Toads grow longer legs to sprint into new territory

CANE toads in Australia have developed longer legs to invade more territory.

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 cover 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, of 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," Mr Shine said in a report in the journal Nature.

Researchers studied toads about 37 miles east of Darwin, the capital of the Northern Territory. They discovered that the toads to arrive first in new areas had longer hind legs than those that came later. They said efforts to control them should be launched before the toads evolve into even more dangerous adversaries.