Habitat use by southern forest geckos (Mokopirirakau‘Southern Forest’) in the Catlins, Southland

Abstract

Basic biological information is critical to evaluating conservation requirements for native taxa, but is lacking for many cryptic New Zealand lizard species. Southern forest geckos (Mokopirirakau 'Southern Forest') are known only from anecdotes, museum specimens and discoveries of an individual at each of three sites during recent surveys in the Catlins. We used systematic searching, photo identification and radio telemetry at one of these sites (Tahakopa Valley) to investigate habitat use of southern forest geckos. Forty-five hours of searching in 2010Á2011 yielded 28 sightings of 17 individuals including four juveniles (indicating that a breeding population exists). Most geckos were found by searching a boulder used as a diurnal retreat site or in mānuka (Leptospermum scoparium). Two geckos were radio-tracked; both remained within 5 m of capture and exhibited primarily nocturnal behaviour. We recommend further survey work to identify populations and monitoring to evaluate the need for conservation intervention.

Step on it: can footprints from tracking tunnels be used to identify lizard species?

“…New Zealand lizards can be extremely cryptic and difficult to survey and monitor (Bell 2009;Hoare et al 2013). Footprint tracking tunnels may provide a useful method for detecting and monitoring lizards (Siyam 2006;van Winkel 2008), but the latter remains to be verified.…”

“…In New Zealand, lizards are generally visually cryptic and can be difficult to detect (Hare et al 2007;Hoare et al 2013). They are therefore a difficult taxonomic group for which to obtain data on distribution and population size.…”

“…Surveying and monitoring techniques for lizards may be limited by several factors, including low and variable detectability of taxa, observer bias, environmental constraints, and potential impacts on the environment (e.g. disturbance to fragile habitats) (Towns & Ferreira 2001;Francke 2005;Hoare et al 2013).…”

Survey and monitoring methods for New Zealand lizards

“…0.08-0.6 geckos/person hour for southern forest geckos, Mokopirirakau sp. 'southern forest', depending on weather conditions [Hoare et al 2013]). In such cases, other methods such as trapping or use of artificial retreats may yield higher encounter rates.…”

“…It has been used for various New Zealand lizard species, including chevron skinks (Barr 2009), grand and Otago skinks (Reardon et al 2012), small-scaled skinks (O. microlepis [Gebauer 2009]), jewelled geckos (Naultinus gemmeus [Knox et al 2013]) and southern forest geckos (Hoare et al 2013). Reported accuracy rates (i.e.…”