Social networks and social stability in a translocated population of Otago skinks (Oligosoma otagense)

The social behaviour of New Zealand’s native lizards is poorly understood. We explored the social behaviour of the Otago skink (Oligosoma otagense), one of New Zealand’s largest and rarest species of lizards. The Otago skink has previously been observed in the wild in pairs and groups, but little else is known about its social behaviour. We studied the social behaviour of a translocated population of 32 skinks in an outdoor enclosure at Ōrokonui Ecosanctuary. Regular photo surveys were conducted from November 2017 to October 2018 to identify skinks and the social interactions among them. Skinks were observed to be either solitary or interacting in groups consisting of two to eight individuals. Social network analysis was used to determine the strength of the interactions between adult males, adult females, subadults and juveniles. We assessed the stability of social interactions in the population over time by comparing the persistence of social interactions between seasons (summer, autumn/winter and winter/spring) while taking into account the size and composition of a social group. Interactions between adults and subadults were stable across autumn/winter and winter/spring whereas juveniles showed no stability in their interaction patterns during this time. During the course of the study, there was an overall stability in the social networks, indicating that the stability of social interactions present in the translocated population is largely driven by the adults and subadults in the enclosure. Our work suggests that incorporating an understanding of sociality into capture procedures may minimise disruption to social structures and ultimately improve outcomes of translocation.