Prediction and validation of the potential global distribution of a problematic alien invasive species — the American bullfrog
Article first published online: 1 JUN 2007
Diversity and Distributions
Volume 13, Issue 4, pages 476–485, July 2007
How to Cite
Ficetola, G. F., Thuiller, W. and Miaud, C. (2007), Prediction and validation of the potential global distribution of a problematic alien invasive species — the American bullfrog. Diversity and Distributions, 13: 476–485. doi: 10.1111/j.1472-4642.2007.00377.x
- Issue published online: 1 JUN 2007
- Article first published online: 1 JUN 2007
- Bioclimatic modelling;
- biological invasions;
- climate matching;
- human pressure;
- invasion risk;
- Rana catesbeiana;
- spatial scale.
Predicting the probability of successful establishment and invasion of alien species at global scale, by matching climatic and land use data, is a priority for the risk assessment. Both large- and local-scale factors contribute to the outcome of invasions, and should be integrated to improve the predictions. At global scale, we used climatic and land use layers to evaluate the habitat suitability for the American bullfrog Rana catesbeiana, a major invasive species that is among the causes of amphibian decline. Environmental models were built by using Maxent, a machine learning method. Then, we integrated global data with information on richness of native communities and hunting pressure collected at the local scale. Global-scale data allowed us to delineate the areas with the highest suitability for this species. Predicted suitability was significantly related to the invasiveness observed for bullfrog populations historically introduced in Europe, but did not explain a large portion of variability in invasion success. The integration of data at the global and local scales greatly improved the performance of models, and explained > 57% of the variance in introduction success: bullfrogs were more invasive in areas with high suitability and low hunting pressure over frogs. Our study identified the climatic factors entailing the risk of invasion by bullfrogs, and stresses the importance of the integration of biotic and abiotic data collected at different spatial scales, to evaluate the areas where monitoring and management efforts need to be focused.