Translocation of Duvaucel's geckos to Tiritiri Matangi and Motuora Islands, Hauraki Gulf, New Zealand

Summary

In December 2006, 39 Duvaucel's geckos (Hoplodactylus duvaucelii), New Zealand's largest gecko species, were captured from Korapuki Island and translocated to Tiritiri Matangi and Motuora Islands in the Hauraki Gulf, as part of each island's ecological restoration program. The species had been confined to 36 isolated island populations after mammalian predators and habitat loss eliminated it from the mainland. Nineteen geckos were released on Tiritiri Matangi and 20 on Motuora, each implanted with a PIT tag, and half fitted with backpack radio transmitters to track dispersal and habitat use. Massey University researchers worked with the Department of Conservation, local iwi, and the volunteer groups Supporters of Tiritiri Matangi and Motuora Restoration Society to design and run the translocation and its monitoring. Post-release surveys combining radio-telemetry, spotlight searches, footprint tracking tunnels and funnel traps recorded no post-release mortality, and recaptured geckos showed improved body condition over the first year. Island-born juveniles were confirmed twelve months after release, and by 2009 a second wild-bred generation on Tiritiri Matangi confirmed ongoing natural breeding. The main difficulty was detecting a nocturnal, semi-arboreal species at low density: recapture rates stayed low despite the range of monitoring methods used, since effort was concentrated near the release sites and geckos that dispersed further afield may have gone undetected. The project also flagged the small founder population size as a long-term genetic risk requiring further sampling.