Yahoo News 18 Feb 10;
SYDNEY (AFP) – Australia's vile and poisonous plague of cane toads may finally have met its match -- and it comes in a tin of cat food.
After years spent trying to batter, gas, run over and even freeze the toxic toads out of existence, scientists say just a dollop of Whiskas could stop the warty horde.
The cat food attracts Australia's carnivorous meat ants, which swarm over and munch on baby toads killing 70 percent of them.
"It's not exactly rocket science. 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," University of Sydney professor Rick Shine told public broadcaster ABC.
"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."
Australia is beset by millions of cane toads after they were introduced from Hawaii in 1935 to control scarab beetles.
The toads, which are prolific maters, eat anything and are incredibly tough, secrete poison that kills pets and wildlife and injure humans, prompting several -- unsuccessful -- campaigns to wipe them out.
"Even the ones that don't die immediately, die within a day or so of being attacked," 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."
Meat ants devour cane toads
University of Sydney, Science Alert 19 Feb 10;
With cat food as bait, scientists from The University of Sydney's School of Biological Sciences have succeeded in showing that native meat ants can assist in controlling the spread of cane toads.
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.
Now they have further proven their thesis by luring ants to cane toads with cat food.
Professor Shine and his colleagues observed ant-toad interactions on the Adelaide River floodplain 60km east of Darwin, Northern Territory, in the Australian wet-dry tropics during last year's dry season.
Ant densities and toad mortalities increased "more than fourfold" with the addition of cat food baits.
"We can look at an interaction that's already happening, meat ants are already killing millions of cane toads," Professor Shine explains. "We're just looking to make it a bit easier for 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 Professor Shine.
"If we understand the vulnerability of the cane toad we can develop a number of combined tactics to combat this deadly invader," he says.
The team observed the effect of native meat ants on cane toad metamorphs (the first stage of the toad's terrestrial development) near bodies of water, and explored the cane toad's vulnerability to the native predator as a potential means of controlling cane toad numbers.
When cat food was introduced as bait, ant numbers grew and cane toad numbers declined more quickly.
"The end result," the study explains, "is that higher ant densities kill more toads, and kill toads of a wider range of body sizes."
The research continues from a study published by the team last year, which revealed an ecological and behavioural 'mismatch' between cane toads and meat ants. While meat ants posed little enduring threat to native frog and toad species, cane toads were found to be poorly-equipped to escape them.
Cane toads are easy targets for meat ants because unlike their native counterparts they do not try to avoid them at great speed. In addition, cane toads are likely to use the ineffective tactic of crypsis, or immobility, instead of more active escape tactics.
The study found 98 per cent of metamorph toads were encountered by meat ants and 84 per cent were attacked within a very brief (two minute) period. Over 50 per cent of attacks were immediately fatal, while 88 per cent of 'escapee' toads died within 24 hours.
It is hoped the technology will form part of a multi-pronged attack on cane toads.
"No single control will be a silver bullet to eradicate the cane toad from the Australian landscape," says Professor Shine.
However, "if we understand the biology of cane toads and their interactions with Australian fauna we'll be in a much better position to control them."
