Survival of Captive Bred Skinks Following Reintroduction to the Wild is not Explained by Variation in Speed or Body Condition Index

Translocation is a common conservation tool and often involves founders that are reared in captivity. Why some translocations succeed and others fail is not well understood, but may be related to phenotypic changes brought about by captivity. We found that variation in speed and body condition index among a small group of captive-reared Otago skinks (Oligosoma otagense) did not influence their survival after release to the wild. In the first 12 months, 75% of skinks persisted, and this reduced to 58% by 18 months. After combining our results with data for other Oligosoma species, we found that captive-reared skinks pre-release have a higher body condition index and are about 50% slower than wild lizards; however, slower speeds are not consistently associated with higher body condition indices. We suggest that reduced speeds of captive lizards are a function of physiological and behavioural changes associated with captivity, but not necessarily obesity.