Bristle-faced free-tailed bat (Setirostris eleryi)

Conservation status

New South Wales, Biodiversity Conservation Act 2016: Endangered.

Breeding season

The supplied documents do not provide a breeding calendar, young-rearing period or seasonal movement pattern. The table therefore records the evidence gap and identifies clearing risk as present throughout the year wherever works could remove roost trees, disturb habitat or cause fire.

Seasonal timing should be updated if project surveys, local records or additional species research identify breeding, young-rearing or movement periods.

• Roost use: Tree hollows and fissures are documented roosting features, but seasonal occupancy is not provided. Treat potential roosts as occupied unless an appropriate assessment demonstrates otherwise.
• Highest clearing risk: No species-specific low-risk clearing period is provided. Clearing, fire or disturbance can affect roosts and habitat at any time, so retain hollow-bearing trees and apply fauna controls throughout the year.

Identification

The Bristle-faced free-tailed bat is a small, light-built insectivorous bat. Field identification should be confirmed by an experienced bat ecologist because the species is rare and the source profile notes that it is genetically distinct but was previously discussed under Mormopterus.

Adults are light sandy on the back and slightly paler below. Individuals weigh up to 6 grams. The muzzle is long and thin, and stout bristles occur on the nose.

A distinctive large, fleshy projection occurs on the genital region of both males and females. This feature can assist with examination of captured animals by suitably trained and authorised personnel.

Colour: Light sandy-brown above and slightly paler below

Weight: Up to 6 grams

Muzzle: Long and thin

Identification: Distinguishing features

The species differs from other Mormopterus-like free-tailed bats by its light build, long thin muzzle, stout nasal bristles and large fleshy genital projection in both sexes. The source profile states that the bat is genetically distinct, although the taxonomic treatment in that profile refers to the Hairy-nosed Freetail Bat.

• Do not rely on colour alone when separating this bat from other small free-tailed bats.
• Record the muzzle shape, nasal bristles, body mass, sex and genital morphology where examination is authorised.
• Use acoustic identification, measurements and expert confirmation where field identification is uncertain, because the supplied profile does not provide a diagnostic call description.

Identification: Field signs and survey records

The supplied documents do not describe tracks, scats, nests, eyeshine, roost staining or a species-specific call. The strongest field evidence is a confirmed animal record or evidence of use of a suitable hollow or tree fissure within the known or predicted range.

The species has been recorded from only three disjunct locations in New South Wales. Any suspected record from a development site should be documented carefully and submitted to the relevant state authority or specialist database.

• Inspect hollow-bearing live and dead trees and trees with fissures before clearing.
• Record the tree species, hollow or fissure characteristics, position, evidence of use and surrounding vegetation.
• Obtain expert confirmation for captured or acoustic records before treating an observation as this species.

Distribution: National range

The species has a broad but sparsely recorded range across inland and north-western Australia. Records are concentrated in widely separated parts of New South Wales, and the available profile indicates very low detection and population numbers.

The Bristle-faced free-tailed bat is distributed from the southern half of the Northern Territory through central Queensland to north-western New South Wales.

The supplied NSW profile identifies the following NSW IBRA regions and subregions as known or predicted habitat: Brigalow Belt South, Cobar Peneplain, Darling Riverine Plains, Murray Darling Depression and Nandewar.

• Known or predicted NSW subregions include Northern Basalts, Barnato Downs, Canbelego Downs, Nandewar Northern Complex and the Darling Depression.
• Predicted occurrence is also listed for Northern Outwash, Boorindal Plains, Castlereagh-Barwon and the Darling Depression.

Distribution: Known strongholds and subpopulations

In New South Wales, records are from three disjunct locations: Gundabooka National Park south of Bourke, Dhinnia Dthinawan Nature Reserve north of Warialda, and an area near Bonshaw.

The largest reported NSW record is 13 individuals from Gundabooka National Park. The other reported records are one individual from Dhinnia Dthinawan Nature Reserve and two individuals near Bonshaw.

Reported NSW locations: Three disjunct locations

Reported NSW individuals: 16 individuals in the records described in the profile

Largest reported NSW record: 13 individuals at Gundabooka National Park

Distribution: Population status

The species appears to be extremely rare throughout its range. The profile states that it has been recorded from only 15 locations nationally.

The supplied documents do not provide a population estimate, generation length or quantified population trend. Low apparent abundance increases the significance of losing individual roost trees or small habitat patches.

Known national locations: 15

Population estimate: Not provided

Population trend: Not provided

Habitat: Habitat types

The species is associated with inland and north-western Australian woodland, open forest, shrub woodland, floodplain woodland and some wetland vegetation. The clearest structural requirement identified in the supplied documents is the availability of tree hollows and fissures for roosting.

Recorded or predicted habitat includes dry sclerophyll forests, semi-arid woodlands, grassy woodlands, forested wetlands, arid shrublands and riverine or floodplain vegetation.

The regional vegetation associations include box, ironbark, cypress pine, poplar box, mulga, coolabah, black box and river red gum communities.

• Retain native woodland and open forest where it contains hollow-bearing trees or fissured trunks.
• Treat floodplain, riverine and wetland woodland as potential habitat where hollow-bearing trees and connected native vegetation remain.
• Assess regrowth, isolated paddock trees and dead standing trees because the supplied profile identifies both live and dead hollow-bearing trees as conservation features.

Habitat: Structural features

The species is considered dependent on hollows and tree fissures for roosting. The supplied profile does not specify hollow entrance dimensions, hollow depth, tree diameter, tree age or preferred tree species.

Habitat quality can be reduced when hollow-bearing trees are removed, when vegetation structure is changed by weeds or feral browsers, or when fire modifies the habitat.

• Map all hollow-bearing live and dead trees within the proposed clearing footprint and adjacent areas that could be affected by works.
• Record tree condition and hollow or fissure features rather than treating only large intact woodland stands as habitat.
• Avoid removing isolated hollow-bearing trees where practicable, including trees in cleared agricultural land.

Habitat: Climate and elevation

The supplied documents describe the broad geographic range and vegetation associations but do not provide an elevation range, temperature limit or rainfall threshold. Elevation-specific suitability should therefore be assessed from local records, vegetation and roost availability.

Foraging habitat: Diet and feeding habitat

The Bristle-faced free-tailed bat is insectivorous. The supplied documents identify insects as its food but do not describe particular prey groups, feeding height, foraging distance or preferred plant species.

The species feeds on insects. Suitable foraging habitat is likely to include the native woodland, open forest, shrub woodland, riverine woodland and floodplain vegetation listed in the NSW profile, particularly where vegetation structure supports flying insects.

The profile identifies pesticide and herbicide use as a threat because these chemicals may reduce insect availability or result in toxic residues accumulating in bat fat stores.

Food: Insects

Foraging range: Not provided

Preferred prey groups: Not provided

• Retain native vegetation around known or potential roost trees to maintain insect-producing habitat.
• Control pesticide drift near known or potential habitat.
• Assess changes to vegetation structure, weed cover and grazing pressure where works could reduce insect availability.

Foraging habitat: Foraging connectivity

The supplied documents do not provide a measured foraging range or minimum habitat patch size. Because the species is recorded from disjunct locations and depends on hollow-bearing trees, clearing should be assessed for loss of both feeding vegetation and connections between roost trees and surrounding native vegetation.

• Avoid assuming that a roost tree is isolated from foraging habitat simply because it stands in a cleared area.
• Inspect nearby woodland, riparian vegetation, floodplain vegetation and tree lines when assessing the likely use of a site.

Breeding habitat: Breeding biology

The supplied documents do not provide species-specific information on mating, birth timing, litter size, gestation, maturity or lifespan. Breeding habitat should be considered in relation to the species' documented dependence on tree hollows and fissures for roosting.

The available profile does not state whether breeding occurs seasonally, the number of young produced, gestation length, age at maturity or lifespan. It also does not identify maternity roost dimensions or the sex-specific use of roosts.

Until local information is available, hollow-bearing trees and fissured trees within known or potential habitat should be treated as possible maternity or breeding roosts.

Breeding season: Not provided

Litter size: Not provided

Gestation: Not provided

Age at maturity: Not provided

Lifespan: Not provided

Breeding habitat: Breeding habitat features

The strongest documented habitat requirement is access to tree hollows and fissures. The source does not provide dimensions for maternity hollows or identify preferred tree species.

Clearing controls should therefore retain hollow-bearing live and dead trees and avoid disturbance to potential roost trees until an appropriately designed assessment has considered occupancy and breeding use.

• Include hollow-bearing trees in pre-clearing surveys, even where no bat is observed during the survey.
• Use suitably qualified fauna personnel for any capture, exclusion or roost assessment.
• Plan clearing timing only after local survey information and any relevant approval conditions have been reviewed, because the breeding season is not documented in the supplied sources.

Sheltering habitat: Roost features

The species depends on tree hollows and fissures for roosting, based on evidence from the NSW profile and the roosting habits of related Australian free-tailed bats. No roost dimensions or occupancy signs are provided in the supplied documents.

Potential roosts include hollows and fissures in live and dead trees. The profile recommends protecting hollow-bearing live and dead trees within the species' range.

The documents do not specify entrance width, hollow depth, tree diameter, preferred tree species, roost height, colony size or whether the species regularly changes roosts.

Documented refuge types: Tree hollows and tree fissures

Roost dimensions: Not provided

Documented roost colony size: Not provided

• Retain hollow-bearing live trees and standing dead trees wherever practicable.
• Inspect fissured trunks as well as obvious hollows because both features are identified as potential roosting sites.
• Do not remove a tree solely because no bat is visible at the time of inspection.

Sheltering habitat: Pre-clearing application

The species is extremely rare and has been recorded from only 15 locations nationally. A hollow-bearing tree within the known or predicted range should therefore be treated as a potential conservation feature during project planning.

The supplied documents do not describe roost stains, guano, odour, emergence behaviour or other reliable field signs. Roost inspections should be designed and supervised by a bat specialist.

• Map hollow-bearing trees before finalising clearing limits and access tracks.
• Protect retained trees from indirect damage, including fire, machinery impact, soil disturbance and changes to surrounding vegetation.
• Report suspected records to the relevant state authority and retain photographs, coordinates, habitat notes and identification evidence.

Threats: Clearing and roost loss

The main documented risks are loss of hollow-bearing trees, habitat clearing and degradation, fire, reduced insect availability and limited knowledge of the species' distribution and ecology. The species' apparent rarity increases the consequence of impacts at individual sites.

Clearing and removal of hollow-bearing trees can result from firewood collection, agricultural practices and forestry. Construction and infrastructure clearing can create the same direct loss of roosting habitat.

Loss of habitat is more concerning because the species appears to have very low population numbers and only 15 known locations nationally.

• Avoid clearing hollow-bearing live and dead trees.
• Include tree hollows and fissures in ecological constraints mapping and pre-clearing checks.
• Protect retained roost trees from damage caused by plant, stockpiles, access tracks and altered drainage.

Threats: Fire and vegetation change

Fire can directly kill individuals and modify habitat. Weed invasion can change vegetation structure, while feral goats, pigs and rabbits can degrade habitat.

The NSW profile recommends developing burning strategies that reduce impacts on preferred habitat in known foraging areas.

• Keep construction fire management away from retained hollow-bearing trees and known foraging habitat.
• Plan prescribed burning and bushfire mitigation so that hollow-bearing trees and native vegetation are retained.
• Manage weeds and feral browsers where they are degrading habitat around known or potential roosts.

Threats: Insect prey and chemical exposure

Pesticides and herbicides may reduce insect availability or cause toxic residues to accumulate in the bats' fat stores. Chemical drift near habitat is therefore a documented project risk.

• Prevent pesticide and herbicide drift into known or potential habitat.
• Use non-chemical methods where practicable near roost trees and native foraging vegetation.
• Consider indirect effects on insects when assessing vegetation maintenance and pest-control activities.

Threats: Knowledge gaps and other risks

The distribution, ecology and habitat preferences of the species are poorly understood. The supplied documents do not provide species-specific information on road mortality, fragmentation thresholds, predators, disease or hydrology change.

Road and infrastructure projects should still assess these pathways where they involve tree removal, fire, chemical use, drainage change or loss of native vegetation, but site conclusions should not be presented as species-specific without supporting records.

• Record and report all suspected observations because additional records may improve knowledge of the species' range.
• Assess indirect habitat effects, not only the area cleared.
• Treat changes to floodplain or wetland vegetation cautiously where they could alter native woodland structure or insect-producing habitat.

Survey methodology: 1. Call recording

The available NSW profile provides habitat and threat information, but no species-specific survey guideline, detection probability, seasonal activity window or minimum survey effort. Survey design should therefore be prepared by a suitably qualified bat ecologist and adjusted to the site, with methods aimed at detecting a rare, small insectivorous bat that may roost in tree hollows and fissures.

Use ultrasonic bat detectors in areas containing retained hollow-bearing trees, dead trees, tree fissures and likely flight paths.

Deploy detectors across representative habitat and near proposed clearing areas, because the species is apparently extremely rare and has been recorded from only 15 locations nationally.

Have species-level call analysis completed by a suitably experienced bat ecologist, because the profile provides no call description or validated detector settings.

Survey methodology: 2. Roost and habitat inspection

Inspect live and dead trees for hollows, fissures and other features that could provide roosts before clearing or disturbance.

Record the location and condition of hollow-bearing trees and fissured trees, including trees proposed for removal and trees retained near the work area.

Treat all other habitat associations listed for the relevant region as potential foraging habitat where they occur within or near the disturbance footprint.

Survey methodology: 3. Targeted bat searches

Use additional targeted searches where call recording or habitat inspection indicates potential habitat, including searches around tree hollows, fissures, riparian woodland, floodplain woodland and dry sclerophyll woodland.

Consider dusk and night-time observation or trapping only where it is lawful, safe and approved, and where a bat ecologist has selected the method and effort.

Do not describe a site as free of the species from a single negative survey, because the species has few records and the profile states that its ecology, distribution and habitat preferences are poorly understood.

Survey methodology: Minimum effort and reporting

• Set the number of detector nights, detector locations, inspection areas and any trapping effort in a documented, site-specific survey plan, because the supplied documents do not specify nights, hours, trap nights, transect lengths, survey months or weather conditions.
• Record survey dates, start and finish times, weather, detector settings, detector locations, habitat, tree features inspected, personnel and all identifications or non-detections.
• Report records and any suspected detection to the relevant state wildlife database and wildlife authority, including the NSW Department of Climate Change, Energy, the Environment and Water where the project is in NSW.
• Retain call files, photographs, GPS locations, field sheets and expert validation with the project environmental records.

Before habitat disturbance: Avoid and minimise

Treat hollow-bearing trees, fissured trees and connected native vegetation as potential habitat until the pre-clearance assessment demonstrates otherwise. The NSW profile identifies clearing, fire, pesticides, weeds and feral browsers as threats to this species or its habitat.

• Redesign the footprint to retain hollow-bearing live and dead trees, trees with fissures, and native vegetation that connects roosting and foraging areas.
• Retain habitat around known or suspected records and avoid isolating retained trees or vegetation patches from nearby habitat.
• Keep work areas, access tracks, stockpiles and lighting away from retained roost features and likely foraging areas where practicable.
• Prevent unnecessary removal of mature trees and dead standing trees, because the species is thought to depend on hollows and tree fissures for roosting.

Before habitat disturbance: Approvals and work planning

• Check whether the project requires NSW threatened species approvals, licences or other permits before survey, capture, handling or clearing.
• Confirm the Commonwealth status before starting approvals work, because the supplied NSW profile records the species as not listed under the EPBC Act.
• Prepare a fauna management plan that identifies potential roost trees, clearing limits, survey findings, fauna handling authority, stop-work triggers, release sites and reporting duties.
• Stage clearing so that retained habitat is protected before machinery enters the site and so that fauna risks can be reviewed between stages.
• Set the work timing from the site assessment and approval conditions, because the supplied documents do not identify a breeding season or other species-specific seasonal restriction.

Before habitat disturbance: Site preparation

• Complete a pre-clearance survey immediately before works, using the approved survey methods and checking all trees and other habitat features within the disturbance area.
• Mark trees and vegetation to be retained, including hollow-bearing and fissured trees, and clearly mark the approved clearing boundary.
• Install exclusion fencing or other visible controls around retained habitat where these controls can be maintained safely during construction.
• Brief machinery operators and fauna spotter catchers on the species profile, the location of potential roost features and the procedure for a suspected detection.
• Control pesticide and herbicide drift near potential habitat and prevent weed invasion or feral browsing from degrading retained vegetation.

During habitat disturbance: Daily controls

Clearing must be supervised and controlled around trees and other retained habitat. The supplied documents identify direct mortality and habitat modification from fire and clearing as risks, but do not provide a species-specific capture or relocation protocol.

• Check exclusion fencing, clearing markers, retained trees and access controls before work starts each day.
• Keep machinery within the approved footprint and prevent damage to retained hollow-bearing or fissured trees.
• Use a fauna spotter catcher during clearing where required by the approval, fauna management plan or risk assessment.
• Stop work and reassess if fire, smoke, pesticide drift, weed spread, feral animals or other activity threatens retained habitat.

During habitat disturbance: Spotter catcher and machinery procedure

• Maintain direct communication between the fauna spotter catcher, machine operator and site supervisor while each tree or habitat feature is being approached, felled or removed.
• Use staged, controlled clearing around habitat features so the fauna spotter catcher can inspect the feature and direct the operator before the next movement.
• Do not allow untrained workers to capture, handle or release a bat.
• Follow the project approval and the fauna management plan for any capture, temporary containment, transport or release, because the supplied documents do not specify handling limits, equipment or relocation distances.

During habitat disturbance: If a bat is found

• Stop work in the immediate area and protect the animal from machinery, people, heat and further disturbance.
• Keep the animal in place if it can remain safe, and obtain advice from the authorised fauna handler or wildlife authority before moving it.
• Only an appropriately authorised and trained person may capture, handle, contain or relocate the bat.
• If relocation is approved, release it into nearby retained habitat that contains suitable hollow-bearing or fissured trees and is away from active machinery.
• Arrange prompt assessment by a veterinarian or authorised wildlife carer for an injured, grounded or distressed animal, and record the outcome.

During habitat disturbance: Stop-work triggers and records

• Stop work where a bat is found, where a suspected roost is exposed, or where clearing damages a marked retained habitat feature unexpectedly.
• Do not recommence until the fauna spotter catcher, site supervisor and relevant approval holder have agreed on the control response.
• Record the date, time, location, habitat feature, photographs, species identification, people involved, action taken, release or treatment location and recommencement approval.
• Report confirmed or suspected records to the relevant state wildlife database and wildlife authority.

After habitat disturbance: Clearance checks

Post-clearance actions should confirm that approved habitat limits were followed and that retained roost and foraging habitat remains usable. Monitoring effort should reflect the species' rarity and the uncertainty about its ecology.

• Inspect the completed clearing area and its boundary for injured, trapped or displaced fauna and for damage to retained hollow-bearing or fissured trees.
• Check that exclusion fencing, no-go markers and other controls remain in place until machinery, vehicles and construction materials no longer threaten retained habitat.
• Map all retained roost features and any unexpected habitat loss, and compare the result with the approved footprint.

After habitat disturbance: Monitoring and reporting

• Use ultrasonic call monitoring and habitat inspections to monitor retained habitat where required by approval conditions or the fauna management plan.
• Document the monitoring locations, dates, effort, weather, call analysis, habitat condition and any management response.
• Report any detection, mortality, injury, roost discovery or unexpected habitat loss to the relevant authority and wildlife database.
• Review controls if monitoring identifies fire damage, vegetation degradation, pesticide effects, weed invasion or impacts from goats, pigs or rabbits.

After habitat disturbance: Offsets and compliance

• Apply any offset, restoration or compensatory habitat requirement imposed by the project approval.
• Keep approval records, pre-clearance and post-clearance maps, fauna handling records, monitoring results and incident reports for audit.
• Do not treat an offset as a substitute for retaining hollow-bearing and fissured trees within the project area where avoidance is practicable.

Rehabilitation actions: Roost and vegetation restoration

Rehabilitation should restore roosting features, native foraging vegetation and habitat structure used by this species. The NSW profile does not nominate planting species, nest-box designs or rehabilitation success thresholds, so these details must be set by the project ecologist for the local vegetation community.

• Retain existing hollow-bearing live and dead trees wherever possible and protect them from fire, machinery, weeds and feral browsers.
• Where approved and locally suitable, install artificial roost structures only as a supplementary measure, with design, placement and inspection specified by a bat ecologist.
• Replant locally native vegetation that matches the cleared vegetation community and restores tree cover, understorey structure and insect-producing habitat.
• Restore connections between retained trees, riparian areas, floodplain woodland and other native vegetation used for foraging.

Rehabilitation actions: Habitat structure and threats

• Retain or reinstate suitable fallen timber, logs and other natural shelter features where they do not create a construction or fire risk.
• Manage weeds so that vegetation structure and native insect habitat are maintained around retained and rehabilitated roost areas.
• Control goats, pigs and rabbits where they are degrading habitat or preventing regeneration.
• Prevent pesticide and herbicide drift into rehabilitated or retained habitat.

Rehabilitation actions: Fire and wetland settings

• Develop a fire regime that reduces impacts on preferred foraging habitat and protects retained hollow-bearing and fissured trees.
• Include nearby riverine, floodplain, wetland and woodland vegetation in rehabilitation planning where those communities occur in the project area.
• Use locally appropriate drainage and wetland rehabilitation methods that maintain native vegetation and do not create new construction hazards.

Rehabilitation actions: Monitoring and success measures

• Set measurable rehabilitation targets for survival of planted trees, regeneration of native understorey, weed cover, condition of retained roost trees and protection from fire and feral browsers.
• Monitor rehabilitated and retained habitat using repeat inspections and ultrasonic detectors where required by the approval or management plan.
• Review the rehabilitation method if monitoring shows continuing habitat degradation or fails to detect expected improvement in habitat structure.
• Submit confirmed species records and rehabilitation monitoring results to the relevant state wildlife database and authority.

Sources

• Bristle-faced Free-tailed Bat - Threatened biodiversity profile search, NSW Department of Climate Change, Energy, the Environment and Water: https://threatenedspecies.bionet.nsw.gov.au/profile?id=10923
• Bristle-faced Free-tailed Bat - Murray Darling Depression, NSW Department of Climate Change, Energy, the Environment and Water: https://threatenedspecies.bionet.nsw.gov.au/profileData?id=10923&cmaName=Murray+Darling+Depression