Oligosoma elium

Marlborough spotted skink

Oligosoma elium
(Melzer et al., 2017)

Marlborough spotted skink (Marlborough). <a href="https://www.instagram.com/samanimalman/">© Samuel Purdie</a>
Image attribution
Marlborough spotted skink (Marlborough). © Samuel Purdie
Herpetofaunal category
NZ Skinks
Species complex
Conservation Status
Threatened - Nationally Vulnerable
Previous scientific names
Oligosoma aff. lineoocellatum "South Marlborough",
Oligosoma lineoocellatum.
Common names
Marlborough spotted skink

Length: SVL up to 89mm, with the tail being slightly longer than the body length

Weight: Up to at least 10 g

Description

A large, poorly known, and often beautifully coloured skink from the Marlborough and northern Canterbury.

The dorsal colour of Marlborough spotted skinks is often pale green, grey, or brown, with lighter-coloured dots (ocelli) and dark speckles scattered along the dorsal surfaces, continuing onto or fading out on the tail. Marlborough spotted skinks often have cream-coloured dorsolateral stripes which break up on the tail, the flanks are often dark with white or cream flecking, with the lower surfaces being a uniform grey, although they are sometimes flushed with pink.

Similar in appearance to other members within the spotted skink complex (Oligosoma lineoocellatum), and the green skink complex (Oligosoma chloronoton), but generally geographically isolated from these species. 

Life expectancy

Unknown.

Distribution

Marlborough spotted skinks are restricted to Marlborough and northern Cantebury, occurring from around Ward in the north through to Hawarden at their southern limit. A population is also present on Motunau Island.

Ecology and habitat

Marlborough spotted skinks are diurnal, terrestrial, and avid-sunbaskers making them a particularly conspicuous species. They prefer open/sunny areas such as open grassy areas, tussock grassland, rock piles, and scree slopes. When not basking or foraging, Marlborough spotted skinks will take refuge under rocks, logs, or in dense vegetation such as thick grass and complex shrubs.

Social structure

Largely unknown.

Breeding biology

Viviparous (Live bearing). Largely unknown, but likely to be similar to that of the Canterbury spotted skink (Oligosoma lineoocellatum) e.g. females giving birth to 1-3 young between February and March.

Diet

In common with other species of New Zealand skink, the diet of Marlborough spotted skinks includes a wide range of invertebrates, and the berries / fruit and nectar of native plant species. 

Disease

Marlborough spotted skinks have been recorded with species of ectoparasitic mites.

Conservation strategy

Marlborough spotted skinks are regarded as 'Threatened - Nationally Vulnerable' and are becoming increasingly rare due to the ongoing effects of habitat modification and predation by mammalian predators (rodents, mustelids, hedgehogs, and cats). This species is not currently being managed. 

Interesting notes

Marlborough spotted skinks are members of the spotted skink species complex. 'Spotted skinks' are a group of four closely-related species which are difficult to distinguish morphologically (based on appearance) and were originally regarded as one variable and widely distributed species - Oligosoma lineoocellatum (of which the Canterbury spotted skink has retained this scientific name). Spotted skinks are regionally distributed from the southern North Island to the central South Island. Other species include the northern spotted skink (Oligosoma kokowai). Canterbury spotted skink (Oligosoma lineoocellatum) and Mackenzie skink (Oligosoma prasinum).

References

Greaves, S. N., Chapple, D. G., Gleeson, D. M., Daugherty, C. H., & Ritchie, P. A. (2007). Phylogeography of the spotted skink (Oligosoma lineoocellatum) and green skink (O. chloronoton) species complex (Lacertilia: Scincidae) in New Zealand reveals pre-Pleistocene divergence. Molecular Phylogenetics and Evolution45(2), 729-739.

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 Publishing.

Melzer, S., Bell, T., & Patterson, G. B. (2017). Hidden conservation vulnerability within a cryptic species complex: taxonomic revision of the spotted skink (Oligosoma lineoocellatum; Reptilia: Scincidae) from New Zealand. Zootaxa4300(3), 355-379.

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