Arthritis may stop cane toads
2008-12-02 17:48
Sydney - It seems a bad back might be the only thing that can stop the relentless spread of Australia's poisonous cane toads, which are killing native animals as they hop across the nation, researchers say.
Australia's army couldn't stop the cane toads, which number
around 200 million. Residents swinging golf clubs failed and so
did a campaign to freeze them to death in refrigerators.
But now an Australian scientist says evolution has seen the
biggest and fastest cane toads interbreed, resulting in
arthritis and bad backs which could slow them down.
"Cane toads moving across Australia are the fastest
amphibians on earth after their rapid evolution from
slow-moving homebodies into road warriors over the past 70
years," Rick Shine at Sydney University said in a statement received on Tuesday.
Thousands of cane toads moving in a front across tropical
eastern Queensland state can travel 10m
overnight, researchers say.
Those at the front of the invasion near the Western
Australian state border can cover one kilometre on a wet night - 10 times the distance.
"Toads that run at the front of the pack are becoming
bigger and faster. They have different personalities, different
shapes and are developing different physiologies," said Shine.
The bigger, faster toads produce babies with bigger front
legs and longer backs and consequently suffer arthritis.
"We are seeing toads in the Northern Territory with spinal arthritis - big, bony lumps on their spine," said Shine.
Worst environmental mistake
Cane toads are one of Australia's worst environmental
mistakes, ranking alongside the catastrophic introduction of
rabbits.
The toads, introduced in a batch of 101 from Hawaii in 1935
in a failed bid to control native cane beetles, have spread
3 000km from northeast Queensland to Darwin in
Australia's tropical north.
The spread of the toads, whose skin is poisonous, has led
to dramatic declines in populations of native snakes, goanna
lizards and quolls, a cat-sized marsupial.