Curtailing the spread of invasive toads

Invasive species represent a major threat to ecosystems worldwide. In a recent article published in Journal of Applied Ecology, my colleagues and I investigate whether we could halt the spread of one of the world’s worst invaders: the cane toad (Rhinella marina). Cane toads have marched rapidly across the Top End of Australia, but in order to invade further into Western Australia, the toads must disperse through a narrow coastal corridor connecting the Kimberley to the Pilbara. This is a pretty dry part of the world, and so farmers in this region have constructed numerous artificial waterbodies to water their livestock. Unfortunately, these watering points are ideal breeding and refuge sites for cane toads, and thus may serve as critical stepping stones for toads as they attempt to spread along the corridor.

In our paper, we use a stochastic simulation of cane toad spread to show that excluding toads from just one hundred of these artificial waterbodies could significantly reduce the probability that toads could reach the Pilbara. Importantly, this corridor connects extensive patches of suitable habitat for toads, and thus excluding toads from artificial waterbodies could prevent them from occupying 268,000 square kilometres of their potential range in Western Australia; an area of land larger than the State of Victoria! However, before we can implement this strategy, we will need to conduct a much more holistic analysis that considers not only ecological costs, but economic and societal costs as well. The optimal strategy for doing so is a topic for another day…

You can read the article free of charge courtesy of the kind folks at Journal of Applied Ecology. Also check out my co-author Ben Phillips chatting about our work over at The Conversation and on ABC Radio National, and head over to the Faculty of 1000 to read a review of our work by Mark Lonsdale and Hazel Ruth Perry.

Reid Tingley, Benjamin Phillips, Mike Letnic, Gregory Brown, Richard Shine and Stuart Baird (2013). Identifying optimal barriers to halt the invasion of cane toads Rhinella marina in arid Australia, Journal of Applied Ecology, 50, 129-137. doi: 10.1111/1365-2664.12021.