Friday, January 12, 2007

Toadbusters: busting toads!

Toadbusters: busting toads!

January 11, 2007 - The Kimberley Toad Busters group says it has made a significant step forward in its battle to halt the spread of cane toads into Western Australia. The Kimberley-based volunteer group of cane toad busters believes it may have found a way of stopping the relentless spread of the dreaded pest across northern Australia.

Cane toads (Bufo marinus) were introduced to Queensland decades ago to try to stop beetle damage in sugar cane crops. Instead, they became a major invasive species. Cane toads have been steadily moving across northern Australia towards WA for years. Now they are near the border...

In attempts to control the native Cane Beetle, 102 Cane Toads were introduced to Australia from Hawaii in June 1935. They bred immediately in captivity and by August 1935 more than 3000 young toads were released in areas around Cairns, Gordonvale and Innisfail in northern Queensland.

More Toads were released around Ingham, Ayr, Mackay and Bundaberg. Releases were temporarily limited due to environmental concerns, but resumed in other areas after September 1936. Since their release, toads have rapidly multiplied in population. There are now estimated to be 200 million cane toads in Australia, in a range that covers Queensland, the Northern Territory and New South Wales.

Unfortunately for Western Australia, the toads are closing in on its border. And as scientists work on genetic control of the invasive pest, a local community group is taking up the fight.

Kimberley Cane Toads president Lee Scott Virtue said that for the first time cane toads had not returned to an area the group had worked in for the last four months.

The Kimberley Cane Toad group has removed thousands of colonising males from Brownies Dam, two hectares of dams and billabongs, 210km east of the WA border, between Timber Creek and the Victoria River Roadhouse, in the Northern Territory, Ms Virtue said. "The trick is to try and bust them out, get them out of the system before they start calling and that appears to be what we've done. The last three weekends of checking the system out has revealed not a single toad..."

Knowing where the cane toads are and how they are moving means it's easier to know what to do next dry season to stop continuous waves of toads. "We're knocking out eggs, tadpoles and metamorphs", Ms Virtue said. "This consistent approach and the identification of what the toads are doing and where they are going gives us a pretty good opportunity of holding up this frontline."

"By knocking out the females ... it's causing some real ripples in the male toad behaviour in those areas... it's quite possible that we're having a major impact on their ability to breed."

The cane toad 'Buffo marinus' is recognised by the IUCN and the Global Invasive Species Programme as one of the world's 100 worst invaders (Lowe et al. 2000).

Adult Cane Toads are active at night during the warm months of the year. During the day and in cold or dry weather they shelter in moist crevices and hollows, sometimes excavating depressions beneath logs, rocks and debris. They can survive the loss of up to 50% of their body water, and can survive temperatures ranging from 5 - 40ÂșC.

Cane Toads eat almost anything they can swallow, including pet food, carrion and household scraps, but most of their food is living insects. Beetles, honey bees, ants, winged termites, crickets and bugs are eaten in abundance.

Meanwhile, Professor Peter Koopman, from The University of Queensland’s Institute for Molecular Bioscience, is developing a strain of “daughterless” cane toads - toads that can give birth only to sons.

“We hope to transplant a ‘gene’ into toads that will cause any female tadpoles they produce to change course and become males,” he said. “All of the offspring of this genetically engineered toad would thus be male, and they would all be carrying the daughterless gene."

"It’s probably the greenest and safest solution to manage the cane toad problem – it doesn’t involve any toxins or pathogens, so the toads cannot develop immunity against it, and there is no risk to native frog species that we want to protect,” Professor Koopman said.


Cane Toads are considered a pest in Australia because they:
* poison pets and injure humans with their toxins
* poison many native animals whose diet includes frogs, tadpoles and frogs' eggs
* eat large numbers of honey bees, creating a management problem for bee-keepers
* prey on native fauna
* compete for food with vertebrate insectivores such as small skinks
* may carry diseases that are can be transmitted to native frogs and fishes.

"It is important to recognise that the pristine terrestrial and aquatic habitat systems of the Kimberley are already under threat. Current land-care and resource management policies undertaken by land and resource managers have had a detrimental impact on Kimberley bio diversity.

"Most of our plant and animal bio diversity is in a fragile state. The impact of the cane toad, if allowed to happen, will literally destroy one of the last unique bio diversity wilderness frontiers in Australia." - Lee Scott-Virtue.



Kimberley Toad Busters Inc -
Toad busters claim breeding cycle interrupted - ABC News
New hope to halt cane toads - The Age
Bufo marinus - Invasive Species
Australian Museum - Cane Toads, Giant Toads or Marine Toads
Cane Toad - Wikipedia, the free encyclopedia
Northern Australian Cane Toad Site
Killing off the cane toad - University of Queensland

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