February 21, 2010

Cat Food Helps Fight Cane Toads

Australians have discovered a new weapon in the fight against the dreaded cane toad problem plaguing the country: cat food, reports the Associated Press.

According to researchers from the University of Sydney, placing a few tablespoons of cat food next to ponds in the Northern Territory attracts ferocious meat ants. When the baby cane toads come to the surface of the water, the ants turn their attention to them and attack fiercely.

The attempt to wipe out the cane toad from Australia has been an endless battle. The toad, which is native to Hawaii, was introduced in 1935 in a unsuccessful attempt to control beetles that were affecting sugarcane plantations. The toads multiplied quickly, and soon they numbered in the millions. They are a widespread nuisance across much of Australia, and threaten many other indigenous species.

Despite many different methods used to fight the pestilent creatures, their population continues to grow. Golf clubs and cricket bats only do so much damage, and an attempt to freeze or gas them with carbon dioxide proved futile.

Cane toads emit a toxin that attacks the heart of potential predators. Rick Shine, a professor at the University of Sydney who supervised the research, told The Associated Press that for some reason meat ants are not affected by the poisonous toxin.

The cane toad, which can have as many as 30,000 eggs in a single clutch, is an ideal food source for hungry meat ants. Baby cane toads emerge from the pond in numbers in the tens of thousands in a single night. "They are vulnerable to meat ants if the colony discovers there is a source of free food," Said Shine.

Researchers, who conducted the study between July and September 2008, observed thousands of cane toads emerging from the cat-food lined ponds and found that nearly 98% of them were attacked and killed by the meat ants within a few minutes. Of the toads that were able to escape, 80 percent of those died within a day from injuries from the attack.

Shine admitted that "It's a pretty unequal fight." These baby toads are less than a half-inch in size, or about the same size as the meat ant. Yet, the aggressive meat ants have powerful jaws and are capable of killing even larger animals by attacking in numbers. "The toads have this terribly stupid response to attack "” which is just to freeze and do nothing," he said.

Not everyone agrees that the new cat food method is effective. Graeme Sawyer, an official for the environmental group Frogwatch, said the technique is not powerful enough to wipe out the toxic amphibian. He told reporters that the results may be significant in a small number of cane toads, "but when you get areas where there are large numbers of cane toads it doesn't seem to make any difference at all."

Australia's Royal Society for the Prevention of Cruelty to Animals said the technique is inhumane. They agree that the cane toad population must be controlled, but urge researchers to find effective methods that do not involve unnecessary pain or distress.

Shine admitted that the studies didn't have all the right answers. He added that it is unlikely that there will ever be an end to the cane toad crisis in Australia.

The results of the study were published in last week's British Ecological Society's Journal of Applied Ecology.


On the Net: