Robust Skink

Fascinating facts about the Robust Skink

• A single robust skink can grow to a length of up to 33 cm and weigh as much as 105 g, making it the largest endemic skink in New Zealand.
• In captivity, robust skinks have been recorded living to 33 and 55 years.
• On 30 April 1997, conservationists moved exactly 30 robust skinks from Matapia Island to nearby Motuopao Island to seed a new, safe population. The precise, small-scale translocation highlights how a handful of individuals can safeguard an entire species when islands stay rodent-free.
• Juvenile female robust skinks sprint faster than adult males, a speed boost that helps them outrun introduced predators like rats and stoats. This rapid burst capability underscores sprint performance as a key survival tool in a world where every second counts.
• Every night, robust skinks slip into seabird burrows, thick leaf litter, and rocky crevices to stay moist, because their skin loses water quickly. Their reliance on such humid microhabitats teaches us how climate and micro-climate shape the distribution of even the hardiest island reptiles.

At a glance

About the Robust Skink

The robust skink (Oligosoma alani) dominates New Zealand’s reptile world with a stout, thick-set body that can reach a snout-vent length of 150 mm and a total length of up to 33 cm, weighing as much as 105 g. Its mid-dark brown dorsal surface is broken by large cream-pale blotches, while a striking black-edged teardrop beneath each eye and vivid reddish-pink ventral hues set it apart from any other skink. Short limbs and a tapering, robust tail give it a low, powerful silhouette that darts through leaf litter, rocks and seabird burrows in the humid forest floor of the Mercury Islands, where it hides by day and emerges at dusk to hunt. Nocturnal and fiercely territorial, this solitary predator relies on camouflage and speed; juveniles sprint faster than adult males, a trait that doubles as an antipredator tactic and a means to capture mobile invertebrates. Its diet is opportunistically omnivorous, snatching insects, crustaceans, molluscs, and even plant matter such as native kawakawa and nightshade, while occasional reports note predation on diving petrel chicks and smaller lizards. Perhaps the most surprising aspect of its biology is its longevity: captive individuals have lived to 33 and even 55 years, a testament to the species’ slow life-history pace in a climate where viviparity limits them to a single reproductive cycle each year.

More reptiles to discover

Browse Feravox