Water body type explains the occupancy of co-occurring native and invasive freshwater turtles in a tropical assemblage

The continued spread of non-native species worldwide underscores concerns about their ecological impacts. In this study, we surveyed 22 wetlands across an urban landscape to investigate which survey-related and environmental variables (climatic, local-scale wetland features, biotic interactions) influence the occupancy and detection probabilities of native and invasive freshwater turtles. The native turtle, Phrynops geoffroanus, and the invasive species, Trachemys dorbigni and Trachemys scripta elegans, showed low occupancy in the urban landscape, each occurring in only 23% of the surveyed wetlands. Phrynops geoffroanus primarily occupied lakes with more basking sites, while its detection probability increased with the number of observers. Trachemys dorbigni had the highest detection probability, which decreased with precipitation, and its occupancy was associated with lakes and negatively affected by predator presence. Trachemys scripta elegans occupancy was also related to lakes, with its detection probability increasing with the number of observers and decreasing with precipitation. Our findings highlight similarities in detection probability and occupancy among native and invasive turtles, emphasising observer effects on detectability. The spatial segregation of species by water body type may facilitate their coexistence. Identifying habitat features linked to urban native turtle presence, especially in shared habitats with invasive species, could improve conservation and management strategies.