The Invasive Species Council (ISC) has raised concerns about this unusual rafting behaviour as Australia prepares for more cyclones, calling it clear evidence that “fire ant densities are increasing”.
“The recent heavy rainfall and wild weather in the region could accelerate the spread of fire ants, one of the world’s worst invasive species,” warned Invasive Species Council advocacy manager Reece Pianta.
“Fire ants are more active before or after rainfall and can form large floating rafts which move with water currents to establish footholds in new areas. We have recently seen evidence of this rafting behaviour on cane farms south of Brisbane.”
These super pests have the potential to wreak havoc on ecosystems, cause agricultural losses, and even kill humans and animals with their stings.
As wild weather continues to batter the country, two more cyclones are forming near the coasts and likely to impact the country in the next few days.
Tropical Cyclone Anggrek, currently a category one storm and the first of the season, is moving at a sluggish pace toward the south.
The Bureau of Meteorology warns that the cyclone is expected to pass west of the Cocos (Keeling) Islands on Thursday night or Friday morning, potentially bringing damaging wind gusts and increased rainfall to the region.
Tropical Cyclone #Anggrek is currently near the Cocos Islands. The category 1 system is expected to move southwards over the next few days. It's highly unlikely to impact mainland Aus, but gale force winds could be felt in the Cocos Islands.
Latest: https://t.co/tXIDmsdn29 pic.twitter.com/nDt9rHBIKQ
— Bureau of Meteorology, Australia (@BOM_au) January 16, 2024
The slow-moving system also carries the risk of rough seas, moderate swells, and flooding in low-lying areas on the northern side of the islands. As the cyclone drifts south, it is expected to gain strength over the next 48 hours.
Meanwhile, on the mainland, another storm system is brewing off the Queensland coast, possibly developing into a cyclone by Monday.
With more rainfall on the way, Australia faces the dual threat of more days of flooding and fire ants’ relentless spread via floodwaters.
Rafting is a survival strategy employed by these ants when their environment is inundated with water. Individual fire ants clump together to create floating structures that allow them to float over the waters and move as a colony.
The sightings of these ants have recently spread as far as the New South Wales province, despite efforts to contain them in Queensland, where they were first spotted in 2001. Last week, ants took over a northern Gold Coast sporting ground, leading to a local cricket match getting cancelled.
Researchers from the Centre of Excellence of Biosecurity Risk Analysis say they have the potential to drive some of Australia’s species to extinction.
A fire ant infestation at a northern Gold Coast sporting ground has forced the cancellation of a key local cricket fixture. The two-day tie between Helensvale and Mudgeeraba was scrapped when the nest was spotted on Tuesday. https://t.co/tIEQ9JOpss #7NEWS pic.twitter.com/jNMugvx2n1
— 7NEWS Gold Coast (@7NewsGoldCoast) January 11, 2024
The origin and spread of these ants, which are native to South America, is a mystery. Nobody knows how they arrived in Australia but some experts have pointed out that it could be through shipping.
Communities in southeast Queensland and northern New South Wales are being urged to stay vigilant, as these resilient ants are hitching rides on flood currents to establish footholds in new areas.
An absence of natural predators in Australia make it an ideal habitat for fire ants. Experts warn that if unchecked, these ants could potentially occupy the entire continent, except the most extreme cold regions.
Invasive Species Council CEO Andrew Cox earlier said that unless Australia ramped up its eradication programme, it could suffer a damage bill of billions of dollars.