North Australian environmentalists say time is running out to save a rare miniature crocodile from extinction.
Ten dead freshwater crocodiles have been discovered in a remote billabong on Auvergne Station near the Northern Territory and Western Australia border.
Post-mortem results showed they died from eating cane toads.
Toadbuster volunteer Sandy Boulter says the rare pygmy crocodile on Bullo River Station further west may suffer a similar fate.
"It doesn't matter the size of the animal, the toxin of the cane toad will kill all of our Australian fauna. Birds, fish, reptiles.
"Cane toads are mighty clever, vigorous little animals and ... they are only 20 kilometres from the pygmy crocodile population."
Toads moving on Kununurra
The Friends of the Kimberley Toadbusters group say almost forty cane toads have also been found on Newry Station, about fifty kilometres from the Northern Territory - Western Australia border.
The group says it's the first time large numbers of male toads have attempted to colonise this close to Kununurra.
Volunteer Sandy Boulter says the pest could reach Western Australia by the end of the year.
"One of (our) teams found three male toads in the culvert beside the Victoria Highway in Fish Creek.
"Five kilometres back they found 32 males and this is the closest that we have found the cane toads on the Victoria Highway corridor."
Cane toad threat to Australian pygmy crocodile
By Nick Squires in Sydney
Last Updated: 11:01am GMT 05/02/2008
A British zoologist is spearheading a campaign to save a unique pygmy crocodile from the depredations of Australia's most dreaded pest, the cane toad.
In a field of science which could scarcely be more Australian, Yorkshire-born Dr Adam Britton is one of the foremost authorities on crocodile conservation and research.
He fears that without prompt action, the toxic toads could wipe out the pygmy freshwater crocodiles, which may constitute a separate sub-species or even species.
Isolated in remote rivers and creeks by plunging waterfalls and steep sandstone escarpments, they are on average around half the size of normal freshwater crocs.
Both saltwater and freshwater crocodiles eat cane toads but quickly die from the poison contained in the amphibians' skin.
The pygmy crocodiles are found in just two known locations - around the Bullo River, on the border of the Northern Territory and Western Australia, and in the Liverpool River in Arnhemland, on the opposite side of the NT.
Their combined population is believed to be in the low hundreds, making them highly vulnerable to extinction.
Time is already running out. Cane toads have already invaded the Liverpool River, but it is so remote that scientists have no idea how badly they have impacted on the pygmy croc population. Toads are swiftly advancing on the Bullo River and are believed to be less than 25 miles away.
Wildlife volunteers have found nearly a dozen dead freshwater crocodiles in the region in recent weeks, all of which died after eating cane toads.
"In one particular incident we found a crocodile hauling itself out of the Victoria River, and it died in its tracks with its tail in the water and its snout on the bank," said Sandy Boulter, a volunteer with a local "toad-busting" conservation group which rounds up and kills the pests.
The Bullo River population of pygmy crocodiles is in the middle of the toads' advance. "We need more testing to establish if the pygmies are genetically different from normal freshwater crocodiles, but either way they are unique," said Dr Britton.
"They're stunted because they live in a marginal habitat with poor food sources - fish are much smaller in the upper reaches of these creeks."
While normal freshwater crocodiles grow up to nine feet long, the pygmies reach barely half that length. Researchers have found adult females which measure just 25 inches.
The cane toad's march has been relentless since a small group was released into Queensland in the 1930s in the hope that they would prey on a destructive sugar cane beetle.
They have hopped across the Northern Territory and are poised to invade neighbouring Western Australia.
The only hope of saving the rare pygmy crocs, Dr Britton believes, is to set up a captive breeding programme at a cost of around £40,000 to £80,000.
But so far neither the Northern Territory nor federal governments has agreed to provide the funding.
"Everyone knows about the giant saltwater crocs of the Northern Territory, but these little pygmies are at the opposite extreme. I believe that like the big salties, they could be a huge tourist asset," said Dr Britton, who comes from Wakefield but moved to Australia 11 years ago.
"As far as we know, Australia is the only place in the world where these creatures are found. This is our last chance to get out there and do something about the threat posed by the toads."