Re-introduction of shore skinks to offshore islands in the Auckland region, New Zealand

Summary

In 2006, researchers from Massey University, working with New Zealand's Department of Conservation and local community groups, translocated 120 shore skinks (Oligosoma smithi) from Tawharanui Regional Park to two predator-controlled sites in the Auckland region: Tiritiri Matangi Island and Motuora Island, plus a captive-breeding facility at Massey University, each receiving 30 to 40 animals. The releases aimed to establish self-sustaining populations on islands where the species was historically present but locally absent, using captive breeding to reduce pressure on the wild source population. Shore skinks were selected partly for their fast maturation and diurnal, visually active behaviour, which makes them useful indicator species and public conservation ambassadors. Post-release monitoring combined live-trap grids, pitfall traps, artificial refuges and hand capture, since the species is difficult to detect at low density. By the 2007-2008 summer, Tiritiri Matangi showed clear signs of establishment, with island-born juveniles and gravid females caught in trapping grids. Motuora fared worse: large winter storms likely destroyed refuges and trap grids, and only one or two adults were recorded there over the same period. Unpredictable weather, the difficulty of detecting a cryptic, low-density species, and limited funding for disease-screening were the main challenges. The project judged good communication among the Department of Conservation, the Auckland Regional Council, local iwi and volunteer groups essential to sustaining long-term monitoring.