Cane toads weren't allowed to compete in the Olympics, but scientists have raced cane toads in the laboratory and calculated that they would not be able to invade Melbourne, Adelaide or Hobart and are unlikely to do well in Perth or Sydney, even with climate change.
According to research by Dr Michael Kearney, from the Department of Zoology at the University of Melbourne, and collaborators from Australia and the USA, the cane toad's march will grind to a halt once it is physically too cold for the toads to hop.
"The cane toads cannot survive in much of Southern Australia because they would be too cold to move about and forage or spawn" said Dr Kearney.
Their study is unique in that it is based on an understanding of the capabilities of the toad itself whereas many other studies some predicting that Melbourne would be invaded by the toads are based on correlations between climate and the places the toads are living at now, which can lead to errors.
Since their introduction to Australia in the 1930s, cane toads have been steadily advancing across Australia and have already invaded Brisbane and Darwin. Once used as pest control, the toads are now a devastating pest themselves so an accurate prediction of their final range and rate of movement is essential.
If there were a cane toad Olympics, all eyes would be on the weather: because they are cold-blooded, the toad's ability to move depends on its body temperature which fluctuates with its environment.
Dr Kearney and his colleagues, including Dr. Ben Phillips from the University of Sydney and Dr. Chris Tracy from Charles Darwin University, set up a 2m sprint event for toads at a range of different temperatures to see what temperatures would slow toads down the most.
The team used field-collected toads from four populations across the invasion front.
"We found that cane toads can barely hop once they get below about 15 degrees Celsius", s
|Contact: Nerissa Hannink|
University of Melbourne