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Diadem Leaf-nosed Bat (Hipposideros diadema)

The Diadem Leaf-nosed Bat is a large, insect-eating microbat that roosts in caves, mines and other sheltered structures, and forages around vegetation edges and open gaps. It can be affected by clearing, roost disturbance, lighting and damage to caves, mines, culverts or buildings; it is listed as least concern in Australia, but in Queensland it is a colonial breeder and interference with a breeding place requires a high risk species management program.

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 diadem leaf-nosed bat breeds in Australia, with the documented breeding-risk period from October to January. Timing may vary between regions and years, and records for the species are limited, so treat accessible caves, mines, culverts, buildings and other suitable roosts as potential breeding places until surveys show otherwise. Colonies may range from solitary males to 250 or more bats. Bats hang separately from ceilings, often about 20 to 25 cm apart. An active breeding place may contain pregnant or lactating females, pups attached to females or crèched young. Avoid disturbance during this period, especially in caves, mines and other accessible roosts.

Breeding mode: Colonial breeder. Females congregate during the breeding season, while males may roost alone.

Breeding frequency: One breeding season is documented for the species.

Litter size: One pup per female.

Gestation: Not recorded.

Fledging and weaning: Not recorded. Young may remain attached to females or occur as crèched young during the breeding-risk period.

Age at maturity: Not recorded.

Breeding places and colony size: Caves and disused mines are the main documented roosts, with additional records from buildings and culverts. Suitable sites have large chambers, high domed ceilings, multiple entrances, temperatures of 25 to 26.5°C and humidity of 65 to 80%. Colony size ranges from one individual to 250 or more bats.

Timing can shift between years and regions, so use warm, calm, dry night surveys, acoustic monitoring, emergence watches and targeted roost inspections to confirm local activity before clearing or construction.

  • Roosting and colony use: Roosts may be occupied throughout the year, including caves, disused mines, buildings and culverts, and some sites are shared with other microbats.
  • Breeding activity: The documented breeding-season consideration period is October to January, when females may be heavily pregnant, carrying young or nursing crèched young.
  • Dependent young and crèching: Young may be attached to females or present as crèched young during the October to January breeding-risk period.
  • Active breeding-place indicators: Use pregnancy, lactation, pups attached to females and crèched young as evidence that a roost is an active breeding place.
  • General night activity and foraging: Adults are active year round, with foraging commonly near vegetation edges, gaps, creeks and other open flyways, usually within 0.3 to 2.5 km of the roost.
  • Highest clearing risk: Clearing, demolition, tree or roost removal and exclusion works are most likely to harm pregnant females, dependent young and maternity colonies from October to January.

Identification: Appearance and measurements

The Diadem Leaf-nosed Bat is the largest Hipposideros bat recorded in Australia. It is usually identified by its large size, complex nose-leaf and distinctive echolocation call.

Fur is commonly pale grey to light brown, with pale buff spots on the shoulders and belly. Some colonies include rufous or orange individuals without spots.

The ears are broad at the base and sharply pointed. The nose-leaf is well developed, with four depressions separated by ridges in the upper section and three supplementary leaflets on each side of the lower section.

  • Weight: 32 to 57 g.
  • Forearm length: 77.5 to 85.1 mm.
  • Large body and broad, pointed ears.
  • Short tail, usually enclosed by the small tail membrane.

Identification: Calls and similar species

The echolocation call is readily distinguishable from calls of other microbats when a suitable recording is obtained. The call has a constant frequency of about 55 to 58 kHz, lasts about 11 milliseconds per pulse, and ends with a downward sweep to about 47 kHz.

Call identification should be checked by an experienced analyst, especially where several leaf-nosed bats occur. The Queensland form is commonly referred to as Hipposideros diadema reginae and may be treated as a distinct species in some taxonomic works.

  • Use a calibrated Anabat or similar detector for confirmation.
  • Record the call, location, time and habitat.
  • Do not rely on call frequency alone where recordings are poor or bats are flying close together.

Identification: Field signs

Look for bats hanging from cave or mine ceilings, usually with space between individuals. Roost entrances may have guano, staining or a noticeable bat odour, but signs can be faint where bats move between several sites.

This species does not build a nest. Droppings below a perch may contain insect remains and can help identify regular use, but droppings alone do not confirm a maternity roost.

  • Guano below ledges, ceilings, bridges or culvert joints.
  • Dark staining or polished surfaces where bats regularly hang.
  • Bat odour in enclosed, warm and humid spaces.
  • Emerging bats at dusk and repeated detector passes near an entrance.

Distribution: Australian range

The Diadem Leaf-nosed Bat is associated with tropical and subtropical northern Australia. Project mapping identifies the species in Queensland and New South Wales, while the Queensland form has its main documented range in northern and central Queensland.

The Queensland form is recorded from Cape York Peninsula south to Townsville and inland from Cairns to Chillagoe. Records include Iron Range, Hinchinbrook Island, Cape Melville, Cairns, Coen and Chillagoe.

For a development site, check current state mapping and local records rather than assuming that absence from a broad regional map means the species is absent.

  • Mapped states and territories: Queensland and New South Wales.
  • Strongest documented Queensland range: Cape York Peninsula, the Wet Tropics, north Queensland islands and inland areas around Chillagoe.
  • A record at Undara Volcanic National Park confirms use of lava tube cave habitat.

Distribution: Wider species complex

The wider Hipposideros diadema species complex extends from the Nicobar Islands through Southeast Asia and New Guinea to the Solomon Islands, with populations in northern Australia. Records outside Australia may represent different subspecies or taxonomic units.

Distribution: Site assessment

Give particular attention to sites containing caves, mine workings, lava tubes, rocky escarpments, cliff lines, large culverts or accessible buildings. A site can be relevant even when bats are not seen during a daytime inspection.

  • Search local government, state wildlife and Atlas of Living Australia records.
  • Inspect connected habitat, not only the construction footprint.
  • Consider nearby roosts and flyways within the surrounding landscape.

Habitat: Vegetation communities

The species uses a range of vegetation communities where suitable roosts and insect-rich foraging areas are available. Retain the connections between roosts, vegetation edges, waterways and open flight spaces.

Habitat includes lowland rainforest, Melaleuca forest, eucalypt woodland, deciduous vine thicket and open woodland. Foraging can also occur near small human settlements.

  • Rainforest margins and canopy gaps.
  • Melaleuca stands and wet lowland vegetation.
  • Eucalypt woodland with mature trees and hollow-bearing limbs.
  • Vine thickets, open woodland and riparian vegetation.

Habitat: Landforms and site features

Inspect gullies, gorges, scarps, rocky outcrops, cliff lines and creek corridors. These features can provide both roost access and sheltered flight paths.

  • Caves, lava tubes and rock fissures.
  • Disused mines, mine adits and shafts.
  • Creeks, rivers and vegetated drainage lines.
  • Vegetation edges and gaps beside open areas.

Habitat: Habitat condition

The species can forage in modified landscapes, but clearing may remove roost trees, feeding habitat and movement routes. Retain mature vegetation around likely roosts and avoid creating bright, exposed gaps between roosts and feeding areas.

  • Keep canopy links and riparian vegetation where practicable.
  • Retain mature trees, peeling bark and hollow-bearing trees until inspected.
  • Limit dust, noise and artificial light near caves, mines and other suspected roosts.

Foraging habitat: Where to look

The Diadem Leaf-nosed Bat mainly uses perch hunting. It hangs from a perch, detects passing prey with echolocation, then makes a short flight to capture the insect.

Foraging is commonly recorded along vegetation edges, beside canopy gaps and over creeks or other open spaces with nearby cover. The species may forage in small settlements where suitable roosts and insect habitat remain.

  • Edges between woodland and cleared areas.
  • Gaps beside rainforest, vine thickets and Melaleuca forest.
  • Creeks and rivers with canopy cover.
  • Gullies, gorges, scarps and mine entrances.

Foraging habitat: Foraging distance

Recorded foraging distances from the roost average about 1.08 km, with a range of 0.3 to 2.5 km. Treat nearby vegetation and waterways as part of the roost's functional habitat.

Average distance: About 1.08 km from the roost

Recorded range: 0.3 to 2.5 km

Foraging habitat: Diet and worksite risks

The diet includes beetles, scarab beetles, weevils, moths, ants and plant bugs. Clearing, pesticide use, dust and artificial light can reduce insect availability or change flight behaviour.

  • Avoid unnecessary night lighting near roost entrances and flyways.
  • Keep lighting directed away from vegetation edges and waterways.
  • Manage pesticide use around retained habitat.
  • Avoid blocking narrow flight paths between roosts and feeding areas.

Breeding habitat: Breeding period

Females gather to raise young, making a maternity roost more sensitive than an ordinary day roost. During the breeding period, avoid actions that can dislodge bats, separate young from adults or cause the colony to abandon the site.

For Queensland project planning, treat October to January as a maternity-risk period. Females may be heavily pregnant, carrying young or nursing young that are temporarily crèched.

  • Most microbats breed in the warmer months.
  • A single pup is typical for many microbat species, but species-specific reproductive details should not be assumed without confirmation.
  • If pregnant or lactating females, pups or crèched young are seen, stop intrusive roost work and obtain specialist advice.

Breeding habitat: What confirms a maternity roost

A maternity roost is confirmed by evidence that females are congregating to raise young. Look for pregnant or lactating females, pups attached to females, or young gathered in a crèche.

  • Pregnant females with enlarged abdomens.
  • Lactating females or visible mammary development.
  • Pups attached to adults.
  • Flightless or newly volant young inside the roost.

Breeding habitat: Survey and timing

Use passive and active acoustic monitoring, emergence watches, harp traps or mist nets where authorised, and careful roost searches. During the breeding season, do not enter or handle bats in a way that could cause distress, abandonment or dislodgement of young.

  • Watch the entrance from before dusk until emergence activity has finished.
  • Use detectors at likely entrances, flyways, vegetation edges and nearby water.
  • Keep people, lights and equipment away from the roost entrance unless the method has been assessed as safe.
  • Use an experienced bat ecologist for any internal roost inspection.

Sheltering habitat: Known roost types

The species roosts in warm, humid spaces with suitable ceiling height, access and protection from predators. Caves and mines are the main known roosts, but buildings and culverts can also be used.

Known roosts include caves and disused mines. Records also include buildings and culverts. The species may share roosting sites with other microbats.

  • Large cave chambers.
  • Disused mines, mine adits and shafts.
  • Culverts, bridges and enclosed drainage structures.
  • Buildings, sheds and other quiet structures.
  • Rock fissures, outcrops and cliff lines near suitable habitat.

Sheltering habitat: Roost conditions

Reported roost conditions are warm and humid, with temperatures of 25 to 26.5 degrees Celsius and humidity of 65 to 80 percent. Large chambers, high domed ceilings and multiple entrances are preferred.

  • Check for stable temperature and humidity.
  • Retain entrances and internal flight space.
  • Do not remove rubble that blocks corridors without specialist assessment.
  • Do not remove bark sheets from trees where bats may be sheltering.

Sheltering habitat: Trees and temporary shelters

Hollow trees, tree branches, old sheds and peeling bark may provide shelter for this species or other microbats. Records of foliage roosting exist for related forms, but foliage roosting by the Queensland form remains uncertain.

  • Inspect hollow-bearing trees before clearing.
  • Check loose bark, branch junctions and dense foliage where suitable.
  • Use an endoscope or pole camera where safe and appropriate.
  • If a hollow-bearing tree must be removed, use staged or soft felling under ecological supervision.

Colonies and breeding places: What a colony looks like

A colony or maternity roost may be hidden in a cave, mine, culvert, building or other enclosed space. Colonies need special care because one site can hold many local bats and disturbance during breeding can cause injury, abandonment or loss of young.

Bats usually hang separately from the ceiling rather than forming a tight cluster. Individuals may be spaced about 20 to 25 cm apart, and a large roost can appear quiet during the day.

  • Solitary males may occupy a roost alone.
  • Recorded groups range from one bat to at least 250 bats.
  • Larger groups of up to 2,000 to 3,000 individuals have been reported for the species.
  • Females may gather in larger groups during the breeding season.

Colonies and breeding places: Recognising an active breeding place

An active breeding place is indicated by pregnant or lactating females, pups attached to adults, or young gathered inside the roost. Emergence of many bats from one entrance, fresh guano and repeated detector activity support evidence of current use but do not by themselves confirm breeding.

  • Observe from outside first and avoid entering during emergence.
  • Use an emergence watch over more than one suitable evening where conditions allow.
  • Combine visual observations with acoustic recordings.
  • Treat a suspected maternity roost as active until a suitably qualified person confirms otherwise.

Colonies and breeding places: Site fidelity and protection

The species' level of fidelity to individual roosts is not well defined. Assume that caves, mines and structures used repeatedly by bats may be important, particularly where suitable roosts are scarce.

  • Avoid sealing, illuminating, cleaning, blasting or modifying a suspected roost without assessment.
  • Maintain entrances, internal chambers, ceiling space and flight paths.
  • Keep works, vibration and visitor access away from roosts during the maternity period.
  • Do not rely on bat boxes as a replacement for a natural cave, mine or maternity roost. They are a supplementary measure only.

Colonies and breeding places: Queensland approval consideration

The Diadem Leaf-nosed Bat is a least concern species in Australia, but it is treated as a colonial breeder in Queensland. Interference with its breeding place requires a high risk species management program under the Nature Conservation (Animals) Regulation 2020.

  • Confirm whether the work affects a breeding place before clearing or construction.
  • Obtain the required Queensland approvals and management program before disturbing the site.
  • Use a fauna spotter catcher with appropriate bat experience for planned works.

Threats: Roost loss and structural damage

Development impacts are most likely where works remove roost structures, interrupt flight routes or disturb bats in enclosed roosts. Manage the roost and its surrounding habitat together.

Mining, cave destruction, demolition and modification of buildings, culverts or bridges can remove roosts. Repairs to cracks, joints, lift holes and other access points may also block bats from a structure.

  • Inspect caves, mines, culverts, bridges and buildings before work.
  • Retain roost entrances and internal flight space.
  • Do not remove rubble or bark from a potential roost without assessment.
  • Stage works so alternative roost access is maintained where authorised.

Threats: Clearing and habitat fragmentation

Clearing mature trees, hollow-bearing trees, peeling bark and vegetation edges can remove shelter and feeding habitat. Linear clearings and transport corridors can also interrupt movement between roosts and foraging areas.

  • Retain mature trees and connected vegetation around known or potential roosts.
  • Protect creek corridors, gullies and canopy edges.
  • Inspect trees before felling and use staged or soft felling where required.
  • Avoid clearing more vegetation than the approved footprint.

Threats: Disturbance, light and noise

People entering caves or mines, construction vibration, traffic noise and artificial light can alter roost use, foraging and movement. Light near entrances may make bats avoid a roost or flyway and can increase collision risk where bats are forced into exposed routes.

  • Keep night lighting away from roost entrances and nearby flyways.
  • Use directional, shielded lighting with the lowest practical intensity.
  • Control noise and vibration near caves, mines and maternity roosts.
  • Restrict recreational access and unauthorised entry to sensitive roosts.

Threats: Other land management risks

Pesticide use, loss of insect-rich vegetation, feral predators and vehicle collisions can affect bats. Roads and rail corridors may also reduce activity near retained habitat.

  • Limit pesticide drift into retained feeding habitat.
  • Maintain vegetation around waterways and forest edges.
  • Use fauna-sensitive traffic controls near known roosts and flyways.
  • Include Australian bat lyssavirus precautions in handling and rescue procedures.

Survey methodology: 1. Desktop assessment

Survey for the diadem leaf-nosed bat should combine call detection with targeted searches of likely roosts. The species is readily recognised by its distinctive call, but survey results should be interpreted with weather, habitat and roost access recorded.

Map caves, disused mines, mine adits and shafts, fissures, rocky outcrops, cliff lines, buildings, culverts and hollow-bearing trees before field work begins.

Also map vegetation edges, gullies, gorges, creeks, canopy gaps and other likely flyways. The species often forages close to roosts, including at vegetation edges and gaps beside open space.

Check records for known roosts and colonies. Treat a known roost as potentially reused unless surveys show otherwise.

  • Review aerial imagery, geological mapping, planning records, previous ecological reports and local landholder knowledge.
  • Identify roosts that could be affected by vibration, lighting, noise, clearing, excavation, bridge or culvert works.
  • Plan survey access so that caves, mines and other roost features are not damaged or unnecessarily entered.

Survey methodology: 2. Acoustic and visual detection

Use passive detectors for the whole night at multiple locations and over multiple nights. Place detectors at potential flyways, vegetation edges and gaps beside open space.

The diadem leaf-nosed bat has a constant frequency call of about 55 to 58 kHz, followed by a downward sweep to about 47 kHz. Pulses are about 11 milliseconds long. Confirm records with suitable call analysis and, where possible, a second method.

Use active acoustic transects from dusk for at least two hours. Walk gullies, gorges, scarps with caves, creeks, mine entrances, vegetation edges and other likely flight paths with a detector and spotlight.

  • Survey on warm, calm, dry nights where practicable.
  • Keep GPS tracks for active transects.
  • Record detector model, settings, location, start and finish time, weather, moon or light conditions, habitat and nearby roost features.
  • Record call files and retain the original files for independent checking.

Survey methodology: 3. Roost and colony surveys

Inspect suitable roosts only where safe and authorised. The species uses caves and disused mines, and is also recorded from buildings and culverts. Other potential features include hollow trees, branches, fissures, rocky outcrops and cliff lines.

Colonies may range from solitary males to at least 250 individuals. Larger groups of two to three thousand have also been reported for the species. Individuals may hang separately from the ceiling, with about 20 to 25 cm between bats.

Use emergence watches at cave, mine, building, culvert and tree roosts. Watch from a position that does not block entrances or disturb the roost. Use an endoscope or pole camera for hollow trees where this can be done safely and without damaging the tree or animals.

  • Record the roost type, entrance number, chamber form, ceiling height, temperature, humidity, access points, bat numbers and signs of use.
  • Look for fresh droppings, staining, audible activity, roost odour, bats entering or leaving, and visible pups or females carrying young.
  • Do not remove rubble, bark sheets or other material from a potential roost.
  • Use a harp trap or mist net only under an approved method and with trained personnel. Set traps beside or over water, along escarpments, in gullies, gorges or riparian corridors, and check them frequently.

Survey methodology: 4. Breeding place confirmation and records

For this colonial breeder, a breeding place is any roost where young are raised. Confirm maternity use by recording pregnant or lactating females, females carrying young, pups attached to females, or crèched young.

Breeding activity should be assumed possible from October to January unless a suitably qualified ecologist confirms otherwise. Most microbats breed in the warmer months and commonly produce one pup each year.

Record enough information for another ecologist to relocate the site and assess change over time.

  • Record species, sex and age class where known, numbers, behaviour, photographs where permitted, call files and survey effort.
  • Map all entrances, flight paths, nearby foraging habitat and the proposed disturbance footprint.
  • Record whether bats are solitary, in a small group, or in a larger colony.
  • Stop or modify the survey if bats show distress, young become dislodged, or the method could cause abandonment.

Before habitat disturbance: 1. Avoidance, approvals and permits

Avoid roosts and breeding places wherever practicable. Plan clearing and construction around the breeding season, obtain the required approvals, and make sure every person on site understands the stop work process.

Design the project to retain caves, mines, hollow-bearing trees, buildings, culverts, bridges and other roost features. Retain connected vegetation, flyways and nearby foraging habitat where practicable.

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 current Queensland requirements with the Department of the Environment, Tourism, Science and Innovation before work starts.

Assess whether the action may affect a matter of national environmental significance. Make an EPBC referral where the legal threshold is met. Check state and territory permits, wildlife permits, scientific permits and animal ethics requirements before trapping, handling, exclusion or relocation.

  • Obtain written approval for the survey and management method before entering restricted roosts or trapping bats.
  • Include the roost, breeding place, colony, exclusion and rescue procedures in the construction environmental management plan.
  • Do not rely on the species being listed as least concern to justify disturbance of an active breeding place.

Before habitat disturbance: 2. Pre clearance survey and breeding assessment

Complete a targeted pre clearance survey of all potential roosts within and near the work area. Include caves, mines, mine shafts and adits, fissures, rocky outcrops, cliff lines, culverts, bridges, buildings and hollow-bearing trees.

Use acoustic monitoring, emergence watches, roost inspections and trapping where appropriate. Inspect hollow-bearing trees with an endoscope or pole camera where safe.

Confirm whether a roost is active and whether it is being used for breeding before exclusion, felling, demolition, vibration or lighting works.

  • Survey warm, calm, dry nights where practicable.
  • Mark all active and potential roosts on construction plans and on the ground.
  • Record maternity evidence, colony size, entrances, flight paths, surrounding habitat and the proposed disturbance distance.
  • If the status of a roost cannot be confirmed, manage it as potentially active until a qualified ecologist approves the next step.

Before habitat disturbance: 3. Timing, buffers and exclusion

Avoid disturbance to maternity roosts during October to January. There is no established migration schedule for this species, so do not assume that a roost is unused outside that period.

Set a no entry and no works zone around each active roost. The ecologist should determine the extent from the roost type, entrance, flight paths, vibration, noise, lighting and proposed activity. Use a larger exclusion area where these effects cannot be controlled.

Only use exclusion devices outside the maternity season and after confirming that no bats remain inside. Exclusion must not trap bats, block alternative exits or expose them to injury, heat or predators.

  • Do not exclude bats from a maternity roost while pups are dependent or unable to fly.
  • Use staged exclusion with monitoring before permanent closure or demolition.
  • Use a two stage or soft felling method for hollow-bearing trees where removal is approved. Retain the hollow section where safe and inspect it before final handling.
  • Do not remove bark sheets, rubble blocking roost corridors or other roost material unless the approved method specifically allows it.

Before habitat disturbance: 4. Crew induction and site controls

Give all workers, subcontractors and machinery operators a site induction before work near a roost or breeding place. Explain the species, marked exclusion areas, lighting limits, rescue pathway and stop work authority.

Keep artificial light away from roost entrances, flyways and foraging edges. Direct unavoidable lighting downward and use the lowest practical intensity and shortest operating period.

Control dust, vibration, noise and access near caves, mines, bridges, culverts and hollow-bearing trees.

  • Nominate a fauna spotter catcher or ecologist who can stop work immediately.
  • Display a site map showing roosts, exclusion zones, access routes and emergency contacts.
  • Prohibit unauthorised entry into caves, mines, shafts and other roosts.
  • Tell workers never to handle a bat. Report any bat, pup, injured animal or suspected roost damage immediately.

During habitat disturbance: 1. Sequential clearing and supervision

Clear in a controlled sequence and keep the fauna spotter catcher close to the work front. Work must stop when an animal, colony, active breeding place or unexpected roost is found.

Clear vegetation in stages from the least suitable habitat towards retained habitat and known safe areas. Retain roost trees, flyways and vegetation edges until the fauna spotter catcher has inspected them.

Use two stage or soft felling for approved hollow-bearing tree removal. First disturb or partially cut the tree under supervision, then leave it for inspection before final felling where the approved method allows.

Inspect felled hollow sections, bark slabs, cavities, culverts and structural voids before they are moved, filled or demolished.

  • Keep machinery out of marked exclusion zones.
  • Use low speed and controlled movement near hollow trees, bridges, culverts and roost entrances.
  • Stop work if bats emerge unexpectedly, young are found, a colony is exposed, or a roost is damaged.
  • Record the time, location, activity and people present for every stop work event.

During habitat disturbance: 2. Stop work and active breeding places

The fauna spotter catcher has authority to stop work. Stop immediately if an active colony, maternity roost, breeding place, occupied hollow, cave, mine, culvert, building roost or injured bat is found.

Keep people, machinery, vehicles and lights away from the feature. Do not enter, seal, dismantle or relocate anything until the approved ecologist has assessed it.

If a breeding place is confirmed, protect it under the relevant Queensland species management program and project approvals. Replan the activity, timing and exclusion method before restarting.

  • Maintain a quiet exclusion area and prevent public or worker access.
  • Do not use smoke, water, loud noise, chemical repellents or unapproved exclusion devices.
  • Do not remove pups or separate females from young.
  • Recheck the feature after the approved response and document the decision to resume work.

During habitat disturbance: 3. Handling, rescue and injured animals

Only authorised and trained fauna personnel may capture or handle a bat. Treat every bat as capable of biting and as a potential source of Australian bat lyssavirus.

Use appropriate protective equipment and an approved capture method. Do not handle bats bare handed. Keep handling brief, quiet and cool, and avoid unnecessary restraint.

If an injured, grounded or trapped bat is found, secure the area and contact the nominated wildlife carer, veterinarian or wildlife authority. Do not release an injured bat without professional advice.

  • Do not give food or water unless directed by a veterinarian or wildlife carer.
  • Place a recovered bat in a secure, ventilated container suitable for the species and keep it away from noise, heat, pets and public access.
  • Record the finder, location, condition, photographs, handling time and destination.
  • Report any bite, scratch or contact with saliva immediately and follow workplace and health authority procedures.

During habitat disturbance: 4. Records and communication

Maintain a daily fauna register throughout clearing and construction. Keep records with the project environmental file and provide them to the supervising ecologist and approval holder.

Use photographs, GPS points and call files where they help confirm a roost, colony or incident. Do not publish sensitive roost locations where this could increase disturbance.

  • Record survey and clearing dates, weather, personnel, equipment, habitat cleared and habitat retained.
  • Record every bat sighting, capture, release, injury, death, roost entry, exclusion, colony and breeding observation.
  • Record all stop work events, approvals, corrective actions and restart times.
  • Notify the relevant regulator or approval body where a condition, permit or species management program requires reporting.

After habitat disturbance: 1. Post clearance checks

Post clearance checks should confirm that no bats, pups or roost features were missed. Follow up incidents and relocated animals until the ecologist is satisfied that the approved outcome has been achieved.

Inspect cleared areas, felled hollow trees, buildings, culverts, bridge structures, mine features and excavation edges at the end of each work shift and before the next stage begins.

Check for bats in cavities, under bark, in machinery, behind cladding and in structural voids. Use a pole camera or endoscope where safe and appropriate.

Complete a final walkover of the disturbance footprint and adjacent exclusion zones after clearing.

  • Search at a time that allows safe detection and does not disturb an active maternity roost.
  • Record evidence that each potential roost was empty, retained, excluded or transferred under the approved method.
  • Keep all retained roosts and exclusion zones clearly marked until the project ecologist releases them.
  • Repeat checks after major vibration, demolition, flooding, fire or other events that could alter a roost.

After habitat disturbance: 2. Monitoring and relocated animals

Monitor retained roosts, replacement structures and nearby habitat after works where required by the approval or management program. Use emergence watches and acoustic detectors to check continued use and activity.

Where an animal has been relocated or released, record the release site and condition. Arrange follow up with the wildlife carer or ecologist if the animal was injured, immature or displaced from a breeding place.

Do not assume that a replacement structure is successful because it is occupied by another bat species. Confirm use by the diadem leaf-nosed bat with calls, sightings or other suitable evidence.

  • Inspect replacement roosts for damage, overheating, flooding, obstruction and predator access.
  • Record bat presence, species, numbers, breeding evidence, emergence behaviour and nearby habitat condition.
  • Compare monitoring results with the pre works baseline where one exists.
  • Continue monitoring for the period specified by the approval, species management program or ecological management plan.

After habitat disturbance: 3. Reporting and incident review

Prepare a completion report that links each management action to the project plan, approval and species management program. Include maps, photographs, survey data, call files, trapping records and incident records.

Review every unexpected bat death, injury, colony disturbance, roost loss, exclusion failure and lighting or noise issue before the next work stage.

Update the construction method if monitoring shows continued disturbance, loss of roost function or unsafe conditions.

  • Report noncompliance, injury, death and damage to a breeding place through the approval holder and relevant authority channels.
  • Record the cause, immediate response, people notified, corrective action and prevention measure.
  • Hold a toolbox review with the crew after each significant incident.
  • Retain records for future maintenance, approvals and restoration planning.

After habitat disturbance: 4. Site handover

Before handover, confirm that retained roosts, exclusion devices, replacement structures, lighting controls and habitat protection measures are complete and secure.

Provide the landholder and maintenance team with a map of sensitive sites and clear instructions for future works.

  • Include a no disturbance instruction for active breeding places and known roosts.
  • Explain that bridge, culvert, building and mine maintenance can affect roosts even after construction is complete.
  • Set a contact pathway for future bat observations, injuries and proposed maintenance.
  • Transfer monitoring results and management commitments into the long term site management plan.

Rehabilitation actions: 1. Restore roost and foraging habitat

Rehabilitation should restore connected foraging habitat and protect the roost conditions that support colonies. Replacement structures can supplement habitat, but they should not be used to justify removal of a suitable natural roost.

Retain and protect existing caves, mines, hollow-bearing trees, mature trees, bark habitat, buildings, culverts and bridge features that remain suitable for bats.

Replant cleared areas with locally appropriate native vegetation that reconnects roosts with creeks, gullies, forest edges, canopy gaps and other foraging areas. The species commonly forages at edges and gaps and may travel up to 2.5 km from a roost.

Protect retained habitat from compaction, erosion, firewood collection, rubbish, vandalism and unauthorised cave or mine entry.

  • Use locally sourced plants suited to the soil, drainage and regional vegetation community.
  • Retain fallen hollow limbs where safe and useful, while keeping them clear of machinery and fire risk.
  • Maintain safe access to water and riparian vegetation without creating new disturbance at roost entrances.
  • Control erosion and sediment near creeks, gullies, caves, mines and culverts.

Rehabilitation actions: 2. Replacement and supplementary roost structures

Use bat boxes or other artificial roost structures only where they suit the local habitat and the project ecologist supports their design and placement. They are supplementary measures and may not replace a cave, mine, hollow tree or other established roost.

For this species, prioritise structures that provide suitable temperature, humidity, darkness, predator protection and access. The species has been associated with roost conditions of about 25 to 26.5 degrees Celsius and 65 to 80 percent humidity, although conditions vary among sites.

Where a cave, mine, culvert or building roost is lost, consider a purpose built roost structure designed by a bat specialist. Do not install a box as a token measure without a monitoring and maintenance plan.

  • Place structures near retained foraging habitat and potential flight paths, but away from bright lights and heavy traffic.
  • Inspect boxes and artificial roosts for overheating, water entry, damage, obstruction and predator access.
  • Use more than one design or location only where the ecologist identifies a clear habitat need.
  • Record installation date, design, materials, orientation, location and inspection results.

Rehabilitation actions: 3. Vegetation, weeds and water

Control weeds that suppress native regeneration, block flyways or alter roost access. Use methods that avoid poisoning bats, contaminating water or damaging retained trees and cave entrances.

Restore native canopy, shrub and ground layers around roosts and along movement routes. Retain vegetation edges and gaps that can support perch hunting.

Protect permanent and seasonal water features used by bats for drinking, movement and trapping surveys.

  • Use staged weed control so that shelter and flyways are retained while regeneration establishes.
  • Prevent sediment, fuel, concrete washout and herbicide from entering creeks, pools, culverts and cave systems.
  • Keep water points free of entangling mesh and other hazards.
  • Avoid creating open, brightly lit areas between roosts and foraging habitat.

Rehabilitation actions: 4. Lighting and long term monitoring

Design permanent lighting to keep roost entrances, flyways, vegetation edges and water crossings dark wherever practicable. Use shielded, downward facing lights with the lowest practical intensity and operating period.

Monitor restored habitat and replacement roosts during warm, calm, dry conditions where possible. Use passive acoustic monitoring, emergence watches and targeted roost inspections.

The diadem leaf-nosed bat is poorly known in some parts of its range, so adapt management when monitoring identifies unexpected roost use or breeding activity.

  • Check for continued bat activity at retained and replacement roosts over multiple survey nights.
  • Record species, call detections, colony size, breeding evidence, roost condition, lighting and weather.
  • Inspect after storms, flooding, fire, vandalism and major maintenance.
  • Use monitoring results to adjust lighting, weed control, access restrictions, roost design and future clearing methods.

Sources