Predictors of translocation success of captive-reared lizards: implications for their captive management

Islands are biodiversity hotspots, but their native inhabitants are vulnerable to predation from exotic predators. Conservation of island endemics has often involved translocating captive-reared populations to predator-free refugia. However, the long-term success of these translocations has rarely been assessed. We investigated the traits that maximize post-translocation survival in a cohort of captive-reared Suter's skinks Oligosoma suteri and compared traits normally associated with survival and persistence of lizards (body condition, speed and overall size) to that of wild-born skinks 6 years after release onto a predator-free island in the north-east of New Zealand. Our models showed that larger lizards, and lizards with lower body condition, had improved survival. While sprint speed of captive-reared lizards did not differ significantly to that of wild skinks, diving ability of captive-reared skinks was poor, with only female captive-reared lizards diving during trials. Our results indicate that the traits associated with higher survival after release are not necessarily obvious and may be influenced by adaptation to captive conditions. Long-term monitoring post-translocation is therefore vital to determine the success of the translocation.