SCIENCE ALERT (Australia) 08 May 08 Training Natives to Fear Cane Toads
New research suggests that exposing native animals to smaller cane toads could teach them to stay away from the pests, before more dangerous invaders arrive.
Setting cane toads loose in areas of Australia that don't already have them may sound like a crazy idea, but research by the University of Sydney's Professor Rick Shine suggests this could lessen the toad's impact.
Professor Rick Shine, winner of the prestigious Macfarlane Burnet Medal and Lecture, presented his findings on 7 May at the Australian Academy of Science's Science at the Shine Dome event in Canberra.
The cane toad, Bufo marinus, is a huge pest in eastern Queensland and is rapidly spreading westwards across the Northern Territory into Western Australia, and south through New South Wales.
One of its biggest impacts is killing native Australian animals that eat the poisonous toad. Populations of the Northern Quoll, a threatened species, have been decimated by eating cane toads, as have native goannas, snakes, and freshwater crocodiles.
"We've had no effective way to stop the impact of cane toads on our native fauna," said Professor Shine. "The problem is that all of the toads at the invasion front are very large animals - so large that when a predator attacks one, it is exposed to a lethal dose of poison.
"But if the first cane toad that a predator encounters is a small one, it can survive the experience and learn to stay away from other toads. So we can teach native animals to stay away from cane toads, by giving them a scare with a smaller, less poisonous cane toad, and reduce the number of native animals dying.
"Small toads could be dropped into areas in advance of the spreading cane toad front, to act as 'teacher toads' for native animals. Native animals survive their first encounter with the cane toads, but get slightly ill and learn to keep away.
"To stop these 'teacher toads' becoming a menace in their own right, we can use sterile male toads for this purpose - toads that are unable to reproduce. Producing sterile male cane toads in large numbers is straightforward, due to research by Professor Michael Mahony at Newcastle University."
Professor Shine and his research group, Team Bufo, have collected detailed data on the effectiveness of 'teacher toads' on native fish, frogs and marsupial predators, but more work needs to be done with reptiles.
"Native frogs, fish and mammals learn very quickly when they encounter the 'teacher toads', but we need to do more research with snakes," said Professor Shine.
http://www.sciencealert.com.au/news/20080805-17296-4.html
NORTHERN TERRITORY NEWS (Darwin, Australia) 08 May 08 'Crazy' cane toad research rejected (Matt Cunningham)
A scientist wants to reduce the impact of cane toads by setting them loose where they do not yet exist.
Professor Rick Shine, head of the University of Sydney's Team Bufo which conducts research at Fogg Dam, said small, sterile, male toads should be introduced into unaffected areas so native wildlife could adapt to them.
But the plan has been labelled "crazy'' by Territory toadbusters who have been fighting to stop the spread of the poisonous pest.
Some native species, including the northern quoll, have beendecimated by eating the toxic cane toads.
Professor Shine said if small toads were introduced the animals could learn to stay away from them without being killed.
"The problem is that all of the toads at the invasion front are very large animals -- so large that when a predator attacks one, it is exposed to a lethal dose of poison,'' he said.
"But if the first cane toad that a predator encounters is a small one, it can survive the experience and learn to stay away from other toads.
Professor Shine presented his findings at the Science at theShine Dome event held by the Australian Academy of Science in Canberra yesterday.
But his research has already been ridiculed by Darwin's Frogwatch organisation.
Darwin Lord Mayor and Frogwatch co-ordinator Graeme Sawyer said Professor Shine had to be joking. "I don't know which planet this guy's off,'' he said.
Mr Sawyer said the small toads would soon grow to become large toads and, although sterile, the males' mating calls would attract female toads to the same areas.
Fellow Frogwatch member Ian Morris said research shows small toads are also devastating tolocal wildlife.
"The initial arrival of toads is devastating to the ecosystem,'' he said.
"I would be very cautiousof feeding a new area withsmall toads.''
http://www.ntnews.com.au/article/2008/05/08/4061_ntnews.html
