Cane toads with the personality to boldly go where no cane toad has gone before pave the way for more timid toads to rapidly take over new territories, say Australian researchers.
First introduced into Queensland in the 1930s, cane toads are now found as far south as Sydney and as far west as Kununurra. Despite originating from the rainforests of South America, the toads have managed to conquer some of the hottest and driest parts of the Australian continent.
To understand why cane toads continue to venture into new and potentially hostile environments, the scientists put cane toads from a recently established population in the Northern Territory through a mix of behavioural tests.
They found that some toads were bold and daring, while others were shy and cautious, they report in the journal PLoS One .
It is this mix of bold and shy personalities that has given the cane toads a foothold in Australia, says study co-author Professor Rick Shine of the University of Sydney.
"It is a pretty amazing situation that most frogs are stay-at-home creatures and don't really move too far from where they live, yet here we have got cane toads romping across the landscape," Shine says.
"But if cane toads were all timid then presumably they would still be sitting in Queensland."
To examine how personality traits varied within a cane toad population, the researchers set up feeding stations in the field using artificial lights to attract both insects as food and wild cane toads.
At some of the feeding stations the researchers placed a single cane toad in a mesh enclosure while the other feeding stations were left empty, allowing the wild toads to choose between an empty foraging site or one with another toad present.