Movements and Microhabitat Use of Translocated Big-Headed Turtles (Platysternon megacephalum) in Southern China

Asian turtles have declined substantially in recent decades because of the large-scale collection of wild individuals for the food, pet, and medicine trades. This has hampered studies into the ecology and natural history of turtles in their natural habitats because many species have become so rare that they are simply unavailable for study. One way to re-establish or supplement these turtle populations is through translocation (either of wild-caught individuals or those raised in farms). However, successful translocation is partly dependent upon released individuals maintaining site fidelity. We translocated 16 big-headed turtles, Platysternon megacephalum, in southern China to study their movements and microhabitat use in the wild and use this information to evaluate the feasibility of translocation as a conservation technique for this species. Translocated turtles generally moved short distances (daily range: 0-89.6 m), with males moving further than females and both sexes moving further at night than during the day. Additionally, big-headed turtles rarely used terrestrial habitats (the maximum distance an individual was located from the stream was 5.8 m) and remained hidden in refugia most of the time. Some sex differences in microhabitat use were also apparent; females were visible less often, spent more time on land (which coincided with the nesting season), remained closer to the stream bank, used shallower water, and used different types of refugia than males. The very short distances that bigheaded turtles moved, combined with their consistent fidelity to the stream and cryptic behavior, all suggest that this species would be a good candidate for larger-scale translocation experiments. To our knowledge, this is the first published study of movement patterns and habitat use of translocated semiaquatic or aquatic turtles outside of Europe and the first published radiotelemetry study of turtles from mainland China.