Abstract
Translocations are increasingly used in species conservation, but success rates can be low. Experimental approaches are needed to compare the outcomes of translocation strategies, including those involving head-starting (the rearing of juveniles in captivity before release). Here, we studied the reintroduction of head-started and wild-caught juveniles of a distinctive reptile, the tuatara Sphenodon punctatus, on the South Island of New Zealand. We compared morphometric, ecophysiological, behavioural and spatial aspects for juveniles from three groups (wild-caught from a warmer climate, head-started from a warmer climate and head-started from the local climate), focusing on the first 5 months of summer following release. Group did not affect body condition at recapture, but wild-caught juveniles, despite being the only animals with ticks at release, grew faster and had higher inferred body temperatures than individuals head-started in a warmer climate. Wild-caught juveniles were less frequently seen emerged than juveniles head-started at the release site, and no animals had ticks at the summer's end. Mean dispersal distance and home-range size did not differ significantly between groups, and all groups had high survival (96.4-100% over first summer; at least 66.7-73.3% after the first winter following release). We conclude that, for most metrics, post-release performance of head-started and wild-caught juvenile tuatara was similar, and that head-started groups can differ between each other as much as between captive and wild. Our results emphasize the species-specific nature of translocation outcomes.