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East Coast Free-tailed Bat (Micronomus norfolkensis)

The East Coast Free-tailed Bat is a hollow-roosting insectivorous bat of eastern Australia, recorded from southern Queensland to southern New South Wales. It uses dry sclerophyll forest, woodland, floodplain and wetland habitats, mangroves, and some buildings, so clearing, hollow-bearing tree removal, demolition and artificial light need specific controls on development sites.

Conservation status

New South Wales, Biodiversity Conservation Act 2016: Vulnerable.

Queensland, Nature Conservation Act 1992: Colonial breeder. Least concern in Queensland, but it breeds in colonies, so tampering with a breeding place needs a high risk species management program rather than the low risk program.

Breeding season

The timing below is based on the documented breeding observations for New South Wales. No migration from Australia is described. Confirm local timing where a roost is occupied, particularly in northern parts of the range.

Mating dates, gestation length, litter size, maturity, lifespan and a species-wide torpor period are not well documented. Dates should therefore be treated as the documented NSW timing rather than a complete national calendar.

  • Breeding, births: Births are reported in late November or early December. Maternity roosts may be in tree hollows or roof spaces.
  • Young, lactation and dependence: Lactation continues until late January. Juveniles are reported to be able to fly by late January.
  • Foraging and local movement: The species is active year round. No seasonal migration is described, and it may move up to 10 km from a roost in one night.
  • Roost occupancy and exclusion planning: Occupied tree and building roosts require project-specific inspection. One exclusion proposal nominated March to May or September to October, avoiding the breeding period and periods when winter torpor may occur.
  • Highest clearing risk: Clearing or disturbance is most likely to harm the species from late November through January, when births, lactation and newly flying juveniles occur. Avoid disturbance of maternity roosts during this period.

Identification

This is a small, fast-flying free-tailed bat that is most reliably identified by expert analysis of ultrasonic calls and by its roosting behaviour. Visual identification alone is unlikely to be reliable during clearing or building inspections.

No adult body measurements, weight, pelage description, sex-based differences or diagnostic photograph have been published. Treat unidentified free-tailed bats as potentially threatened where suitable roost habitat is present, and use an experienced bat ecologist for call analysis or capture-based confirmation.

Adult size and weight: Not documented.

Sex differences: Not well documented.

Identification: Calls and similar species

The call is a low-frequency free-tailed bat call. In the Mandalong analysis, Micronomus norfolkensis was separated from Mormopterus species 2 by regular alternation of pulses and characteristic down-sweeping tails.

Calls can overlap with other free-tailed and broad-nosed bats. The Mandalong survey recorded 212 call sequences, of which 185 were suitable for analysis and 107 were confidently identified to species level. Identification should therefore record confidence, rather than treating every sequence as certain.

Useful call features: Mainly flat calls, regular alternation of pulses and characteristic down-sweeping tails.

Call identification caution: Mormopterus species 2 and other microbats may be difficult to separate from short or poor-quality recordings.

Identification: Roost and field signs

At buildings, inspect roof cavities, exposed sarking, wall gaps, overlapping roof sheets and other enclosed spaces before demolition or exclusion. Useful signs include bats emerging at dusk, audible activity in the roof and accumulated guano. In one documented roof roost, bats used the entire roof space and guano was present on sarking and the attic floor.

In trees, inspect hollow-bearing eucalypts and bark fissures. Emergence observations and a suitably timed inspection are more useful than searching for tracks or scats, which are not described as diagnostic field signs for this species.

  • Record the location and dimensions of every hollow-bearing tree or potential bark roost within the clearing footprint.
  • Use dusk emergence observations and ultrasonic detectors before removing a tree, demolishing a structure or sealing a building.
  • Stop work and obtain fauna ecologist advice if bats, fresh guano or active roosting are found.

Distribution: Range and bioregional setting

The known range is confined to eastern Australia. The species is concentrated in coastal and near-coastal New South Wales, especially the Hunter Estuary, Newcastle, Lake Macquarie and Morisset areas.

The species is distributed from southern Queensland to southern New South Wales, east of the Great Dividing Range. A complete state-by-state or formal bioregion-by-bioregion distribution has not been published.

Documented habitats include the Hunter Estuary and surrounding floodplain, freshwater wetland, mangrove, swamp oak and dry sclerophyll communities. Additional records occur around Morisset and Lake Macquarie, and at a development site in western Sydney.

Queensland: Southern Queensland is the northern part of the documented range.

New South Wales: The species extends south to southern New South Wales and is listed as Vulnerable in New South Wales.

Formal bioregions: Not well documented.

Distribution: Known concentrations and records

A large roosting population was documented around mangroves in the Hunter Estuary, where more than 700 animals had previously been trapped. The study area covered approximately 76,500 hectares and used a 15 km buffer around two mangrove patches containing multiple maternity roosts.

The species was recorded at 57.4 percent of 47 acoustic survey sites in the Hunter study. Activity was especially high in mangrove forest and freshwater wetland, although mangroves were interpreted mainly as roosting habitat rather than primary feeding habitat.

Hunter Estuary trapping record: More than 700 animals trapped around two mangrove patches containing multiple maternity roosts.

Hunter acoustic survey: 5,981 passes recorded across 47 sites, with the species detected at 57.4 percent of sites.

Highest mean activity: 403.4 plus or minus 170.7 passes per night in mangrove forest, compared with 7.9 plus or minus 2.1 in freshwater wetland.

Distribution: Population information

A national population estimate, population trend, generation length and reliable total number of subpopulations are not available. Acoustic passes are activity measures and must not be converted directly into animal numbers.

The Hunter Estuary records indicate a substantial local concentration associated with maternity roosts. Other records, including roof roosts around Morisset and habitat use at western Sydney sites, show that the species can occur in fragmented and modified areas when suitable roosts and feeding habitat remain.

National population estimate: Not provided.

Population trend: Not provided.

Generation length: Not provided.

Habitat: Habitat types

The species uses a range of wooded and wetland habitats, but local activity is strongly associated with habitat type. Retained hollows, floodplain and wetland vegetation, and connected remnants are important considerations during project design.

Documented habitat includes dry sclerophyll forest, woodland, swamp forest, mangrove forest, freshwater wetland and floodplain vegetation. The species also uses isolated paddock trees and remnant vegetation when these are close to larger forest remnants.

In the Hunter Estuary study, freshwater wetland, swamp oak forest and dry sclerophyll forest on sand supported more activity than dry sclerophyll forest on undulating slopes. The species avoided or rarely used urban areas compared with a similar free-tailed bat.

Habitat: Vegetation structure and site features

Important features include mature hollow-bearing eucalypts, small tree hollows, bark fissures, open woodland structure and nearby productive wetland or floodplain habitat. Water bodies and their vegetated buffers can provide roosting and foraging habitat for threatened microbats.

The species may use paddock trees and isolated remnants where they are close to larger forest remnants. Retain connected remnants and avoid creating unnecessary gaps between roost trees, woodland and wetland feeding areas.

Study buffer associated with activity: The local-scale study tested habitat variables within buffers from 250 m to 5 km, with 500 m urban land-use variables supported in some models.

  • Map hollow-bearing trees and potential bark roosts before finalising the clearing footprint.
  • Protect retained vegetation from accidental clearing, machinery damage, dust, rubbish, weeds, vibration and excessive night lighting.
  • Retain wetland, floodplain and riparian vegetation where practicable, including habitat around larger water bodies.

Habitat: Elevation and climate

A formal elevation limit or climatic envelope has not been established. In the Hunter study, activity was associated with low elevation, floodplain and freshwater wetland settings, as well as dry sclerophyll forest on sand.

Elevation pattern: Low-elevation areas were associated with higher activity in one supported local habitat model; a species-wide elevation limit is not provided.

Range climate: Eastern Australian coastal and near-coastal environments from southern Queensland to southern New South Wales.

Foraging habitat: Diet and feeding habitat

The East Coast Free-tailed Bat is an aerial insectivore. It feeds on small insects in open airspace above and within woodland and forest canopies, with especially high foraging activity recorded over freshwater wetland habitat.

The species feeds on small insects and forages above and within the canopy of open forests and woodlands. In the Hunter Estuary study, the greatest percentage of feeding activity was recorded in freshwater wetland.

Riparian and floodplain habitats may provide productive feeding areas because insect prey can be abundant there. Mangroves supported very high bat activity, but the study interpreted mangroves mainly as roosting habitat because bats quickly moved out after leaving roosts and foraging activity was relatively low.

Prey: Small insects.

Highest recorded foraging habitat: Freshwater wetland had the greatest percentage of foraging activity in the Hunter Estuary study.

  • Retain freshwater wetlands, floodplain vegetation, riparian corridors and open woodland near known or potential roosts.
  • Avoid night lighting directed into wetland edges, riparian corridors, canopy gaps and known flight paths.
  • Prevent dust, rubbish, weed invasion and water quality impacts that could reduce insect-producing habitat.

Foraging habitat: Foraging range and movement

The maximum recorded movement over one night in the Hunter Estuary study was 10 km from a roost. A separate assessment reported foraging distances of up to 6 km from roosting locations.

These distances mean that a small clearing may still affect a roost if it removes nearby wetland, floodplain, woodland or canopy flight habitat. Assess the wider retained habitat around a roost, not only the tree or structure containing the bats.

Maximum movement in one night: 10 km from a roost in the Hunter Estuary study.

Reported foraging distance: Up to 6 km from roosting locations in the cited habitat assessment.

Breeding habitat: Breeding roosts

Breeding occurs in maternity roosts, which may be in large tree hollows or buildings. Although breeding information is limited, the timing of births and juvenile flight identifies a high-risk clearing period.

Natural maternity roosts are associated with tree hollows, including hollows in mature eucalypts. The species can also form maternity roosts in roof spaces and other man-made structures.

A roof at Mandalong was highly suspected to be a maternity roost after juvenile bats were reported and at least 35 bats were observed leaving the building, although the exact number of East Coast Free-tailed Bats was not known.

  • Treat any occupied roof, ceiling cavity, hollow-bearing tree or enclosed building cavity as potential breeding habitat until assessed by a fauna ecologist.
  • Do not exclude bats, remove a suspected maternity tree or demolish an occupied structure during the breeding period.

Breeding habitat: Breeding biology

Births, lactation and juvenile flight have been documented, but litter size, gestation length, age at maturity and lifespan are not well documented. Breeding timing may vary locally, so confirm the timing with a project-specific ecologist where an occupied roost is present.

Births: Late November or early December.

Lactation: Continues until late January.

Juvenile flight: Juveniles are able to fly by late January.

Litter size: Not provided.

Gestation: Not provided.

Age at maturity: Not provided.

Lifespan: Not provided.

Sheltering habitat: Natural roosts

The species is primarily a hollow-roosting bat but can use bark fissures and artificial structures. Roost protection should focus on mature trees, occupied buildings and safe access to replacement roosts where exclusion cannot be avoided.

The species roosts mainly in tree hollows. All natural roosts described in habitat assessments occurred in hollow spouts of large mature eucalypts. Small hollows were also recorded as potential habitat, and the species may use paddock trees and isolated remnants near larger forest remnants.

Bark fissures in native vegetation may provide casual roosting habitat. Three hollow-bearing trees and vegetation with potentially suitable bark fissures were identified at one highly modified development site, but the assessment considered them suitable for casual rather than maternal or breeding roosting.

Natural roost type: Hollow spouts in large mature eucalypts are the documented natural roost type.

Casual roost features: Tree hollows and bark fissures.

  • Retain large mature eucalypts, hollow-bearing trees, hollow spouts, dead limbs and suitable bark features wherever practicable.
  • Before removing a hollow-bearing tree, conduct a targeted inspection or stagwatch and dismantle the tree under the direction of a licensed fauna ecologist.
  • Keep retained trees outside the clearing footprint protected from root damage, trunk impact, soil disturbance and machinery storage.

Sheltering habitat: Buildings and structures

The species can roost in roof cavities and other man-made structures. A documented roof roost used the entire roof space, with access through gaps between sarking and walls or between overlapping sheets. Bats were heard in the roof and guano was found on sarking and the attic floor.

Before demolition or exclusion, inspect roof cavities, ceiling spaces, wall cavities, culverts and other enclosed structures. A building may be a maternity roost even when individual bats are not seen during a daytime inspection.

Documented roof access: Gaps between sarking and walls or between overlapping roof sheets.

Documented compensatory provision: Fifteen bat boxes were proposed for one occupied roof roost.

  • Undertake a licensed fauna assessment before demolishing or sealing a structure that could contain bats.
  • If exclusion is approved, undertake it outside the breeding period and outside periods of torpor, using a staged method that prevents bats being trapped inside.
  • Where exclusion is unavoidable, provide and monitor compensatory roosts. One documented proposal used 15 bat boxes on trees and controlled release at dusk.

Threats: Clearing and roost loss

The main project risks are loss of hollow-bearing trees and roosting structures, removal of maternity roosts, loss of wetland and floodplain feeding habitat, and indirect disturbance from lighting, noise and construction activity.

Clearing can remove hollow-bearing trees, bark fissures, canopy flight space and nearby feeding habitat. At one school development site, 0.45 hectares of native vegetation and three hollow-bearing trees were proposed for removal, with potential loss of casual roosting habitat.

The loss of an occupied building roost can disrupt breeding and displace a local group. A documented roof exclusion assessment considered that exclusion after breeding could still disrupt breeding opportunities for part of the local population.

  • Avoid clearing hollow-bearing trees and retain potential roost trees within connected vegetation.
  • Do not remove trees or structures until pre-clearance checks, exclusion controls and fauna rescue procedures are in place.
  • Use a staged, ecologist-supervised dismantling method where removal of an occupied hollow or structure cannot be avoided.

Threats: Lighting, noise and construction disturbance

Artificial light can change bat foraging behaviour and reduce the suitability of adjacent habitat. Construction noise, vibration, dust, rubbish, machinery and vehicle movements can also reduce habitat quality and increase edge effects.

The species was less associated with urban habitat than the similar Mormopterus species 2 in the Hunter study. This supports careful control of lighting and disturbance near retained woodland, wetlands and known roosts.

  • Use the minimum lighting needed for safety and direct lights away from roosts, wetland edges, retained canopy and flight paths.
  • Avoid night works near an occupied maternity roost unless specifically assessed and authorised.
  • Prevent construction runoff, rubbish and weed spread into retained habitat.

Threats: Fragmentation, habitat change and other pressures

Loss and fragmentation of floodplain, wetland and riparian vegetation can reduce feeding habitat and connectivity between roosts and feeding areas. Hydrology changes, including draining wetlands or altering floodgates, may affect insect prey and bat activity.

No species-specific disease, road mortality rate, fire response or predator impact has been identified. These risks should still be managed as general fauna risks where projects remove cover, increase vehicle movements, alter water regimes or create exposed canopy gaps.

Hydrology evidence: Draining, insect spraying and tidal floodgate management require further investigation as factors affecting floodplain bat communities.

Disease evidence: No species-specific disease has been identified.

Fire evidence: No species-specific fire response has been identified.

  • Maintain links between roost trees, remnant woodland, floodplain vegetation and wetlands.
  • Avoid draining, filling or isolating freshwater wetlands and protect the hydrology of retained floodplain habitat.
  • Apply site fauna speed controls and pre-clearance procedures where roads or access tracks pass through known bat habitat.
  • Retain canopy and avoid unnecessary new gaps that may increase exposure to predators.

Survey methodology: 1. Passive ultrasonic detection

Survey for the East Coast Free-tailed Bat should combine ultrasonic detection with inspection of likely roosts. Give priority to hollow-bearing trees, mature vegetation, wetlands, riparian areas and buildings or other structures with enclosed cavities.

Deploy calibrated ultrasonic detectors at likely flyways, tree hollows, wetland margins and building or structure entrances. The species is an open-air forager and may be detected above and within open forest and woodland canopies.

Use species-level call analysis with a regional call key and retain uncertain records at species-group level where calls cannot be separated reliably.

Published local effort: One detector at each of 47 sites, for two entire nights per site.

Published study period: 25 January to 25 February 2011, after the maternity season and after young were flying.

Published detector placement: Microphones were housed in a 1 m tall plastic pipe, aimed upwards at 45 degrees.

  • Sample for two entire nights at each site where practicable, following the published local study design.
  • Aim microphones into open air, along flyways and away from dense vegetation to reduce sound attenuation.
  • Do not survey on windy or rainy nights, or on a full moon, where these conditions could reduce comparability or affect activity.
  • Calibrate detectors before the survey period and record detector type, microphone position, weather, start and finish times, and survey effort.
  • Treat call sequences as an activity index, not a count of individual bats, because repeated recordings may represent the same animal.

Survey methodology: 2. Habitat-based site selection

Select detector locations using habitat features known to support this species. The published study recorded the highest activity in mangrove forest and freshwater wetland, with additional use of dry sclerophyll forest on sand, swamp oak forest and other woodland habitats.

Do not exclude a site only because it is modified or near development. Records include use of buildings, isolated remnant vegetation and paddock trees near larger forest remnants.

Published study area: 47 sites across seven habitat types, with sites at least 250 m apart.

Reported maximum nightly movement: 10 km, based on unpublished information cited by the study.

Reported foraging distance: Up to 6 km from roosting locations in the habitat assessment.

  • Cover hollow-bearing trees, mature eucalypts, wetland edges, riparian vegetation, mangroves where present, open woodland and likely flight paths.
  • Include buildings, sheds, culverts and roof spaces where bats may roost, particularly where there are gaps, enclosed cavities or signs of guano.
  • Use repeat detector locations where a decision depends on absence, because regional habitat models can produce false negative and false positive predictions at local scale.
  • Record the surrounding habitat type and the amount of urban land use near each detector, as activity was lower in urban areas in the local study.

Survey methodology: 3. Roost and maternity inspection

Inspect hollow-bearing trees and structures before clearing or demolition. The species roosts mainly in tree hollows, but it also uses bark fissures and man-made structures.

Treat a roof, shed, wall cavity or other enclosed structure as a potential maternity roost where bats, juveniles, guano, noise or repeated emergence are observed.

Documented maternity timing: Females give birth in late November or early December; lactation lasts until late January, and juveniles can fly by late January.

Documented building roost evidence: A residential roof was suspected to be a maternity roost after 88 East Coast Free-tailed Bat call recordings, observed juvenile bats and bats emerging from both roof apexes.

  • Conduct an emergence observation at dusk where a structure or tree hollow may be occupied.
  • Use visual observation with ultrasonic detectors at likely exits, and inspect accessible roof or cavity spaces only where this can be done safely.
  • Do not enter or open a suspected maternity roost during the breeding period unless the action is authorised and a species-specific management plan addresses the risk.
  • Record the structure or tree location, entrance points, evidence of occupancy, estimated activity, photographs and the limitations of the inspection.

Survey methodology: Minimum effort and reporting

  • Use two full detector nights per site as the documented minimum where passive acoustic survey is the primary method, and increase repeat effort where absence would affect clearing or approval decisions.
  • Survey representative habitat and all potential roost features within the disturbance footprint, not only mapped high-quality vegetation.
  • Have calls analysed by a person experienced with the species and report definite, probable, possible and species-group identifications separately.
  • Submit confirmed records, survey metadata and spatial coordinates to the relevant state wildlife database, such as the NSW BioNet Wildlife Atlas where the work is in New South Wales.
  • Report the detector model, calibration, microphone position, weather, dates, nights, habitat type, call-analysis method and any limitations with the survey results.
  • Obtain current advice on state survey and licensing requirements before fieldwork, because the cited studies and licence material are from different years.

Vegetation associations: Eucalypt forest

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

Documented habitat includes dry sclerophyll forest, woodland, swamp forest, mangrove forest, freshwater wetland and floodplain vegetation.

Automatically indexed from existing profile text. Not a verified preference, mapped occurrence or habitat requirement. Check the original source and regional qualifiers before use.

Evidence: Unreviewed profile-derived candidate

Confidence: Not independently verified

Region: Scope as described in the quoted profile text; not independently verified. Profile states: NSW, QLD.

Habitat use: general

Attribution gap: No sentence-level reference is attached to the original profile block. Review the profile bibliography; this candidate is not source-verified.

Vegetation associations: Woodland

Documented habitat includes dry sclerophyll forest, woodland, swamp forest, mangrove forest, freshwater wetland and floodplain vegetation.

Automatically indexed from existing profile text. Not a verified preference, mapped occurrence or habitat requirement. Check the original source and regional qualifiers before use.

Evidence: Unreviewed profile-derived candidate

Confidence: Not independently verified

Region: Scope as described in the quoted profile text; not independently verified. Profile states: NSW, QLD.

Habitat use: general

Attribution gap: No sentence-level reference is attached to the original profile block. Review the profile bibliography; this candidate is not source-verified.

Vegetation associations: Wetland or sedgeland

Documented habitat includes dry sclerophyll forest, woodland, swamp forest, mangrove forest, freshwater wetland and floodplain vegetation.

Automatically indexed from existing profile text. Not a verified preference, mapped occurrence or habitat requirement. Check the original source and regional qualifiers before use.

Evidence: Unreviewed profile-derived candidate

Confidence: Not independently verified

Region: Scope as described in the quoted profile text; not independently verified. Profile states: NSW, QLD.

Habitat use: general

Attribution gap: No sentence-level reference is attached to the original profile block. Review the profile bibliography; this candidate is not source-verified.

Vegetation associations: Mangrove

Documented habitat includes dry sclerophyll forest, woodland, swamp forest, mangrove forest, freshwater wetland and floodplain vegetation.

Automatically indexed from existing profile text. Not a verified preference, mapped occurrence or habitat requirement. Check the original source and regional qualifiers before use.

Evidence: Unreviewed profile-derived candidate

Confidence: Not independently verified

Region: Scope as described in the quoted profile text; not independently verified. Profile states: NSW, QLD.

Habitat use: general

Attribution gap: No sentence-level reference is attached to the original profile block. Review the profile bibliography; this candidate is not source-verified.

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: Alluvial flats and floodplains

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

It uses dry sclerophyll forest, woodland, floodplain and wetland habitats, mangroves, and some buildings, so clearing, hollow-bearing tree removal, demolition and artificial light need specific controls on development sites.

Automatically indexed from existing profile text. Not a verified preference, mapped occurrence or habitat requirement. Check the original source and regional qualifiers before use.

Evidence: Unreviewed profile-derived candidate

Confidence: Not independently verified

Region: Scope as described in the quoted profile text; not independently verified. Profile states: NSW, QLD.

Habitat use: general

Attribution gap: No sentence-level reference is attached to the original profile block. Review the profile bibliography; this candidate is not source-verified.

Water and wetland associations: Water-associated habitat mentioned in profile

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

Documented habitat includes dry sclerophyll forest, woodland, swamp forest, mangrove forest, freshwater wetland and floodplain vegetation.

Automatically indexed from existing profile text. Not a verified preference, mapped occurrence or habitat requirement. Check the original source and regional qualifiers before use.

Evidence: Unreviewed profile-derived candidate

Confidence: Not independently verified

Region: Scope as described in the quoted profile text; not independently verified. Profile states: NSW, QLD.

Habitat use: general

Attribution gap: No sentence-level reference is attached to the original profile block. Review the profile bibliography; this candidate is not source-verified.

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: Avoid and minimise

Plan the work around the species' roosting requirements, particularly hollow-bearing trees and enclosed structures. Avoid removing a maternity roost where practicable, and keep nearby foraging and movement habitat connected.

Development example: A documented project proposed clearing 0.45 ha of vegetation and identified three hollow-bearing trees and bark fissures that could provide casual roosting habitat.

  • Retain hollow-bearing trees, mature eucalypts and vegetation with bark fissures wherever practicable.
  • Retain wetlands, mangroves, riparian vegetation and open woodland used for foraging, including vegetated margins around water bodies.
  • Avoid clearing isolated trees and remnant vegetation where they are close to larger forest remnants, because the species can use these features.
  • Retain wildlife corridors linking roosting habitat with wetlands, riparian areas and larger forest remnants.
  • Avoid removal or demolition of occupied roofs, sheds, culverts and other structures until occupancy, breeding status and lawful exclusion methods have been assessed.
  • Keep artificial lighting, construction noise, dust, rubbish and machinery activity away from retained habitat where practicable, especially at roost entrances and along flyways.

Before habitat disturbance: Approvals and fauna planning

New South Wales status in the project material: Vulnerable under NSW legislation.

Recommended exclusion window in the documented residential case: March to May, or September to October, outside the breeding period and winter torpor.

  • Check the current Commonwealth listing and EPBC Act referral requirements before finalising the impact assessment.
  • Check the relevant state threatened species listing, wildlife licence requirements and any conditions applying to capture, handling, exclusion, relocation or harm.
  • Prepare a fauna management plan that identifies roosts, hollow-bearing trees, work limits, exclusion methods, the fauna spotter catcher's authority, stop-work triggers and release locations.
  • Stage clearing so retained habitat remains available before any occupied tree, building or structure is removed.
  • Schedule exclusion or disturbance outside the documented breeding period and avoid periods when bats may be in winter torpor unless a licensed ecologist confirms that the action is appropriate.

Before habitat disturbance: Pre-clearance preparation

Documented replacement measure: Fifteen bat boxes were proposed on trees at a residential site before exclusion of a suspected maternity roost.

  • Complete a pre-clearance inspection of every tree, building, roof, culvert and other structure within or immediately beside the work area.
  • Mark retained hollow-bearing trees, roost structures, wetland margins, riparian buffers, access routes and no-go areas before machinery enters the site.
  • Install exclusion fencing where it can prevent machinery, vehicles and personnel entering retained habitat without creating a barrier to bat flight.
  • Confirm a nearby retained release area before any approved capture or relocation, and prepare suitable temporary holding equipment and transport arrangements.
  • Brief machinery operators and supervisors on the species' appearance, likely roost locations, stop-work triggers and the requirement to follow the fauna spotter catcher's directions.
  • Where a building roost must be excluded, obtain project-specific approval and install replacement roosting opportunities before exclusion, rather than relying on emergency relocation.

During habitat disturbance: Daily controls and machinery interface

Use a controlled clearing sequence with a fauna spotter catcher present for activities that may affect roosts or habitat. Work must stop when an occupied roost, injured bat or unexpected habitat feature is found.

  • Inspect the work area each morning for bats, fresh guano, damaged habitat features, fallen limbs and changes to exclusion fencing.
  • Keep machinery within marked limits and maintain no-go zones around retained trees, wetland margins, structures and release areas.
  • Use the fauna spotter catcher to direct the order and method of clearing, and require operators to stop immediately when directed.
  • Clear in stages towards retained habitat only where the fauna management plan confirms that this will not drive bats towards traffic, machinery, people or exposed predators.
  • Minimise night lighting and direct unavoidable lighting away from retained vegetation, roost entrances and wetland edges.
  • Prevent rubbish, fuel, sediment, dust and weeds from entering retained habitat or water bodies.

During habitat disturbance: Trees, structures and habitat features

Apply specific controls to hollow-bearing trees and occupied buildings. For other features, follow the approved fauna management plan and the directions of the licensed fauna ecologist or fauna spotter catcher.

The species is not known to depend on rocks, burrows or logs, so do not assume these features are occupied without site evidence.

Documented structure control: The residential case proposed sealing roof egress points only after bats had been removed and transported to prepared bat boxes.

  • Do not fell a hollow-bearing tree until it has been inspected and, where required by the management plan, monitored for use by a licensed fauna ecologist.
  • Dismantle a hollow-bearing tree under fauna ecologist supervision where a threatened microbat may be present, and retain or relocate the hollow only as directed by the approved method.
  • Inspect old houses, sheds, roof cavities, wall cavities and other enclosed structures before demolition or removal.
  • Do not seal a structure while bats may be inside unless the exclusion method has been designed and approved to prevent entrapment.
  • Protect wetlands and water bodies with the specified project buffers and controls, because these areas can provide roosting and foraging habitat.

During habitat disturbance: Animal response, stop work and records

  • Stop work if a bat is found in a tree, structure, debris or machinery exclusion zone, or if a suspected maternity roost, juvenile, injured animal or unexpected hollow is identified.
  • Keep people, machinery and dogs away from the animal and do not chase, handle or move it unless the authorised fauna handler directs the response.
  • Have only appropriately authorised and trained personnel capture or handle the bat, using the conditions of the relevant wildlife licence and project approval.
  • Relocate a healthy animal only to nearby retained habitat or an approved replacement roost, and only under the fauna management plan and ecologist direction.
  • Take an injured or grounded bat to a veterinarian or authorised wildlife carer through the approved fauna response process.
  • Record the date, time, location, species identification, evidence of breeding, action taken, handler, release or treatment location, photographs and any permit or incident number.
  • Resume work only after the fauna spotter catcher and project environmental officer confirm that the stop-work trigger has been resolved.

After habitat disturbance: Post-clearance checks

Confirm that clearing has not left bats trapped in structures or isolated habitat. Keep replacement roosts and retained habitat under active management, and document outcomes against approval conditions.

  • Inspect cleared trees, structures, debris piles and work areas for live, injured or trapped bats before the area is released to the construction team.
  • Recheck retained hollow-bearing trees, replacement boxes and nearby structures after the first dusk period where the work involved an occupied or potentially occupied roost.
  • Confirm that roof entrances or other exclusion points are sealed only after the approved exclusion process is complete and no bats remain inside.
  • Remove temporary fencing only when the environmental representative confirms that retained habitat no longer requires protection.

After habitat disturbance: Monitoring and reporting

Published local acoustic benchmark: The local study used two entire nights at each site and recorded activity as the number of passes per night.

  • Monitor replacement bat boxes and retained roost features using emergence observations and ultrasonic detectors where the approval or fauna management plan requires it.
  • Repeat acoustic monitoring at the same detector locations and with comparable effort where a before and after comparison is required.
  • Record use of replacement roosts, evidence of juveniles, bat activity, mortality, injuries, unauthorised clearing, lighting changes and weed or predator incursions.
  • Report non-compliance, unexpected impacts, injured or dead bats and failed exclusion immediately through the project incident and approval reporting process.
  • Submit confirmed records and significant observations to the relevant state wildlife database.

After habitat disturbance: Maintain controls and offsets

  • Maintain retained trees, wetland buffers, riparian corridors, replacement boxes, exclusion fencing and lighting controls for the period specified in the approval or fauna management plan.
  • Repair or replace damaged bat boxes and inspect them for occupancy, pests, water ingress and structural failure.
  • Apply any required biodiversity offsets or habitat restoration commitments to the approved impact area and habitat values, rather than treating a bat box as a substitute for all lost natural hollows.
  • Review the management plan if monitoring shows that bats continue to use the work area, replacement structures are not used, or activity has declined in retained habitat.

Rehabilitation actions: Restore habitat structure

Rehabilitation should restore connected roosting and foraging habitat, with priority given to hollow-bearing trees, wetland and riparian vegetation, and mature woodland structure. Natural hollows take many years to develop, so protect existing trees and use replacement structures only as an interim or supplementary measure.

Documented habitat association: The species occurs in dry sclerophyll forest, woodland, swamp forest and mangrove forest, and uses wetlands and riparian areas for foraging.

Documented natural roost feature: Natural roosts are mainly in tree hollows, with occasional use of buildings and bark fissures.

  • Protect and retain surviving mature eucalypts and all suitable hollow-bearing trees within the rehabilitation area.
  • Replant local native eucalypt woodland and riparian vegetation suited to the site, using the approved local provenance species list rather than a generic planting mix.
  • Restore wetland and waterbody margins with native vegetation and maintain the buffers required by the project approval.
  • Reconnect isolated remnants with retained or restored vegetation corridors leading to larger forest, riparian and wetland areas.
  • Retain fallen timber and other natural structure where safe and compatible with bushfire and construction requirements. Logs and rocks have not been identified as specific roost features for this species.

Rehabilitation actions: Replacement roosts and site protection

Documented box provision: Fifteen bat boxes were proposed for one residential exclusion project.

  • Install bat boxes only where an approved plan identifies a loss of roosting habitat and a fauna ecologist has selected suitable trees, orientation and maintenance arrangements.
  • Install replacement boxes before exclusion or clearing where they are intended to receive displaced bats.
  • Treat bat boxes as supplementary roosts and continue protecting mature hollow-bearing trees because boxes do not replace the long-term value of natural hollows.
  • Control weeds, rubbish, domestic animals and feral predators around retained vegetation, wetland margins and roost trees.
  • Manage artificial lighting so that restored vegetation, wetland edges and roost entrances remain dark enough to retain bat movement and foraging opportunities.

Rehabilitation actions: Monitoring and success measures

  • Inspect planted areas for survival, recruitment, weed cover, erosion, connectivity and protection from machinery and grazing.
  • Monitor retained trees, replacement boxes, wetland margins and restored vegetation with comparable ultrasonic detector effort and emergence observations where required.
  • Use continued confirmed records, regular activity, evidence of roost use and absence of construction-related mortality as project-specific performance measures.
  • Investigate and rectify failed plantings, unused replacement boxes, new lighting impacts, predator activity or loss of wetland and riparian function.
  • Report rehabilitation results, monitoring data, maintenance actions and any corrective measures to the approval authority and relevant state wildlife database where required.

Sources