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Mount Jukes Leaf-tailed Gecko (Phyllurus isis)

The Mount Jukes broad-tailed gecko is a small, forest-dwelling leaf-tailed gecko endemic to two known localities in mid-eastern Queensland: Mount Blackwood and Mount Jukes. It is listed as Vulnerable in Queensland, so clearing or construction within its known range requires species-level identification and habitat assessment.

Conservation status

Queensland, Nature Conservation Act 1992: Vulnerable.

Breeding season

Phyllurus isis is an egg-laying, nocturnal gecko, but wild monthly timing is not documented. Related Phyllurus information indicates breeding can occur year round, with more breeding in spring, so avoid treating any month as risk free without local assessment.

Reproductive mode: Oviparous

Clutch size: 2 eggs recorded for Phyllurus isis

Incubation: Not recorded for Phyllurus isis; 65 to 90 days reported for Phyllurus species in captivity

Size at hatching or birth: Not recorded

Age at maturity: Not recorded for Phyllurus isis; other Phyllurus species may mature by 3 years in captivity

Nest or egg sites: Not recorded for Phyllurus isis; other Phyllurus species may lay eggs under a leaf or log

Breeding frequency: Not recorded for Phyllurus isis; other Phyllurus species may breed year round in suitable conditions

Confirm timing locally before clearing, because rainfall and temperature may alter breeding, hatching and night activity, and wild seasonal timing for Phyllurus isis has not been published.

  • Mating: Wild mating months are not recorded. Other Phyllurus species may mate year round, with breeding more pronounced in spring, from September to November.
  • Gravid females: A gravid female is recorded for Phyllurus isis, but the period when females carry eggs is not known. Year round potential is based on related Phyllurus breeding observations.
  • Egg laying: Phyllurus isis lays eggs and a clutch of two is recorded, but wild laying months and nest sites are not documented. Other Phyllurus species may lay throughout the year, with more breeding in spring, from September to November.
  • Incubation: Wild incubation timing is not recorded for Phyllurus isis. A 65 to 90 day incubation period is reported for other Phyllurus species, so eggs laid in any month may remain present across following months.
  • Hatchlings: Hatching months are not recorded for Phyllurus isis. Year round potential follows the related Phyllurus breeding pattern and the reported 65 to 90 day incubation period.
  • Active period: Phyllurus isis is reported as nocturnal and crepuscular, with no seasonal activity period stated. Treat adults as potentially surface active in every month, particularly during suitable night conditions.
  • Highest clearing risk: Clearing may affect adults, gravid females, eggs and hatchlings in any month because wild timing is unresolved and related Phyllurus species can breed year round. Risk is highest from September to November because spring breeding is more pronounced in related Phyllurus species.

Identification

This is a small, flattened leaf-tailed gecko with a broad, leaf-like tail. The species is the smallest and least spiny member of Phyllurus described in the supplied sources.

Adults reach a maximum snout-to-vent length of 76 mm. Another published account gives a size of approximately 70 mm. The body and head are flattened, the limbs are long and slender, and the digits are clawed.

The tail is flared at the base and tapers to a pointed tip, producing a broad, leaf-like outline. The original tail has distinct white bands.

Maximum snout-to-vent length: 76 mm

Body form: Flattened head and body, with long, slender limbs

Tail: Broad and leaf-like, flared at the base and pointed at the tip

Weight: Not reported in the supplied sources

Identification: Separating features

The most useful diagnostic feature is the rostral groove. In Phyllurus isis, a single groove partially divides the rostral scale. The flank tubercles are small.

It can be separated from the similar P. ossa by the single partial rostral groove and smaller flank tubercles. It differs from P. caudiannulatus by its flared original and regrown tail and by the rostral groove being partial rather than fully dividing the rostral. The ventral surface is immaculate, unlike the peppered brown pattern described for P. nepthys. The original tail is distinctly white-banded, unlike P. platurus.

  • Check the rostral scale for one groove that only partly divides it.
  • Look for small flank tubercles.
  • Check that the original tail is broad, flared and distinctly banded in white.
  • Use the ventral colour pattern and tail form with the rostral characters, rather than relying on size alone.

Identification: Field signs and sex

The supplied sources do not describe tracks, scats, calls, nests, sloughs, eyeshine or other indirect field signs. They also do not provide reliable external characters for separating males and females.

The holotype was a gravid female, but this does not provide a field sexing character. Identification of an animal found during clearing should be based on clear photographs and the diagnostic scale, tubercle, colour and tail characters.

  • Do not treat an unconfirmed leaf-tailed gecko observation as Phyllurus isis without checking its locality and diagnostic characters.
  • Record clear photographs of the head, rostral area, flank, underside and tail where this can be done safely and lawfully.
  • Avoid handling unless authorised and necessary for the assessment.

Distribution: National and state range

Phyllurus isis has a very restricted known distribution in Queensland. The supplied sources identify no confirmed Australian localities outside Mount Blackwood and Mount Jukes.

The species is endemic to Australia and is currently documented only from Queensland. The known range is in the Mackay district on the mid-eastern Queensland coast.

The named localities are Mount Blackwood and Mount Jukes. Mount Blackwood National Park is given as the type locality.

Australia: Endemic

Known state: Queensland

Known localities: Mount Blackwood and Mount Jukes

Regional setting: Mackay district, mid-eastern Queensland coast

Distribution: Strongholds and population information

The two named mountains are the only documented strongholds or subpopulations in the supplied material. The sources do not provide a mapped area of occupancy, abundance estimate, density, population trend or confirmed connectivity between the two localities.

One source states that the species was known only from the original description at the time of its assessment. Treat records from outside the known range as requiring careful verification.

Known subpopulations: Two named localities, Mount Blackwood and Mount Jukes

Population size: Not reported

Population trend: Not reported

Known abundance: The supplied material describes the species as known only from the original description

Habitat: Documented habitat

The documented habitat information is limited to forest. The supplied sources do not define a vegetation association, elevation band, canopy structure, rock type, moisture regime or microhabitat requirement.

The preferred natural habitat is described as forest. The known localities are Mount Blackwood and Mount Jukes in mid-eastern Queensland.

No vegetation community, elevation limit, climatic threshold or specific structural feature is provided in the supplied sources.

Habitat type: Forest

Known region: Mackay district, mid-eastern Queensland coast

Elevation limits: Not reported

Vegetation community: Not reported

  • Treat native forest within or near the known Mount Blackwood and Mount Jukes localities as potential habitat until a suitably qualified ecologist has assessed it.
  • Retain habitat in place while identification and targeted survey decisions are being made.

Foraging habitat: Information available for project work

The supplied sources do not describe the diet, prey, feeding method, feeding height or foraging range of Phyllurus isis.

No species-specific food plants, prey items, feeding substrates or foraging distances are given. The species is described as a forest gecko, but the documents do not support a more detailed account of its feeding habitat.

During project assessments, potential feeding habitat should therefore be considered as part of the forest habitat used by the species, rather than being limited to a particular tree size, plant species or ground feature.

Diet: Not reported

Known prey: Not reported

Foraging range: Not reported

Feeding height or substrate: Not reported

  • Do not infer the absence of the species from a lack of visible feeding signs.
  • Record the forest type and the condition of habitat around any observation, because species-specific foraging requirements are not documented.

Breeding habitat: Breeding biology

Phyllurus isis lays eggs, but the supplied material gives very little information about its breeding season or breeding microhabitat.

The species is oviparous. The available natural history account gives a clutch size of two eggs. The breeding season, incubation period, age at maturity and lifespan are not reported in the supplied sources.

No specific nesting substrate, egg-laying site or breeding habitat feature is documented.

Breeding mode: Oviparous

Breeding season: Not reported

Clutch size: 2 eggs

Gestation: Not applicable to an egg-laying species

Incubation: Not reported

Age at maturity: Not reported

Lifespan: Not reported

Breeding habitat: Breeding habitat for project planning

The sources do not identify a particular tree, hollow, rock crevice, leaf litter layer or other feature used for laying eggs. Forest habitat at known localities should be treated as potentially supporting breeding until survey and habitat assessment are complete.

  • Avoid assuming that breeding habitat can be identified from a single visible nest feature.
  • Where clearing is proposed in known or suspected habitat, plan timing and salvage measures with a qualified herpetologist because the breeding season is not documented.

Sheltering habitat: Known information gaps

The supplied documents do not identify the day refuges, nesting shelters or overwintering sites used by Phyllurus isis.

No shelter type, refuge size, hollow dimension, burrow, rock crevice, bark feature, ground-cover requirement or roosting position is reported.

The flattened body, long slender limbs and leaf-like tail describe the animal, but they do not establish a particular sheltering structure.

Refuge type: Not reported

Refuge dimensions: Not reported

Burrows or dens: Not reported

Hollows or roosts: Not reported

  • Do not clear or disturb potential forest refuges on the assumption that the species uses only trees, only the ground or only rock features.
  • Treat sheltering habitat as unresolved and retain suitable forest until an ecologist has assessed the site.

Threats: Habitat loss and project disturbance

Phyllurus isis is listed as Vulnerable in Queensland and has a highly restricted known distribution. The supplied sources identify several general threats to reptiles, but do not quantify their effects on this species.

Habitat loss from land clearing is identified as a general threat to reptiles. For this species, the concern is heightened by the small known range and the lack of published abundance information.

Construction, infrastructure corridors and associated access works can remove or degrade forest habitat at or near the two known localities. The supplied sources do not provide a species-specific clearing threshold or buffer distance.

Queensland status: Vulnerable

Known range: Mount Blackwood and Mount Jukes

Species-specific clearing threshold: Not reported

  • Confirm the species identity and locality before clearing within or near Mount Blackwood and Mount Jukes.
  • Avoid clearing native forest until a suitably qualified ecologist has assessed the potential habitat and required approvals.
  • Keep disturbance footprints as small as practicable and prevent unnecessary vehicle movement through retained habitat.

Threats: Other documented threats

The supplied conservation material lists habitat degradation by introduced species, climate change, road mortality, feral predators including dogs, cats, pigs and foxes, cane toads and emerging diseases as general reptile threats. It notes that these threats may not apply specifically to this species.

Fire and hydrology change are not discussed in the supplied sources. Their significance for Phyllurus isis cannot be assessed from the available material.

Road mortality: Listed as a general reptile threat

Feral predators: Dogs, cats, pigs and foxes are listed as general threats

Cane toads: Listed as a general threat

Disease: Emerging disease is listed as a general threat

Fire and hydrology change: Not discussed in the supplied sources

  • Control domestic animals and feral predators around work areas where this can be done under approved procedures.
  • Manage vehicle speeds and access on project roads to reduce the general risk of reptile road mortality.
  • Prevent the spread of pathogens and invasive species through standard hygiene and site biosecurity procedures.
  • Do not assume that fire or hydrology changes are harmless simply because species-specific effects are not documented.

Survey methodology: 1. Nocturnal spotlighting

Phyllurus isis is a small, forest-dwelling, nocturnal leaf-tailed gecko known from Mt Blackwood and Mt Jukes in mid-eastern Queensland. The supplied sources do not provide a species-specific survey guideline or minimum survey effort, so project surveys must follow the current Queensland guidance and approval conditions for threatened reptiles.

Conduct nocturnal searches in suitable forest habitat, including retained vegetation around proposed clearing areas and access tracks.

Search trunks, branches, foliage, rock surfaces and other sheltered surfaces where a flattened, arboreal gecko may be visible.

Use the species' reported morphology to guide identification: it is the smallest and least spiny Phyllurus, with a maximum snout-to-vent length of 76 mm and a broad, leaf-like tail.

Record the date, start and finish times, weather, temperature if measured, wind, rainfall, observers, route, search area and all detection locations.

The supplied sources do not specify the required number of nights, search hours, transect length or weather conditions, so do not claim absence from a site solely because spotlighting did not detect the species.

Maximum snout-to-vent length: 76 mm

Known range: Mt Blackwood and Mt Jukes, mid-eastern Queensland

Survey methodology: 2. Habitat-based searches

Map and inspect forest habitat within and adjacent to the disturbance footprint before selecting survey routes.

Give particular attention to retained trees and vegetation that provide vertical structure, shaded surfaces and connections between forest patches.

Use photographs and precise coordinates for any candidate gecko, shed skin, carcass or other evidence, and retain the original image files.

Have an experienced reptile ecologist confirm records because several Phyllurus species occur in eastern Australia and the supplied diagnosis relies on characters such as the rostral groove, flank tubercles, tail shape and colour pattern.

Survey methodology: 3. Trapping and supplementary methods

Do not set pitfall, funnel or arboreal traps solely on the basis of the information supplied here, because the sources do not state that these methods are suitable for P. isis or provide trap numbers, trap nights or checking intervals.

If a Queensland approval or current survey guideline requires supplementary trapping, use only the approved design, checking frequency, weather limits and animal-welfare controls.

Use a fauna spotter catcher and a suitably qualified reptile ecologist to assess any animal found during searches or clearing.

Treat an observation outside the documented Mt Blackwood and Mt Jukes range as requiring careful verification and prompt submission to the relevant Queensland authority.

Survey methodology: Minimum effort and reporting

  • Obtain and apply the current Queensland threatened fauna survey guidance and any site-specific approval conditions before finalising survey effort.
  • Survey all suitable forest habitat within the disturbance footprint and inspect adjoining retained habitat where clearing could affect connectivity or refuge sites.
  • Document survey dates, personnel, methods, effort, conditions, routes, negative results, photographs and coordinates in the project fauna report.
  • Submit verified records, including reliable negative survey information where required, to the relevant Queensland wildlife database.
  • Retain records of permits, inductions, spotter catcher qualifications, animal handling, relocation, injury treatment and stop-work events.

Before habitat disturbance: Avoid and minimise

The species has a restricted documented distribution and is listed as Vulnerable in Queensland. Avoiding forest removal is the preferred control, followed by staged works and active fauna management.

  • Check whether the project footprint overlaps the documented range around Mt Blackwood or Mt Jukes before design is fixed.
  • Retain suitable forest habitat, mature vegetation, connected forest strips and other features identified during the pre-clearance assessment.
  • Keep disturbance, lighting, vehicle movement and temporary storage out of retained habitat wherever practicable.
  • Use the smallest practicable clearing footprint and retain continuous links between habitat patches.
  • Do not rely on generic reptile threat information as proof of a site-specific impact; confirm the actual habitat and clearing pathway for the project.

Before habitat disturbance: Approvals and planning

  • Confirm the current EPBC Act status before works commence and obtain an EPBC referral or approval if the species is listed or the project otherwise triggers the Act.
  • Confirm Queensland threatened wildlife status, survey requirements, permits and authority conditions before disturbing habitat or handling an animal.
  • Prepare a fauna management plan that identifies exclusion zones, survey timing, spotter catcher responsibilities, machinery controls, relocation sites, injury response and reporting.
  • Stage clearing so that retained habitat and escape routes remain available while each work area is inspected and cleared.
  • Schedule works to avoid periods or conditions identified by the approved survey and fauna management plan as unsuitable for safe detection or handling.

Before habitat disturbance: Site preparation

  • Complete a documented pre-clearance survey of all suitable forest habitat before machinery enters the work area.
  • Mark retained vegetation, no-go areas, access routes, relocation habitat and any habitat features requiring hand removal or specialist inspection.
  • Install exclusion fencing where it can keep machinery and personnel out of retained habitat without trapping animals inside the work area.
  • Brief all workers on the species' appearance, the stop-work procedure, the location of no-go areas and the requirement to report every fauna observation.
  • Arrange suitable containers, lighting, gloves, first-aid materials and transport arrangements before clearing begins.

During habitat disturbance: Daily controls

Clearing should proceed under direct fauna supervision in small, controlled stages. The spotter catcher must have authority to pause work whenever an animal or uninspected habitat is encountered.

  • Inspect exclusion fencing, no-go markers, access routes and relocation areas at the start of each shift.
  • Confirm that the spotter catcher, machinery operators and supervisors understand the day's clearing sequence and communication signals.
  • Clear only the area that has been surveyed and released for work that day.
  • Keep machinery outside retained habitat and operate at a speed that allows the spotter catcher to inspect surfaces and respond safely.
  • Stop work during conditions that prevent effective searching or create an unacceptable risk to workers or animals, as specified in the fauna management plan.

During habitat disturbance: Spotter catcher and machinery

  • Position the spotter catcher where the active clearing face and machinery movements can be observed without entering an unsafe operating zone.
  • Use a clear stop signal and require the operator to shut down and make the plant safe before the spotter catcher approaches an animal or habitat feature.
  • Inspect vegetation and ground features progressively rather than allowing machinery to clear ahead of the approved search area.
  • Do not permit untrained workers to capture, handle or relocate the gecko.
  • Record the location, time, activity, response and outcome for every animal found.

During habitat disturbance: Animal and habitat response

  • If a suspected P. isis is found, stop work in the immediate area and keep workers, vehicles and machinery away from the animal.
  • Have the authorised spotter catcher or other person named in the approval confirm the identification and decide whether handling is necessary.
  • Handle the animal only under the relevant Queensland authority, permit and animal-welfare procedure.
  • Relocate an animal only to nearby retained habitat that has been selected in the fauna management plan and is suitable for this forest-dwelling species.
  • Place an injured animal in an appropriate secure container, keep it cool and quiet, and arrange prompt assessment by a veterinarian or authorised wildlife carer.
  • Do not resume work until the animal has been safely dealt with and the spotter catcher has released the area.
  • Inspect and hand-remove habitat features identified by the fauna management plan before machinery disturbance, rather than moving them without inspection.
  • Do not assume that a generic hollow, log, rock or wetland procedure is suitable for this species, because the supplied sources do not identify a specific dependence on any of these features.

During habitat disturbance: Stop-work triggers and records

  • Stop work if a suspected P. isis is found, if an unsearched section of habitat is entered, if exclusion controls fail, or if the spotter catcher cannot safely supervise the activity.
  • Stop work if a new habitat feature or construction change creates a risk not covered by the fauna management plan.
  • Notify the project environmental officer and relevant supervisor of each stop-work event before restarting.
  • Record identification evidence, photographs, coordinates, habitat description, handling, relocation, injury treatment, release site, personnel and times.
  • Report any confirmed record or mortality through the approval process and to the relevant Queensland wildlife database.

After habitat disturbance: Post-clearance inspection

Post-clearance actions should confirm that no animal remains in the work area, that controls remain effective and that all records required by approvals have been completed.

  • Inspect the cleared area and its edges after each staged clearing event for live animals, injured animals, carcasses and signs of failed exclusion controls.
  • Ask the spotter catcher to confirm that all approved sections were searched and that no fauna issue remains unresolved before the area is handed to construction crews.
  • Repeat targeted nocturnal searches if required by the fauna management plan, approval conditions or an unexpected detection during works.
  • Check retained forest connections and relocation areas for damage from machinery, vehicles, lighting, sediment or storage.

After habitat disturbance: Monitoring and reporting

  • Monitor retained habitat and any relocation site at the frequency and duration required by the approved management plan.
  • Compare monitoring records with pre-clearance results, including survey effort, observations, mortality, relocation outcomes and habitat condition.
  • Submit required records to Queensland authorities and update the relevant wildlife database with verified observations.
  • Report non-compliance, injury, mortality, unexpected records and control failures to the project environmental officer and approval agencies within the required timeframe.
  • Maintain exclusion fencing, no-go markers, lighting controls and access restrictions until the project environmental officer confirms that they are no longer needed.

After habitat disturbance: Offsets and corrective action

  • Assess whether offsets, rehabilitation or additional habitat protection are required under the approval, Queensland requirements or the project's impact assessment.
  • Do not treat an offset as a substitute for avoiding and minimising clearing of the species' restricted forest habitat.
  • Implement corrective action if monitoring shows damage to retained habitat, failed relocation controls or continuing fauna mortality.

Rehabilitation actions: Restore forest structure

Rehabilitation should restore connected forest structure within the documented habitat range and protect retained habitat from further disturbance. The supplied sources do not identify particular plant species, nest-box designs, log densities or fire intervals for P. isis, so restoration targets must be set from local reference sites and approved ecological advice.

  • Use locally appropriate native plant species from nearby reference forest and obtain species selection advice from a Queensland ecologist or land manager.
  • Re-establish connected native vegetation rather than isolated planting blocks wherever the project has removed a link between forest patches.
  • Protect planted and regenerating areas from trampling, vehicles, stock, weeds and other site-specific pressures.
  • Retain naturally regenerating trees and understorey where they are compatible with safety and infrastructure requirements.

Rehabilitation actions: Retain and reinstate habitat features

  • Retain suitable fallen timber, rocks and other natural shelter features where they are safe and consistent with the approved rehabilitation design.
  • Reinstate locally representative habitat features only where their placement has been assessed as safe and ecologically appropriate.
  • Do not install hollows or nest boxes as a default measure, because the supplied sources do not establish that P. isis depends on them.
  • Maintain dark, connected retained forest where artificial lighting could reduce the suitability of habitat or interfere with nocturnal searches.

Rehabilitation actions: Weeds, predators and fire

  • Control weeds that suppress native forest regeneration or reduce the quality of retained habitat.
  • Manage feral predators and domestic animals where they are identified as a project risk, using methods approved for the site.
  • Prepare fire management with local Queensland advice, protecting retained and rehabilitated forest while meeting legal and safety requirements.
  • Do not apply a fixed fire interval or predator-control program for this species unless it is supported by the approved management plan or current expert advice.

Rehabilitation actions: Monitoring and success measures

  • Monitor plant survival, regeneration, weed cover, canopy and understorey development, connectivity, retained habitat condition and damage from construction activities.
  • Use repeat nocturnal searches under the approved survey method to check whether the rehabilitated area is being used by P. isis or other target reptiles.
  • Set measurable success criteria before rehabilitation begins, including vegetation establishment, weed thresholds, control maintenance and completion dates.
  • Compare monitoring results with nearby reference forest and adapt planting, weed, predator, lighting or access controls when targets are not met.
  • Submit rehabilitation and fauna monitoring results with the project's required environmental reports and Queensland wildlife records.

Sources