The cane toad (Bufo marinus), is a large, terrestrial true toad native to Central and South America, but due to his ferocious appetite has since been introduced to various islands throughout Oceania and the Caribbean islands as a method of agricultural pest control.
The cane toad is now considered a pest and an invasive species in many of its introduced regions; of particular concern is that its toxic skin kills many animals—native predators and otherwise—when ingested.
In March last year Professor Rick Shine and colleagues Georgia Ward-Fear and Greg Brown found encouraging evidence of the deadly effect of native meat ants on young cane toads.
The cat food attracts Australia’s carnivorous meat ants, which swarm over and munch on baby toads, killing 70% of them.
The research, funded by the Australian Research Council and published in the February edition of the Journal of Applied Ecology, reveals that meat ants can be used with low risk of collateral damage to native wildlife. The approach is also logistically feasible, low technology and inexpensive.
Unlike many previous efforts at pest control in Australia, like the cane toad itself, the use of meat ants promises to be "a useful component of a broadly-based ecological approach," says University of Sydney Professor Rick Shine.
"It’s not exactly rocket science," Shine told national broadcaster ABC. "We went out and put out a little bit of cat food right beside the area where the baby toads were coming out of the ponds.
"The ants rapidly discovered the cat food and thought it tasted great. The worker ants then leave trails back to the nest encouraging other ants to come out there and forage in that area, and within a very short period of time we got lots of ants in the same area as the toads are," he said.
"Even the ones that don’t die immediately, die within a day or so of being attacked," Professor Shine said, adding that native frogs were able to dodge the hungry ants.
"It’s a simple, low-risk way of reducing the number of baby toads coming out of those ponds."
See video about cane toads (flash required)