Length: SVL up to 80mm, with the tail being equal to or slightly longer than the body length

Weight: unknown

Description

A very sleek and variable species of grass skink with a snout-vent-length (SVL) up to 80 mm. Southern grass skinks typically have a tan-brown dorsal surface with a dark mid dorsal stripe extending down the tail and conspicuous pale dorsolateral stripes that can be smooth or notched. This species possesses a dark brown lateral band with smooth or notched borders that are usually pale. The ventral surface, including throat and chin, is typically uniform grey, brown, tan-brown, cream, white or yellow. Eye colour is typically brown-tan, sometimes slightly green. This species usually possess a pale stripe on the forelimbs. Subdigital lamellae 16-24 (van Winkel et al. 2018; Jewell 2008) . 

Life expectancy

Unknown.

Distribution

A very widespread species of grass skink. Found in Otago, Southland, southern Canterbury, and Foveaux Strait (incl. Stewart Island). This species is also found at a variety of elevations from lowland coastal areas, right up into the mountains. 

Ecology and habitat

Southern grass skinks are a very frequently seen species because they are diurnal, avid sun-baskers, and terrestrial. This species has been recorded in densities as high as 4000 per hectare (Wilson et al. 2017). Southern grass skinks inhabit a range of habitats including coastal dune habitat, wetlands, grassland, shrublands, rocky shrubland/herbfield, screes, tussock, stony river beds and even cities.

Social structure

Unknown.

Breeding biology

This species reproduces annually and is mature at about 3 years old. Mating likely takes place around March, with 3-6 offspring born in the summer months (November-February) (van Winkel et al. 2018).

Diet

Feeds on small invertebrates and small fruits/sugar sources. 

Disease

Southern grass skinks are known hosts for the ectoparasitic mites Odontacarus lygosomae, and Ophionyssus scincorum, as well as the blood parasite Hepatozoon lygosomarum.

They are known hosts for the trematode Dolichosaccus leiolopismae, a species seemingly restricted to Aotearoa's reptile fauna (Allison & Blair, 1987).

Conservation strategy

This species is not being actively managed. However, when land is developed/destroyed, this species is often salvaged and relocated to suitable habitat. This species is also present at a number of predator-resistant sanctuaries. 

Interesting notes

This species has been observed occupying insect burrows.

Southern grass skinks are members of a cryptic species complex which includes the northern grass skink (Oligosoma polychroma), Waiharakeke grass skink (Oligosoma aff. polychroma Clade 2), south Marlborough grass skink (Oligosoma aff. polychroma Clade 3), Canterbury grass skink (Oligosoma aff. polychroma Clade 4), and Tussock skink (Oligosoma chionochloescens). The various species are regionally distributed, similar in both appearance and habit, and were once regarded as a single highly variable species - the 'common skink'. There are currently no known morphological features to distinguish Southern grass skinks from the other species within the complex. 

References

Allison, B., & Blair, D. (1987). The genus Dolichosaccus (Platyhelminthes: Digenea) from amphibians and reptiles in New Zealand, with a description of Dolichosaccus (Lecithopyge) leiolopismae n. sp. New Zealand journal of zoology, 14(3), 367-374.

Allison, B., & Desser, S. S. (1981). Developmental stages of Hepatozoon lygosomarum (Doré 1919) comb. n.(Protozoa: Haemogregarinidae), a parasite of a New Zealand skink, Leiolopisma nigriplantare. The Journal of Parasitology, 852-858.

Chapple, D. G., Ritchie, P. A., & Daugherty, C. H. (2009). Origin, diversification, and systematics of the New Zealand skink fauna (Reptilia: Scincidae). Molecular phylogenetics and evolution, 52(2), 470-487.

Cree, A. (1994). Low annual reproductive output in female reptiles from New Zealand. New Zealand journal of zoology, 21(4), 351-372.

Daugherty, C. H., Patterson, G. B., Thorn, C. J., & French, D. C. (1990). Differentiation of the members of the New Zealand Leiolopisma nigriplantare species complex (Lacertilia: Scincidae). Herpetological monographs, 61-76.

Frank, H., & Wilson, D. J. (2011). Distribution, status and conservation measures for lizards in limestone areas of South Canterbury, New Zealand. New Zealand Journal of Zoology, 38(1), 15-28.

Freeman, A. B. (1997). Comparative ecology of two Oligosoma skinks in coastal Canterbury: a contrast with Central Otago. New Zealand Journal of Ecology, 153-160.

Hardy, G. S. (1977). The New Zealand Scincidae (Reptilia: Lacertilia); a taxonomic and zoogeographic study. New Zealand journal of zoology, 4(3), 221-325.

Hitchmough, R., Barr, B., Knox, C., Lettink, M., Monks, J. M., Patterson, G. B., Reardon, J. T., van Winkel, D., Rolfe, J., & Michel, P. (2021). Conservation status of New Zealand reptiles, 2021. New Zealand threat classification series 35. Wellington: New Zealand Department of Conversation.

Jewell, T. (2008). A photographic guide to reptiles and amphibians of New Zealand. Auckland: New Holland.

Jewell, T. (2022). Discovery of an abrupt contact zone supports recognition of a new species of grass skink in southern New Zealand. Jewell Publications, Occasional Publication #2022B.

Jones, C., Moss, K., & Sanders, M. (2005). Diet of hedgehogs (Erinaceus europaeus) in the upper Waitaki Basin, New Zealand: implications for conservation. New Zealand Journal of Ecology, 29-35.

Lettink, M., & Cree, A. (2007). Relative use of three types of artificial retreats by terrestrial lizards in grazed coastal shrubland, New Zealand. Applied Herpetology, 4(3), 227-243.

Lettink, M., & Seddon, P. J. (2007). Influence of microhabitat factors on capture rates of lizards in a coastal New Zealand environment. Journal of Herpetology, 41(2), 187-196.

Liggins, L., Chapple, D. G., Daugherty, C. H., & Ritchie, P. A. (2008). A SINE of restricted gene flow across the Alpine Fault: phylogeography of the New Zealand common skink (Oligosoma nigriplantare polychroma). Molecular Ecology, 17(16), 3668-3683.

Lord, J. M., & Marshall, J. (2001). Correlations between growth form, habitat, and fruit colour in the New Zealand flora, with reference to frugivory by lizards. New Zealand Journal of Botany, 39(4), 567-576.

Mockett, S. (2017). A review of the parasitic mites of New Zealand skinks and geckos with new host records. New Zealand journal of zoology, 44(1), 39-48.

O’Donnell, C. F., Weston, K. A., & Monks, J. M. (2017). Impacts of introduced mammalian predators on New Zealand’s alpine fauna. New Zealand Journal of Ecology, 41(1), 1-22.

Patterson, G. B., & Daugherty, C. H. (1990). Four new species and one new subspecies of skinks, genus Leiolopisma (Reptilia: Lacertilia: Scincidae) from New Zealand. Journal of the Royal Society of New Zealand, 20(1), 65-84.

Patterson, G. B., & Daugherty, C. H. (1995). Reinstatement of the genus Oligosoma (Reptilia: Lacertilia: Scincidae). Journal of the Royal Society of New Zealand, 25(3), 327-331.

Reardon, J. T., & Tocher, M. (2003). Diagnostic morphometrics of the skink species, Oligosoma maccanni and O. nigriplantare polychroma, from South Island, New Zealand. Wellington: Department of Conservation.

van Winkel, D., Baling, M., Hitchmough, R. 2018. Reptiles and amphibians of New Zealand – a field guide. Auckland university press, Auckland New Zealand.

Wotton, D. M., Drake, D. R., Powlesland, R. G., & Ladley, J. J. (2016). The role of lizards as seed dispersers in New Zealand. Journal of the Royal Society of New Zealand, 46(1), 40-65.