Long Legged Cane Toads Lead Australia Invasion
Date: 16-Feb-06
Country: UK
The toads, which are a threat to native species, were introduced into Australia 70 years ago to control insect pests in sugar cane fields.
They now spread across a range of a million square kilometres in the north and east of the country.
Their territory is likely to get larger because the toads' longer legs make them faster, according to Richard Shine and researchers at the University of Sydney.
"We find that toads with longer legs can not only move faster and are the first to arrive in new areas, but also that those at the front have longer legs than toads in older populations," Shine said in a report in the journal Nature.
The researchers studied toads leading the invasion about 60 km (37 miles) east of the northern city of Darwin. They discovered that the first toads to arrive in new areas had longer hind legs than those that came later.
The scientists believe the toads evolved longer legs to conquer new territory to get to better food supplies.
They added that efforts to control the pests should be launched before the toads evolve into even more dangerous adversaries.
