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North-western Free-tailed Bat (Ozimops cobourgianus)

The North-western Free-tailed Bat, Ozimops cobourgianus, is an Australian microbat associated particularly with mangroves and nearby coastal habitats in the north and north-west. It can roost in small crevices and spouts in dead mangrove branches, so clearing, pruning, construction and disturbance may affect roosts that are difficult to see. The species is least concern nationally, although it is listed as a Priority 1 species in Western Australia and Queensland treats its breeding places as high risk when they are disturbed.

Conservation status

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 North-western Free-tailed Bat is poorly known, so its breeding calendar is based mainly on the general pattern for Australian microbats. Breeding is most likely in the warmer months, from spring to late summer, with some variation between northern regions and years.

Breeding mode: Live-bearing mammal. Females give birth to pups in a shared colony or maternity roost.

Breeding frequency: Usually one pup per female each year.

Litter size: One pup is the usual pattern for Australian microbats. Species-specific litter size is not recorded.

Gestation, fledging and weaning: Not recorded for the North-western Free-tailed Bat.

Maternity roosts: For this species, recorded roosts include small spouts, crevices and dead upper branches of mangrove trees, especially mature Avicennia marina. Microbat maternity roosts can also occur in tree hollows, fissures, loose bark, caves, mines, culverts, bridges and buildings.

Colony size and site fidelity: Typical colony sizes and site fidelity are not recorded. A colony is a group of bats using a shared roost, and a maternity roost is a place where females raise pups.

Recognising an active breeding place: Look for pregnant or lactating females, pups, repeated emergence at dusk, bats returning to the same roost, fresh droppings and concentrated bat activity. Confirm use with an emergence watch, acoustic recording using Anabat or similar equipment, and targeted inspection where safe. Harp traps or mist nets may assist species identification under suitable permits and animal welfare controls.

Clearing and construction care: Treat a roost where young are raised as a breeding place. Avoid disturbance during the maternity season where practicable. If removal cannot be avoided, use exclusion devices outside the maternity season, and use two-stage or soft felling for hollow-bearing trees. Bat boxes may provide supplementary roosting habitat, but they are not a substitute for retaining active maternity roosts.

Timing can shift between years and regions, so local acoustic surveys, emergence watches and roost inspections should guide clearing decisions.

  • Breeding and births: Breeding is expected mainly from spring to late summer, but the species-specific timing is poorly known.
  • Dependent pups: Dependent young may remain associated with the maternity roost after births, extending into early autumn.
  • Colony and maternity roost use: Microbats commonly form shared colonies during the breeding season, and roosts containing young need additional protection.
  • Adult flying and foraging: Adults are expected to remain active throughout the year, although species-specific seasonal activity data are limited.
  • Highest clearing risk: The highest risk is during the warmer breeding period, especially when maternity roosts contain pups or dependent young.

Identification: Appearance and field identification

This is a poorly known free-tailed bat. Field identification should be approached cautiously because several free-tailed bats have overlapping echolocation characteristics and reliable identification may require an experienced bat ecologist.

Do not rely on a brief view of a flying bat to identify this species. Species-specific descriptions of body size, weight, colour and diagnostic external features are not sufficiently established for routine site use.

Record the location, habitat, flight behaviour and roost feature, then arrange confirmation by a suitably experienced ecologist where the result may affect clearing or construction decisions.

Family: Molossidae

Group: Free-tailed bats

  • Use photographs only as supporting evidence, not as the sole basis for identification.
  • Keep the scientific name Ozimops cobourgianus with the field record because older reports may use Mormopterus cobourgianus or Mormopterus loriae cobourgiana.

Identification: Calls and similar species

Ultrasonic call recording is a practical way to investigate possible presence. Use an Anabat, Songmeter or similar detector, and have calls analysed by a person familiar with northern Australian free-tailed bats.

Calls may overlap with other species. A conservative result such as a species group or probable identification is more appropriate than forcing a species-level call identification.

Useful survey tools: Ultrasonic detector, emergence watch, harp trap or mist net, and roost inspection equipment.

  • Deploy detectors near mangroves, likely flyways, creek lines, open edges and suspected roost trees.
  • Record the detector location, date, weather, habitat and analysis method.
  • Use more than one evidence type where a breeding place or clearing decision is involved.

Identification: Field signs

Bats may leave droppings, staining or an odour below a regularly used roost, but signs can be slight and may be obscured by foliage, mud or tidal conditions.

Look for repeated bat activity at dusk, bats entering or leaving crevices, and fresh droppings beneath dead branches, hollows, culverts, bridges or buildings.

  • Do not enter a suspected roost or block an opening without an approved method and a suitable fauna specialist.
  • A lack of visible droppings does not rule out a roost, especially where the site is exposed to rain or tides.

Distribution: Australian range

The North-western Free-tailed Bat is endemic to Australia. Records are concentrated along the northern and north-western coast, with mapped occurrence in the Northern Territory, Queensland and Western Australia.

In Western Australia, the species has been recorded along the coast from Lake McLeod to Point Torment and is associated with mangrove stands. Records are sparse across that range.

In the Northern Territory and Queensland, check coastal and near-coastal mangrove habitats, adjoining vegetation and other suitable roosting features. A lack of local records should not be treated as proof that the species is absent.

Mapped states and territories: Northern Territory, Queensland and Western Australia

Overseas range: None. The species is endemic to Australia.

  • Prioritise database searches and local records around mangrove communities, tidal creeks, estuaries and coastal development areas.
  • Check both the project footprint and nearby retained habitat, because bats can commute between roosts and feeding areas.

Distribution: Interpreting records on site

A detector record may indicate activity in the wider area rather than a roost within the footprint. Conversely, a roost may be present even when short-term acoustic surveys do not detect the species.

The species was detected acoustically during a Western Australian fauna survey using three detector locations over three nights, but it was not recorded during that field survey. This illustrates why survey results need to be interpreted with habitat and survey conditions.

  • Map all records against mangroves, dead branches, drainage lines, bridges, culverts and buildings.
  • Treat mature mangroves and adjoining coastal vegetation as higher priority areas for follow-up checks.

Habitat: Vegetation to check

The strongest habitat association is with mangroves and adjoining coastal areas. Mature mangrove communities, tidal margins and dead or damaged branches deserve particular attention before clearing, pruning or construction.

Inspect mature Avicennia marina mangroves and other mangrove stands, especially where trees contain dead upper branches, small spouts or narrow crevices.

Also check mangrove edges, scattered coastal vegetation, tidal creek margins and adjoining areas that may provide flight paths or alternative roosts.

Recorded habitat association: Mangroves, particularly mature Avicennia marina, and adjoining areas

  • Map mangrove patches inside and beside the work area.
  • Mark trees with dead upper branches, loose bark, crevices or cavities for a targeted fauna inspection.
  • Retain connected mangrove edges where practicable.

Habitat: Landforms and site features

Give additional attention to estuaries, mudflats, tidal creeks, coastal flats and rocky or built structures near mangroves. These features may support movement between roosting and feeding areas.

Culverts, bridges, buildings, sheds and other structures can provide alternative roost spaces for microbats and should be checked before demolition or modification.

  • Include retained vegetation and nearby structures in the pre-clearing inspection.
  • Check under bridges, around culverts and inside accessible buildings for bats, droppings, staining and odour.
  • Keep an exclusion and rescue plan ready where work will affect a suspected roost.

Foraging habitat: Likely flight and feeding areas

The species diet and detailed foraging ecology are poorly known. As a general guide for a free-tailed microbat, assess open airspace and insect-rich edges as well as the roost habitat itself.

Survey open airspace above and beside mangroves, tidal channels, mudflats, coastal flats and vegetation edges. Bats may commute along linear features such as creek lines, tracks and forest edges.

Do not assume that a treeless area has no value. Open coastal habitats can provide flight space between roosts and feeding areas.

  • Place detectors where bats can fly freely, without dense foliage directly around the microphone.
  • Sample both mangrove edges and adjoining open areas when the project may remove or fragment coastal vegetation.

Foraging habitat: Lighting and night works

Artificial light can alter bat movement and insect activity around roosts and flight paths. Limit unnecessary lighting near mangroves, suspected roosts and retained vegetation.

Where night work is unavoidable, use directional, shielded lighting and avoid shining lights into crevices, tree crowns or known emergence routes.

  • Turn off temporary lighting when it is not required.
  • Keep light spill away from retained habitat and likely commuting edges.
  • Recheck lighting if bat activity changes after construction begins.

Breeding habitat: Maternity habitat

The North-western Free-tailed Bat is treated as a colonial breeder for Queensland management purposes. Species-specific breeding dates and reproductive measurements are poorly known, so plan around the general microbat breeding season and confirm activity on site.

Microbat maternity roosts may occur in tree hollows, fissures, loose bark, caves, mines, culverts, bridges or buildings. For this species, small crevices and spouts in dead upper mangrove branches are especially relevant.

A maternity roost is a place where young are raised. Any roost containing pups, or used by pregnant or lactating females, should be managed as a breeding place.

General microbat breeding period: Most microbats give birth to one pup in the warmer months, usually spring to late summer.

  • Inspect dead and hollow-bearing mangrove trees before pruning, felling or earthworks.
  • Check nearby structures where the project includes demolition, bridge work, culvert replacement or building refurbishment.
  • Avoid disturbing suspected maternity habitat until the site has been assessed by a qualified fauna ecologist.

Breeding habitat: How to confirm a maternity roost

Confirmation may involve an emergence watch at dusk, acoustic monitoring, a careful roost-tree inspection and, where appropriate, harp trapping or mist netting. Pregnant or lactating females and pups are strong evidence of a maternity roost.

Use an endoscope or pole camera where a cavity can be inspected without damaging the tree or disturbing bats. Do not use intrusive methods during the period when young may be flightless.

  • Plan surveys with the project ecologist and obtain required approvals before trapping or handling bats.
  • Use more than one survey method where the decision involves clearing a hollow-bearing or dead tree.
  • Record the number and condition of roost features, not only the number of bats seen.

Breeding habitat: Clearing controls near breeding habitat

Where a hollow-bearing tree must be removed, use a two-stage or soft-felling approach under the direction of a qualified fauna spotter catcher and ecologist. The aim is to give bats an opportunity to leave and to reduce injury from sudden collapse.

Exclusion devices may be used outside the maternity season where a specialist confirms that young are not dependent on the roost. Exclusions must not trap bats inside or prevent dependent young from being reunited with females.

  • Stop work if pups, lactating females or a concentrated emergence are found.
  • Use bat boxes only as a supplementary measure. They do not replace retention of natural roost trees or confirmed maternity habitat.
  • Document the decision, timing, weather, inspection results and any rescued or relocated bats.

Sheltering habitat: Natural roosts

Roosts may be hidden in small spaces and can be overlooked during a standard vegetation inspection. Search both natural features and built structures before clearing, demolition, pruning or vibration-producing work.

Inspect small crevices, spouts, loose bark, dead upper branches and hollows in mangroves, particularly mature Avicennia marina. Dead branches can look structurally insignificant while still providing a narrow roost space.

Also assess fissures, caves and mines where they occur in the wider project area, especially if they are connected to mangrove or coastal habitat.

  • Use binoculars, a pole camera or endoscope where safe and suitable.
  • Inspect from the ground first and avoid climbing or cutting into a potential roost.
  • Mark trees with likely roost openings and include them in the clearing plan.

Sheltering habitat: Built structures

Microbats may use culverts, bridges, buildings and other sheltered structures. Check expansion joints, gaps, roof spaces, cavities, ledges and drainage structures before demolition or modification.

Look for bats during the day and observe emergence at dusk where access and safety controls allow.

  • Complete a pre-work inspection after the structure has been unused or quiet for a suitable period, as agreed by the project ecologist.
  • Install an approved one-way exclusion only after confirming that no dependent young are inside and that the timing is outside the maternity period.
  • Keep alternative roost features available where a roost must be lost.

Sheltering habitat: Safe handling and exclusion

Do not seal, foam, fell or flood an occupied roost without a site-specific method. Sudden exclusion can kill trapped bats or separate mothers from pups.

If a bat is found during work, stop the immediate task, protect the animal from people and machinery, and contact the fauna spotter catcher or project ecologist.

  • Use soft materials and staged works around occupied trees where directed.
  • Never handle bats without appropriate training, personal protective equipment and rabies lyssavirus risk controls.
  • Record all incidents and update the site environmental controls.

Colonies and breeding places: What a colony or maternity roost looks like

Colonies are shared roosts where bats live in close association, particularly during breeding. A single maternity roost can contain a substantial share of the local population, so a small tree, cavity or structure may have a large local consequence.

A colony may be hidden in a hollow, narrow crevice, loose bark, dead mangrove branch, cave, culvert, bridge or building. From the ground, there may be little more than a small opening and occasional bat activity.

At an active site, look for repeated entry and exit, concentrated emergence at dusk, droppings below the opening, staining, odour, audible movement and bats returning after foraging.

  • Watch the site at dusk from a safe position rather than opening or disturbing the roost.
  • Inspect likely openings with an endoscope or pole camera where this can be done safely and lawfully.
  • Treat a site as potentially active until survey evidence shows otherwise.

Colonies and breeding places: Colony size and site fidelity

A reliable species-specific colony size is not established for the North-western Free-tailed Bat. Microbat colonies can vary with season, habitat and breeding stage, and the number of bats visible at an entrance may not represent the whole colony.

Bats may return to suitable roosts and may use a group of nearby roosts. Retain alternative roost features and avoid assuming that a vacant roost has permanently lost its value.

Species-specific colony size: Not established. Manage shared roosts as potentially significant until assessed.

General colony behaviour: Microbats form colonies during the breeding season, and any roost where young are raised is a breeding place.

  • Map all suitable roosts within the work area and nearby retained habitat.
  • Use repeat observations where the project could affect a suspected maternity roost.
  • Do not remove several nearby roost features in one operation unless the management plan specifically addresses the loss.

Colonies and breeding places: Why colonies need special care

Disturbance at a maternity roost can cause adults to abandon the site, leave young exposed or become trapped during exclusion. Clearing one roost tree may affect many bats at once.

In Queensland, tampering with the breeding place of a least concern colonial breeder requires a high risk species management program under the Nature Conservation (Animals) Regulation 2020. Confirm the approval pathway before work starts.

Queensland management: A high risk species management program is required for tampering with the breeding place of a least concern colonial breeder.

  • Engage the project ecologist early where a shared roost or breeding place may be affected.
  • Schedule noisy, dusty or vibration-producing work away from the maternity period where practicable.
  • Use a documented fauna management plan for inspection, exclusion, soft felling, rescue and contingency actions.

Colonies and breeding places: Surveying an active breeding place

Use acoustic monitoring, emergence watches and careful roost inspection to build the evidence base. Harp traps or mist nets may assist with identifying sex and reproductive condition, but they require suitable expertise, approvals and animal welfare controls.

An active maternity roost is supported by pregnant or lactating females, pups, repeated emergence and return activity, or direct observation of young.

  • Survey outside the maternity season before installing exclusion devices.
  • Keep a record of weather, survey duration, detector settings, observation times and the location of every roost feature.
  • Use bat boxes as supplementary habitat only, not as a substitute for protecting an active colony site.

Threats: Mangrove clearing and pruning

The main work-site risk is the loss or disturbance of hidden roosts in mangroves and nearby structures. The species is least concern nationally, but local colonies can still be affected by a single clearing or construction decision.

Removing mangroves, mature trees or dead upper branches can destroy roost crevices and reduce connected habitat. Pruning may be as harmful as felling where the affected branch contains a roost.

In Western Australia, mangrove habitat should be avoided where this species may occur, particularly where the project footprint includes mature mangroves.

  • Delineate mangrove exclusion zones before machinery enters the site.
  • Retain mature and dead habitat trees where safe to do so.
  • Use a staged inspection and soft-felling method for unavoidable tree removal.

Threats: Breeding-place disturbance

Noise, vibration, lighting, smoke, dust and repeated human activity can disturb a maternity roost. Exclusion or demolition at the wrong time can separate females from pups or trap bats inside.

Stop work and seek ecological direction if pups, lactating females or a concentrated emergence is observed.

  • Avoid maternity-season disturbance where practicable.
  • Do not install one-way devices until the roost has been checked and the method approved.
  • Set clear stop-work triggers in the site induction and environmental management plan.

Threats: Loss of roosts in structures

Bridge repairs, culvert replacement, building demolition and roof works can remove roosts that were not visible in the initial inspection. Works can also close access to a roost or expose bats to heat, light and predators.

Inspect structures before demolition or modification, and provide replacement features only where a specialist confirms that they are suitable.

  • Use staged demolition where bats are present.
  • Retain cracks, cavities and sheltered spaces that are safe and compatible with the completed structure.
  • Do not rely on bat boxes alone to offset the loss of a natural or established roost.

Threats: Fragmentation, fire and altered site conditions

Removing mangrove edges, filling tidal areas, changing drainage or increasing night lighting can reduce the value of adjoining habitat and flight paths. Fire, severe vegetation damage and repeated disturbance may also remove roost features.

Manage the wider habitat around a roost, not only the tree or structure containing the opening.

  • Keep flight paths and habitat connections between roosts and coastal areas where practicable.
  • Control light spill and unnecessary night activity near retained habitat.
  • Include post-work monitoring where a colony, maternity roost or important mangrove patch has been affected.

Survey methodology: 1. Desktop assessment

The North-western Free-tailed Bat is poorly known and can be difficult to separate from other free-tailed bats by call alone. Use more than one survey method where clearing could affect mangroves, hollow-bearing trees, bridges, culverts, buildings or other potential roosts.

Check current records and habitat before planning field work. Focus on mangroves and adjoining areas, particularly mature Avicennia marina and trees with dead upper branches, crevices or spouts.

Map all potential roosts and likely flight paths. Include buildings, bridges, culverts, caves, mines and other structures that could provide a dark, sheltered roost.

Check the applicable state, territory and local requirements. Confirm whether the species has a state conservation priority in the project area, as status and approval requirements can differ between jurisdictions.

  • Search relevant government fauna databases and previous project reports.
  • Review recent aerial imagery for mangrove stands, mature trees, bridges, culverts and buildings.
  • Treat a lack of records as a lack of evidence, not evidence that bats are absent.

Survey methodology: 2. Acoustic and activity surveys

Use Anabat, SongMeter SM4BAT+ or a similar ultrasonic detector at potential roosts, along mangrove edges and in likely foraging areas. Record the detector location, habitat, date, start and finish time, weather and equipment settings.

Survey during suitable weather when bats are active. Avoid heavy rain, strong winds and very cold conditions. Repeat surveys over several suitable nights because activity and call quality vary.

A practical baseline is to deploy detectors for at least three nights across representative locations, then increase effort where habitat is extensive, calls are difficult to identify or construction risk is high. Three detector nights over three locations has been used for regional microbat assessment, but this is not a species-specific detection guarantee.

  • Analyse calls with appropriate software and retain the original recordings.
  • Have difficult calls reviewed by an experienced bat ecologist.
  • Report records as confirmed, probable or species group where call overlap prevents reliable species identification.
  • Use call records to guide, but not replace, inspection of potential roosts.

Survey methodology: 3. Roost and maternity surveys

Inspect likely roosts in mangrove branches, tree hollows, fissures, loose bark, caves, mines, culverts, bridges and buildings. Use an endoscope or pole camera where safe access allows.

Carry out emergence watches from before sunset until bat activity has reduced. Use thermal or night-vision equipment where available and avoid shining bright lights into entrances.

Use harp traps or mist nets only under an appropriate animal ethics approval, permit and experienced supervision. Handle bats only by trained and authorised people.

Confirm a maternity roost by finding pregnant or lactating females, pups, or repeated use by females with young. A roost where young are raised is a breeding place.

  • Record entrance dimensions, roost structure, surrounding vegetation, signs of use, observed bats and emergence numbers where these can be counted safely.
  • Do not enter a cave, mine, culvert or confined structure without a documented safety assessment and suitable controls.
  • Treat a suspected maternity roost as active until competent survey work shows otherwise.

Survey methodology: 4. Survey records and interpretation

Record the species name used in the report, Ozimops cobourgianus, and any former name used in databases. This helps reconcile records identified under older taxonomy.

Record negative results with the same detail as positive results. Include survey limitations, detector failures, poor call quality, weather and any habitat that could not be inspected.

There is no dependable typical colony size for this species. Do not assume that a small entrance, a single bat or a quiet detector site represents a small or unimportant roost.

  • Map all confirmed and suspected roosts and breeding places.
  • Photograph habitat and entrances where this can be done without disturbance.
  • Provide raw acoustic files, call identifications, trap records and emergence-watch results to the project ecologist.

Before habitat disturbance: 1. Avoidance, approvals and permits

Plan around the roost, not just the animal seen during the day. Colonies and maternity roosts can be concealed, may be reused, and can contain a large share of the local population, so avoid disturbance wherever practicable.

Redesign the work footprint to retain mangroves, mature mangrove trees, hollow-bearing trees, dead branches and known roost structures. Avoid removing a roost tree where a practicable alternative exists.

Check whether the action could have a significant impact on a matter protected under the EPBC Act and seek an EPBC referral decision where required. Do not rely on a state approval as a substitute for Commonwealth assessment.

In Queensland, obtain the required high risk species management program for tampering with the breeding place of a least concern colonial breeder. Confirm other Queensland permits for handling, trapping, exclusion or disturbance.

Obtain the relevant wildlife, animal ethics, clearing, development and state or territory approvals before field work starts.

  • Give the ecologist and fauna spotter catcher copies of all conditions and permit limits.
  • Include roost protection, stop-work triggers and reporting duties in the environmental management plan.
  • Use the most protective applicable requirement where approvals overlap.

Before habitat disturbance: 2. Colonies and breeding places

A colony is a group of bats sharing a roost or breeding site. A maternity roost is a place where females raise young. The site may be in a tree crevice, dead branch, hollow, loose bark, cave, mine, culvert, bridge or building.

The species has been recorded roosting in small spouts and crevices in dead upper branches of mangroves. Other microbat roost types remain possible where suitable shelter is present.

The species may show site fidelity, and repeated use can occur even when bats are absent during a daytime inspection. There is no reliable typical colony size for this species, so do not use a low count to set a low level of protection.

Microbats commonly give birth to one pup in the warmer months, usually spring to late summer. Avoid disturbance during this period unless the work is necessary, approved and supported by a suitable management plan.

  • Mark the breeding place and an agreed no-go area on plans and in the field.
  • Keep machinery, lighting, vibration and personnel away from the roost unless the approved method specifically allows access.
  • Treat observed pups, lactating females or repeated female use as evidence of an active maternity roost.

Before habitat disturbance: 3. Pre-clearance inspection

Complete a pre-clearance inspection shortly before work. Search mangroves, dead branches, hollow-bearing trees, loose bark, rock fissures and built structures within the work area and the area likely to be affected by noise, vibration, lighting or access.

Use an endoscope or pole camera for hollows and crevices where this can be done safely. Complete emergence observations where daytime inspection cannot establish whether a roost is occupied.

Inspect for bats, pups, droppings, staining, audible movement, fresh scratches, odour and repeated emergence or re-entry. Do not insert equipment into a cavity if it could injure an animal.

  • Mark potential roost trees and structures before machinery arrives.
  • Brief the spotter catcher on the location of every suspected roost.
  • Refresh the inspection if works are delayed, the work footprint changes or a new structure is exposed.

Before habitat disturbance: 4. Exclusion and timing controls

Do not exclude bats from a suspected maternity roost during the maternity season. Exclusion devices should be installed outside the maternity season and only under an approved method supervised by a suitably qualified bat ecologist.

Use one-way devices only after confirming that bats can leave safely and cannot become trapped. Keep the exclusion in place long enough to demonstrate that the roost is no longer occupied before removal or demolition.

Do not seal a cavity, fell a tree or remove a bridge component while bats are inside. Where occupancy is uncertain, delay work and obtain further advice.

  • Avoid exclusion during spring to late summer unless the approved management plan specifically addresses maternity risk.
  • Check the device regularly for blockage, damage and trapped animals.
  • Remove temporary exclusion devices only after the ecologist confirms that the structure is clear and the approval conditions allow it.

Before habitat disturbance: 5. Induction and work controls

Induct all workers on the species, its roost types, colony risks and the stop-work procedure. Show workers photographs and maps of no-go areas before clearing starts.

Explain that bats, pups and roost structures must not be handled or moved by general site staff. Only authorised and trained personnel may capture, handle, assess or release bats.

Include lighting, vibration, noise, access and vegetation-clearing controls in the daily work plan.

  • Keep a fauna spotter catcher present for all relevant clearing and demolition.
  • Give the spotter catcher authority to stop work without waiting for supervisor approval.
  • Display emergency contacts for the fauna lead, wildlife carer, veterinarian and project manager.
  • Confirm that lifting equipment and an exclusion zone are available before work begins.

During habitat disturbance: 1. Sequential and soft clearing

Use staged, low-disturbance clearing and keep the fauna spotter catcher in control of decisions affecting bats. Stop work whenever a bat, active roost or breeding place is found outside the approved method.

Clear in stages from the edge of the work area towards retained habitat. Retain potential roost trees until they have been inspected and a method has been approved.

Use two-stage or soft felling for hollow-bearing trees and trees with crevices. First disturb or lower limbs in a controlled way, then pause so animals can leave, before completing the removal.

Avoid dropping hollow-bearing limbs or roost structures. Lower them slowly where the approved method requires retention or inspection.

  • Clear under the supervision of the fauna spotter catcher.
  • Keep machinery outside marked exclusion areas until the spotter catcher releases the area.
  • Stop if a tree, branch or structure differs from the pre-clearance assessment.
  • Search felled material and exposed cavities before moving or chipping them.

During habitat disturbance: 2. If a bat, colony or breeding place is found

Stop work immediately and establish a quiet exclusion zone. Keep people, vehicles, dogs and bright lights away from the animal or roost.

Do not touch, shine lights directly into, smoke, flood, block or otherwise disturb the roost. Do not attempt to drive bats out unless this is part of the approved method.

Contact the project ecologist and fauna spotter catcher. Reassess the approval conditions and decide whether the roost can be retained, whether work can move elsewhere, or whether a lawful exclusion method is required.

If pups or lactating females are present, treat the site as an active maternity roost and do not proceed with disturbance until the approved management response is confirmed.

  • Record the exact location, habitat, structure, number of bats if safely countable, signs of breeding and the work being undertaken.
  • Protect the roost from weather, heat, vibration and further damage.
  • Do not claim a roost is inactive because no bats are visible during a daytime check.

During habitat disturbance: 3. Handling and release

Handle bats only when necessary, by authorised and trained personnel using the approved method. Use suitable gloves and containers, and minimise handling time, noise, heat and bright light.

Never pick up a bat with bare hands. Do not release an injured, cold, weak or grounded bat without advice from a wildlife carer or veterinarian.

Release healthy animals only where the fauna ecologist confirms that the location, timing and method meet permit and welfare requirements.

  • Keep the container secure, ventilated, shaded and labelled with the time and location of capture.
  • Record sex, age class, reproductive condition, injuries, species identification and release details where these can be assessed safely.
  • Do not relocate a colony or maternity roost as a routine response to clearing. Seek specific ecological and regulatory advice first.

During habitat disturbance: 4. Injured or dead animal pathway

Stop nearby work and keep people away from an injured or grounded bat. Ask the fauna lead or wildlife carer for instructions before moving it.

Use an appropriately qualified wildlife carer or veterinarian for assessment and treatment. Escalate suspected disease or unusual mortality through the relevant government wildlife authority.

If an animal is dead, preserve it only where authorised and record the circumstances. Do not retain specimens without the required permission.

  • Record the location, time, apparent cause, condition, photographs and people involved.
  • Check for additional animals in the roost, tree, machinery or debris.
  • Review the work method before restarting.

During habitat disturbance: 5. Daily records and stop-work reporting

Maintain a daily fauna log for inspections, sightings, captures, exclusions, injuries, deaths, stop-work events and approvals obtained.

Record the operator, equipment, habitat affected, weather, time, action taken and whether work resumed.

Report any breach of an approval, injury, death, active breeding place or unapproved disturbance to the project manager and relevant authority within the required timeframe.

  • Keep acoustic files, photographs, maps, permit records and release or carer details with the project environmental records.
  • Update the clearance map after every new roost or animal record.
  • Obtain written approval from the fauna lead before restarting work after a bat-related stop.

After habitat disturbance: 1. Immediate post-clearance checks

Post-clearance checks confirm that animals have not been left in cavities, debris or structures and that controls worked as intended. Review the outcome before moving to the next work stage.

Inspect felled trees, removed limbs, demolished structures, debris piles and exposed cavities before they are chipped, buried or removed.

Use an endoscope, pole camera or careful visual inspection where cavities remain. Check for live or dead bats, pups and signs of occupancy.

Complete a final walk-through of the work area and retained habitat at the end of each clearing stage.

  • Keep suitable escape routes open during checks.
  • Do not leave a roost cavity exposed to heat, rain or predators while waiting for advice.
  • Record the condition of retained trees and structures.

After habitat disturbance: 2. Reporting and compliance

Prepare a clearance report that compares the approved method with what occurred in the field. Include all bat records, suspected roosts, breeding places, injuries, deaths, exclusions and stop-work events.

Submit reports to regulators, approval holders and land managers as required by the relevant permit or management program.

Update the site risk assessment if the species was detected, a roost was affected or habitat differed from the desktop assessment.

  • Attach maps, photographs, acoustic results, emergence-watch data and handling or release records.
  • Document all corrective actions and their completion date.
  • Retain records for the period required by the approval or management system.

After habitat disturbance: 3. Monitoring relocated or retained animals

Where an approved action has moved animals or altered a roost, monitor the receiving or retained habitat for continued use, injury, exclusion failure and signs of breeding.

Use emergence watches, acoustic detectors and inspections suited to the structure. Repeat monitoring when the risk assessment or approval requires it.

Do not interpret absence on one night as proof that a roost has failed or been abandoned.

  • Check artificial or retained structures after severe weather and construction vibration.
  • Record bat activity, roost condition, breeding evidence and any maintenance needed.
  • Escalate repeated absence, injured animals or renewed entry into a hazardous structure to the project ecologist.

After habitat disturbance: 4. Incident review

Review every unplanned interaction with a bat or roost before the next clearing stage. Identify whether the issue arose from survey limits, poor marking, induction failure, equipment movement or an unsuitable method.

Change the work sequence, exclusion zone, survey effort or supervision level where needed.

Share the outcome with the crew during a short toolbox talk and update the site environmental controls.

  • Close out corrective actions by a named person.
  • Record lessons for future work in mangroves, hollow-bearing trees and built roost structures.
  • Suspend similar work if the approved controls are not working.

Rehabilitation actions: 1. Restore habitat and roost opportunities

Rehabilitation should restore connected roosting and foraging habitat rather than simply replace cleared trees. Because this species is associated with mangroves and has poorly understood breeding requirements, use local habitat knowledge and monitor whether replacement features are used.

Retain and protect mangroves, mature trees, dead branches and natural crevices wherever practicable. Restore cleared mangrove edges and adjoining vegetation with locally appropriate species and natural drainage.

Leave suitable retained dead wood where it is safe and does not create a secondary hazard. Do not create artificial hollows in unstable trees.

Protect restored areas from vehicles, fire, grazing, repeated pruning and future clearing.

  • Use local provenance plants where available and appropriate.
  • Reconnect retained vegetation patches and flight paths where the project layout allows.
  • Map restored habitat and potential roost features for future inspections.

Rehabilitation actions: 2. Bat boxes and artificial roost structures

Use bat boxes, artificial roosts or other replacement structures only as supplementary measures. They do not replace an occupied natural maternity roost or justify clearing suitable mangrove habitat.

Select a design and placement with advice from a bat ecologist. Match the structure to the local climate, likely bat species, access requirements and predator risk.

Install replacement structures before disturbance where practicable, and monitor them for heat stress, water entry, damage, occupancy and breeding use.

  • Place boxes away from bright lights and high levels of construction disturbance.
  • Provide more than one suitable roost option where the risk assessment supports replacement structures.
  • Keep installation and maintenance records, including location, height, orientation, condition and inspection dates.
  • Remove or repair unsafe structures promptly.

Rehabilitation actions: 3. Weeds, water and lighting

Control weeds without removing retained roost trees, dead branches or natural shelter. Use methods that protect mangrove soils, tidal flows and adjoining wet areas.

Maintain natural water movement and avoid sediment, chemical runoff and altered drainage in mangrove rehabilitation areas.

Use the lowest practical lighting level near retained or restored habitat. Direct lights away from roost entrances, mangrove edges and flight paths, and use timers or motion controls where suitable.

  • Inspect rehabilitation areas after rain, flooding and construction activity.
  • Prevent weed spread from machinery and imported fill.
  • Keep fuel, chemicals and wash-down water away from mangroves and other roost habitat.
  • Remove temporary lighting when the work stage is complete.

Rehabilitation actions: 4. Long-term monitoring

Monitor restored habitat and replacement structures over multiple seasons where a roost or breeding place was affected. Include the warmer months, usually spring to late summer, when maternity use is most likely for microbats.

Use acoustic detectors, emergence watches and direct inspections where safe. Record occupancy, breeding evidence, habitat condition and any threats.

Set clear success measures with the project ecologist. Revise planting, weed control, lighting or roost design if bats do not use the area or if habitat condition declines.

  • Inspect retained and artificial roosts at agreed intervals and after major storms.
  • Compare monitoring results with the pre-clearance baseline.
  • Report monitoring outcomes to the approval holder and relevant regulator where required.
  • Keep monitoring records with the project environmental management file.

Sources