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Northern Broad-nosed Bat (Scotorepens sanborni)

The Northern Broad-nosed Bat is a small insect-eating microbat that roosts in tree hollows and sometimes in buildings. It occurs in the Northern Territory, Queensland and Western Australia, and may be encountered wherever suitable hollows, gaps and connected woodland habitat are retained on a works site. It is listed as least concern, but in Queensland it is also treated as a colonial breeder, so disturbing a breeding place requires the high risk species management program for least concern colonial breeders.

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

Northern Broad-nosed Bats are colonial breeders, with births documented in November. The species is poorly known, so the wider activity pattern follows the general pattern for Australian microbats, with breeding usually in the warmer months and some variation between tropical, arid and subtropical areas.

Breeding mode: Live-bearing mammal that breeds in colonies or shared maternity roosts.

Litter size: One or two young. Births have been recorded in November.

Gestation: Not recorded.

Fledging and weaning: Not recorded. Young should be treated as dependent from late spring through summer unless a competent assessment confirms otherwise.

Roost and maternity-roost sites: Old tree hollows, fissures and gaps, loose bark, and small gaps in houses, sheds, buildings, culverts, bridges, caves or mines may provide roosting habitat. Species-specific use of every listed structure is not confirmed.

Colonies and breeding places: The species generally roosts in small colonies, although colonies in buildings can be large and smelly. Numerical colony sizes and site fidelity are not recorded. An active breeding place is confirmed by pregnant or lactating females, pups, or repeated emergence and return activity. Treat an occupied hollow or structure as a breeding place until checked.

Survey and protection: Use Anabat or similar acoustic detectors, emergence watches, and, where suitable and authorised, harp traps or mist nets. Inspect hollows with an endoscope or pole camera. If removal cannot be avoided, use two-stage or soft felling under a fauna spotter-catcher. Exclusion devices should be installed only outside the maternity season. Bat boxes are supplementary and do not replace retained natural roosts.

Breeding timing may shift between years and regions, particularly across the species' tropical, arid and subtropical range, so field evidence should guide the final work window.

  • Mating and births: Plan for maternity activity from October, with November the documented birth month.
  • Dependent pups: Dependent young are most likely from November through summer, but the end of dependency is not recorded for this species.
  • Maternity colonies and breeding-place occupancy: Shared maternity roosts may be occupied during the warmer breeding period, so inspect hollow-bearing trees and structures before disturbance.
  • Roosting and foraging activity: Adults may roost and forage throughout the year, with local activity affected by temperature, rainfall, food availability and disturbance.
  • Highest clearing risk: The highest risk is October to December, extending through summer where pups or an active maternity colony are present; retain buffers and allow the breeding cycle to finish where practicable.

Identification: Appearance

The Northern Broad-nosed Bat is a slender microbat with a short, squarish muzzle. Females are larger than males, and body colour varies from yellow-brown to reddish-brown above, with pale grey underparts.

Look for the swollen glandular areas on each side of the muzzle. A conspicuous glandular tubercle occurs between the corner of the mouth and the base of the ear.

The species is small and can be difficult to identify by eye during a fast-moving clearing operation. Handle suspected bats carefully and have a fauna spotter-catcher confirm the identification where needed.

Identification: Calls and similar species

The combined Little Broad-nosed Bat and Northern Broad-nosed Bat call type has a characteristic frequency of 38.0 kHz, with a reported range of 34.6 to 41.4 kHz. Calls are curvilinear, and the initial rising section can be distinct or absent.

Anabat calls cannot reliably separate the Northern Broad-nosed Bat from the Black-tipped Broad-nosed Bat, Chalinolobus nigrogriseus, across the overlapping frequency range. Acoustic records should therefore be treated as a Scotorepens greyii or S. sanborni type unless a suitably qualified specialist can resolve the identification.

  • Use at least three consistent search-phase pulses when assessing a call.
  • Exclude attack-phase pulses and feeding buzzes from identification.
  • Do not use Anabat recordings as a direct measure of abundance.

Identification: Field signs

There is no nest. Inspect beneath hollow-bearing trees, building gaps and other likely roost entrances for small dark droppings, urine or oil staining, and an accumulated bat odour.

Fresh squeaks or calls from a hollow, bats entering or leaving at dusk, and droppings below an entrance are useful signs. A strong smell and many droppings can indicate a larger building-roosting colony.

Distribution: Australian range

The Northern Broad-nosed Bat is mapped in the Northern Territory, Queensland and Western Australia. Records are associated with northern and eastern Australian environments, but the species can be overlooked because it is difficult to separate from related bats in acoustic recordings.

For project planning, consider the species wherever suitable roosting and foraging features occur in the mapped parts of the Northern Territory, Queensland and Western Australia.

The Queensland management profile describes the broad-nosed bat group as widespread across northern and eastern Australia. Local occurrence can be patchy and is likely to depend on hollow-bearing trees, buildings and connected vegetation.

Mapped jurisdictions: Northern Territory, Queensland and Western Australia

Local records in one Queensland project profile: A2, A3 and incidental locations

Distribution: How to apply distribution information on site

Do not assume that a lack of previous records means the species is absent. Check suitable hollows, building gaps and retained vegetation before clearing.

Acoustic detections may identify the broad-nosed bat call type without confirming this species. Combine call data with roost inspections and, where appropriate, harp trapping or mist netting.

Habitat: Vegetation and landforms

The Northern Broad-nosed Bat uses a range of arid and tropical environments. On a development site, focus on mature trees, waterways, woodland edges and structures that provide both roosting places and access to flying insects.

The species is associated with streams through open woodland and savannah. It also occurs in monsoon forest and paperbark forest.

Give particular attention to riparian strips, drainage lines, wetland edges, mature woodland patches and vegetation links between these areas.

  • Old trees with hollows
  • Open woodland and savannah
  • Monsoon forest
  • Paperbark forest
  • Vegetated stream margins and drainage lines

Habitat: Features to check before clearing

Mark hollow-bearing trees, dead standing trees, trees with loose bark or fissures, and structures with gaps that could provide roost access. Retain vegetation that connects roosts with nearby feeding areas where practicable.

Inspect culverts, bridges, sheds and buildings if they contain cracks, joints, roof spaces or other sheltered gaps. These features can be used even where surrounding habitat has been modified.

Foraging habitat: Food and foraging areas

This bat catches small insects in flight and can move quickly through the air while diving and twisting after prey. It may also forage close to the ground or other surfaces, so works areas should not be assessed only by looking at the open canopy.

Recorded prey includes midges, mosquitoes and mayflies. Productive areas are likely to include stream margins, wetland edges, paperbark vegetation, woodland openings and other places where flying insects concentrate.

Maintain dark, connected flight paths between roosts and water or vegetated feeding areas where the project design allows.

  • Streams and drainage lines
  • Open woodland and savannah edges
  • Paperbark and wetland vegetation
  • Openings near retained mature trees
  • Edges of buildings, bridges and other structures

Foraging habitat: Site observations

Watch for bats flying low along tracks, drainage lines and vegetation edges shortly after dusk. A dusk emergence watch can show whether bats from a hollow or structure are using nearby habitat.

Keep lighting, dust, noise and temporary barriers away from likely flight paths where feasible. Avoid creating dead ends between retained vegetation and active construction areas.

Breeding habitat: Maternity habitat

Northern Broad-nosed Bats are colonial breeders. The available species information is limited, so treat suitable hollow-bearing trees and building gaps as potential breeding places until surveys show that they are inactive or unsuitable.

Likely maternity places include hollows in old trees and sheltered gaps in houses, sheds and other buildings. Other microbat roosts can occur in fissures, loose bark, caves, mines, culverts and bridges, so these features should also be checked where present.

Most microbats give birth to one pup in the warmer months, usually from spring to late summer. A Queensland profile for the combined broad-nosed bat entry records one or two young in November.

Breeding habitat: Confirming an active breeding place

A maternity roost is best confirmed by evidence such as pregnant or lactating females, dependent pups, repeated adult activity, or young bats emerging from the feature. An emergence watch should be carried out without blocking the entrance or disturbing the roost.

Use acoustic detectors to identify activity and consider harp traps or mist nets only under an approved survey design and with appropriately experienced personnel. Inspect tree hollows with an endoscope or pole camera where this can be done safely and without harming bats.

  • Record the feature, entrance, surrounding habitat and observed bat activity.
  • Treat a hollow with dependent young as an active breeding place.
  • Stop work if bats or pups are found during clearing.

Breeding habitat: Planning around breeding

Where an active maternity place is close to a project boundary, retain a clearly marked buffer and allow the breeding cycle to finish where possible. The buffer should remain until the roost has vacated and a qualified fauna spotter-catcher confirms that work can proceed.

If exclusion is needed, use an exclusion device outside the maternity season and only after confirming that no bats or dependent young remain. Never seal a roost while bats are inside.

Sheltering habitat: Natural roosts

The main sheltering features are old tree hollows and small gaps in buildings. Roost use can change between nearby features, so clearing teams should inspect the full area rather than relying on a single known tree.

Inspect hollow-bearing trees, dead trees with cavities, large limbs with splits, deep fissures and loose bark. Hollows may be high in the trunk or limbs and may not be visible from ground level.

Keep surrounding vegetation where practicable. It provides cover during movement between roosts and may reduce exposure to construction activity.

Sheltering habitat: Built structures

Small gaps in houses, sheds and other buildings can support roosting colonies. Check roof spaces, wall cavities, eaves, cladding joints, bridge components, culverts and other sheltered voids.

Large or smelly colonies in buildings should be treated as a strong indication that the structure is being used regularly. Arrange an inspection before demolition, repairs, lighting changes or exclusion work.

Sheltering habitat: Replacement features

Bat boxes can provide supplementary roosting opportunities, but they do not replace an active natural maternity roost. Install them only as part of a site-specific plan, with suitable placement, maintenance and monitoring.

Where a hollow-bearing tree must be removed, use staged or soft felling under fauna spotter-catcher supervision. Fell in sections, lower the roost feature carefully, and place the hollow-bearing limb in nearby habitat at a similar height where feasible.

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

A colony is a group of bats sharing a roost, particularly during the breeding season. A maternity roost can be a hollow, building gap or other enclosed feature where females gather and raise young, and one site can contain a substantial part of the local breeding group.

Northern Broad-nosed Bats generally roost in small colonies, although colonies in houses can be large and smelly. There is no dependable numerical colony size for this species, so do not use a small entrance or limited daytime activity to rule out a colony.

A maternity roost may show repeated dusk emergence, bats returning at dawn, droppings below the entrance, urine or staining, a noticeable odour, or calls from within the feature. Young may be heard or seen near the entrance when they are becoming mobile.

Typical description: Small colonies, with potentially large colonies in houses

Site fidelity: Treat an occupied or previously used roost as potentially reusable. Avoid removing it until its use and timing have been assessed

Colonies and breeding places: Recognising an active breeding place

The clearest evidence is pregnant or lactating females, dependent pups, or repeated observations of young at the roost. An emergence watch, internal inspection with an endoscope or pole camera, and targeted acoustic monitoring can be combined to assess activity.

Survey before clearing and again immediately before work if the feature has not been inspected recently. A fauna spotter-catcher should record the feature, evidence, species or call type, and whether dependent young are present.

  • Inspect accessible hollows with a pole camera or endoscope.
  • Use dusk emergence observations without shining lights into the entrance.
  • Check buildings, bridges, culverts and other enclosed features before demolition or modification.
  • Flag active or potential breeding places and establish a no-go buffer.

Colonies and breeding places: Why colonies need special care

Disturbing a maternity roost can separate mothers from pups, trap bats inside a structure, or cause the loss of a large share of the local breeding group. Bats may also be forced into construction areas or across roads when nearby habitat is cleared suddenly.

Use staged clearing, retain buffers, and work away from retained habitat rather than driving bats towards machinery or traffic. In Queensland, tampering with the breeding place of this least concern colonial breeder requires the high risk species management program, not the low risk program used for other least concern animals.

Threats: Loss of hollow-bearing trees

The main risks on works sites are the loss of hollow-bearing trees, disturbance of maternity roosts and removal of connected feeding habitat. The species is listed as least concern, but local colonies can still be affected quickly when a roost is cleared.

Clearing old trees and dead standing trees removes established roosts that can take many years to form. Prioritise retention of hollow-bearing trees and include them in the pre-clearance inventory.

Where removal cannot be avoided, inspect the hollows, use staged or soft felling, and relocate suitable hollow sections into nearby habitat at a similar height where feasible.

Threats: Disturbance to maternity roosts

Noise, vibration, demolition, tree felling and exclusion during the breeding period can harm adults and dependent young. Do not seal, fell or demolish an occupied feature.

If a maternity site is found, pause work, establish a buffer, and allow the breeding cycle to finish where practicable. Any exclusion should occur outside the maternity season and only after confirming that the roost is empty.

Threats: Loss of feeding and movement habitat

Forestry, agricultural clearing, housing and construction can remove feeding grounds and break links between roosts, water and woodland. Protect stream margins, paperbark areas, open woodland and other retained vegetation where possible.

Use sequential clearing from already disturbed areas towards retained vegetation. Keep fauna-friendly fencing, minimise temporary lighting near flight paths, and avoid disconnecting habitat patches.

Threats: Poor detection and incorrect identification

The species can be missed during acoustic surveys and cannot reliably be separated from Chalinolobus nigrogriseus using the described call methods. A single negative detector result should not be used to clear a suitable hollow or building gap.

Use a combination of acoustic monitoring, emergence watches, direct inspection and trapping methods where appropriate. Have a fauna spotter-catcher present during clearing and stop work if bats, pups or an occupied roost are found.

Survey methodology: 1. Desktop assessment

Survey the Northern Broad-nosed Bat as a roosting and colonial breeding species. Use more than one method where hollow-bearing trees, buildings, bridges, culverts or other potential roosts may be affected.

Map hollow-bearing trees, old buildings, bridges, culverts, caves, mines, dense riparian vegetation and other structures that could provide shelter.

Review previous records, local fauna databases, project surveys and nearby habitat connections. Check whether the project occurs in the Northern Territory, Queensland or Western Australia and confirm the relevant wildlife controls before field work.

  • Mark all potential roost features on project plans.
  • Record whether each feature will be retained, buffered, inspected, modified or removed.
  • Treat a roost used by young as a breeding place, even if the species is not listed as threatened.

Survey methodology: 2. Acoustic and capture surveys

Deploy Anabat or similar detectors near likely flight paths, water, riparian vegetation, tree hollows and structures. Survey in suitable weather, with low wind and no heavy rain, and sample more than one night where the project risk warrants it.

Use search-phase calls for analysis. A minimum of three consistent search-phase pulses is needed for call identification, and longer sequences are preferred.

Northern Broad-nosed Bat calls can be confused with Chalinolobus nigrogriseus and with the related Scotorepens greyii. Do not rely on acoustics alone where a management decision depends on species-level certainty.

Use harp traps or mist nets only under the direction of appropriately authorised and experienced personnel. Handle bats briefly and release them at the capture site unless a wildlife carer or veterinarian is required.

  • Record detector locations, dates, start and finish times, weather, habitat, structure type and equipment settings.
  • Retain the original sound files and document the identification confidence.
  • Record capture effort, trap or net location, checking frequency, species, sex, reproductive condition, age class and release location.

Survey methodology: 3. Roost and breeding-place checks

Inspect tree hollows, loose bark, fissures, buildings, bridges, culverts and similar features before disturbance. Use a pole camera, endoscope, cherry picker or tree-climbing equipment where safe and authorised.

Conduct emergence watches from before sunset until activity has finished. Look for bats leaving or returning, repeated use of an entry point, fresh droppings, staining, noise, odour and social calls.

A maternity roost is confirmed by pregnant or lactating females, dependent pups, or bats carrying or leaving with young. A building colony may be large and strongly odorous, while tree roosts are often concealed and may appear inactive during a daytime inspection.

Most microbats breed in the warmer months. Plan additional care from spring to late summer, and allow a breeding cycle to finish where an active maternity roost is found and works can safely wait.

  • Record the feature type, entrance location, height where known, signs of use, number of bats observed and photographs.
  • Do not block, enter or disturb a suspected roost during inspection without an agreed method and appropriate authority.
  • Treat uncertainty as a reason to retain the feature or obtain further advice, not as evidence that it is unused.

Survey methodology: 4. Survey limitations and interpretation

Anabat recordings do not measure abundance, and not every bat flying near a detector will be recorded. Dense vegetation, tall forest, obstructions and poor weather can reduce detection.

Acoustic records that cannot be separated reliably from similar species should be reported at the most defensible taxonomic level. Seek expert review where the result affects clearing or roost decisions.

A single negative inspection does not rule out a concealed or intermittently used roost.

  • Combine acoustic results with habitat inspection, emergence observations and, where suitable, harp trapping or mist netting.
  • State the survey conditions, limitations and confidence in every report.
  • Escalate any evidence of a colony, maternity roost or dependent young before disturbance begins.

Before habitat disturbance: 1. Approvals and permits

Avoid roost loss wherever practicable. Before clearing or construction, confirm the approval pathway, inspect all relevant habitat features and brief the entire work crew on the stop-work process.

Assess the action under the Environment Protection and Biodiversity Conservation Act 1999. Make an EPBC referral if the action may have a significant impact on a protected matter, and follow any referral outcome or approval conditions.

In Queensland, Northern Broad-nosed Bat is a least concern colonial breeder. Tampering with its breeding place requires the high risk species management program pathway for a least concern colonial breeder, rather than the low risk pathway used for other least concern animals.

Confirm Queensland Nature Conservation Act and Regulation requirements, approved SMP conditions and any permits for catching, handling, relocating or otherwise interfering with wildlife. Confirm the equivalent state or territory requirements in the Northern Territory and Western Australia.

Use only appropriately licensed fauna spotter catchers, wildlife carers and other authorised personnel for capture, handling, exclusion or relocation.

  • Keep approvals, permits, SMP documents, method statements and contact details at the work front.
  • Do not assume that least concern status removes the need for approval or a colonial breeder SMP.
  • Obtain specialist advice before disturbing a maternity roost or occupied breeding place.

Before habitat disturbance: 2. Avoidance and timing

Retain hollow-bearing trees, old buildings and other occupied roost structures in place wherever possible. Design access, laydown areas, lighting and exclusion zones around them.

Microbats commonly raise young in the warmer months, usually from spring to late summer. Schedule removal, demolition or exclusion outside the maternity period where practicable, after confirming that the roost is inactive.

There is no established migration schedule to use for this species. Manage risk by checking for current roost use and breeding activity rather than assuming that bats have moved seasonally.

  • Allow an active breeding place to remain undisturbed until the breeding cycle has finished where the project can safely wait.
  • Set a clearly marked buffer around an occupied or suspected roost and retain it until the fauna ecologist confirms that it is no longer in use.
  • Keep lighting, vibration, dust, noise and access away from retained roosts as far as practicable.

Before habitat disturbance: 3. Pre-clearance inspection

Arrange a fauna spotter catcher to inspect every hollow-bearing tree and other potential roost before clearing. Use cameras on poles, endoscopes, cherry pickers or tree climbing where required and safe.

Inspect buildings, sheds, bridges, culverts and other structures for entry gaps, droppings, staining, odour, noise, bats and pups. Complete an emergence watch when a daytime inspection cannot determine use.

Repeat the inspection immediately before clearing if a feature was not inspected, conditions have changed, or the feature may have been occupied since the earlier survey.

  • Flag occupied, suspected and uninspected features before machinery enters the area.
  • Map each feature and identify the planned treatment, such as retain, buffer, exclude, soft fell or demolish under supervision.
  • Stop planning for removal if pregnant or lactating females, pups or a colony are found.

Before habitat disturbance: 4. Exclusion and crew induction

Use exclusion devices only outside the maternity season and only after a competent person confirms that dependent young are absent. Exclusion must prevent re-entry without trapping bats inside.

Do not seal a roost entrance while bats may be present. Do not use exclusion as a substitute for retaining an occupied breeding place.

Brief operators, supervisors and contractors before work starts. Explain the appearance of bats, roost signs, the marked buffers, the authority of the spotter catcher and the reporting chain.

  • Provide a site map showing no-go areas and roost buffers.
  • Use fauna-friendly fencing and prevent access to retained habitat and roost structures.
  • Confirm two-way radio contact between the spotter catcher and machinery operators.

During habitat disturbance: 1. Controlled and sequential clearing

The fauna spotter catcher must control fauna risk at the work front. Work must stop whenever a bat, colony, occupied roost or potential breeding place is found and the approved response has not been confirmed.

Clear in stages, moving from already disturbed or cleared ground towards retained vegetation. This gives animals an escape route and reduces the need to cross machinery areas or roads.

Keep the spotter catcher visible to operators and clear of machinery. Use two-way radios and maintain direct communication throughout clearing and grubbing.

Use soft felling for an occupied or potentially occupied hollow-bearing tree when removal cannot be avoided. Fell sections carefully, make cuts at least 50 cm from the roost feature where that method applies, and lower the feature without dropping it.

  • Pause between stages so the spotter catcher can inspect the next feature.
  • Place a relocated hollow or roost section in adjacent suitable habitat at a similar height where feasible.
  • Stop immediately if a bat is exposed, falls, is trapped or begins flying during felling.

During habitat disturbance: 2. Active colony or breeding place

If a colony, maternity roost, pup or breeding place is found, stop work in the immediate area. Protect the feature with flagging, barricades and a buffer, and prevent vibration, entry and machinery access.

Contact the project ecologist and approval holder. Confirm whether the breeding cycle can be completed and whether the work method remains lawful under the Queensland SMP or other applicable approval.

Do not move a maternity colony or handle pups unless this has been planned and authorised by a suitably qualified person. If removal is unavoidable, use the approved soft-felling, exclusion or relocation method.

  • Record the location, feature type, evidence of breeding, estimated activity and photographs.
  • Keep the buffer in place until the fauna ecologist confirms that the roost has vacated or authorises the next step.
  • If the feature cannot be safely inspected, treat it as potentially occupied and obtain specialist direction before disturbance.

During habitat disturbance: 3. Handling and injured animals

Only authorised and trained personnel may capture, carry, examine or release bats. Use appropriate personal protective equipment and the approved rabies and lyssavirus safety procedures.

Place a healthy bat in a clean calico bag only under the fauna spotter catcher's direction. Keep it quiet, secure and out of heat, and release it at dusk at a suitable nearby location approved by the fauna specialist.

Do not release an injured, cold, dehydrated or grounded bat without assessment. Contact the nominated wildlife carer or veterinarian and transport the animal only as directed.

  • Keep people and untrained workers away from grounded or flying bats.
  • Never pick up a bat with bare hands.
  • Record the animal's condition, handler, temporary holding location, treatment or referral and release or transfer outcome.

During habitat disturbance: 4. Records and stop-work authority

The fauna spotter catcher has authority to stop work where fauna, a roost or a breeding place may be at risk. Supervisors must support that decision and must not restart work until the response is documented.

Maintain a fauna register for every animal and feature encountered. Include species or identification level, date, location, capture and release condition, action taken and release or transfer location.

Report any breach of a buffer, unapproved handling, injury, mortality or disturbance to the project manager and approval holder immediately.

  • Photograph and map roosts, hollows, colonies and exclusion devices.
  • Record machinery, work stage, weather and people involved in every incident.
  • Update the clearing plan before work resumes.

After habitat disturbance: 1. Immediate post-clearance checks

Post-clearance checks confirm that no animal has been left behind and that retained roosts remain functional. Review every incident before the next clearing stage or similar activity begins.

Inspect felled limbs, hollow sections, building cavities, debris piles and the edge of the cleared area after each work stage. Look for live or injured bats, pups, carcasses and signs of a missed roost.

Check relocated hollow sections and any approved roost structure for movement, damage, flooding, excessive exposure and access by predators.

Keep the spotter catcher present until the approved inspection is complete and the area is safe for the next activity.

  • Search under and around felled hollow sections before machinery removes them.
  • Recheck nearby retained trees and structures if clearing has altered access, shade, drainage or lighting.
  • Escalate any live bat or breeding evidence under the incident procedure.

After habitat disturbance: 2. Reporting and compliance

Prepare a clearing and fauna report for the project manager and relevant regulator or approval holder. Include survey methods, effort, maps, roost decisions, animals handled, incidents, permits and mitigation outcomes.

Report injuries, deaths, active breeding places, unauthorised disturbance and SMP non-compliance through the required regulatory pathway.

Keep acoustic files, photographs, field sheets, fauna registers and release records with the project environmental records.

  • Compare completed works with the approved clearing footprint and conditions.
  • Record why any buffer, exclusion or relocation method was changed.
  • Close out each stop-work event with a named decision maker and supporting advice.

After habitat disturbance: 3. Monitoring relocated animals and roosts

Inspect relocated hollow sections and retained roosts after severe weather, nearby vibration or further construction. Use emergence watches or acoustic detectors where ongoing use needs to be demonstrated.

Monitor for continued bat activity, droppings, staining, odour, damaged entrances and signs of breeding. Monitoring effort should match the risk and any approval condition.

Do not assume that a bat box or relocated hollow has replaced an occupied maternity roost until use has been demonstrated.

  • Set inspection dates before the roost is moved or the tree is felled.
  • Record activity, structure condition, weather, lighting and nearby works at each visit.
  • Escalate declining use or repeated disturbance to the project ecologist.

After habitat disturbance: 4. Incident review

Review all injuries, mortalities, failed exclusions, missed roosts and unexpected colonies with the fauna spotter catcher and project ecologist.

Identify whether the cause was survey timing, poor communication, inadequate buffering, equipment failure or a change in site conditions. Amend the method statement before similar work continues.

Share lessons with operators and contractors at the next toolbox meeting.

  • Update the site risk register and fauna management plan.
  • Replace damaged signs, fencing, cameras or exclusion devices.
  • Record corrective actions, responsible people and completion dates.

Rehabilitation actions: 1. Restore roosting and movement habitat

Rehabilitation should restore roosting, foraging and movement habitat around the work area. Retaining natural hollows and mature trees is preferred to relying on artificial structures.

Replant local native trees and shrubs that link retained woodland, riparian areas and known roost features. Protect planted areas from vehicles, grazing, fire impacts and repeat clearing.

Retain fallen hollow limbs where they are safe and suitable for fauna. Place relocated hollow sections securely at a similar height in adjacent habitat, as directed by the fauna specialist.

Restore drainage and ground conditions around culverts, bridges and riparian areas without blocking bat access or creating unsafe entrapment points.

  • Use locally appropriate native species and structural layers.
  • Keep future hollow development in mind by retaining mature trees and recruiting trees.
  • Maintain safe access to retained roosts for future inspection.

Rehabilitation actions: 2. Artificial roost structures

Use bat boxes or other artificial roost structures only as a supplementary measure and only where the local habitat, species and microclimate are suitable. They do not replace an occupied maternity roost or a mature hollow-bearing tree.

Select, install and orient structures under advice from a bat ecologist. Provide more than one suitable option where practicable because bats may reject a structure that is too hot, exposed, damp or disturbed.

Inspect artificial structures for occupancy, overheating, water entry, damage, pests and maintenance needs. Do not open or move an occupied structure during the maternity period.

  • Place structures near retained habitat and safe flight paths.
  • Keep them away from intense night lighting and regular machinery activity.
  • Record the design, location, installation date, condition and evidence of use.

Rehabilitation actions: 3. Water, weeds and lighting

Protect streams, dams, drainage lines and other water sources used by flying insects and foraging bats. Prevent sediment, pollutants and construction waste from entering water.

Control weeds in a way that retains native cover, avoids poisoning or trapping bats and does not unnecessarily remove roost trees or dense shelter.

Use the lowest practical light levels near retained roosts, waterways and movement routes. Direct lights away from entrances and use shielding, timers or motion controls where suitable.

  • Keep waste, food and standing hazards away from restored habitat.
  • Stage weed control outside sensitive roost and breeding periods where practicable.
  • Inspect restored areas after rain, weed treatment and major construction changes.

Rehabilitation actions: 4. Long-term monitoring

Monitor restored habitat, retained hollows, relocated roost features and artificial structures for condition and bat use. Include emergence observations, acoustic monitoring and inspection of signs where these methods are suitable.

Continue monitoring through the warmer months when breeding activity is most likely, while following any approval-specific timing and effort requirements.

Use results to repair structures, adjust lighting, control weeds and improve habitat connections.

  • Record dates, weather, observer, method, detector settings, activity and roost condition.
  • Report evidence of pregnant or lactating females, pups or a new colony promptly.
  • Keep monitoring records with the project's environmental management and rehabilitation reports.

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