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Greater Broad-nosed Bat (Scoteanax rueppellii)

The Greater Broad-nosed Bat is a large insectivorous microbat of eastern Australia. It roosts in tree hollows, including very large hollow trees used as maternity roosts, and forages in productive wet forests, gullies, riparian vegetation and, in some regions, old-growth mangroves. Clearing, hollow-tree removal, fragmentation and disturbance to understorey or maternity roosts can affect the species on development sites.

Conservation status

New South Wales, Biodiversity Conservation Act 2016: Vulnerable.

Breeding season

The available breeding information is limited. The calendar below uses the reported January birth period, the documented use of maternity roosts and the known sensitivity of hollow trees and understorey to disturbance. Local surveys should refine the timing for each project.

The supplied documents do not provide a complete mating, gestation or juvenile-development calendar. A maternity roost should be treated as occupied until a qualified fauna spotter-catcher confirms otherwise.

  • Breeding and births: A single young is reported to be born in January. Maternity roosts may contain 50 to 100 bats.
  • Young dependent in or near maternity roosts: The duration of dependence is not reported. Treat the period around the January birth as sensitive and do not disturb a maternity roost while young may be present.
  • Roost movement: Roost switching has been recorded throughout the study period, with some maternity roosts changed almost daily and others used for several days. No seasonal migration is documented.
  • Highest clearing risk: Highest risk is around the reported January birth period and any time an occupied maternity roost is present. Clearing that removes hollow trees or disturbs understorey during the winter preparation period may also affect the species.

Identification

The Greater Broad-nosed Bat is a robust microbat with a broad head and short, squarish muzzle. It is most reliably identified by a combination of morphology, reference calls and, where needed, expert confirmation because several broad-nosed bats overlap in eastern Australia.

Adults have upperparts ranging from mid-brown to dark cinnamon-brown, a paler crown, tawny-olive underparts and pinkish-brown skin on the face, ears and flight membranes. The ears are widely spaced, short and rounded, with a concave rear edge below the apex.

Body form: Large and robust, with a broad head and short, squarish muzzle.

Fur: Mid-brown to dark cinnamon-brown above, with tawny-olive underparts.

Identification: Field separation

The broad head, short squarish muzzle, short rounded ears and robust build help separate this species from smaller broad-nosed bats. Appearance alone may not be sufficient where Eastern Broad-nosed Bat, Little Broad-nosed Bat or other vespertilionid bats are present, so records from clearing sites should be checked against current identification keys and, where necessary, acoustic or specialist review.

  • Do not identify a bat from a brief view during tree felling alone.
  • Record photographs, body measurements where safe, roost-tree details and calibrated acoustic files when species confirmation is needed.

Identification: Signs at a work site

The strongest field sign is an occupied or recently used hollow-bearing tree. The species may occur in groups of 50 to 100 at maternity roosts, but maternity roost use can change frequently. Radio-tracked bats changed roosts almost daily at some sites and used some roosts for several days; one maternity roost was used again two years later.

  • Inspect large hollows and cavities before felling, particularly in large old trees that are substantially larger than neighbouring trees.
  • Treat a hollow as potentially occupied even when bats are not visible during a daytime inspection.
  • Use a fauna spotter-catcher for any bat found during felling and stop work around the roost feature until the animal and roost are managed.

Distribution: National range

The species occurs in eastern Australia, mainly from north-eastern Queensland through New South Wales to north-eastern Victoria. Records are concentrated in coastal and foothill systems, gullies and river systems associated with the Great Dividing Range, but its distribution remains poorly known because it is infrequently captured.

The documented range extends from the Atherton Tableland in north-eastern Queensland, through eastern and tableland New South Wales, to north-eastern Victoria. In New South Wales it is associated with gullies and river systems draining the Great Dividing Range and with wetter forest regions near the coast.

Broad geographic range: North-eastern Victoria to the Atherton Tableland, with extension to the coast over much of the range.

New South Wales pattern: Widespread on the New England Tablelands in the cited NSW profile, but associated mainly with wetter gullies and tall forest.

  • Queensland: Atherton Tableland and other eastern, high-rainfall areas.
  • New South Wales: coastal forests, foothills, gullies and the New England Tablelands.
  • Victoria: north-eastern Victoria is included in the published eastern Australian range.

Distribution: Strongholds and subpopulations

The supplied studies identify coastal plains and foothills as potentially important habitat because beetles are a major food source and the sites are more productive. Recorded habitat includes wet sclerophyll forest in gullies and old-growth mangroves. The southern CRA material treated the species as a coastal species and did not set a Tablelands target because records there were scarce and considered unreliable.

  • Coastal plains and foothills with productive forest.
  • Wet gullies and river systems.
  • Old-growth mangrove habitat where suitable hollow trees remain.

Distribution: Population information

There is no reliable national population estimate or documented population trend in the supplied material. The species is described as infrequently captured and poorly known, which limits confidence in distribution models and local absence records.

National population estimate: Not available in the supplied documents.

Population trend: Not established in the supplied documents.

Maternity group size: Often 50 to 100 bats at studied maternity roosts.

Habitat: Vegetation and landform

The Greater Broad-nosed Bat uses tall, wet and productive forest, especially in gullies and along drainage systems. Habitat can also include drier forest along gullies, coastal vegetation and old-growth mangroves where large hollow-bearing trees are available.

Typical habitat includes tall wet forest, wet sclerophyll forest in gullies, foothill forest, riparian vegetation and high-rainfall coastal forest. The species can extend into drier forest along gullies and has been recorded in old-growth mangroves.

  • Wet sclerophyll forest in gullies.
  • Tall forest near the coast and foothills.
  • Eucalypt forest with productive understorey and nearby drainage lines.
  • Old-growth mangroves where hollow-bearing trees occur.

Habitat: Structural features

Large hollow-bearing trees are the key habitat feature identified in the supplied documents. Maternity roost trees were typically very large and larger than neighbouring trees. Riparian vegetation and understorey are also important because clearing and disturbance of these features were identified as threats to feeding habitat.

Maternity roost tree feature: Very large hollow trees, typically larger than neighbouring trees.

  • Retain very large old trees and all suitable hollows within and beside the work area.
  • Retain riparian vegetation, wet gullies and connected forest around hollow-bearing trees.
  • Avoid unnecessary disturbance to the understorey, especially where it forms productive feeding habitat.

Habitat: Elevation and climate

The species is associated with warmer, wetter coastal and foothill conditions in much of its range. One source describes New South Wales records as not occurring above 500 metres, while the Southern CRA material reports the species in alpine ash forests at 700 to 1000 metres. Elevation records should therefore be checked against the local survey and identification evidence rather than used alone to exclude habitat.

Reported New South Wales limit: One NSW profile states that the species does not occur above 500 metres.

Other reported elevation: The Southern CRA material describes alpine ash forest records at 700 to 1000 metres.

Foraging habitat: Diet

The Greater Broad-nosed Bat is a predator of relatively large insects and usually feeds in productive forest near gullies, drainage lines and other areas supporting abundant prey. Beetles are the main recorded prey in most studied areas.

Faecal analysis identified beetles as the main prey at most study areas. Recorded beetle prey included Scarabaeidae, Cerambycidae and Carabidae. Flies, bugs and moths were also eaten, and hair from other bat species confirmed that the species can be carnivorous.

  • Beetles, especially scarab, longhorn and ground beetles.
  • Flies, bugs and moths.
  • Other bats, recorded from hair in droppings of wild-caught individuals.

Foraging habitat: Foraging settings

The species is associated with productive forest, wetter gullies, riparian vegetation and areas above water. Coastal plains and foothills may be particularly important because they support productive forest and abundant beetles. The supplied documents do not provide a measured foraging distance or home-range size.

Foraging range: A measured home range or foraging distance is not provided in the supplied documents.

  • Retain forest around creeks, gullies and drainage lines.
  • Avoid clearing productive understorey and riparian vegetation around known or potential roost trees.
  • Do not infer absence from a lack of captures at a single detector or trapping location.

Breeding habitat: Breeding biology

Breeding depends on large hollow-bearing trees in forested habitat. Maternity colonies can be sizeable, and roost use may change between trees, so an apparently empty tree does not demonstrate that the breeding site is unused.

A single young is reported to be born in January. The 2023 study found maternity groups often contained 50 to 100 bats. Other breeding parameters were not provided in the supplied documents.

Mating period: Not reported in the supplied documents.

Birth period: January is reported for the single young.

Litter size: One young.

Gestation: Not reported.

Age at maturity: Not reported.

Lifespan: Not reported.

Maternity group size: Often 50 to 100 bats in the NSW study.

Breeding habitat: Maternity habitat

Maternity roosts were in very large hollow trees that were typically larger than neighbouring trees. The surrounding habitat ranged from wet sclerophyll forest in gullies to old-growth mangroves. Roost fidelity varied, with some maternity roosts used almost daily for several days and another used again two years later.

  • Retain very large hollow-bearing trees and nearby mature trees.
  • Protect the roost tree and surrounding forest during the birth period and while young may be dependent.
  • If a maternity roost is found, delay clearing where possible until the breeding cycle is complete and obtain specialist advice before any disturbance.

Sheltering habitat: Roost trees

Tree hollows are the main documented refuge for the Greater Broad-nosed Bat. The species may use several roost trees, and maternity roosts can occur in large old trees within wet forest, gullies, riparian areas or old-growth mangroves.

The species roosts in tree hollows, with large hollows needed for maternity roosts. Radio-tracked bats used roost trees in wet sclerophyll forest gullies and old-growth mangroves. Used trees were not always occupied continuously.

Roost feature: Tree hollows, especially large hollows in very large trees.

Roost switching: Some maternity roosts were changed almost daily, while others were used for several days.

  • Retain all hollow-bearing trees within the clearing footprint and in adjoining retained habitat.
  • Prioritise very large old trees and trees substantially larger than surrounding trees for retention.
  • Inspect cavities before felling and use a fauna spotter-catcher where roosting bats are suspected.

Sheltering habitat: Protection during works

The loss of hollow-bearing trees was identified as a major threat. If a roost cannot be retained, soft-felling and relocation of the roost feature are general microbat management measures described for infrastructure works, but they should only be used under the direction of a qualified fauna spotter-catcher and relevant regulator.

  • Stop work immediately if bats are exposed during felling.
  • Allow bats to leave at dusk where this is safe and authorised, rather than handling them unnecessarily.
  • Where an occupied roost cannot be avoided, use staged or soft-felling methods and relocate the roost feature into adjacent suitable habitat where practicable.
  • Maintain a no-go buffer around a suspected maternity roost until the roost has been vacated or an approved management action is in place.

Threats: Clearing and hollow loss

The main documented risks are loss of hollow-bearing trees, clearing of riparian and foraging habitat, fragmentation and disturbance to understorey. Risks are highest when clearing affects a maternity roost or occurs while dependent young are present.

Habitat clearing, including clearing of riparian vegetation, was ranked as a high threat in the Southern CRA material. Removal of hollow-bearing trees through logging or development was also identified as a major risk. Loss of large trees reduces both maternity and general roost options.

  • Avoid clearing very large hollow-bearing trees.
  • Retain riparian vegetation and mature trees around gullies and drainage lines.
  • Survey hollows before clearing, including trees outside the direct footprint that may be affected by access tracks, edge effects or tree-fall zones.

Threats: Fragmentation, fire and understorey disturbance

Fragmentation was identified as a threat, although the species can feed in remnants. Disturbance or loss of understorey through logging, burning or changes in fire timing and frequency may reduce foraging habitat. The Southern CRA material identifies the winter preparation period as a sensitive time for understorey disturbance.

  • Keep retained forest connected around roost trees, gullies and riparian corridors.
  • Avoid unnecessary understorey removal beneath and around known roost trees.
  • Plan burning and vegetation treatment outside periods identified by the local ecologist as sensitive for roosting and foraging.

Threats: Roads, predators, disease and hydrology

The supplied documents do not identify road mortality, predation or disease as quantified threats specific to this species. Roads and construction access can nevertheless increase clearing, fragmentation and disturbance around hollow trees, so these effects should be assessed at each site. Changes to water levels, drainage or mangrove and gully vegetation may reduce habitat where the species depends on wet gullies, riparian forest or old-growth mangroves.

  • Check road alignments, stockpiles, lighting and access tracks for indirect effects on roost trees and connected forest.
  • Do not assume that a site is low risk because no dead or injured bats are found during clearing.
  • Apply bat handling hygiene and lyssavirus vaccination requirements for personnel handling bats, as specified in the project management plan.

Survey methodology: 1. Review records and map habitat

The supplied documents identify the Greater Broad-nosed Bat as a poorly known, infrequently captured species that uses hollow-bearing trees and productive forest, gullies, riparian vegetation and, in some areas, old-growth mangroves. Targeted surveys are needed where works may affect these features, but the supplied survey guideline extract does not provide a species-specific numeric effort prescription. Do not substitute a generic bat survey for a habitat and roost assessment.

Review state wildlife database records and recent local survey data before selecting methods. Records are sparse and unreliable in some inland areas, so an absence of records is not evidence that the species is absent.

Map tall wet forest, wetter gullies, riparian vegetation, productive foothill forest, old-growth mangroves and all hollow-bearing trees within and adjacent to the work area.

Treat large hollow-bearing trees as potential maternity roost habitat, even when bats are not detected during a survey. Maternity colonies commonly contain 50 to 100 bats, and very large hollows may be used as maternity roosts.

Survey methodology: 2. Ultrasonic detection and visual observation

Use specialist ultrasonic detectors at suitable flight paths, gullies, creek lines, forest edges and other productive foraging areas identified during the habitat assessment.

Run surveys during the warmer active season and repeat them across suitable weather conditions because activity and insect availability vary with temperature and rainfall. The supplied documents do not specify a fixed number of nights or recording hours for this species, so set effort in a project-specific survey plan prepared by a qualified bat ecologist.

Record detector location, date, start and finish times, weather, wind, rainfall, temperature, detector settings and the number and quality of identifiable call sequences.

Use call identification cautiously. The species is infrequently captured and poorly known, and acoustic identification should be checked by an experienced bat ecologist where the result affects clearing or approval decisions.

Survey methodology: 3. Roost and maternity site assessment

Inspect hollow-bearing trees, dead limbs, tree fissures and other potential roost features in the clearing footprint and adjoining retained habitat before works begin.

Look for bats, guano, staining, odour, scratch marks and audible activity at hollow entrances, but do not assume that a quiet hollow is unused.

Give particular attention to very large hollows and trees substantially larger than neighbouring trees, as these features have been used as maternity roosts.

Where a potential maternity roost may be affected, use an ecologist-designed emergence, re-entry or other appropriate roost assessment and allow for repeated observations if required. Do not seal, fell or exclude bats from a suspected maternity roost until the breeding risk has been assessed.

Recorded maternity colony size: Often 50 to 100 bats

Known roost settings: Very large hollow trees, wet sclerophyll forest gullies and old-growth mangroves

Survey methodology: Minimum effort and reporting

  • Use a qualified ecologist to document the survey design, including the number of detector locations, survey nights, recording hours, weather limits and any roost inspection effort.
  • Increase effort when habitat is suitable but initial surveys produce no detections, because the species is infrequently captured and distribution data are limited.
  • Report all records with coordinates, date, survey method, call files or photographs where available, habitat description, roost feature details and confidence in identification.
  • Submit confirmed and probable records to the relevant state wildlife database and notify the project regulator or approval authority where required.
  • Retain raw acoustic files, field sheets, photographs, tree maps and decisions about whether habitat was occupied.

Before habitat disturbance: Avoid and minimise

Avoid clearing the habitat features most likely to support roosting and foraging. The main controls are retention of large hollow-bearing trees, protection of gullies and riparian vegetation, and careful treatment of any suspected maternity roost.

  • Redesign the work area to retain very large hollow-bearing trees, dead limbs with hollows, wet gullies, riparian vegetation and connected forest between roosting and foraging areas.
  • Avoid clearing productive foothill forest, wetter gullies and old-growth mangroves where these occur in or beside the project area.
  • Retain understorey and ground vegetation in adjoining habitat because the species uses productive forest for feeding and disturbance to foraging habitat may affect it, particularly during the winter preparation period.
  • Avoid fragmenting retained habitat with unnecessary access tracks, temporary compounds or widened easements.

Before habitat disturbance: Approvals and work planning

Status in supplied species record: EPBC Act not listed; New South Wales vulnerable

  • Confirm the current conservation status in the state or territory where the project is located before clearing, because the supplied records identify the species as vulnerable in New South Wales and not listed under the EPBC Act.
  • Obtain any state or territory fauna, threatened species, clearing and animal handling approvals that apply to the project and the proposed relocation or exclusion method.
  • Refer the project under the EPBC Act if the current national listing or the proposed action requires referral, even though the supplied species record states that it is not currently listed.
  • Prepare a fauna management plan that identifies roost trees, maternity risk, exclusion methods, authorised handlers, release habitat, veterinary contacts, stop-work triggers and reporting requirements.
  • Stage clearing so that roost and foraging habitat are retained while the project ecologist confirms that no active maternity roost will be disturbed.

Before habitat disturbance: Pre-clearance preparation

  • Complete a pre-clearance inspection of all trees and limbs proposed for removal, with a qualified ecologist or fauna spotter catcher experienced in microbats present where hollows or suspected roosts occur.
  • Mark no-go trees, riparian vegetation, retained understorey, access limits and exclusion zones on plans and on the ground before machinery arrives.
  • Use fauna-friendly exclusion fencing where it can safely separate animals from active work areas without blocking movement between retained roosting and foraging habitat.
  • Brief machine operators on the location of hollow-bearing trees, the approved felling sequence, the spotter catcher's authority to stop work and the procedure for an animal or roost discovery.

During habitat disturbance: Daily controls and machinery interface

Clearing must be controlled as a fauna operation, not treated as ordinary vegetation removal. A fauna spotter catcher must have clear authority to pause machinery, inspect habitat features and direct the handling of any bat found.

  • Inspect the work area each day before clearing, including trees, limbs and habitat retained beside the work footprint.
  • Keep the fauna spotter catcher in direct communication with the machine operator and stop machinery whenever a hollow, roost feature or animal requires inspection.
  • Clear progressively towards retained habitat where safe, so mobile fauna has an escape route and is not driven into machinery or traffic.
  • Do not fell or push a hollow-bearing tree until the spotter catcher and ecologist have confirmed that the tree is approved for removal.
  • Stop work if a maternity roost, occupied hollow, injured bat, dead bat or unidentified bat is found, or if clearing extends beyond the approved footprint.

During habitat disturbance: Hollows, trees and other habitat features

Soft-felling clearance from roost feature: At least 50 centimetres

Relocated roost feature: Place in nearby retained habitat at a similar height where feasible

  • Avoid removing trees containing large hollows or suspected maternity roosts wherever practicable.
  • If removal of an occupied or inactive roost tree cannot be avoided, use a soft-felling method in sections and lower limbs carefully rather than allowing the tree to fall uncontrolled.
  • Keep cuts at least 50 centimetres from an identified roost feature and relocate the limb containing the feature into nearby retained habitat at a similar height where this is safe and approved.
  • Do not destroy or relocate a suspected maternity roost until the breeding cycle has been assessed and the ecologist has approved the action.
  • Retain fallen hollow logs, understorey and riparian vegetation unless their removal is necessary for safety or the approved works.

During habitat disturbance: If a bat is found

  • Stop the relevant work and keep people, machinery and pets away from the bat.
  • Allow only an appropriately authorised and trained fauna spotter catcher or wildlife carer to capture, examine, transport or release the bat.
  • Use a suitable clean holding container or calico bag only for the shortest practical period, keep the bat shaded and quiet, and follow the approved fauna management plan.
  • Release a healthy bat at dusk into nearby retained habitat that provides suitable hollow-bearing trees and connected foraging habitat, subject to approval and advice from the project ecologist.
  • Transport an injured or distressed bat to the nominated wildlife carer or veterinarian and record the handover.
  • Do not handle a bat without the required vaccination, training and personal protective equipment, because Australian bat lyssavirus is a human health risk.

After habitat disturbance: Post-clearance checks

Completion of clearing does not end the risk. Check retained habitat, confirm that controls remain effective and document every fauna and roost decision so that the approval holder can demonstrate compliance.

  • Inspect the cleared area, retained trees and relocated roost features after each clearing stage for injured, trapped or displaced bats.
  • Confirm that no hollow-bearing tree, riparian buffer, retained understorey or no-go area was damaged outside the approved footprint.
  • Check that relocated hollow limbs remain stable, accessible and protected from machinery, vandalism and follow-up maintenance.
  • Arrange additional acoustic or roost monitoring where a suspected maternity tree was retained near works, where a bat was found, or where the ecologist identified a material risk.

After habitat disturbance: Monitoring and corrective action

  • Monitor retained roost trees and nearby foraging habitat at the frequency specified in the fauna management plan and approval conditions.
  • Investigate any loss of a hollow-bearing tree, repeated bat injury, roost abandonment or unexpected clearing and apply corrective actions promptly.
  • Maintain exclusion fencing, no-go markers and access controls until the ecologist confirms that construction and rehabilitation no longer threaten retained habitat.
  • Keep records of inspections, detections, injuries, releases, veterinary treatment, tree removals, roost relocations and corrective actions.

After habitat disturbance: Reporting and offsets

  • Provide the regulator and approval holder with the required fauna and clearing reports, including maps, survey results, raw acoustic records, photographs and incident records.
  • Report confirmed records to the relevant state wildlife database and update the project species register.
  • Assess offsets only where required by the applicable approval or offset policy, and ensure any offset protects the habitat features identified for this species rather than relying on area alone.

Rehabilitation actions: Restore roost and foraging habitat

Rehabilitation should restore connected forest structure and the roost and feeding features used by the Greater Broad-nosed Bat. Retention of existing mature trees is more reliable than attempting to replace large hollows after clearing.

  • Protect all retained mature and hollow-bearing trees from firewood collection, further clearing, soil compaction and machinery damage.
  • Replant locally appropriate eucalypt and other native forest species that match the retained wet sclerophyll, foothill, riparian or mangrove community at the site.
  • Restore continuous understorey and canopy links between retained trees, gullies, drainage lines and other forest remnants.
  • Reinstate suitable fallen hollow logs and relocated hollow limbs where the rehabilitation design and safety assessment allow it.
  • Do not install nest boxes as a substitute for retaining natural large hollows unless a qualified ecologist specifies their use, design, location and maintenance.

Rehabilitation actions: Manage threats during recovery

  • Control weeds and prevent vegetation changes that reduce the productive forest and understorey used for foraging.
  • Use a fire management plan that avoids unnecessary loss of understorey and protects hollow-bearing trees and retained roost features.
  • Limit night lighting, unnecessary noise and vehicle access near retained roost trees and gullies during the active rehabilitation period.
  • Prevent domestic animal access and manage feral predators where they threaten bats or other fauna using approved methods.

Rehabilitation actions: Measure success

  • Inspect planted areas for survival, natural regeneration, weed cover, understorey recovery, erosion and protection of retained trees at the intervals in the rehabilitation plan.
  • Confirm that relocated hollow features remain secure and usable, and replace or repair them if they fail.
  • Use repeat ultrasonic monitoring at retained gullies, riparian areas and restored forest when the project ecologist considers it necessary to test continued use by the species.
  • Record habitat condition, bat detections, roost observations and any new threats, and adapt rehabilitation actions when monitoring shows that the intended habitat structure is not developing.

Sources