Male-biased movement in pygmy bluetongue lizards: implications for conservation

Abstract

Context Translocation has become an increasingly common tool in the conservation of species. Understanding the movement patterns of some species can be important to minimise loss of individuals from the translocation release site. Aims To describe seasonal and sex-biased movements within populations of an endangered Australian lizard. Methods We monitored seasonal movement in the endangered pygmy bluetongue lizard (Tiliqua adelaidensis) by using pitfall trapping, with a total of 49 440 trap-nights from three sites over 2 years. Other studies have shown that individual pygmy bluetongue lizards normally remained closely associated with their spider burrow refuges, with very little movement. Thus, we interpreted any captures detected through pitfall trapping as out of burrow movements. We investigated whether there was any seasonal, age or sex bias in moving individuals. Key results We found that male pygmy bluetongue lizards were more likely to move than were females. After adults, neonates were the second-most captured age class. Spring was the peak movement time for adults, whereas movement of neonates occurred in autumn. Key conclusions The majority of movement can be attributed to males in the breeding season, whereas females move very little. Implications The present study provides some baseline data that would allow more informed decisions about the most appropriate individuals in a population to choose for a translocation program and the times to conduct translocations to allow the maximum chance for establishment.