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THE INDEPENDENT (Joahannesburg, S Africa) 14 February 06 Fat, ugly and poisonous - and he's mutating
Paris (AFP): The cane toad (Bufo marinus), a species which was introduced into the Australian state of Queensland 70 years ago to tackle insect pests in canefields and has since become an ecological catastrophe.
Weighing in at to up 2kg, the unwanted anuran has extended its range to more than a million square kilometres in tropical and sub-tropical Australia, crushing native species in its relentless advance.
A team of toad watchers positioned themselves on the front line of the invasion, 60km east of the city of Darwin, and for 10 months caught toads, some of which they radiotagged and let loose again.
They were astonished to find that the creatures can hop up to 1,8km a night during wet weather, a record for any frog or toad.
The creatures can hop up to 1,8km a night during wet weather, a record for any frog or toad
But even more remarkable was the discovery that the first toads to arrive at the front invariably had longer hind legs than those which arrived later.
By comparison, the toads which are living in the long-established Queensland colonies have much shorter legs.
The case is being seen as a classic example of Darwinian evolution - animals that are stronger, faster or smarter are able to stake out new territory and defend it against those that are weaker, slower or less astute.
The findings also neatly explain a puzzle surrounding the cane toad.
From the 1940s to 1960s, the critter expanded its range by only 10km a year.
On Tuesday, though, it is advancing at the rate of more than 50km annually.
The reason: with longer legs, the mutating species is able to travel further, faster.
The authors, led by Richard Shine of the university's School of Biological Sciences, say the cane toad is a chilling lesson for governments to combat invasive species as soon as possible, "before the invader has had time to evolve into a more dangerous adversary."
Fat, ugly and poisonous - and he's mutating

DISCOVERY-ANIMAL PLANET () 15 February 06 Toxic Toads Evolving Super-Fast (Larry O'Hanlon)
Fat, toxic toads at the leading edge of an Australian invasion have evolved longer legs than those behind the front lines, report biologists.
The alarming discovery not only means the toads can spread more quickly over the continent, but it raises the possibility that under the right conditions, animal evolution can happen in just decades, not eons.
That, in turn, has major implications for animals adapting to global warming, as well as biological pest control projects, which generally take for granted that carefully studied animals introduced to fight off invasive species can not evolve into something troublesome.
The inexorable, seven-decade-long expansion of cane toads from their disastrous introduction to Queensland in 1935 has long been monitored by biologists.
One such biologist was recently driving along a toad-crowded road one night, along the invasion front about 40 miles east of Darwin, when he noticed how desperately the toads were hopping grimly toward him, all facing the same way: into virgin territory.
"It was just like an invasion in a science fiction movie," said biologist Richard Shine of the University of Sydney.
Shine is a snake specialist, but when the toads began heading toward his study area, he decided it would be wise to "know thine enemy" before they arrived, he explained.
So for years Shine and his colleagues have been tracking cane toads, and as a matter of course they weigh the toads and measure them. Those records came in handy when they discovered that some cane toads at the invasion front were covering an unprecedented mile-and-a-quarter (two kilometers) each night.
"Sure enough, there was a pattern," said Shine of their astonishing leg-length discovery.
Not only were the legs of pioneer toads significantly longer, but the same athletic build dies out among toads as areas become more settled.
In other words, there appears to be a great advantage to getting the first crack at virgin territory. That boils down to the opportunity to produce more viable tadpoles that grow up to continue the line. For seven decades now that advantage has been awarded to cane toads with the longest legs. That has lead to the steady breeding of longer and longer-legged toads that can keep beating the crowd.
The disheartening result is that the toad invasion rate has increased from seven miles per year in the 1950s to a whopping 30 miles per year today, report Shine and his colleagues in the Feb. 16 edition of Nature.
The silver lining is that the cane toads are showing how quickly some species can adapt to new environments, a challenge now facing innumerable species worldwide as the global climate warms, said ecologist and rapid evolution researcher David Skelly of Yale University.
"We never think of evolutionary changes happening that fast," said Skelly of his fellow ecologists.
That has to change, because the cane toads are just a high profile case of something that is being seen in many organisms all over the planet, he said.
"It doesn't mean that we have no problem (with climate change) or that all species will be viable," said Skelly. But there is evidence that many species might be more able to adapt than previously believed.
Another place where people have to start thinking about rapid evolution is at the federal and state agencies where they evaluate exotic species for release as biological checks on exotic pests, said Skelly.
Right now those agencies don't consider the possibility that a new exotic species will very likely change in its new environment, for better or worse. It's time they started thinking differently, he said.
http://animal.discovery.com/news/briefs/20060213/toad.html

TOWNSVILLE BULLETIN (Australia) 17 February 06 Toads not mutants (Daniel Bateman)
The Northern Territory is for wimps -- North Queenslanders have been battling super-sized cane toads for more than 60 years.
Researchers said this week that the territory was being invaded by mutant cane toads that were five times faster than their predecessors from the 1940s.
James Cook University toad expert Ross Alford, however, said the cane toads were not mutant variants of toads elsewhere in Australia, rather ancestors of the faster, stronger toads normally seen at the front of an invasion, such as those that originated in North Queensland decades ago.
"I'm not sure you can say for sure they are mutants yet," Prof Alford said.
"It would just be the result of 60 years of the bigger, faster toads being the ones that moved the fastest.
"The toads that are all over the place first do tend to leave a lot more offspring than your average toad because there's nothing competing with them and it does take the predators a little while to kind of home in on them.
"And so for the first year or so they are really successful and if that happens over 60 years, you could end up with a bit of a change.
"These are the sprinters -- a long line of athletes in the family, you might say."
The University of Sydney scientists' research found the toads had long, faster legs which made up 45 per cent of their body length.
Prof Alford said this confirmed that bigger toads were at the frontline of the toad invasion.
"Lots of animals' legs just don't grow in proportion, for example you think about humans," he said.
"Children have proportionally really big heads, so as humans get bigger their heads get relatively smaller and similar sorts of things happen with all kinds of body parts.
"It's possible what they're looking at is what we've known for ages, which is just that toads are bigger at the front of the invasion."
Prof Alford said there was an opportunity for evolution within cane toad populations.
"Because there are very large numbers of them, there is more opportunity for evolution because the more animals you've got, the more chance there is to have a few unusual ones survive," he said.
"And it is possible that not just because they are bigger, but because the big ones travel faster and have been at the front of the invasion for 60 years now, that it's been reinforced by genetics."
http://townsvillebulletin.news.com.au/common/story_page/0,7034,18173556%5E14787,00.html

NORTHERN TERRITORY NEWS (Darwin, Australia) 18 February 06 20,000 on cane toad express (Emma Gumbleton)
Up To 20,000 tiny cane toads have invaded Darwin's outskirts.
In the past three days, businesses off the Stuart Highway at Holtz have reported toadlets in numbers so large they completely cover the ground.
Workers at Butler Place are trying to catch and freeze the quick-moving toadlets, which are under a centimetre long.
"You should see the driveway in the morning," employment specialist Sandra Cook said.
"There was literally hundreds. It looked like a plague of crickets.
"I opened the side door (of the shed) and hundreds jumped out. They started jumping on my feet."
The road runs alongside a storm water drain.
Spokesman for FrogWatch North Paul Cowdy said it takes only one female toad to cause such a massive outbreak, laying 20,000 eggs at a time.
It's the third toad outbreak in the greater Darwin area so far, with smaller toad explosions at Marlows Lagoon and McMinns Lagoon. Diesel contractor Peter Sulhan said he tracked the tiny pests back to the drain after toads started knocking on his door.
"At the front door of my shed, all these little toadlets hopping around," he said. "In the mornings, especially after the rain it's shocking. You get hundreds. You couldn't count them, you'd lose count at about 50."
Mr Cowdy said: "These are the first outbreaks and I think we can expect to see more from now until the beginning of the Dry," Mr Cowdy said.
"In terms of stopping cane toads, it's best to catch them before they breed. After that it's quite hard."
Toadlets have only a one per cent chance of reaching adulthood.
20,000 on cane toad express