Orange shows current cane toad range, the lighter shade shows the new predicted range.

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Posted 25 February 2009

A new approach by researchers in predicting the range of invasive species in Australia under climate change shows cane toads are likely to move about 100km further south.

The researchers have also predicted that the toad’s breeding season in northern Australia could be reduced by as much as four months.
Michael Kearney and colleagues came up with the new range after modeling the likely impacts of climate and topography on the energy and water-balance off the different life-cycle stages of the toad, as well as the potential for activity, development, and survival.

This method, based on physiological constraints, contrasts with the more usual practice of simply extrapolating from species occurrence, and is likely to yield more realistic predictions.

Their method also allows for predictions about the potential for species to evolve around constraints. For example, there is potential for cane toads to expand further south if they evolve changes in their thermal sensitivity.

References
Kearney, M., B. L. Phillips, C. R. Tracy, K. A. Christian, G. Betts, and W. P. Porter. 2008. Modelling Species Distributions without Using Species Distributions: The Cane Toad in Australia under Current and Future Climates. Ecography 31: 423-34.