Re-introduction of skink and gecko species to Marotere Islands, Northland, New Zealand

Summary

New Zealand's Department of Conservation re-introduced two rare, range-restricted lizards, the Mokohinau skink (Cyclodina townsi) and McGregor's skink (Cyclodina macgregori), plus the more widespread Pacific gecko (Hoplodactylus pacificus), to three Marotere (Chickens) Islands after Pacific rats (kiore) were eradicated from Whatupuke in 1993, Lady Alice in 1994, and Coppermine in 1997. Because local Maori iwi Ngatiwai considered kiore a taonga (treasure), the department negotiated their removal only from the Marotere group, not neighbouring Taranga Island, and committed to monitoring how resident species responded, sharing consistently positive results with the community through workshops. Source populations were assessed by capture surveys, with Sail Rock chosen for McGregor's skinks and Muriwhenua/Middle Stack for Mokohinau skinks (the latter eroding and expected to become unsuitable), while Pupuha Island supplied Pacific geckos; at least 30 lizards were moved per translocation starting in 1997, individually measured, sexed, and photo-identified rather than toe-clipped, per Ngatiwai's wishes. Skinks were monitored via baited pitfall traps and geckos via artificial shelters, checked twice yearly. The first Mokohinau skink release into forest largely failed, with only three recaptured, prompting a shift to beach-site releases that proved far more successful; six years after gecko releases, previously undetected wild geckos were also discovered nearby, showing some had survived the rat era undetected. The project rated itself Successful, having met its five-year survivorship and ten-year breeding-evidence criteria for most releases, though the fifteen-year self-sustaining-population criterion remains too early to assess.