NATIONAL POST (Toronto, Ontario) 15 February 06 Adaptive toad nothing to cheer about: Australian nuisance
(AFP) He's fat, ugly and poisonous -- and he's mutating.
He's the cane toad (Bufo marinus), a species that was introduced into the Australian state of Queensland 70 years ago to tackle insect pests in canefields.
Weighing in at to up two kilograms, the unwanted anuran has extended its range to more than a million square kilometres in tropical and subtropical Australia, crushing native species in its relentless advance.
A team of University of Sydney toad watchers positioned themselves on the front line of the invasion, 60 kilometres east of the city of Darwin, and for 10 months caught toads, some of which they radio-tagged and released.
They were astonished to find that the creatures can hop up to 1.8 kilometres a night during wet weather. But even more remarkable was the discovery that the first toads to arrive at the front invariably had longer hind legs than those that arrived later.
By comparison, the toads that are living in the long-established Queensland colonies have much shorter legs.
The case is seen as a classic example of Darwinian evolution -- animals that are stronger, faster or smarter stake out new territory and defend it against those that are weaker, slower or less astute.
The research appears this week in the science journal Nature.