T.E.R:R.A.I.N - Taranaki Educational Resource: Research, Analysis and Information Network

Skink (Rainbow or Plague) Lampropholis delicate

Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Family: Scincidae
Genus: Lampropholis
Species: L. delicata
Binomial name: Lampropholis delicate
Common name: Rainbow Skink, Dark-flecked garden sun skink, Garden skink, Plague skink.

Lampropholis delicata is a small lizard accidentally introduced to New Zealand in the early 1960s from Australia and are now posing a threat to our rare native lizards as they reproduce much more rapidly than native lizards, laying up to eight eggs three times per year (more than five times as fast as most native lizards) and mature in less than half the time of native lizards. They compete with other native lizards and mammals for food and habitat. They also prey on many native invertebrates.
Since being introduced their range has extended through the North Island, and are currently found from Northland to Waikato and the Bay of Plenty, with outlying populations at Whanganui, Palmerston North and Foxton Beach. They are more common in suburban gardens than in adjacent native bushland.

Rainbow skinks are not present or established in the South Island. If you suspect that you have found this pest in the South Island, call MPI Biosecurity New Zealand on 0800 80 99 66.

They are small lizards, measuring about 3-4 cm long from nose to hind legs excluding the long thin tail. Its scales are smooth. The back and sides are greyish-brown to rich brown, often with darker and paler flecks and an iridescent rainbow or metallic sheen when seen in bright light. A narrow yellowish-brown stripe is usually present on the outer edge of the back. The species can also have two distinct forms: a prominent white stripe and a less prominent white stripe. This dimorphism is not strictly distinguished by gender.
Although smaller than native skinks, they do look very similar but can be easily distinguished with one distinctive feature, they have one large scale on the top of their head, whereas New Zealand native skinks have two smaller scales. See graphic below

Thanks to Wikipedia for text and information http://creativecommons.org/licenses/by-sa/3.0/