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Centralian Bluetongue (Tiliqua multifasciata)

The Centralian Bluetongue is a terrestrial skink of arid inland and north-western Australia. It can occur in a range of dry habitats, including sandplains, dunes, mulga woodland and samphire country, so clearing inspections should include both vegetated areas and ground refuges. It is not listed under the EPBC Act and is listed as Vulnerable in New South Wales.

Conservation status

New South Wales, Biodiversity Conservation Act 2016: Vulnerable.

Breeding season

Centralian Bluetongues mate in August and give birth mainly in December and January. Gravid females, newborns and animals sheltering during cooler months can be vulnerable to clearing, so confirm local conditions before works.

Reproductive mode: Live-bearing.

Litter size: 1 to 4 young in captive records. The species is also described as having large litters, but no larger numerical range is provided.

Incubation or gestation: Approximately 3 to 4 months. Captive records report 107, 120 and 124 days.

Size at hatching or birth: Not recorded for this species.

Age at maturity: Not recorded.

Nest or egg sites: Not recorded. No nest is expected for a live-bearing species.

Breeding frequency: Not recorded.

Confirm timing locally before clearing, because rainfall and temperature influence activity, mating and the onset of births across this arid species' range.

  • Mating: Mating is recorded in August, during the tropical dry season. The species may respond to local temperature and rainfall conditions.
  • Gravid females: Gestation is approximately 3 to 4 months, with captive records of 107 to 124 days. Females mated in August may carry embryos from late winter through December, with the greatest likelihood immediately before December and January births.
  • Births: Northern populations, including Centralian Bluetongues, give birth in December and January at the onset of the wet season. Captive guidance gives a broader late summer to early autumn period for bluetongues generally.
  • Newborns: Newborns are most likely to be present in December and January, following the documented birth period. Young are born fully formed and can feed independently shortly after birth.
  • Active period: No species-specific activity months are recorded. Centralian Bluetongues are diurnal, sometimes crepuscular or nocturnal, especially in summer, so surface activity is expected year round but is likely to increase in warmer months.
  • Winter inactivity: Cooler months are associated with substantially reduced activity and feeding, and animals may remain in shelter. Exact brumation months are not recorded for this species, so May to August is an operational planning period rather than a confirmed dormancy season.
  • Highest clearing risk: Risk is highest in December and January, when births and newborns are documented, and from May to July when reduced activity may leave animals sheltering in cover, soil or other refuges. August also requires care because mating occurs and some females may be gravid.

Identification

This is a large, heavy-bodied bluetongue skink with a broad head and a conspicuous blue tongue, although the supplied documents provide limited field description beyond its size and defensive bite. Handle suspected animals carefully because bluetongues can deliver a painful and bloody bite.

The Centralian Bluetongue reaches a maximum length of 35 cm. No body weight range is given in the supplied documents.

The species is recorded in the Lake Wells fauna survey material, where it is listed as Tiliqua multifasciata and Central Blue-tongue.

Maximum length: 35 cm

Weight: Not stated in the supplied documents

Defensive behaviour: May open its mouth and bite when approached or handled

Identification: Similar species

The Western Bluetongue, Tiliqua occipitalis, is also listed in the regional fauna material. The supplied documents do not provide a diagnostic comparison of colour, banding, tongue colour or scale counts, so uncertain animals should be photographed and referred to an experienced herpetologist or suitable identification key.

The maximum length given for the Western Bluetongue is 40 cm, compared with 35 cm for the Centralian Bluetongue. Size alone is not a reliable field separation.

Centralian Bluetongue maximum length: 35 cm

Western Bluetongue maximum length: 40 cm

Identification: Field signs and handling

The supplied documents do not describe species-specific tracks, scats, calls, nests, sloughs or eyeshine. A live animal is therefore the most reliable field record for this profile.

Do not place hands near the head of a captured animal. Keep the animal supported and use an approved fauna handling and release procedure.

  • Record the location, habitat, photographs and direction of movement for each observation.
  • Use a licensed or authorised fauna handler where capture is needed.
  • Release the animal promptly into suitable cover close to the point of capture, subject to project permit conditions.

Distribution: Documented range

The supplied material supports an arid inland and north-western Australian distribution, with a confirmed project record from the Lake Wells area. It does not provide a complete national range map, population estimate, trend assessment or list of stronghold populations.

The species is described as occurring in most habitats in the arid north-west and interior. The Lake Wells survey area is in the Great Victoria Desert region of Western Australia, and Tiliqua multifasciata was recorded during the fauna survey material.

The documents do not establish the full state by state range. Western Australia is the only state directly represented in the supplied records.

Biogeographic setting documented: Arid north-west and interior Australia, including the Great Victoria Desert region

Project record: Lake Wells area, Western Australia

States directly documented in the supplied records: Western Australia

Distribution: Population information

No population size, density, subpopulation structure or population trend is provided. The Lake Wells table records two Centralian Bluetongues in the survey results, but the document warns that repeated daily records may represent the same individuals.

Survey count shown in the supplied table: 2 records for Tiliqua multifasciata

Population size and trend: Not stated

  • Do not convert survey counts into a population estimate.
  • Treat isolated records as evidence of presence, not evidence of a viable local population.

Habitat: Habitat types

The Centralian Bluetongue uses dry habitats across the arid north-west and interior. The Lake Wells survey material includes several habitat types within the species’ recorded survey setting, but it does not identify a single preferred vegetation community.

The species is reported from most habitats in the arid north-west and interior. Habitat types represented in the Lake Wells survey include sandplain, sand dune, clay-loam dune, gypsum dune, mulga woodland and samphire.

The available documents do not give an elevation range, rainfall threshold or temperature limit.

Recorded habitat settings in the survey area: Sandplain, sand dune, clay-loam dune, gypsum dune, mulga woodland and samphire

Elevation limits: Not stated

Climate limits: Not stated beyond the arid north-west and interior

Habitat: Features to retain during works

Retain connected patches of native ground cover and avoid unnecessary disturbance to dry shelter sites within otherwise suitable arid habitat. The supplied documents do not quantify required patch size, vegetation height or canopy cover.

Where clearing is unavoidable, inspect the full range of habitat types present rather than limiting searches to woodland or dune crests.

  • Mark habitat edges before clearing and keep machinery within the approved disturbance footprint.
  • Inspect sand, clay-loam, gypsum and mulga habitats separately where they occur within the work area.
  • Keep retained habitat connected wherever practicable.

Foraging habitat: Diet and feeding sites

The supplied documents do not provide a wild diet, prey list, feeding method or foraging range for the Centralian Bluetongue. They do show that the species occupies a broad range of arid habitats, so foraging areas may occur across the ground layer within and between those habitats.

No field diet or prey remains are described. The captive husbandry sheet lists fruits, vegetables, flowers, insects, small mice, raw meat, pet food and snails as captive food items, but this should not be treated as a wild diet.

For project assessment, retain native ground cover and the soil surface across suitable habitat. These areas are likely to provide feeding opportunities, but the supplied documents do not identify particular food plants or prey species.

Wild diet: Not stated

Named captive foods: Fruits, vegetables, flowers, insects, small mice, meat, pet food and snails

Foraging range: Not stated

Foraging habitat: Field application

Search effort should cover habitat edges, low cover and undisturbed ground within the clearing footprint. Do not assume that an animal found in one habitat type is restricted to that habitat, because the species is reported from most arid habitats.

  • Inspect before soil stripping, grading and vegetation removal.
  • Record the habitat type at each observation and the animal’s direction of travel.
  • Avoid leaving food scraps or artificial food sources on site.

Breeding habitat: Breeding biology

Centralian Bluetongues produce live young. The supplied material places reproduction in late summer or early autumn and states that bluetongues produce more than four young in a litter, but it does not provide species-specific gestation, maturity or lifespan data.

The species-specific breeding site is not described. Retain suitable dry habitat, ground cover and shelter throughout the period when females may be carrying young or young animals are dependent.

The captive advice states that bluetongues produce live young in late summer or early autumn. It gives a litter size of more than four for bluetongues, without separating the figure by species.

Reproductive mode: Live-bearing

Breeding and birth period: Late summer to early autumn

Litter size: More than four young, reported for bluetongues generally

Gestation: Not stated

Age at maturity: Not stated

Lifespan: Not stated

Breeding habitat: Breeding habitat features

No specific birthing refuge, mating site or nursery habitat is identified. Avoid clearing connected ground cover and shelter in late summer and early autumn, particularly where adults or juveniles are observed.

  • Complete pre-clearance searches before disturbance in suitable arid habitat.
  • Protect retained cover around any live observation until the animal has moved clear of the work area.
  • Record juveniles separately from adults where size and features allow.

Sheltering habitat: Likely refuge features

The supplied documents do not describe wild dens, burrows, hollows or refuge dimensions for the Centralian Bluetongue. They indicate that bluetongues require shaded and dry shelter in captivity, which supports retaining ground cover and dry refuge features during works.

The captive guidance recommends a shaded area, a permanently dry area during wet weather, and a low, flat hide box with leaf litter or dead grass. These are husbandry recommendations, not measurements of wild shelter use.

No wild shelter size, burrow depth, hollow use or den structure is provided for this species.

Shelter conditions described in the supplied material: Shade, dry areas, low shelter and leaf litter or dry grass

Wild refuge dimensions: Not stated

Burrow depth: Not stated

Sheltering habitat: Pre-clearance response

Inspect under and beside ground cover, debris and other dry refuges before clearing. Relocate animals only under the relevant permit, authorisation and fauna handling procedure.

Because bluetongues may be active at night during hot weather, avoid assuming that an apparently empty refuge is unoccupied.

  • Lift or disturb cover slowly and from a position that keeps the handler away from the animal’s head.
  • Check both shaded and dry refuge areas before machinery enters the footprint.
  • Recheck disturbed refuge areas before backfilling or compacting soil.

Threats: Clearing and construction

The supplied documents do not provide a species-specific threat assessment. On development sites, the main foreseeable risks are direct mortality during clearing, loss of suitable arid habitat, vehicle collision and disturbance or burial of shelter sites.

Vegetation removal, soil stripping, trenching and stockpiling can kill or injure animals sheltering at ground level. Fragmentation can also reduce movement between suitable arid habitat patches, although the documents do not quantify this effect for the species.

Roads and vehicle movements create a direct collision risk. Schedule slow vehicle movements and use fauna spotters where animals are detected or where the risk assessment identifies suitable habitat.

  • Undertake pre-clearance searches before grubbing, grading and trenching.
  • Keep clearing within the approved footprint.
  • Use fauna spotters during high-risk clearing and immediately stop work if an animal is found.
  • Install fauna egress measures in open trenches and inspect them at the required frequency.

Threats: Fire, predators and other pressures

The supplied documents do not assess the effects of fire, introduced predators, disease or hydrology change on Centralian Bluetongue populations.

Avoid creating long-term waterlogging or removing dry refuge areas where these features are part of the local habitat. Do not leave food waste that could attract predators to retained habitat.

  • Keep fire management within the approved environmental controls and avoid unplanned burning of retained habitat.
  • Maintain clean work areas and secure waste and food.
  • Record injured or dead bluetongues and report patterns of mortality to the project environmental officer.

Survey methodology: 1. Plan the survey

The Centralian Bluetongue occurs in arid habitats across inland and north-western Australia. The supplied documents do not provide a species-specific survey guideline or prescribed survey effort, so use the project’s approved fauna survey requirements and record the conditions and effort used.

Confirm the species identification, project footprint, habitat types and likely disturbance area before fieldwork.

The species has been recorded in a Level 2 vertebrate fauna survey, including a November to December 2018 survey at the Lake Wells study area. Treat nearby records as evidence of potential occurrence, not as a substitute for a project survey.

Maximum length: 35 cm

Activity note: Bluetongues may be active at night during hot weather

Habitat context: Most habitats in the arid north-west and interior

  • Search the full disturbance footprint and adjacent retained habitat where animals may move during clearing.
  • Record survey dates, start and finish times, weather, temperature, wind, rainfall, ground conditions, observers, methods, distances searched and habitat searched.
  • Use experienced observers who can distinguish the Centralian Bluetongue from other Tiliqua species and record clear photographs where identification is uncertain.

Survey methodology: 2. Spotlighting and active searching

Spotlight during suitable warm conditions, with particular attention to the evening and night period when bluetongues may be active during hot weather.

Walk slowly through all habitat within the disturbance area and inspect beneath ground cover, around shrubs, beside logs and rocks, and along movement routes. These search targets are general practice for a ground-dwelling lizard because the supplied documents do not identify a species-specific shelter feature.

  • Use a consistent transect route or search area and record the length or area covered by each observer.
  • Repeat searches on more than one suitable night where the project risk and approval conditions require greater confidence in absence.
  • Do not rely on a single daytime inspection, particularly during hot weather when the species may be active after dark.

Survey methodology: 3. Trapping and supplementary methods

The supplied documents do not prescribe pitfall, funnel-trap, cage-trap, tile, artificial shelter or transect effort for Centralian Bluetongues.

Use trapping only where it is authorised in the project survey design and managed by appropriately trained personnel, with methods selected for local conditions and the welfare of non-target reptiles.

  • Document the number and type of traps, trap nights, checking frequency, weather conditions and any animal welfare incidents if trapping is used.
  • Use active searching and spotlighting as supplementary methods where trapping is unsuitable or not approved.
  • Stop or modify trapping when heat, rain, flooding, predators or other conditions create an unacceptable welfare risk.

Survey methodology: Minimum effort and reporting

  • Meet the current survey requirements of the relevant state or territory and any approval or permit conditions before starting fieldwork.
  • Survey all habitat proposed for clearing and explain any areas that could not be searched.
  • Report raw records with coordinates, date, time, method, observer, photographs, habitat description and whether the animal was captured, observed or handled.
  • Submit confirmed records to the relevant state wildlife database and provide records required by the project approval authority.
  • State clearly where the supplied documents do not define a species-specific survey effort, and justify the effort selected for the site.

Before habitat disturbance: Avoid and minimise

The species is not listed under the EPBC Act in the supplied project information, and the project brief identifies a Vulnerable state listing in New South Wales. Confirm the current listing and permit requirements for the state or territory in which the project occurs before disturbance.

Retain suitable arid habitat outside the construction footprint wherever practicable, because the species occurs across most habitats in the arid north-west and interior.

Keep connected strips of retained habitat between undisturbed areas where practicable, so ground-dwelling lizards can move away from works.

Avoid unnecessary removal of ground cover, rocks, logs, shrubs and other shelter features, even though the supplied documents do not identify a single feature used specifically by this species.

  • Use the smallest practicable clearing footprint and keep machinery within marked work areas.
  • Locate access tracks, laydown areas and stockpiles in already disturbed areas where practicable.
  • Prevent soil, spoil, rubbish and chemical storage from spreading into retained habitat.

Before habitat disturbance: Approvals and work planning

Check whether the species is listed under the relevant state or territory legislation at the time of the project, and obtain any required wildlife, handling, relocation or clearing permits.

Because the supplied project information identifies the species as not listed under the EPBC Act, an EPBC referral is not indicated on that information alone; confirm the current Protected Matters and approval position for the project site before relying on this conclusion.

  • Include the species in the project fauna management plan where suitable habitat occurs or records are known nearby.
  • Schedule clearing to avoid periods of extreme heat and other conditions that increase animal welfare risks.
  • Stage clearing so animals can move towards retained habitat and so the fauna spotter catcher can inspect each work area before machinery enters.

Before habitat disturbance: Prepare the site

Complete a pre-clearance survey of the approved disturbance area shortly before clearing, using the project’s approved methods.

Mark the clearing boundary, retained habitat, access routes and no-go areas before machinery arrives.

Use fauna exclusion fencing only where it is suited to the site and does not trap animals inside the work area or prevent movement to retained habitat.

  • Brief all workers on the species’ identification, the stop-work process and the requirement to follow the fauna spotter catcher’s directions.
  • Remove waste, loose materials and artificial hazards from the work area before clearing.
  • Confirm the location of an authorised handler, suitable temporary holding equipment, a nearby release area and a veterinary or wildlife carer contact before work starts.

During habitat disturbance: Daily controls

Clearing must be controlled by an authorised fauna spotter catcher who can direct machinery, inspect exposed habitat and manage any animal found. The documents provide general information on the species’ habitat and behaviour but do not set a species-specific relocation distance or handling protocol.

Inspect the work area before machinery starts each day, including retained edges, ground cover, logs, rocks, shrubs, stockpiles and open trenches.

Keep the fauna spotter catcher in a position where the operator can see and follow directions before each movement of the machine.

Clear progressively in small sections towards retained habitat where safe and consistent with the approved clearing method.

  • Maintain fauna exclusion fencing, gates and escape routes throughout the work period.
  • Check trenches, pits, pipes and other excavations at the start and end of each shift and after breaks.
  • Do not leave open excavations, spoil piles or machinery in a way that blocks movement to retained habitat.

During habitat disturbance: Handling and relocation

If a Centralian Bluetongue is found, stop the immediate activity and allow the fauna spotter catcher to assess the animal and the surrounding hazards.

Only an appropriately authorised and trained person should capture, handle or relocate the animal.

Use calm, low-stress handling and keep handling to the minimum needed to move the animal from immediate danger.

  • Relocate the animal to nearby suitable retained habitat within its local area, using the project approval and permit conditions to determine the release location.
  • Do not move the animal across roads, into unsuitable habitat or outside the approved relocation area.
  • Do not hold the animal for longer than necessary, and do not release it into direct machinery traffic, exposed heat or another immediate hazard.
  • Take a photograph and record the location, time, condition, action taken and release location.

During habitat disturbance: Habitat features and stop-work triggers

Inspect logs, rocks, dense ground cover, shrubs, burrows and other shelter features before they are moved or crushed.

Where a shelter feature is occupied, stop work around that feature and allow the fauna spotter catcher to manage the animal before handling the feature.

The supplied documents do not identify hollow-bearing trees, wetlands or a particular burrow design as important for this species, so manage those features under the project’s general fauna procedures where they occur.

  • Stop work if the animal cannot be safely removed, if machinery enters an unsearched area, or if a worker cannot maintain visual contact with the fauna spotter catcher.
  • Stop work and obtain veterinary or wildlife carer assistance for an injured, heat-stressed or otherwise compromised animal.
  • Record all stop-work events, animals found, injuries, mortalities, relocations, unplanned clearing and corrective actions.

After habitat disturbance: Inspect and monitor

Post-clearance checks confirm that animals and shelter features have not been left in the disturbed area and that control measures remain effective. Use the approval conditions and fauna management plan to set the monitoring period and reporting recipients.

Complete a post-clearance inspection of the entire cleared area, including trenches, pits, stockpiles, equipment, retained edges and access routes.

Repeat checks after clearing where work leaves excavations, spoil, barriers or other hazards that could trap or injure reptiles.

Monitor retained habitat where the project approval or risk assessment identifies a need for follow-up searches.

  • Repair damaged exclusion fencing and maintain gates, escape ramps and other fauna controls until the area is no longer hazardous.
  • Remove temporary materials and waste that could provide unsafe shelter or obstruct movement.
  • Record monitoring dates, search effort, weather, observations, injuries, mortalities and any further management action.

After habitat disturbance: Report and review

Provide a fauna clearance and incident report to the project environmental officer and the relevant approval authority where required.

Submit verified occurrence records to the relevant state wildlife database, including negative survey information where the database or approval process accepts it.

Review the clearing method after any Centralian Bluetongue capture, injury or mortality and amend the fauna management plan before the next work stage.

  • Report any unexpected listing, permit issue or significant impact risk to the project environmental officer before continuing affected works.
  • Retain photographs, coordinates, handling records, permits and spotter catcher logs with the project environmental records.
  • Assess whether offset or other compensatory requirements apply under the approval framework if habitat loss cannot be avoided.

Rehabilitation actions: Restore habitat structure

Rehabilitation should restore connected, low-disturbance habitat in the arid setting where the species occurs. The supplied documents do not name plant species or define a Centralian Bluetongue rehabilitation design, so use locally sourced native species and site-specific ecological advice.

Reinstate locally appropriate native ground cover, shrubs and other vegetation consistent with the pre-clearing community and surrounding retained habitat.

Replace suitable logs and rocks removed during works where this can be done safely and without creating hazards or obstructing drainage.

Remove construction waste, compacted spoil and unnecessary barriers so ground-dwelling lizards can move through the rehabilitated area.

  • Use local seed or plant material where practicable and control weeds during establishment.
  • Do not install nest boxes or create artificial hollows as a default measure for this species, because the supplied documents do not identify tree hollows as Centralian Bluetongue habitat requirements.
  • Prevent domestic and feral animals from accessing rehabilitation areas where predator control is part of the approved environmental plan.

Rehabilitation actions: Fire, erosion and site protection

Manage fire and fuel loads in accordance with the local ecological community, state requirements and the project fire plan.

Control erosion and surface water movement so rehabilitation retains ground cover and does not develop unsafe washouts or pits.

Fence or otherwise protect rehabilitation areas from vehicles, stock and repeated disturbance until vegetation and ground structure are established.

  • Keep access tracks and maintenance routes outside rehabilitation areas wherever practicable.
  • Control weeds before they set seed and record treatment areas, dates and products used.
  • Do not use chemical baits or treatments in a way that could expose reptiles or their prey to avoidable harm.

Rehabilitation actions: Measure success

Monitor rehabilitation against the surrounding retained habitat, using fixed photographs and repeat inspections at intervals set by the project approval or rehabilitation plan.

Measure vegetation establishment, ground cover, weed abundance, erosion, survival of planted material and the condition of reinstated logs or rocks.

Record any Centralian Bluetongue observations using coordinates, date, time, method and photographs, and submit confirmed records to the relevant state wildlife database.

  • Investigate failed revegetation, persistent weeds, erosion, predator access or continuing vehicle damage and implement corrective action.
  • Continue monitoring until the agreed rehabilitation criteria are met and the site no longer presents avoidable fauna hazards.
  • Report rehabilitation results, fauna observations and corrective actions to the approval authority where required.

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