Basking Platforms as a Method to Monitor Freshwater Turtles

ABSTRACT Effective survey methods are critical to optimize conservation efforts for freshwater turtles. However, conventional trapping procedures often fail to detect or accurately represent juvenile cohorts. Combining trail cameras with basking platforms may provide a useful alternative method to sample juvenile turtles, but its efficacy remains unknown. Our study aimed to 1) quantify the effectiveness of basking platforms as a tool for surveying freshwater turtle populations and 2) determine whether the size structure of turtle samples differed between basking platforms and conventional trapping. Up to 18 basking platforms were deployed in 2022 and 2023 at six sites (3 platforms per site) in the New England Tablelands region of New South Wales, Australia, where Bell's turtle ( Myuchelys bellii ) and the eastern long‐necked turtle ( Chelodina longicollis ) co‐occur. Time‐lapse trail cameras above the basking platforms documented turtle occurrences and body sizes, calculated from images using the software ImageJ. Both species basked on the platforms, taking 1–24 days to use the platforms and most commonly basked in late summer and early autumn. M. bellii was detected on platforms at four sites and C. longicollis at five sites. Platforms detected 1–20 M. bellii (x̄ = 2.33) and 1–10 C. longicollis basking events per day (x̄ = 3.01). Small turtles appeared in 26.4% of images of M. bellii and 23.5% of C. longicollis . A wider distribution of body sizes was recorded from basking platform images than from trapping data, including turtles less than 100‐mm straight carapace length. Our results suggest that basking platforms are a valuable passive survey method for detecting freshwater turtles and juvenile cohorts in particular.