and 2020 at Shute Harbour in the Whitsundays found the ants were likely to be linked to outbreaks in Townsville.
The Invasive Species Council said significant work had been done to manage the feral pest around Cairns. But funding cuts, made years ago under the former Newman government, had left Townsville city council “picking up the slack” in the absence of more support.
“They’re limping along,” Cox said. “We’re saying they need $3m a year, shared equally between the state and federal governments.”
A spokesman for Ley said she was reviewing the letter and would monitor the response from the Queensland government.
“The Australian government may also become involved in pest issues where there is a threat to a matter of national environmental significance such as in the Wet Tropics of Queensland World Heritage area,” he said.
He said the government had committed $9m over three years – matched by the Queensland government – to address yellow crazy ant infestations in and adjacent to the world heritage area. But Cox said this money was targeted at Cairns and a slightly smaller pool of funding was needed for Townsville.
In a letter to the Invasive Species Council, Furner said the council would need to show how “re-infestation” of Townsville would be prevented during and after a proposed management program.
He told Guardian Australia that such information was required because the proposal called for a commitment of about $30m over 10 years. Furner added that yellow crazy ants had been deemed non-eradicable, which meant new incursions could occur.
“We will always work with key stakeholders on the best way to manage risks from pests and weeds,” he said.