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Christmas Island grass-skink (Subdoluseps bowringii)

The Christmas Island grass-skink is an introduced, ground-dwelling lizard recorded on Christmas Island. Its insect-eating habits and use of ground cover mean it may compete with native animals or affect local invertebrates, so sightings and possible spread between sites warrant attention.

Key facts

Type: Pest animal, reptile.

Native to: South and Southeast Asia, including parts of India, southern China and mainland Southeast Asia.

Established in: WA.

Other names: Bowring’s supple skink, Bowring’s skink.

Best time to act: Search during daylight, when the species is active, and revisit sites throughout the year.

Identification

  • A small, slender skink with four legs and a body that grows to about 82 mm from snout to vent.
  • The body is generally brown or bronze, often with darker and paler lengthwise stripes.
  • It is active during the day and commonly moves through leaf litter or other ground cover.
  • It can burrow, so it may disappear quickly beneath loose soil or litter.
  • Look-alike: It can be confused with other small skinks; use a clear photograph and seek expert identification when the markings are not distinctive.

Where it lives

On Christmas Island it lives on the ground in forest and leaf litter, and uses terrestrial and burrowing habitats.

Why it matters

  • It eats insects and other invertebrates, which may put it in competition with native insect-eating animals.
  • As an introduced ground-dwelling lizard, it may affect native species through competition or predation, but the extent of any impacts should not be assumed from a sighting alone.

How it spreads

  • It could be moved between sites if individuals or eggs are carried in soil, leaf litter, plant material or equipment.
  • Check freight, vehicles and gear before moving them, especially when they have been in areas where the skink occurs.

Control methods

  • Confirm the identification and record the location, date and a photograph before taking action.
  • Where removal is authorised, use trained personnel and approved humane capture methods; do not use pesticides or poisons.
  • Check treated areas again and repeat searches, including beneath leaf litter and other ground cover.
  • Report suspected sightings to Parks Australia on Christmas Island, or to the relevant state or territory biosecurity authority elsewhere.

Site hygiene and welfare

  • Before leaving an infested site, inspect and clean boots, vehicles, machinery and other gear, removing soil and leaf litter where skinks or eggs could be concealed.
  • Avoid carrying soil, litter or uninspected plant material between sites.
  • Use methods set out in the national model codes of practice and standard operating procedures for the species.
  • Coordinate control with neighbours and the local government biosecurity plan, as isolated effort is quickly undone by reinvasion.

Classification by state

  • Australia (national): No national listing. Managed under state and territory law.
  • Queensland: Prohibited matter. Report it to Biosecurity Queensland on 13 25 23 within 24 hours and do not move or deal with it. Everyone must also take all reasonable and practical steps to minimise its risks (the general biosecurity obligation).
  • New South Wales: Prohibited dealing. All dealings are prohibited in NSW, so it must not be kept, bred, sold, moved or released. Report any sighting to NSW DPIRD. The general biosecurity duty applies: anyone dealing with it must prevent, eliminate or minimise the risk it poses.
  • Victoria: Prohibited pest animal. It is a prohibited pest animal in Victoria. The Victorian Government is responsible for controlling it, so report any sighting to Agriculture Victoria.
  • South Australia: Not declared. Not declared under the Landscape South Australia Act 2019. Other laws may still apply.
  • Western Australia: Not listed. Not found in the Western Australian Organism List. Check with DPIRD before moving or keeping it.
  • Tasmania: Not a declared pest. Not a declared pest or prohibited matter in Tasmania. Importing animals is still controlled by Biosecurity Tasmania.
  • Northern Territory: Prohibited entrant. Wildlife that is not native to the NT is a prohibited entrant, so you need an NT permit to bring it in or keep it. Report any wild sighting to the NT Government.
  • Australian Capital Territory: Not declared. Not declared under the Biosecurity Act 2023 (ACT). A general biosecurity duty still applies.

Legal obligations

Every state and territory places a duty on landholders and people working on land to prevent the spread of invasive species, such as the general biosecurity obligation in Queensland and the general biosecurity duty in New South Wales. Declarations and control requirements differ between states and local government areas, so check the current official list before work starts.

  • Western Australia: Biosecurity and Agriculture Management Act 2007 (WA), administered by the WA Department of Primary Industries and Regional Development

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