Post-Translocation Movements of a Freshwater Turtle Include Homing Behaviour

Abstract

Freshwater turtles are crucial to aquatic ecosystems and among the most threatened vertebrates globally. As wetlands are increasingly affected by urbanisation and climate change, translocating turtles may become increasingly common to prevent population declines. Freshwater turtle responses to translocation remain poorly understood. This study examined the movement responses of the southwestern snake-necked turtle, Chelodina oblonga, following relocation from a wetland slated for urban development. We radio-tracked 40 of 268 turtles translocated to two wetlands, monitoring them for up to 228 days and analysing movement responses in relation to size, sex and release wetland using generalised linear models. Over half (54%) of the tracked turtles permanently left their release wetlands, and 38% homed back to their original wetland via a 3.2–7.0-km estuarine river and a steep, ~15-m high terrestrial bank. Movement out of the release wetlands was unrelated to turtle size or sex but significantly influenced by release wetland. Homing probability was not affected by size, sex or release wetland. Turtles were more likely to leave the release wetland closer to the source, possibly due to its smaller size or drying conditions. Release wetland significantly influenced the timing of both 'any' and 'homing' movements. Sex affected the timing of both movement types, while size influenced only 'any' movement timing. The study highlights that the characteristics of translocation sites are important in retaining translocated turtles. The study adds to the limited understanding of the movement responses of translocated freshwater turtles and has direct implications for the design of translocation programs.