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Limestone Billy Hills Camaenid Land Snail (Westraltrachia recta)

Westraltrachia recta is a camaenid land snail known from a small number of records in the Kimberley region of Western Australia. Its biology and habitat requirements are poorly documented, so development works in potential habitat should use precautionary survey and clearing procedures. It is listed as Priority 1 on the WA DBCA Priority Fauna List.

Conservation status

Western Australia, WA Threatened and Priority Fauna List: Priority 1.

Seasonal guidance

Species-specific activity, breeding and seasonal survey information is not available. The row below is a general planning window only, not a statement about when the snail is active.

Species-specific seasonality: Not recorded

Do not use this general planning row to infer seasonal absence or reduced risk.

  • Pre-clearance planning and checks: Planning window only. Arrange checks before disturbance and adapt timing to project conditions; no activity months are known for this species.

Identification: Appearance and size

Identification information for this species is very limited. Confirm any suspected record with a suitably experienced mollusc specialist.

Westraltrachia recta is a camaenid land snail. Its size, shell appearance and diagnostic features have not been documented.

Identification: Similar species

Other Westraltrachia species are known, but no characters for distinguishing them from W. recta are documented. Do not identify the species from a general shell resemblance alone.

Identification: Field signs

Species-specific field signs have not been documented. As general land-snail search practice, look for live snails and shells in likely sheltered ground-level microhabitats, and photograph and retain location details for expert review where permitted.

Distribution: Known range

Records indicate a restricted known distribution in Western Australia, but they do not establish the full range.

Atlas of Living Australia records show eight records in WA at two distinct 0.1-degree locations, spanning latitudes -18.4 to -18.2 and longitude 125.8. Records outside WA were excluded from this summary as likely errors.

Distribution: WA region

The DBCA list identifies the Kimberley region. This does not show that the species is absent from other areas.

Distribution: Locality limits

The name Limestone Billy Hills appears in the DBCA common name, but no precise site coordinates are available for that named locality. Treat the occurrence information as an indication of a limited known range, not as a complete distribution map.

Habitat: Known habitat

The species is a land snail, but its habitat at occupied sites has not been described.

No taxon-specific vegetation type, geology, soil, landform or site conditions have been documented.

Habitat: Precautionary search areas

As general land-snail survey practice, include sheltered ground-level features and nearby vegetation or ground cover in searches. These are search considerations for land snails generally, not confirmed habitat requirements for W. recta.

Foraging habitat: Diet and feeding

The species’ diet, feeding behaviour and foraging locations have not been documented.

Do not assume a particular food source or use feeding signs to identify the species.

Foraging habitat: Search precautions

As a general land-snail precaution, avoid disturbing ground cover or collecting material unnecessarily while checking for snails. Record the microhabitat and condition of any suspected find for assessment.

Breeding habitat: Breeding information

Breeding biology and breeding habitat have not been documented.

Breeding season, egg-laying sites, clutch size and juvenile appearance are unknown. Do not schedule works on the assumption that a particular season is free of breeding risk.

Breeding habitat: Planning approach

As general land-snail practice, have an ecologist check suitable ground-level features before disturbance and seek specialist advice if eggs, juveniles or aggregations are suspected. These signs have not been documented specifically for W. recta.

Sheltering habitat: Known refuges

The species’ sheltering behaviour and preferred refuges are not documented.

No specific refuge type, activity pattern or response to dry conditions has been documented for Westraltrachia recta.

Sheltering habitat: General search practice

For land snails generally, search carefully around ground-level cover and sheltered features rather than relying only on open-surface searches. Avoid turning or removing cover unless the survey method and approvals allow it, and replace any moved material carefully.

Threats: Status and evidence

The DBCA Priority 1 listing reflects the species’ poorly known status and limited number of known locations.

Priority 1 means the species is poorly known and known from few locations, with none on conservation lands. This is a DBCA priority category, not a listing under the Biodiversity Conservation Act 2016. There is no national listing.

Threats: Threat information

Specific pressures, population trend and conservation actions for W. recta are not established.

Threats: Works-site risk

As a precaution for a poorly known land snail, consider direct mortality and loss of occupied microhabitat during clearing as potential project risks. This is general risk management, not a documented threat assessment for the species.

Survey methodology: 1. Desktop assessment

No validated species-specific survey method or detectability information is available. Use a suitably experienced ecologist and document the limits of each survey.

Check the latest DBCA priority fauna information and available occurrence records for the project area. Confirm whether the site falls within or near the known Kimberley record area, and retain the search dates and data sources.

Survey methodology: 2. Field search

As general land-snail practice, search suitable ground-level cover and sheltered features carefully, using a consistent, recorded search effort. Survey season, time of day, weather conditions and search effort have not been specified for W. recta.

Survey methodology: 3. Record and verify

Photograph suspected live animals and shells in place where possible. Record coordinates, date, observer, search effort and immediate microhabitat. Do not claim a confirmed identification without appropriate diagnostic evidence or specialist review.

Vegetation associations

Source-checked associations and automatically indexed candidates are separated below. An association does not establish site presence, preference or dependence.

No species-specific vegetation association has been indexed or source-checked in this evidence library. This is an evidence gap, not evidence of no association.

Ecosystem associations

Source-checked associations and automatically indexed candidates are separated below. An association does not establish site presence, preference or dependence.

No species-specific ecosystem association has been indexed or source-checked in this evidence library. This is an evidence gap, not evidence of no association.

Soil and substrate associations

Source-checked associations and automatically indexed candidates are separated below. An association does not establish site presence, preference or dependence.

No species-specific soil association has been indexed or source-checked in this evidence library. This is an evidence gap, not evidence of no association.

Water and wetland associations

Source-checked associations and automatically indexed candidates are separated below. An association does not establish site presence, preference or dependence.

No species-specific water association has been indexed or source-checked in this evidence library. This is an evidence gap, not evidence of no association.

Fauna records and mapped habitat: Not yet analysed

Record locations can be overlaid with mapping, but record frequency alone does not measure habitat preference. No species is excluded from desktop assessments by this analysis.

No quality-controlled record-to-map analysis has been completed for this species. The existing generalised distribution dots and indicative range polygons have not been treated as precise occurrence coordinates.

A defensible run needs dated, independently attributable records, coordinate uncertainty, duplicate and captive-record checks, layer versions and regional scope. Preference and absence require additional survey-effort and detection evidence.

Habitat limitations and contrary evidence: No supported exclusion recorded

Not recorded is not the same as cannot occur. Low suitability, resident habitat, breeding habitat and occasional movement are different conclusions.

This library has not established a vegetation, ecosystem or soil-type exclusion for this species. This does not mean all habitat is suitable; the evidence needed to justify an exclusion has not been assembled.

Habitat limitations and contrary evidence: Before using a negative association

  • Confirm the taxon, geographic region, life stage and habitat function covered by the evidence.
  • Check survey methods, season, repeated effort and detectability before interpreting non-detection.
  • Investigate credible contradictory records and microhabitats absent from broad mapping.
  • Do not convert a missing map class, low record count or failed data request into species absence.

Before habitat disturbance: 1. Map and brief

Plan surveys and controls early because the species is known from few locations and its habitat requirements are poorly documented.

Review the proposed clearing footprint against available occurrence information and the DBCA regional listing. Brief the ecologist and clearing crew on uncertainty around identification and habitat.

Before habitat disturbance: 2. Survey and mark

Arrange a targeted pre-clearance search by an experienced ecologist. If a suspected snail or potentially occupied feature is found, mark and avoid the area while identification and appropriate controls are assessed.

Before habitat disturbance: 3. Set controls

Define no-go areas, access routes and a stop-work process before clearing begins. Keep disturbance within the approved footprint and ensure the crew knows who to contact about a suspected find.

During habitat disturbance: 1. Clear carefully

Use staged, supervised works and stop locally if a suspected individual or occupied feature is encountered.

Keep machinery and personnel within marked limits. Where appropriate to the site and approved method, expose ground-level cover gradually so the ecologist can check it before it is removed.

During habitat disturbance: 2. Respond to finds

Stop work in the immediate area, protect the find from trampling and machinery, and notify the supervising ecologist. Photograph and record it in place; do not handle or relocate it unless directed under the relevant approvals and response procedure.

During habitat disturbance: 3. Resume by approval

Resume work near the find only after the ecologist has assessed it and the agreed response has been implemented. Record the decision and any additional exclusion or survey measures.

After habitat disturbance: 1. Document

Close out the works with clear records and follow-up on any suspected or confirmed occurrence.

Record survey coverage, conditions, findings, photographs, coordinates, disturbance limits and any stop-work response. State clearly where survey access or detectability was limited.

After habitat disturbance: 2. Report and review

Refer suspected records for specialist verification and follow applicable DBCA and project reporting procedures. Review any incident or new record with the project ecologist before further works in the area.

Rehabilitation actions: 1. Restore the footprint

Species-specific rehabilitation requirements are not documented. Rehabilitation should avoid unsupported assumptions about suitable habitat.

Rehabilitate disturbed areas in line with the approved project plan. Where relevant to that plan, retain or reinstate ground cover and surface features without moving material from a suspected occupied area.

Rehabilitation actions: 2. Monitor and adapt

If a suspected or confirmed record was associated with the work area, seek ecologist advice on whether follow-up checks are appropriate. General rehabilitation measures are not proven requirements for W. recta.

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