Woodworthia "Southern Alps"

Southern Alps gecko

Woodworthia "Southern Alps"

Southern Alps Gecko (Otago). © Samuel Purdie
Image attribution
Southern Alps gecko. © Samuel Purdie
Herpetofaunal category
NZ Geckos
Species complex
Conservation Status
Not Threatened
Previous scientific names
Hoplodactylus maculatus
Common names
Southern Alps gecko

Length: SVL up to 72mm, with the tail being equal to or slightly longer than the body length

Weight: 5-10 grams

Description

A locally abundant, undescribed cryptic species complex that is part of the W. maculata (or ‘common gecko’) group. Southern Alps geckos are a medium-sized, robust, grey-brown variably marked gecko found throughout the central Eastern South Island high country, from Marlborough to Otago. Most likely encountered basking or under rocks on stable scree slopes and outcrops in the sub-alpine, although known to occur arboreally in shrublands.

Southern Alps Gecko have a greyish top surface with alternating bands/blotches (striping rare). Sides are greyish with pale or darker coloured blotches, flecks or streaks. Belly surface light brown. Mouth lining and tongue pink, commonly with a grey tip on the tongue. Eye colour grey to green. Rostral scale in contact or virtually in contact with nostrils. Toes with tapering distal phalanges. Sub-digital lamellae 9–12.

Two major sub-clades found north and south of the Rakaia River:

  • The northern group often larger, darker grey/brown in colour, and less stocky, with a longer neck, less finely divided markings and usually lacking the canthal stripe.
  • The southern group varies in body size considerably between individual populations over quite short distances. Neck and snout stocky with a prominent canthal stripe. Silvery grey in colour.

Range abuts:

  • Minimac gecko (Woodworthia "Marlborough mini") smaller, distinguished by warmer lighter background colour, and with distinctive head markings (narrow stripe through eye continuing to back of the head) and rostral scale well separated from nostrils.
  • Raukawa gecko (Woodworthia maculata) in the Kaikōuras, found at lower altitudes, and usually with more contrasting black and brown markings, distinctly longer distal phalanges, a longer snout, longer intact tail, spiny ‘eyebrows’ and brown (vs. green) eyes.
  • Pygmy gecko (Woodworthia "pygmy") in the Rangitata Valley, in north Canterbury and south Marlborough. Frequently found together under the same rock. Pygmy gecko much smaller, with narrower toes and fewer lamellae (7–9), and rostral scale well separated from nostrils.
  • Waitaha gecko (Woodworthia cf. brunnea) at edges of the Canterbury Plains, but usually separated by altitude, and Waitaha gecko brown (vs. grey), with more contrasting markings, and brown to yellow (vs. green to grey) eye. 
  • Korero gecko (Woodworthia "Otago/Southland large") in the Waitaki Valley and at the northern end of the Dunstan Mountains, but Korero gecko bigger
  • Kawarau gecko (Woodworthia "Cromwell") around Wanaka and at the northern end of the Dunstan Mountains, but Kawarau gecko species slenderer, with longer narrower toes and distinctly longer distal phalanges.

Life expectancy

Unknown, but likely to be similar to other Woodworthia e.g. up to 50+ years.

Distribution

Eastern South Island high country, from central Marlborough down to northern Otago. Northern outlier population in Wairau Valley.

Ecology and habitat

Generally nocturnal but occasionally seen basking in daylight. Primarily terrestrial and saxicolous (rock-dwelling) although some populations are known to be arboreal. Southern Alps geckos live at lower elevations between mountain ranges, but also range up into the alpine (1800 metres a.s.l). Can be found in the stable bases of scree slopes, rocky river terraces and shattered outcrops in dry sub-alpine. Known to inhabit rocks like greywacke and schist. 

Social structure

Found both solitary and communally, in population groups of up to a dozen or more.

Breeding biology

Twin viviparous offspring born late summer. Likely biennial in high altitude populations.

Diet

Likely feeds on a combination of invertebrates, nectar and seasonal fruit. Potentially a key sub-alpine pollinator and seed spreader. May feed on smaller gecko species including cannibalism.

Disease

Orange mites typically found on approximately a third of individuals. Ticks rarely sighted.

Conservation strategy

Given the common occurrence and wide range of this species, it is regarded as Least Concern. However, future morphological & genetic research may split the species complex further. There is significant morphological variation between populations across the range which is worth protecting.

Interesting notes

Southern Alps geckos are members of the 'common gecko' complex, a group of closely related species which are regionally distributed throughout New Zealand. Historically, most of these were considered a single highly-variable species - Hoplodactylus maculatus (the so called 'common gecko'). The 'common gecko' has now been separated into over ten different species.

References

Hitchmough R (1997): A Systematic Revision of the New Zealand Gekkonidae. Victoria University, Wellington, New Zealand.

Hitchmough R, Barr B, Lettink M, Monks J, Reardon R, Tocher,M, van Winkel D, Rolfe J (2015): Conservation status of New Zealand reptiles, 2015. New Zealand Threat Classification Series 17. Department of Conservation, Wellington, New Zealand.

Morgan-Richards M, Hinlo A, Smuts-Kennedy C, Innes J, Ji W, Barry M, Brunton D, Hitchmough R (2016): Identification of a Rare Gecko from North Island New Zealand, and Genetic Assessment of Its Probable Origin: A Novel Mainland Conservation Priority?. Journal of Herpetology 50(1):77-86, BioOne.

van Winkel D, Baling M, Hitchmough R (2019): Reptiles and Amphibians of New Zealand, A Field Guide.  Auckland University Press, Auckland, New Zealand.