Evaluating Local Factors Shaping the Distribution of the Invasive American Bullfrog in a Mountainous Region of Argentina

Abstract

Areas with aquatic ecosystems invaded by the American bullfrog face the challenge of managing its proliferation worldwide. This amphibian is native to eastern North America and is now invasive in several regions. This study reports a new invasive population in the Ctalamochita River basin (Río Tercero, Córdoba Province; Argentinian) and outlines its potential distribution using a species distribution model. Utilizing a MaxEnt model at a small geographic scale allowed us to explore the effects of local land use on the distribution of the species Aquarana catesbeiana. By combining 26 bullfrog records with 10 environmental variables, we identified coverage (coverage natural: pond coverage) as the most influential factor in the model. Our analysis also revealed positive associations between bullfrog presence and average annual precipitation, pH, percentage of sand, percentage of organic matter and distance from the nearest locality. Notably, our results demonstrate the significant role of humans as intentional dispersers of bullfrog. MaxEnt shows four most relevant areas, of which two: Río de Los Sauces to Villa Cañada de Álvarez and Villa Cañada de Sauce, are already colonized by the species. While the areas of Lutti and Cerro Pelado reservoir have a high probability of occurrence of bullfrog. Given the conservation significance of these areas, predicting the probability of bullfrog establishment is critical for risk assessment and conservation planning. Implementing control and monitoring strategies in Córdoba province is crucial to prevent bullfrog spread and mitigate environmental impacts in natural habitats.