Naultinus grayii

Northland green gecko

Naultinus grayii
(Bell, 1843)

Northland green geckos. <a href="https://www.instagram.com/nickharker.nz/">© Nick Harker</a>
Image attribution
Northland green geckos. © Nick Harker
Herpetofaunal category
NZ Geckos
Species complex
Conservation Status
At Risk - Declining
Previous scientific names
Naultinus elegans grayi,
Naultinus simpsoni,
Hoplodactylus grayi.
Common names
Northland green gecko,
Gray's gecko.

Length: SVL up to 95mm, with the tail being longer than the body length

Weight: up to 23 grams

Description

A large and often beautifully patterned green gecko from the far north of New Zealand. Northland green geckos - along with the barking gecko (Naultinus punctatus) - are regarded as the largest species in the genus Naultinus.

Dorsal (upper) surface green, often with grey or gold markings along dorsal edges. Males may have faint pale blue flanks. Ventral (lower) surface bright pale green, sometimes with yellow tinge. Canthal scales (scales on the snout) are flat. Deep blue lining of mouth with bright red tongue, lower lip white. Eyes are light orange/brown. Soles of feet are light grey green.

Can be differentiated from elegant geckos (Naultinus elegans) by a red (versus blue) tongue, and from Aupōuri geckos (Naultinus flavirictus) by a blue (versus mauve) mouth colour. Northland green geckos can be distinguished from both species by having flat (versus domed) canthal scales.

Click here for information on how Northland green gecko differ in appearance from other species in the Naultinus group.

Life expectancy

Reports on life expectancy vary, Northland green gecko may live up to 25 years.

Distribution

Upper Northland: Bay of Islands to Houhora Harbour area.

Ecology and habitat

Northland green gecko are diurnal (active during the day) and strongly arboreal (tree dwelling) although they will move through grasslands and ground cover between habitats. They often inhabit pioneer scrubland and regenerating forest types, in particular occupying the foliage of trees and shrubs, including manuka and kanuka trees.

All green geckos have prehensile tails which act as a climbing aid.

Social structure

All green gecko species are solitary and can often be aggressively territorial. In captive group situations green geckos can often display aggressive behaviour, particularly biting, towards conspecifics (particularly aggression between males as a result of competition for mates). Green geckos will also display aggressive behaviour if threatened; this consists of mouth gaping, biting, lunging, and vocalisation (a barking sound).

Breeding biology

Northland green gecko are viviparous, giving birth to one or two live young. Sexual maturity is reached between one and two years. Some keepers have noticed that green gecko in captivity appear to express ‘choice’ as to when to mate and reproduce according to conditions (D. Keall, personal communication, September 22, 2016).

Northland green gecko give birth from late summer to early autumn with a gestation period of 7.5 months.

Diet

The diet of Northland green gecko is omnivorous, and consists primarily of invertebrates such as flies, beetles, spiders and moths. Green geckos are generally ‘sit and wait’ predators for invertebrates, however will forage for soft berries and nectar from native flowers within their home range.

Disease

Northland green gecko have a number of recorded parasites, bacteria and fungi including: the nematode Skrjabinodon poicilandri; Basidiobolus ranarum; Aeromonas; Pseudomonas; Citrobacter; Serratia; Streptococcus; Salmonella; Proteus; Enterobacter; Rhodotorula glutinisKloeckera africana, Cryptococcus a. albinus; Acanthamoeba sp; Mastigamoeba sp; Naegleria sp; Vahlkamfia sp.

Xanthomatosis has been recorded in Northland green gecko.

Conservation strategy

DOC classify Northland green gecko as 'at risk' with a predicted decline of 10-70%.

References

Dick, B.B. (1983). The gastro-intestinal microflora of Naultinus grayi. Unplublished report to the New Zealand Herpetological Society, p. 29.

Garner, M.M., Lung, N.P., Murray, S. (1999). Xanthomatosis in geckos: Five cases. Journal of zoo and wildlife medicine 30, 3, 443-447.

Gill, B.J., & Whitaker, A.H. (1996). New Zealand frogs and reptiles. Auckland: David Bateman Limited.

Hitchmouth, R.A. (1979). The ecology and behaviour of two green gecko (Naultinus) species (Unpublished master’s dissertation). University of Auckland, Auckland, New Zealand.

Hitchmough, R.A., Barr, B., Lettink, M., Monks, J., Reardon, J., Tocher, M., van Winkel, D., Rolfe, J. (2016). Conservation status of New Zealand reptiles, 2015; New Zealand threat classification series 17. Wellington: New Zealand Department of Conservation.

Jewell, T. (2011). A photographic guide to reptiles and amphibians of New Zealand. Auckland: New Holland Publishers Ltd.

Nielson , S.V., Bauer, A.M., Jackman, T.R., Hitchmough, R.A., & Daugherty, C.H. (2011). New Zealand geckos (Diplodactylae): Cryptic diversity in a post-Gondwanan lineage with trans-Tasman affinities. Molecular Phylogenetics and Evolution, 59, 1, 1-22.

Robb, J. (1980). New Zealand amphibians and reptiles in colour. Auckland, New Zealand: Collins.

Robb, J., & Hitchmough, R.A. (1980). Review of the genus Naultinus grey (Reptilia: Gekknonidae). Records of the Auckland Institute and Museum, 16, 189-200.

van Winkel, D., Baling, M. & Hitchmough, R. (2018). Reptiles and Amphibians of New Zealand: A field guide. Auckland: Auckland University Press, 376 pp.