How much more invasive can the four worst invasive amphibians become?

In a new collaborative project led by Desiree Andersen from the Lab of Animal Communication at Ewha Womans University, we assessed the risk of invasion by the four most invasive amphibian species worldwide:  Duttaphrynus melanostictus, Rhinella marina, Lithobates catesbeianus and Xenopus laevis.

Invasive species have a massive impact on their environment and predicting geographical zones at risk of invasion is paramount to the control of further invasions. We modeled global habitat suitability for all four species using ecological niche factor analysis to predict the most susceptible areas to invasion. 

Models showed suitable climatic conditions for all four species expanded beyond their current native and invasive ranges. Tropical, subtropical, and island biomes around the world were among the areas with the highest ENFA suitability for all four species. Further, marginality statistics indicate niche expansion in D. melanostictus, and generalism in the three other species. As only climatic variables were used in the modelling, these results show the ultimate distributions if all landscape conditions are met without significant barriers to invasion.