Social clustering behavior in hatchling western saw-shelled turtles (Myuchelys bellii)

Abstract

Captive rearing and head starting are invaluable tools in conservation, but the success of these efforts often depends on their ability to adequately prepare animals for the challenges and social environments they will face in the wild. The importance of early social environments is well-documented in birds and mammals, but little attention has been paid to reptiles, despite the common use of head starting and increased recognition of complex social behaviors in reptiles. In this study, we examined early social behaviors in captive-reared hatchling western saw-shelled turtles (Myuchelys bellii) to determine (1) if they chose to bask together on a single platform or disperse across platforms (regardless of kinship), (2) if they chose to cluster together or disperse randomly when on the same basking platform (regardless of kinship), (3) if they chose to bask predominantly on platforms with kin vs. non-kin. (4) if they chose to cluster more tightly with kin than non-kin when on a given platform. We found evidence turtles preferred to bask together on the same platform (instead of dispersing across basking platforms) at night, but not during the day (question 1), and we found strong evidence that when on the same platform, turtles clustered together more tightly than expected by chance (question 2). The clustering was particularly tight during the night. We did not find any evidence that behaviors were mediated by kinship (questions 3 and 4). The results for questions 1 and 2 suggest that M. bellii hatchlings prefer being close to one another and may be more socially complex than previously recognized. This could have important implications for planning head starting efforts.