Non-Native Herpetofauna Continue to Proliferate in the World's Most Invaded Herpetofauna Community

The spread of non-native species continues to increase around the globe, highlighting the importance of understanding both the dynamics of the invaded communities in which non-natives comprise a high percentage of the total fauna and the factors that may influence non-native establishment and spread. As the global hotspot for non-native reptiles and amphibians, South Florida's herpetofaunal community provides a unique opportunity to study native/non-native community dynamics. In addition, despite high levels of development and habitat loss, South Florida has a network of protected natural areas, allowing insight into the impacts of natural vs. anthropogenic areas on native and non-native richness and abundance. Surveys conducted in Miami-Dade County in 2017 demonstrated that non-native species already dominated both natural and anthropogenic parks and provided a baseline to examine dynamic changes in the community. In 2022, we replicated the surveys from 2017 at the same 30 sites. We found that non-native richness and abundance have increased significantly (19% and 33% increase in overall alpha diversity and abundance, respectively) in just 5 years' time. We found no correlation between these non-native increases and decreases in either native species richness or abundance. Notably, non-native species richness increased more rapidly at anthropogenic sites, with two rock-loving species, Agama picticauda and Leiocephalus carinatus, standing out as the most rapidly spreading non-native herpetofauna. Our findings demonstrate that there is continued expansion of non-native herpetofaunal populations even in the highly invaded community of Miami-Dade County and that protection of natural habitat may help slow the spread of non-native species.