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Olive Whistler (Pachycephala olivacea)

The Olive Whistler is a small, stocky forest bird of wet forests on the ranges of eastern Australia. It is associated with high elevation and wet forest habitats, and clearing, fragmentation, fire and introduced predators can affect habitat occupied by the species on development sites.

Conservation status

New South Wales, Biodiversity Conservation Act 2016: Vulnerable.

South Australia, National Parks and Wildlife Act 1972: Endangered.

Breeding season

The only documented seasonal information is the September to January breeding period. No seasonal migration pattern is provided, so the species should be treated as potentially present year round in suitable habitat unless local survey data show otherwise.

Seasonal information is based on the documented September to January breeding period. The supplied documents do not provide dates for incubation, fledging, post-breeding movement or migration.

  • Breeding: Breeding is reported from September to January.
  • Young: Dependent young are not separately documented. September to January is the breeding period, so checks should allow for nests or dependent young during this interval.
  • Highest clearing risk: Clearing and disturbance are most likely to harm the species from September to January because this overlaps the documented breeding season and the beginning of breeding has been noted during project activity.

Identification

The Olive Whistler is a small, stocky whistler with a large head and strong bill. It is most likely to be detected by its rich, melodious call in wet forest, rather than by prolonged views in dense vegetation.

Adults are about 22 cm long, with the tail making up about 10 cm. The male has a dark grey head, olive-brown upperparts, a grey throat and buff-brown underparts. Females are duller overall.

The species has a stocky build, large head and strong bill. Its call is described as rich and melodious, and may be a useful detection feature where dense understorey limits visibility.

Identification: Separating similar birds

Use the combination of olive-brown upperparts, dark grey male head, grey throat, buff-brown underparts, stocky shape and strong bill when separating it from other whistlers.

The duller female can be harder to identify visually. Confirm records with a clear call, repeated observations or photographs where possible, particularly in areas containing other Pachycephala species.

Identification: Field signs and handling

No species-specific tracks, scats, nests, tree hollows, burrows or other ground signs are described in the supplied documents. Aural detection and direct observation are therefore the main field methods supported by the available information.

If a bird is captured during clearing, use the Australian Bird and Bat Banding Scheme recommended band size of 04 and follow current fauna spotter catcher and animal welfare procedures.

Recommended band size: 04

Distribution: State and regional range

The Olive Whistler has a disjunct distribution in eastern Australia. The supplied documents confirm records or modelled assessment in south-eastern Queensland and eastern New South Wales, but do not provide a complete national range map or population estimate.

The species is associated with wet forests on the ranges of the east coast. In New South Wales, the documented disjunct areas include Barrington Tops, the Macpherson Ranges, Illawarra, the Snowy Mountains and the Brindabella Range.

A known population occurs in the Richmond to Tweed area. The species is also identified with high elevation southern rainforest in south-eastern Queensland, including the Main Range and McPherson Range area.

  • Treat suitable wet forest above 500 m in the Richmond to Tweed area as potential habitat during project planning.
  • Retain and inspect connected wet forest on ranges and high elevation sites in the documented Queensland and New South Wales regions.

Distribution: Strongholds and population information

The south-eastern Queensland assessment identifies the Olive Whistler among species associated with high elevation southern rainforest and among taxa regarded as largely restricted to the Main Range and McPherson Range area.

The Eden fauna modelling project treated the Olive Whistler as a priority forest bird and produced a model for its predicted distribution in the Eden area. The supplied text does not give a national population size, density, home range or quantified population trend.

Eden modelling records: 54 total records, comprising 15 presence or absence records and 39 presence-only records.

National population: Not stated in the supplied documents.

Population trend: Not quantified in the supplied documents.

Distribution: Project application

The species was recorded within 5 km of the Mooball and Round Mountain project stages in the Tweed region. The cited assessment considered adverse impacts difficult to mitigate, so presence of wet forest habitat should trigger early ecological review before clearing or disturbance.

Habitat: Forest type and setting

Olive Whistlers use wet forest habitats on the eastern ranges. The supplied documents provide stronger information on forest type and elevation than on particular plant species or stand measurements.

The main habitat is wet forest on ranges along the east coast, including wet eucalypt forest and high elevation southern rainforest.

In south-eastern Queensland, the species is associated with the Main Range and McPherson Range area. In the Richmond to Tweed population, known habitat is described as wet forest above 500 m.

Documented elevation reference: Above 500 m for the Richmond to Tweed population.

Documented habitat types: Wet forest, wet eucalypt forest and high elevation southern rainforest.

Habitat: Structural features

The documents do not specify required tree diameter, canopy height, understorey density, hollow size or minimum patch area. As a practical precaution, assess intact wet forest and connected forest on ranges rather than relying only on mapped vegetation boundaries.

Fragmented forest remnants may retain habitat value, but the species is specifically identified as being affected by clearing and fragmentation. Retain links between wet forest patches wherever project design allows.

  • Map all wet forest patches and their connections before finalising clearing limits.
  • Inspect retained forest edges and adjoining construction areas for Olive Whistler activity, especially at sites above 500 m in the Richmond to Tweed region.
  • Avoid treating narrow retained strips as equivalent to intact forest without field assessment.

Foraging habitat: Diet and feeding habitat

The Olive Whistler feeds in wet forest, taking both plant and animal foods. The available documents do not define its foraging radius or the relative importance of particular food plants.

The recorded diet comprises berries and insects. Foraging habitat is therefore likely to include fruiting vegetation and foliage or other substrates supporting insect prey within wet forest.

The species' stocky form and strong bill are consistent with a bird that can handle berries, but the supplied documents do not describe specific feeding techniques or preferred plant species.

Recorded food: Berries and insects.

Foraging range: Not stated in the supplied documents.

  • Retain fruiting native vegetation within and beside wet forest where practicable.
  • Avoid unnecessary removal of dense wet forest understorey and edge vegetation during access preparation.
  • Schedule pre-clearing inspections across both retained forest and the proposed clearing footprint because birds may forage outside the area where they are first detected.

Breeding habitat: Breeding biology

Breeding is reported from September to January. The supplied documents do not describe the nest, clutch size, incubation period or age at maturity, so these details should not be inferred during impact assessment.

The breeding season extends from September to January. This period overlaps with the start of breeding during the documented project activity in the Tweed region.

No clutch size, incubation period, fledging period, age at maturity or lifespan is provided in the supplied documents.

Breeding season: September to January.

Clutch size: Not stated in the supplied documents.

Incubation: Not stated in the supplied documents.

Age at maturity: Not stated in the supplied documents.

Lifespan: Not stated in the supplied documents.

Breeding habitat: Breeding habitat protection

Breeding habitat is expected to be within wet forest on the ranges, including wet eucalypt forest and high elevation rainforest. The documents do not identify nest-tree species, nest height or nest placement.

During September to January, apply particular care to clearing, loud construction and vegetation disturbance in occupied or potentially occupied wet forest. Retain connected forest and avoid creating new isolated edges around retained habitat.

  • Complete targeted pre-clearing fauna checks before vegetation removal in the breeding season.
  • Establish exclusion areas around any active nest or dependent young found by the fauna spotter catcher, in accordance with project approvals and current animal welfare requirements.
  • Record the location and habitat context of all detections to support refinement of retained habitat boundaries.

Sheltering habitat: Likely shelter context

The supplied documents do not identify a specific shelter, nest or roost structure for the Olive Whistler. Shelter should be assessed at the habitat scale, with emphasis on intact wet forest and dense vegetation on ranges.

The species is associated with wet forests, wet eucalypt forest and high elevation southern rainforest. These habitats may provide foliage cover and protection from exposure, but the documents do not specify the vegetation density or structure required.

No information is provided on nest dimensions, nest height, tree hollow use, burrows, roosts, dens or refuge sizes.

Known refuge type: No species-specific refuge type is described in the supplied documents.

Known refuge size: Not stated in the supplied documents.

  • Retain wet forest cover around confirmed detections and along connections between forest patches.
  • Inspect dense vegetation and forest edges during pre-clearing checks rather than relying only on searches for hollows or ground signs.
  • Do not assume that absence of a visible nest means the habitat is unused.

Threats: Clearing and fragmentation

The documented threats are habitat loss and fragmentation, fire, foxes and cats. These risks are relevant to clearing projects because wet forest removal can reduce habitat directly and increase edge exposure in retained forest.

Clearing and fragmentation of wet forest are identified threats. Fragmentation can reduce the amount of suitable forest and isolate the disjunct populations described for New South Wales.

Construction access, temporary work areas and edge widening should be included in the impact assessment, not only the permanent infrastructure footprint.

  • Avoid clearing wet forest on ranges wherever practicable.
  • Keep retained patches connected and minimise new edges through compact work areas and existing access routes.
  • Rehabilitate temporary disturbance areas with locally appropriate native wet forest vegetation.

Threats: Fire and predators

Fire is identified as a threat. Fire planning should consider the condition and continuity of wet forest, particularly where construction may open dry edges or increase ignition sources.

Foxes and cats are also identified threats. Construction compounds, food waste and poorly managed materials can increase opportunities for introduced predators around retained habitat.

  • Use project fire controls that reduce ignition risk and avoid unnecessary burning in or beside wet forest.
  • Keep construction waste and food securely contained.
  • Report fox and cat activity near retained habitat and apply approved predator management measures where required.

Threats: Roads and hydrology

The supplied documents do not separately quantify road mortality, vehicle disturbance, disease or hydrology change for the Olive Whistler. These issues should still be assessed where roads, drainage works or altered runoff affect wet forest habitat.

Maintain existing drainage patterns where possible and prevent sediment, pollutants and construction runoff from degrading retained wet forest.

  • Use low-speed controls and fauna awareness measures on roads through or beside occupied wet forest.
  • Design drainage and erosion controls to avoid drying, waterlogging or sediment deposition in retained forest.
  • Include indirect effects from road widening, noise, night lighting and increased access in the project fauna assessment.

Survey methodology: 1. Diurnal searches and call playback

Survey the Olive Whistler in wet forest on ranges, particularly forest above 500 m. It is a small, quiet bird that feeds on berries and insects, so surveys should combine direct observation with call detection and targeted searches of retained wet forest.

Search retained wet forest and rainforest edges during the breeding period from September to January, when birds may be calling and breeding activity is occurring.

Use quiet walking transects through suitable forest, stopping regularly to listen and scan the mid-storey and canopy for the bird or its distinctive calls.

Record the observer, date, start and finish times, weather, route, habitat type, elevation where available, and every visual or aural detection.

Use call playback only where authorised by the relevant state agency, and record the call, volume, duration and response so repeated disturbance can be managed.

Breeding period: September to January

Reported habitat: Wet forests of ranges on the east coast, generally above 500 m in the Richmond to Tweed area

Diet noted in the supplied material: Berries and insects

  • Prioritise wet forest above 500 m, forest on ranges, dense vegetation and areas with abundant fruiting shrubs or trees.
  • Do not treat a single quiet survey as evidence that the species is absent, because the available Eden modelling dataset included both presence only and presence or absence records and the species had 54 total records in that project.

Survey methodology: 2. Dawn and dusk observation

Conduct observation during the first hours after dawn and, where site access permits, the period before dusk, when birds are more likely to move and call.

Spend enough time at each survey point to inspect dense wet forest, forest edges and fruiting vegetation rather than relying only on a straight-line traverse.

Use binoculars and a camera or field notebook to document uncertain records without approaching or pursuing the bird.

  • Record negative results as well as detections, including the area searched and the conditions during the search.
  • Avoid surveys in heavy rain or strong wind where visibility and sound detection are reduced, and document any weather interruption.

Survey methodology: 3. Targeted habitat and impact-area assessment

Before clearing, map all wet forest, rainforest patches, dense understorey, fruiting plants and connecting vegetation within the disturbance footprint and nearby retained areas.

Inspect the proposed impact area and adjacent retained habitat for recent records, feeding activity, calls and movement routes between forest patches.

Use the assessment to identify whether the work could remove or isolate wet forest habitat, because clearing and fragmentation are reported threats to the species.

  • Extend the search beyond the immediate clearing boundary where retained forest is connected to the work area or could be affected by noise, dust, fire or access tracks.
  • Have a qualified ecologist assess the significance of any Olive Whistler record and determine whether additional targeted survey is needed before works proceed.

Survey methodology: Minimum effort and reporting

  • Prepare a survey plan before fieldwork that states the survey area, dates, observers, methods, weather, effort, equipment and limitations.
  • Use the state survey guideline and permit conditions that apply to the project and species, because the supplied documents do not provide a species-specific survey effort such as a set number of nights, trap nights or transect kilometres.
  • Submit verified records, including zero results where required, to the relevant state wildlife database and retain the coordinates, photographs, call recordings and field sheets in the project record.
  • Report any record that changes the impact assessment to the project ecologist, environmental officer and relevant regulator before clearing continues.

Before habitat disturbance: Avoid and minimise

Plan the work around the Olive Whistler's wet forest habitat and September to January breeding period. The main controls are to retain suitable forest, avoid fragmentation and confirm state approval requirements before disturbance.

Avoid clearing wet forest on ranges and forest above 500 m wherever practicable.

Retain connected wet forest, dense understorey and fruiting vegetation, including habitat immediately beside the clearing footprint.

Keep machinery, spoil, access tracks, lighting and storage areas out of retained habitat so that the work does not create additional fragmentation or disturbance.

  • Use the smallest practicable clearing footprint and place temporary facilities in already cleared or degraded areas.
  • Maintain a continuous vegetated connection between retained wet forest patches where one occurs through or beside the project area.
  • Treat fire, foxes and cats as project risks because they are identified threats to the species.

Before habitat disturbance: Approvals and timing

Confirm the current Commonwealth and state conservation status before works begin, and obtain any required state wildlife permits or authority for survey, handling, relocation or disturbance.

The supplied material identifies the Olive Whistler as Vulnerable in New South Wales and does not identify it as nationally listed, so check the current EPBC Act list and referral requirements rather than assuming a referral is unnecessary.

Schedule clearing outside September to January where practicable, or obtain advice from the relevant regulator and the project ecologist if work during that period cannot be avoided.

  • Document the approval pathway, species status check, conditions and nominated fauna spotter catcher in the environmental management plan.
  • Stage clearing so that retained wet forest remains available while each work area is completed.

Before habitat disturbance: Site preparation

Complete a pre-clearance inspection of the footprint and nearby retained wet forest shortly before works begin.

Mark the approved clearing boundary, retained vegetation, access routes and no-go areas with high-visibility bunting or fencing before machinery arrives.

Fence or otherwise exclude machinery from retained habitat where a physical barrier can be installed without blocking fauna movement.

Brief all operators on the Olive Whistler's appearance, habitat, stop-work procedure and the requirement to follow the fauna spotter catcher's directions.

  • Inspect for active birds, nests, injured fauna and feeding activity before each staged clearing area is opened.
  • Place stockpiles, lighting, generators and wash-down areas outside retained wet forest and away from likely movement routes.

During habitat disturbance: Daily controls and machinery coordination

Use a fauna spotter catcher with authority to direct machinery and stop work. Work progressively, keep retained wet forest protected and respond immediately to any Olive Whistler sighting or injury.

Complete a daily pre-start inspection of the work area, exclusion fencing, retained vegetation and access routes.

Keep the fauna spotter catcher ahead of clearing machinery and give them a clear line of communication with the operator.

Clear vegetation progressively from the approved edge towards retained habitat, allowing animals to move away from machinery where safe.

Stop machinery immediately when the fauna spotter catcher gives a stop signal, and do not resume until the area has been checked and the spotter catcher releases it.

  • Do not allow workers to chase, corner, feed, photograph at close range or handle an Olive Whistler without authorisation and suitable training.
  • Keep dogs, unauthorised personnel and vehicles out of retained habitat and any temporary holding area.
  • Control dust, noise, lighting and fire so they do not spread into retained wet forest beyond the approved disturbance area.

During habitat disturbance: Habitat feature handling

Treat dense wet forest, fruiting vegetation and connected understorey as fauna habitat and retain it unless its removal is approved.

Inspect vegetation scheduled for removal for birds, nests and other fauna before each tree or shrub is felled.

If a habitat feature must be removed, use the approved fauna management procedure and have the fauna spotter catcher inspect the feature before, during and after removal.

Do not burn cleared vegetation or leave slash where it blocks retained habitat connections unless the approved management plan allows it.

  • Place salvaged logs, rocks and other approved habitat material in nearby retained habitat only where this will not damage existing vegetation or create a fire or pest risk.
  • Do not install nest boxes or move habitat features as a substitute for avoiding intact wet forest unless the project ecologist and regulator approve that action.
  • Protect nearby fruiting plants and dense understorey from accidental damage by machinery, fire and storage.

During habitat disturbance: Animal encounter, stop work and records

If an Olive Whistler is found, stop work in the immediate area, keep people and machinery back, and allow the bird to leave naturally if it can fly safely.

If the bird is injured, trapped or unable to leave, have it assessed and handled only by an authorised and appropriately trained person under the project fauna management plan and permit conditions.

Relocate a healthy bird only when necessary, using a suitably ventilated container and placing it in nearby retained wet forest selected by the ecologist, with the release location and time recorded.

Send an injured bird to an experienced wildlife carer or veterinarian as soon as practicable, and record the transfer and outcome.

  • Stop work if the species is detected within the active work area, if an occupied nest is found, if exclusion fencing fails, or if the approved clearing boundary is breached.
  • Record every detection, attempted capture, relocation, injury, mortality and release, including coordinates, date, time, habitat, people involved and photographs where appropriate.
  • Notify the project environmental officer and relevant regulator of any mortality, repeated detections, nest disturbance or breach of an approval condition.

After habitat disturbance: Post-clearance checks

Confirm that clearing controls worked and that retained wet forest remains connected and undamaged. Continue monitoring where the project has removed habitat, altered access or increased fire, predator or fragmentation risks.

Inspect the completed clearing area and its boundary for stranded, injured or dead birds and for damage to retained wet forest.

Check exclusion fencing, signage, access controls and rehabilitation barriers at the end of each work stage and after storms or other events that could damage them.

Confirm that no spoil, slash, machinery or lighting has entered retained habitat or blocked a vegetated connection.

  • Keep a fauna spotter catcher or qualified ecologist available for the period specified in the approved fauna management plan after each clearing stage.
  • Repeat targeted searches if Olive Whistlers were detected before or during clearing, or if suitable habitat remains beside the work area.

After habitat disturbance: Monitoring and reporting

Monitor retained wet forest and any adjoining rehabilitation during the period and at the frequency specified by the project approval or fauna management plan.

Use the same mapped observation points or transects where possible so that changes in detections, vegetation condition and connectivity can be compared over time.

Report survey effort, detections, injuries, deaths, control failures, rehabilitation progress and corrective actions to the project environmental officer and regulator where required.

  • Update the state wildlife database with verified records and submit any required incident or compliance reports.
  • Review the control measures if the species is repeatedly detected near the works, if habitat becomes isolated, or if fire, fox or cat activity increases.

After habitat disturbance: Offsets and corrective action

Confirm whether the approved impact assessment requires an offset, habitat restoration measure or other compensatory action for residual loss of wet forest habitat.

Use the project approval and current state policy to determine the location, security and management requirements for any offset or conservation measure.

Apply corrective actions promptly where clearing exceeded the approved footprint or retained vegetation was damaged.

  • Do not count an offset as permission to remove avoidable wet forest habitat.
  • Document the area, condition and tenure of any offset or conservation area in the final environmental report.

Rehabilitation actions: Restore wet forest structure

Rehabilitation should recreate connected wet forest structure and protect the retained habitat that supports the Olive Whistler. The supplied material does not specify a planting list or nest-box design, so use a local reference site and the approved restoration plan rather than selecting species or structures generically.

Revegetate cleared edges and temporary work areas with locally sourced native plants appropriate to the original wet forest and range habitat.

Prioritise dense understorey, mid-storey cover and fruiting plants because the species is reported from wet forest, feeds on berries and insects, and may be affected by habitat fragmentation.

Remove compacted soil, control erosion and prevent weeds from replacing native understorey along the rehabilitation edge.

  • Use local provenance seed or tubestock where available and record the species, source, planting date and area planted.
  • Do not plant invasive, non-local or fire-promoting species in or beside retained wet forest.
  • Reinstate a continuous vegetated connection between retained patches where the project has created a break.

Rehabilitation actions: Habitat features and threats

Retain suitable fallen timber and other approved natural habitat features in rehabilitation areas where they do not create a fire, safety or pest hazard.

Install nest boxes only if a qualified ecologist identifies a site-specific need and the approved plan specifies their design, placement, inspection and maintenance.

Manage foxes and cats around retained and rehabilitated habitat in accordance with approved control programmes, because both are identified threats to the species.

Plan fire management with the relevant land manager so that fire does not remove wet forest understorey or isolate retained patches.

  • Control weeds before they dominate the understorey and continue treatment until native cover is established.
  • Prevent new access tracks, informal vehicle access and stock access through rehabilitated wet forest.
  • Do not move logs, rocks or other material from intact wet forest to another location unless the action is authorised and will not damage the source habitat.

Rehabilitation actions: Success measures and monitoring

Monitor plant survival, native understorey cover, weed cover, erosion, connectivity and damage from fire, vehicles or pests at the intervals required by the approval.

Use nearby undisturbed wet forest as a reference for vegetation structure and record whether rehabilitation is becoming dense enough to provide suitable cover.

Include targeted Olive Whistler searches during the September to January breeding period where the project has affected suitable habitat and monitoring is required.

Species breeding period to consider in monitoring: September to January

Habitat condition to monitor: Wet forest on ranges, including forest above 500 m where relevant to the local population

  • Set measurable completion criteria in the rehabilitation plan for plant survival, native cover, weed control, stable soil and an unbroken vegetated connection.
  • Replace failed plants, repair erosion, remove weeds and repair fencing when monitoring shows that a criterion is not being met.
  • Retain monitoring records, photographs from fixed points, maps, survey results and corrective actions for the life of the approval or management commitment.

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