Feasibility study towards restoring missing fauna of Ōtamahua/Quail Island, with a focus on invertebrates

Abstract

Quail Island/Ōtamahua (85 ha.) located in the Lyttelton Harbour, Banks Peninsula, Canterbury is undergoing ecological restoration. Approximately 100,000 native trees have been planted and all mammalian pests (hedgehogs, rats, cats, rabbits, stoats) apart from mice have been eradicated. The Banks Peninsula tree weta (Hemideina ricta), Leaf vein slug (Pseudaneitea ‘maculata’) and ground beetle Megadromus guerinii have been successfully translocated to the island and have established sustainable populations in the presence of mice. However many flightless invertebrate species are absent from the island compared to similar habitat in the harbour basin and require human assistance to establish. Objectives of this study was to determine the suitability of reptile, bird and invertebrate candidate species for reintroduction to Quail Island, with more detailed information on the sources and methodology for translocation and monitoring for the invertebrate species. No one obvious bird species stands out as being easy to reintroduce to the island. Two species of local lizards could be reintroduced to the island, but it is unknown if the presence of mice is an impediment to their success. A small predator exclusion fence may be an option. Reasonable populations of all candidate carabids and spider species were found apart from Nuisiana arboris. Five ground beetles (Carabidae), five spiders (Arachnida), four aphids (Aphididae), the reticulate stag beetle, a darkling beetle (Tenebrionidae) and a weevil (Curculionidae) species are considered best as candidate species for reintroduction.