Nangur skink

Nangur skink Photo: A Borsboom (DERM)

Common name: Nangur skink; Nangur spiny skink

Scientific name: Nangura spinosa

Family: Scincidae

Conservation status: This species is listed as Endangered in Queensland (Nature Conservation Act 1992) and is Critically Endangered nationally (Environment Protection and Biodiversity Conservation Act 1999). It is ranked as a medium priority under the Department of Environment and Resource Management Back on Track species prioritisation framework.

Description: The Nangur skink has a robust build and grows to approximately 19 cm in length (9.5 cm snout-vent). Adults can weigh in excess of 30 grams with neonates weighing 1.5 grams. It has spiny scales along its back, tail and flanks. The limbs are well developed and the tail tapers to a point. It is dark brown in colour with irregular cross-bands on the body and its underside is cream (Covacevich et al. 1993). The labial scales are edged with black. The mid body scales are in 28 rows and strongly keeled, forming longitudinal ridges.

Habitat and distribution

Nangur skink habitat Photo: L Connell (DERM)

Nangura spinosa was first discovered in 1992 (Covacevich et al. 1993) with a second population found approximately 38 km away in 1997 (Hannah et al. 1997). It is confined to remnant dry rainforest, including semi-evergreen vine thicket at two locations in south-east Queensland. Current estimates suggest a total population size of less than 200 adults with an extent of occurrence of approximately 45 km² (Borsboom et al. 2005). Intensive surveys have failed to find further populations of the Nangur skink at any location other than the original two sites.

To date all known Nangur skinks have been recorded at between 315 m and 600 m altitude on basaltic soil in semi-evergreen vine thickets, hoop pine plantations and araucarian notophyll vine forest (Covacevich et al. 1993; Hannah et al. 1997; Borsboom et al. 2005).

The most common tall tree species growing in Nangur skink habitat are hoop pine Araucaria cunninghammii, red kamala Mallotus philippensis and scrub poison tree Excoecaria dallachyana. Regional ecosystem (RE) polygons identified in known skink locations include:

12.8.13	Araucarian complex microsphyll vine forest on Cainozoic igneous rocks
12.8.21	Semi-evergreen vine thicket with Brachychiton rupestris on Cainozoic igneous rocks
12.12.13	Araucarian complex microphyll to notophyll vine forest on Mesozoic to Proterozoic igneous rocks
12.12.16	Notophyll vine forest on Mesozoic to Proterozoic igneous rocks
12.12.17	Semi-evergreen vine thicket on Mesozoic to Proterozoic igneous rocks

Table 1: Regional ecosystems (Source: Queensland Herbarium 2009. Regional Ecosystem description database Version 6.0b: Department of Environment and Resource Management)

Life history and behaviour

Nangur skink and burrow Photo: A Borsboom (DERM)

The Nangur skink lives in single entrance burrows which may be shared with adults, sub-adults and/or young (Borsboom et al. 2005). Burrows have been measured up to 60 cm in length, terminating in an oval chamber of approximately 5 cm. The burrow entrance can measure 8 cm wide by 3 cm high. Longevity and active use of the burrows vary.

Generally the burrows are well concealed with entrances located at the base of rocks, beneath tree roots, along road embankments or on open ground (Covacevich et al. 1993; Hannah et al. 1997; Borsboom et al. 2005). Burrows associated with rocks and tree roots possibly provide protection from predators digging out entrances.

Research suggests that the majority of skinks prefer burrows that have significant overhanging vegetation but little vegetation at ground level. A large number of burrows are located where there is significant plant density and forest structure. Soil composition is likely to play a role in habitat suitability as it needs to be of a suitable composition to allow burrows to be constructed and maintained (Borsboom et al. 2005).

There is often a smooth ‘resting platform’ in front of the burrow where skinks have been observed basking in the sunlight during warmer months (Wilson & Swan 2008).

The Nangur skink has a varied diet consisting of ground dwelling invertebrates, in particular beetles and spiders (Covacevich et al. 1993). Some of the invertebrates are active at night, suggesting crepuscular and nocturnal activity by the skink (Borsboom 2007).

Currently little is known of the growth, maturation and reproduction of Nangur skinks, though indirect evidence suggests the skink may bear live young (Covacevich et al. 1993). Neonates have been recorded in February and April (Covacevich et al. 1993; Hannah et al. 1997; Wilson & Swan 2008).

Threatening processes

Knowledge of threatening processes that may impact the Nangur skink is limited due to its recent discovery. More research is necessary to improve our understanding of threats and how they impact on the skink.

The following threatening processes are believed to have an impact on the Nangur skink:

Clearing of habitat
Hoop pine plantation harvesting and re-establishment
Illegal collection

Potential threatening processes may include:

Feral animals (cane toads, feral cats, foxes, dingoes and pigs)
Fire
Weeds

Any reduction in population of the Nangur skink may have a dramatic impact on population viability, as small populations are generally more vulnerable to stochastic events, such as fire or climate change.

Recovery actions

A recovery plan is currently being prepared for the Nangur skink. The recovery objective is to improve the status of Nangura spinosa populations in the wild by implementing informed management decisions based on a thorough understanding of the species’ biology and habitat requirements.

The draft recovery plan recommends the following:

Undertake surveys to determine the full extent and area of occupancy of the Nangur skink;
Monitor ecological and biological parameters considered important for the survival of wild populations;
Implement threat abatement programs, including weed and feral animal control;
Modify hoop pine plantation harvesting and re-establishment at sites where the skink occurs; and
Implement a fuel management program to reduce the risk of fire damage to the skink's habitat.

Related information

Nangura spinosa in Species Profile and Threats Database

Borsboom, A, Smyth, G and Rider, E 2005. The rare Queensland skink Nangura spinosa: Surveys, distribution, habitat, threats, management and conservation status. Internal report. Environmental Protection Agency, Brisbane.

Covacevich, JA, Couper, PJ and James, C 1993. A new skink, Nangura spinosa GEN. ET SP. NOV. from a dry rainforest of southeatern Queensland. Memoirs of the Queensland Museum 34(1): 159-167.

Department of Environment and Resource Management. 2009. Survey and Mapping of 2006 Remnant Vegetation Communities and Regional Ecosystems of Queensland, Version 6b (September 2009). Queensland Herbarium, Department of Environment and Resource Management, Brisbane.

Hannah, D, Agnew, G, Hamley, B and Hogan, L 1997. New information on the narrowly-restricted skink Nangura spinosa. Memoirs of the Queensland Museum 42(1): 90.

O’Connor, D and Moritz, C 2003. A molecular phylogency of the Australian skink genera Eulamprus, Gynpetoscincus and Nangura. Australian Journal of Zoology 51: 317-330.

Wilson S and Swan G 2008. A complete guide to reptiles of Australia 2^nd edition, New Holland Publishers (Australia) Pty Ltd, Sydney.

Last updated 11 October 2011