Overview of New Zealand reptiles
New Zealand has a very diverse group of geckos and skinks. The distribution and habits of many are poorly known, and additional species are still being discovered, and others are being established through genetic studies. Geckos are distinguished from skinks by having either velvet-like or bumpy skin and a fixed gaze (they cannot blink). Skinks are sleek and shiny with scales that shed one at a time and that shine in the sun.
The eight groups of New Zealand lizards are quite distinct in their appearance and habits:
- Naultinus (green) geckos are diurnal and tend to be tree-dwelling, and favour shrubland and forest habitats but have been found in tussock grasslands of Otago and are known to occur in plantation forests.
- Woodworthia geckos (usually darker colours such as brown) are nocturnal, and favour rocky outcrops, gullies with rock or log cover and sometimes forest.
- Dactylocnemis geckos are nocturnal and resemble Woodworthia geckos to the untrained eye. Some individuals have a bight mustard-yellow crescent on the nape of the neck, and often also with blotches of the same colour along body and tail. Woodworthia geckos are never coloured this way.
- Mokopirirakau geckos can be brightly coloured and have a distinctive orange/yellow mouth lining. They have slender toes and tend to be arboreal and primarily nocturnal.
- Toropuku geckos are slender and elegant animals with distinctive stripes. They are strictly arboreal in habit and nocturnal.
- Tukutuku rakiurae is the single species in the Tukutuku genus and this species is only found on Stewart Island where it is most commonly located in sub alpine scrub.
- Hoplodactylus geckos resemble Woodworthia in appearance and occupy similar habitats and are also nocturnal.
- Oligosoma skinks are both diurnal and nocturnal and and occur in diverse habitats from rocky and sandy shorelines, to forests, to subalpine habitats. Nocturnal species tend to live in damp, thickly vegetated, lowland areas in northern New Zealand.
Lizards are critical for ecosystem processes; they pollinate native plants and disperse native plant seeds through eating fruit.
Predation by introduced mammals (e.g. cats, rats, mustelids) is the biggest threat posed to New Zealand lizards, and lizards can become exceptionally abundant in the absence of mammalian predation. Loss and/or fragmentation of habitat through development, habitat degradation by introduced browsing mammals (e.g. pigs, livestock, deer, goats, possums), removal of logs and rocks, and excessive collecting also contribute to on-going declines of lizards over all parts of New Zealand.
Description - Ngahere gecko
- A light grey to dark brown arboreal gecko, which sometimes has yellow patches and/or brown and green markings. The inside mouth lining is very distinctively orange.
- This gecko was first described in 1881 but was considered to be a forest gecko until genetic testing confirmed it as a completely independent species.
Association with Plantations
- This species has been found associated with exotic forestry around Karori Reservoir, and at other locations within its range.
Management Options and Methods
- Maintain wide and interconnected zones of potential lizard habitat, e.g. indigenous forest and shrubland, rocky gullies, cliffs and other distinctive habitat types.
- Create buffers around known habitat.
- Consider permanent protection of known habitat.
- Comply with best forest operational management practices to avoid damage to lizard habitat.
- Fell and haul timber away from lizard habitat.
- Exclude livestock from lizard habitat.
- Control possums, deer and goats that could enter lizard habitat.
- Raise awareness of staff and contractors of the presence of lizards and the need to protect them.
- Take photographs or write a detailed description when lizards are found. This can be used for later identification.
- Survey for lizards, particularly if first time planting is being considered for the area. Note that planned surveys require a permit under the Wildlife Act (contact DOC for survey methods and permits).
- Maintain database of sightings of threatened lizards and liaise with DOC.
- Report findings to DOC.
Further Information, Support and References
- Jewell & Morris 2008. Reptiles and Amphibians of New Zealand.
- New Zealand Threat Classification System (DoC website).
- Electronic Atlas of the amphibians & reptiles of New Zealand (DoC website).
- Department of Conservation. 2002. The Penguin guide to New Zealand wildlife: native and introduced birds, mammals, reptiles and amphibians. Auckland, Penguin.
- Gill B., Whitaker A. 1996. New Zealand frogs and reptiles. Auckland, Bateman.
- Department of Conservation, Te Ara, Landcare Research and the New Zealand Herpetological Society websites.