lizard

Alpine regions worldwide support diverse, endemic, and specialised fauna, yet knowledge of the basic ecology of many species is lacking and urgently required for management. Aotearoa New Zealand’s lizards (geckos and skinks) are no exception: of at least 33 species that occur in the alpine zone, ≥ 90% are currently Threatened or At Risk of extinction. Here, we focus on the Cascade gecko: a cryptic and viviparous species found in the Southern Alps | Kā Tiritiri o te Moana in the South Island.

Animals that inhabit the alpine zone often persist in isolated and fragmented populations and possess a range of behaviours and adaptations that enable them to survive in these harsh environments. These characteristics can make them particularly susceptible to escalating anthropogenic threats, including climate change. New Zealand has a diverse lizard fauna, of which approximately 25% of species inhabit the alpine zone. The cryptic nature of many alpine lizards makes them difficult to find and study, limiting effective conservation management.

Understanding the long-term implications of translocation methods is essential when refining best translocation practices for a species. High rates of movement and dispersal away from release sites have been key concerns when hard releasing lizards. A recent proliferation of research on translocation of New Zealand’s endemic green geckos (Naultinus spp.) has confirmed that penning for at least four months promotes initial site fidelity.

Predator-free sanctuaries can assist the conservation of multiple endemic species, but quantitative evidence of these benefits is often lacking, especially for herpetofauna. We measured population responses of three common lizard species (schist geckos, Woodworthia ‘Central Otago’; McCann’s skinks, Oligosoma maccanni; and southern grass skinks, O. aff. polychroma Clade 5) 1 year before and 5 years after mammalian predators were removed inside a mammal-proof fence in a dry grass/shrubland habitat with abundant schist rock in Central Otago, New Zealand.

The capture of animals in live traps poses inherent risks of heat stress and mortality to trapped individuals. Despite a long history of pitfall trap use in New Zealand for monitoring small lizards, the design of traps and their covers often varies; however, the effects that this has on the internal temperature of the traps is unknown. Poor trap design may increase the risk of stress and mortality if internal temperatures exceed thermal limits.

Fruit is an important component in the diet of many lizards, but their role as seed dispersers is often overlooked. Seed retention time and animal movement determine how far a fleshy fruited seed will be dispersed from the parent plant. Seed retention times were investigated in 78 captive Hoplodactylus duvaucelii (Duvaucel’s geckos). Geckos were offered fruits from 10 plant species. Fifty-one geckos consumed fruits and the mean seed retention time was 69 hours (range 31 to 145 hours).