Falla’s skink  (Oligosoma fallai)

Falla's skink is classified as Vulnerable (VU) on the IUCN Red List (1).

One of New Zealand’s largest skinks (2), Falla’s skink (Oligosoma fallai) has, like other skinks, a roughly cylindrical body and short limbs (4). Its mottled brown body, speckled with flecks of yellow, provides camouflage in its natural habitat (5).

Falla’s skink is endemic to the Three Kings Islands, a group of islands situated 60 kilometres off Cape Reinga, the northernmost point of the North Island, New Zealand (2) (3). Within this island group, Falla’s skink inhabits at least seven islands and islets (2).

The Three Kings Islands are rugged, mostly cliff-bound islands, within which Falla’s skink inhabits scrub and forest, particularly low, open forest (2) (3).

Falla’s skinks are omnivorous lizards that feed on invertebrates, seeds, leaves, fleshy fruits, such as the small reddish-purple fruits of the Ngaio tree (Myoporum laetum), and even the spilled regurgitations of sea birds (2) (3). For most of the year, Falla’s skinks are active during the day and are most energetic on warm, sunny days, however, at times this lizard may also be active during the night (2) (3).

Mating is believed to take place in autumn, with live young being born primarily during the summer (2) (6), but some give birth as early as February or as late as the following autumn (3). It is thought that not all female Falla's skinks give birth every year, but those that do give birth to an average of five young (3).

In the past, the habitat of the Three Kings Islands was heavily modified by its Maori inhabitants and by the introduction of goats. It is not known what effect this may have had on skink populations, but with the removal of goats from the islands in 1946, habitat degradation is no longer believed to be a great threat to Falla’s skink (2).

Today, the most significant threats are the possibility of a predator introduction and catastrophic climatic events, which due to the restricted distribution of Falla’s skink, could potentially impact the entire population. Introduced predators are of particular concern as some of the islands in the Three Kings group are less than a kilometre apart, meaning that introduced predators, such as Norway rats, could swim between them (2).

As introduced predators pose the greatest potential threat to this species, an action plan for Oligosoma skinks developed in 2002 focuses on measures which could be taken to ensure against this happening (2). In recent years, introduced rodents have been removed from numerous islands around the North Island (2), which will help lessen the chance of their introduction to the Three Kings Islands. The plan recommends that the Three King Islands should be checked for rodents every six months (2).

View information on this species at the UNEP World Conservation Monitoring Centre.

For further information on Falla’s skink: 

• Towns, D.R., Neilson, K.A. and Whitaker, A.H. (2002) North Island Oligosoma spp. Skink Recovery Plan 2002–2012. Department of Conservation, Wellington, New Zealand. Available at:
  www.doc.govt.nz