Jewelled geckos released in Otago
The Central Otago Ecological Trust (www.coet.org.nz), chaired by Manaaki Whenua ecologist Dr Grant Norbury recently released Jewelled geckos into a 14-ha predator-proof fence near Alexandra. This species has been extinct from Central Otago for many decades, so this translocation represents a significant step in restoring lost lizard communities in this region. A wonderful afternoon was spent releasing 26 geckos (14 more to come). Lucy Anderson, a local child and possible future herpetologist, released the first gecko.
Following human colonisation, fires would have taken a heavy toll on jewelled gecko populations and other arboreal lizards. The resulting loss of mature forests and shrublands (critical for their persistence) is likely to be the primary reason for their disappearance from Central Otago. Returning jewelled geckos to Central Otago can be seen as restoring a missing component of the pre-human Central Otago ecosystem. Due to the fragmented nature of their remaining habitats across Otago jewelled geckos cannot re-colonise these former habitats on their own. The MokoMoko Drylands Sanctuary, near Alexandra provides a great opportunity for restoration of Central Otago’s dryland lizard fauna – and jewelled geckos would have once been a significant component of this ecosystem. Jewelled geckos play an important role in this ecosystem by feeding on invertebrates, consuming berries/spreading the seeds of divaricating shrubs, and providing food for native birds and larger reptiles. Restoring jewelled geckos to MokoMoko fits in with the sanctuary’s goal of re-creating (as best as possible) a pre-European Central Otago drylands ecosystem.
Jewelled geckos are a widespread species of the eastern South Island but are now highly fragmented, and seemingly extinct across much of Otago and Southland. There are no known surviving populations in Central Otago. There are possible historical sightings from around Lakes Wakatipu and Te Anau and recent sightings in the Kakanui Mountains, Ida and Lammermoor ranges, several sites in the Mackenzie Basin, and Otago’s Hunter Valley. This suggests a high likelihood that jewelled geckos would have ranged right across inland Otago and that the lowland dryland environment of MokoMoko is probably within the jewelled gecko’s climatological tolerances. Jewelled geckos have been successfully translocated to Orokonui Ecosanctuary in coastal Otago and to a site on Otago Peninsula (using soft-release; see Knox & Monks 2014), demonstrating their suitability for translocations.
The COET would like to attempt to establish jewelled geckos at MokoMoko by way of translocation of wild-caught specimens to a carefully chosen shrubby location within the sanctuary. COET aims to recreate a diverse assemblage of the lizard species that once flourished in Central Otago. In order to achieve this, several lizard translocations are being planned. Most important of these are translocations of the ‘Nationally Endangered’ western forms of the grand and Otago skinks (Oligosoma grande and O. otagense, respectively). These translocations take precedence over all others; however, translocations of other native species which are unlikely to negatively impact upon grand and Otago skinks are being considered. Asides from the jewelled gecko, other translocations being considered include the green skink (Oligosoma chloronoton), Tuatara (Sphenodon punctatus) and Mountain tree weta (Hemideina maori).