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Grey Grasswren (Amytornis barbatus)

The Grey Grasswren is a small, secretive grasswren restricted to dense lignum, canegrass and sedge communities on inland Australian floodplains and overflow channels. It is listed as Endangered under the EPBC Act and in New South Wales and Queensland, so clearing, fire, grazing, hydrological change and disturbance within dense wetland vegetation require careful assessment.

Conservation status

Commonwealth, EPBC Act 1999: Endangered.

Queensland, Nature Conservation Act 1992: Endangered.

New South Wales, Biodiversity Conservation Act 2016: Endangered.

Breeding season

The species is largely sedentary, but floods and droughts can cause local movements. Breeding records are concentrated in July and August, with recently fledged chicks recorded in August.

Month values are January to December. A value of 0 means not typical, 1 means occurs, and 2 means peak. The breeding calendar is based on the records and observations provided in the supplied documents, not on a complete year-round study.

  • Breeding: Eggs and young have been recorded in July and August. A likely clutch is two eggs, with incubation reported as approximately 13 to 15 days.
  • Young: Recently fledged chicks have been observed in August. The supplied sources do not define the full dependency period.
  • Movement: The species is thought to be largely sedentary, but local movements may occur in response to floods and droughts. Groups of 15 to 40 may forage together outside the breeding season.
  • Highest clearing risk: Clearing or disturbance is most likely to harm the species during the July and August breeding period and around the period when dependent or recently fledged young are present. Dense habitat should be treated as potentially occupied outside these months because the species is sedentary and difficult to detect.

Identification

The Grey Grasswren is a pale grey to cinnamon grasswren with a contrasting black and white facial pattern. It is difficult to see in dense lignum, but may call from the top of bushes when undisturbed.

Adults are 18 to 20 cm long and have grey, ginger-brown and off-white streaked plumage. The head has a broad white superciliary stripe, a black stripe through the eye and a thin black malar line around the throat. The central tail feathers are elongated beyond the adjacent feathers.

Both sexes are similarly coloured. Females and juveniles are generally paler, and juveniles lack the strong adult facial pattern.

Length: 18 to 20 cm

Weight: 15 to 23 g

Plumage: Grey, ginger-brown and off-white with heavy breast streaking

Identification: Similar species

The main identification issue is confusion with the Diamantina River subspecies, Amytornis barbatus diamantina. The two distributions do not overlap, which assists identification where the location is known.

Compared with A. b. diamantina, the Grey Grasswren has less distance between the tips of the black throat crescents and heavier streaking on the breast.

Identification: Calls, nests and field signs

The species is shy and secretive. It may be detected by a soft double-syllable note, a series of three or four high-pitched metallic notes described as a pit-choo sound, or a high-pitched sit-sit-sit call.

It sometimes ventures onto open ground between vegetation clumps to forage, but most observations are from dense lignum. A loose, bulky grass nest is built in lignum or canegrass, usually 30 to 75 cm above the ground.

Species-specific tracks, scats, sloughed skin and eyeshine are not described in the supplied documents. Do not rely on these signs for identification. Playback combined with area searches is the recommended survey approach.

Recommended survey effort for areas under 50 ha: 15 hours over 3 days of area or transect searches, plus 15 hours over 3 days of broadcast surveys

  • Search the tops and edges of dense lignum for calling or preening birds while keeping observers quiet and still.
  • Inspect suitable lignum and canegrass carefully for loose grass nests between 30 and 75 cm above ground.
  • Use broadcast surveys with area searches rather than relying on visual detection alone.

Distribution: National range

The Grey Grasswren is endemic to Australia and has a restricted distribution in the inland Channel Country. Records are associated with tributaries and overflow systems of the Diamantina, Cooper and Bulloo drainage systems.

The known range includes south-western Queensland, north-western New South Wales and parts of South Australia. In New South Wales, the species is recorded from Caryapundy Swamp above the Bulloo Overflow, also known as Bulloorine.

The known New South Wales range is estimated in the supplied fact sheet to be less than 100 km by 100 km.

Australian states recorded: Queensland, New South Wales and South Australia

Estimated New South Wales range: Less than 100 km by 100 km

IBRA bioregion: Channel Country

Recorded Channel Country subregions: Bulloo, Core Ranges and Sturt Stony Desert

  • Queensland: lower Bulloo River and the wider Channel Country.
  • New South Wales: Caryapundy Swamp and the Bulloo Overflow area.
  • South Australia: lower Cooper Creek, the Kallakoopah anabranch of the Diamantina River, and overflow areas of lakes Machattie, Koolivoo and Mipea on Eyre Creek.

Distribution: Strongholds and population status

Caryapundy Swamp and the Bulloo Overflow are identified as important New South Wales habitat. Other known areas include dense lignum systems along the lower Bulloo, lower Cooper Creek, Diamantina and Eyre Creek overflow systems.

The supplied documents do not provide a reliable national population estimate, generation length or quantified population trend. They identify uncertainty about the full distribution of the population and its habitat.

National population size: Not stated in the supplied documents

Population trend: No quantified national trend is stated in the supplied documents

Known New South Wales site: Caryapundy Swamp above the Bulloo Overflow

  • Treat occupied or potentially occupied lignum wetlands as important habitat even when recent sightings are absent.
  • Use regional habitat mapping and historical records to define survey areas because the species is difficult to detect visually.

Habitat: Wetland and floodplain habitat

Grey Grasswrens occupy dense wetland vegetation in the arid Channel Country. Their habitat is defined more by vegetation structure and floodplain position than by permanent surface water.

The species occurs in swampy floodplains, overflow channels and flood pans associated with the Bulloo, Cooper, Diamantina and Eyre drainage systems. It is usually associated with dense, tall lignum interspersed with canegrass, sedges or samphire.

Old Man Saltbush close to lignum is also used. When lignum areas are flooded, birds may move into canegrass or Old Man Saltbush on nearby sand dunes.

  • Dense lignum thickets, including vegetation reported as Muehlenbeckia florulenta and Muehlenbeckia cunninghamii in the supplied sources.
  • Associated sandhill canegrass, Zygochloa paradoxa.
  • Sedge, samphire, spike-rush, channel millet and other dense wetland understorey.
  • Lignum and canegrass around swamps, overflow channels and flood pans.

Habitat: Structural requirements

The species requires dense, tall vegetation that provides continuous cover close to the ground and suitable stems for nesting. Open ground may be used briefly for foraging, but is not a substitute for dense cover.

The supplied documents do not give an elevation limit. They describe an arid inland floodplain species whose habitat value changes with flooding, drought, grazing and fire.

Elevation limit: Not stated in the supplied documents

Climate setting: Arid inland Channel Country

  • Retain mature lignum stands and connected dense understorey.
  • Avoid creating gaps through clearing, vehicle movement, fire or intensive grazing.
  • Map overflow channels, flood pans, swamps and nearby dune vegetation before works begin.
  • Maintain wetland hydrology and allow lignum and associated understorey to regenerate.

Foraging habitat: Diet and feeding sites

Grey Grasswrens forage mainly within dense lignum and associated grasses and sedges. They may move onto open ground between vegetation clumps, particularly where dense cover remains nearby.

Insect larvae make up the bulk of the recorded diet. Mature insects and occasional water snails are also eaten. One supplied source reports small seeds as part of the diet, but the government species profiles emphasise insect larvae, mature insects and water snails.

Foraging occurs almost entirely within dense, tall lignum, with associated canegrass, sedges and other wetland vegetation. Birds sometimes forage on open ground between clumps.

Main food: Insect larvae

Additional food: Mature insects, occasional water snails and reported small seeds

Foraging territories: 10 to 100 ha, with a preliminary mean of 57 ha

  • Retain dense lignum, canegrass and sedge structure that supports insect prey.
  • Avoid removing ground cover or disturbing wetland margins used between vegetation clumps.
  • Protect adjacent Old Man Saltbush and dune vegetation because birds may use these areas when lignum is flooded.

Foraging habitat: Groups and seasonal conditions

Breeding birds are thought to occur in territorial pairs. Outside the breeding season, groups of 15 to 40 individuals may forage together.

The species is not dependent on surface water and can persist in dense lignum for several dry years. Floods and droughts can alter where birds forage and may prompt local movements.

  • Assess the full area of dense lignum and associated vegetation, not only wet ground or areas holding surface water during the survey.
  • Record groups, feeding locations and movement between lignum, canegrass and nearby saltbush.

Breeding habitat: Breeding biology

Breeding information is limited, but nests and young have been recorded in winter. Dense lignum and canegrass provide both nesting material and concealment.

The species is thought to breed mainly in July and August. Recently fledged chicks have been observed in August. Breeding is associated with territorial pairs, although detailed breeding behaviour is not well documented.

Nests are loose and bulky and are placed in lignum or canegrass, 30 to 75 cm above the ground. The supplied sources report a likely clutch of two eggs and an incubation period of approximately 13 to 15 days, but age at maturity and lifespan are not stated.

Breeding season: July and August records of eggs, young and recently fledged chicks

Clutch size: Thought to be 2 eggs

Incubation: Approximately 13 to 15 days

Nest position: 30 to 75 cm above ground in lignum or canegrass

Age at maturity: Not stated in the supplied documents

Lifespan: Not stated in the supplied documents

Breeding habitat: Breeding habitat features

Breeding habitat consists of dense, tall lignum and associated canegrass or sedges on swampy floodplains, overflow channels and flood pans. The vegetation must provide concealed nesting sites above ground and dense cover for adults and young.

Clearing, burning, heavy grazing or vehicle access through nesting vegetation can remove nests and reduce cover during the breeding period.

  • Retain lignum and canegrass stands with dense stems from ground level to at least 75 cm above ground.
  • Avoid disturbance in occupied or suitable nesting habitat during July and August where practicable.
  • Inspect dense vegetation before clearing and use experienced threatened bird surveyors where habitat is present.

Sheltering habitat: Cover and refuge

The Grey Grasswren shelters, roosts, feeds and nests mainly within dense lignum and associated grasses. Dense vegetation is especially important because the species is secretive and difficult to detect.

Dense, tall lignum is the primary sheltering habitat. Canegrass, sedges, samphire and nearby Old Man Saltbush provide additional cover, especially when lignum areas are flooded.

During drought, birds may remain in tall, dense lignum. During floods, they may use canegrass or Old Man Saltbush on surrounding sand dunes.

  • Retain continuous dense vegetation around swamps, flood pans and overflow channels.
  • Avoid slash piles, machinery movements or access tracks that divide lignum stands.
  • Maintain nearby canegrass, sedge and saltbush cover as alternative refuge during flooding.

Sheltering habitat: Roosts and nests

The supplied documents do not describe separate roost structures, cavities, burrows or dens. Birds are described as ground and tussock birds that shelter within dense vegetation.

Nests are loose and bulky grass structures in lignum or canegrass, 30 to 75 cm above the ground. The species may be seen perched and preening at the top of lignum when undisturbed.

Known nest height: 30 to 75 cm above ground

Other shelter structures: No separate burrows, hollows or dens are described in the supplied documents

  • Do not assume that an absence of visible nests means the habitat is unused.
  • Search dense vegetation carefully and minimise disturbance during inspections.
  • Treat dense lignum and canegrass as potential shelter, roosting and nesting habitat throughout the year.

Threats: Clearing, construction and access

The main project risks are loss or thinning of dense lignum and associated ground cover, altered flooding, fire and disturbance during breeding. The species is also exposed to grazing, feral animals and introduced predators.

Clearing lignum directly removes shelter, feeding habitat and nest sites. Fire can also destroy lignum habitat and food resources, while intensive grazing can reduce the density of lignum thickets and associated ground cover.

Construction compounds, access tracks, laydown areas and utility corridors can damage habitat even where the main clearing footprint is small. The supplied species information does not quantify a road avoidance distance or identify roads as a separate species-specific threat.

  • Avoid clearing dense lignum, canegrass, sedge and nearby saltbush in floodplain and overflow habitats.
  • Keep machinery, vehicles, stockpiles and worker access out of retained lignum stands.
  • Fence exclusion zones before works and mark them clearly on plans and in the field.
  • Use pre-clearing surveys and a spotter catcher familiar with cryptic grasswrens where suitable habitat cannot be avoided.
  • Stop work and obtain ecological advice if a nest, pair, group or repeated call location is found.

Threats: Grazing and feral herbivores

Cattle and rabbits are identified as important causes of habitat damage in New South Wales. Cattle, particularly during dry years, damage lignum and canegrass. Rabbits eat lignum bark, and ring-barking can thin stands.

Goats and other feral herbivores can add grazing pressure and degrade habitat. The supplied national assessment notes that the relationship between grazing and artificial watering points is not necessarily direct in this species because core habitat is in natural wetlands.

  • Exclude stock from retained lignum and canegrass where practicable.
  • Control rabbits and other herbivores that thin lignum or reduce ground cover.
  • Prevent new access to wetland habitat through poorly located tracks, watering infrastructure or work areas.

Threats: Fire and hydrology

Fire can destroy lignum habitat and food resources. Burning all suitable habitat in one event can leave birds without shelter or feeding cover.

Hydrological changes can alter flooding patterns, vegetation structure and habitat value. The species is not dependent on permanent surface water, but its wetland vegetation is influenced by floods and droughts.

  • Retain unburned sections of habitat during hazard reduction and wildfire management.
  • Plan fire so that not all dense lignum and associated food resources are burned at once.
  • Assess changes to floodplain flows, drainage, culverts, levees and water regulation before works begin.
  • Maintain natural wetting and drying patterns where possible.

Threats: Predators, disease and fragmentation

Foxes and cats are likely predators, although their effects on the species have not been quantified in the supplied documents. Feral pigs disturb lignum and degrade ground cover.

The supplied documents do not identify a species-specific disease threat. Fragmentation is not separately quantified, but loss of dense vegetation can reduce the connected cover needed for shelter, feeding and movement.

  • Control foxes, cats, pigs, rabbits and other vertebrate pests where they affect occupied habitat.
  • Retain connected lignum and canegrass stands rather than isolated patches.
  • Record predator activity and habitat damage during site inspections and post-construction monitoring.

Survey methodology: 1. Area searches and transects

Survey the Grey Grasswren where dense lignum and associated canegrass, sedges or samphire occur in swamps, overflow channels and flood pans. The species is shy and secretive, so use call detection with systematic searches rather than relying on casual sightings.

Search suitable habitat systematically because Grey Grasswrens are difficult to see in dense vegetation but may call or perch on top of lignum when undisturbed.

Give priority to dense, tall lignum, associated canegrass and sedges, and nearby Old Man Saltbush where the species may forage when lignum is flooded.

The survey guideline specifies 15 hours over 3 days for area searches or transect surveys in areas smaller than 50 hectares.

Survey effort: 15 hours over 3 days

Indicative survey area: Less than 50 hectares

Detection notes: Shy and secretive; may call from the tops of bushes, but is difficult to see in dense habitat

  • Conduct searches slowly through or along the edges of suitable thickets, looking and listening for birds moving between vegetation clumps or briefly using open ground.
  • Record the location of each detection, the vegetation type, the direction of movement and whether the bird was seen or heard.

Survey methodology: 2. Broadcast surveys

Use broadcast, or playback, surveys in combination with area searches because this is the recommended approach for the Grey Grasswren.

The guideline does not specify a particular breeding or seasonal window for broadcast surveys in the species account, so schedule the work when suitable habitat is accessible and avoid conditions that could damage wetland or lignum habitat.

Survey effort: 15 hours over 3 days

Recommended combination: Broadcast surveys with area searches

Key habitat: Dense lignum with associated canegrass, sedges or samphire on swampy floodplains

  • Apply the survey guideline effort of 15 hours over 3 days in areas smaller than 50 hectares.
  • Position observers to detect birds responding from dense lignum and associated canegrass, and allow time to distinguish a response from other grasswren calls.
  • Record the broadcast locations, timing, weather, call sequence used, responses, sightings and any evidence that birds were disturbed.

Survey methodology: 3. Timing, conditions and supplementary methods

Breeding records include eggs or young in July and August, with recently fledged chicks observed in August. Use this period to identify breeding activity, but do not treat the absence of breeding activity as evidence that the site is unoccupied.

The species is thought to be largely sedentary, although movements may occur with floods and droughts, and groups of 15 to 40 birds may forage together outside the breeding season.

The species is generally not dependent on surface water and can persist in dense lignum habitat when it is dry for several years.

Recorded breeding period: July and August

Non-breeding group size: 15 to 40 individuals

Indicative foraging territory: 10 to 100 hectares, with a reported mean of 57 hectares

  • Plan repeated or supplementary searches where flood or drought conditions may have changed habitat use.
  • Avoid entering wetland habitat when access would damage lignum, canegrass, sedges or floodplain soils.
  • Use mist-netting only where banding is required and only in combination with broadcast surveys, as stated in the survey guideline.
  • Do not claim that a site is free of Grey Grasswrens solely because birds were not seen during a short or poorly timed search.

Survey methodology: Minimum effort and reporting

  • Complete, at minimum, 15 hours over 3 days of area searches or transect surveys and 15 hours over 3 days of broadcast surveys for suitable areas smaller than 50 hectares, unless an evidence-based alternative is documented.
  • Map all suitable lignum habitat, survey tracks, broadcast points, detections, nests, flocks and areas not surveyed because of access or safety constraints.
  • Report survey dates, start and finish times, observers, methods, effort, weather, flood or drought conditions, habitat condition and detection results.
  • Submit confirmed records and relevant negative survey information to the relevant state wildlife database and provide records to the project approval authority.
  • Use the survey results with a regional habitat assessment and the species' national, regional and site importance when assessing whether the proposed action may have a significant impact.

Before habitat disturbance: Avoid and minimise

Treat dense lignum wetland habitat as potential Grey Grasswren habitat before clearing, even when birds are hard to detect. The species uses lignum for shelter, roosting, nesting and feeding, and its known range is restricted in parts of inland Australia.

Avoid clearing dense, tall lignum in swamps, overflow channels and flood pans, including associated canegrass, sedges and samphire.

Retain Old Man Saltbush close to lignum where it forms part of the habitat used for foraging or refuge during flooding.

Retain connected patches of lignum and surrounding floodplain vegetation rather than isolating small thickets.

Avoid works that alter flooding patterns, water regulation or wetland structure because hydrological change can reduce the value of habitat.

  • Redesign access tracks, compounds, laydown areas and drainage where they would remove or divide lignum habitat.
  • Keep machinery, spoil, fuels and stockpiles out of retained wetland vegetation.
  • Treat all dense lignum habitat within the project footprint and adjoining work area as potential habitat until survey and ecological assessment show otherwise.

Before habitat disturbance: Approvals and project planning

Confirm the current Commonwealth and state listing status before works begin. The supplied project information identifies the species as nationally listed and endangered in New South Wales and Queensland, while the 2017 survey guideline reproduces an earlier vulnerable classification for the Bulloo subspecies.

Assess whether the action requires an EPBC Act referral and obtain any required state approvals, licences or threatened species permits before clearing.

Prepare a fauna management plan that identifies habitat to be retained, survey effort, exclusion zones, fauna handling arrangements, stop-work triggers, wetland controls and reporting responsibilities.

  • Obtain advice from the relevant Commonwealth and state environment agencies where the proposed action may affect listed Grey Grasswren habitat.
  • Stage works so habitat is cleared only after the pre-clearance survey, marking and fauna management controls are complete.
  • Schedule works to avoid the July and August period where practicable, particularly where nests, eggs or recently fledged young may be present.

Before habitat disturbance: Site preparation

Complete the targeted pre-clearance survey using area searches and broadcast surveys before vegetation disturbance.

Mark retained lignum, canegrass, sedge and wetland areas in the field, and clearly identify no-go zones on construction drawings and GPS data.

Use exclusion fencing where it can protect retained habitat from machinery, vehicles, workers, grazing stock and accidental spoil placement.

Inspect the work area for nests in lignum or canegrass because nests may be 30 to 75 centimetres above the ground.

Typical nest height: 30 to 75 centimetres above ground

Main habitat plants: Dense lignum, associated sandhill canegrass and sedges

  • Brief machinery operators and the fauna spotter catcher on the habitat map, exclusion zones, access routes, stop-work triggers and reporting process.
  • Check fencing and signs daily before machinery enters the work area.
  • Do not burn, mechanically remove or prune retained lignum unless the approved impact assessment and fauna management plan specifically allow it.

During habitat disturbance: Daily controls and machinery interface

Keep the fauna spotter catcher involved throughout vegetation removal and ground disturbance in or near potential habitat. The spotter catcher must be able to direct machinery, stop work and protect retained lignum and wetland features.

Inspect exclusion fencing, signs, access routes, retained vegetation and wetland controls before work starts each day.

Maintain a clear line of communication between the fauna spotter catcher, supervisor and machinery operators.

Clear vegetation in stages and at a speed that allows the spotter catcher to inspect dense lignum and canegrass before the next section is disturbed.

  • Keep machinery outside marked habitat and no-go zones unless the approved method specifically requires entry.
  • Stop machinery immediately when the fauna spotter catcher identifies a Grey Grasswren, nest, dependent young, injured animal or unexpected habitat feature in the active work area.
  • Do not allow workers to chase birds through dense lignum or use machinery to flush them from retained habitat.
  • Keep spoil, sediment, fuel, concrete washout and water discharge away from retained wetland habitat.

During habitat disturbance: Fauna handling and relocation

Grey Grasswrens shelter, roost, nest and feed almost entirely within dense lignum and associated grasses, so inspect the vegetation carefully before removing it.

Only an appropriately authorised and licensed fauna handler should capture, handle or relocate a bird.

If a bird is found, stop work, allow it to move into nearby retained habitat where safe, and follow the fauna management plan rather than attempting unnecessary capture.

Relocate an animal only to suitable nearby retained habitat identified in the plan and approved by the relevant authority.

  • Keep people and machinery away from the bird while the fauna spotter catcher assesses whether it can leave without handling.
  • Do not disturb an active nest, eggs or dependent young; establish a temporary exclusion zone and obtain advice from the project ecologist and relevant authority.
  • Take an injured bird to an appropriately qualified veterinarian or authorised wildlife carer as soon as practicable.
  • Record the location, condition, action taken, handler, relocation site and final outcome for every handled or injured animal.

During habitat disturbance: Stop-work triggers and records

Stop work in the affected area when a Grey Grasswren is detected within the disturbance zone, when an active nest or dependent young is found, or when clearing begins to affect retained lignum or wetland habitat outside the approved footprint.

Stop work when flooding, access conditions, fire or machinery movement could damage habitat or prevent the fauna spotter catcher from safely inspecting the work area.

  • Notify the site supervisor and project ecologist immediately after a stop-work trigger.
  • Define the exclusion distance and restart conditions with the project ecologist and relevant approval authority, because the supplied documents do not prescribe a species-specific construction buffer.
  • Record daily effort, cleared area, habitat condition, detections, nests, stop-work events, fauna interactions, injuries, relocations and corrective actions.
  • Photograph and map any unexpected clearing, hydrological change, fire damage or damage to retained lignum.

After habitat disturbance: Post-clearance checks

Post-clearance work must confirm that no birds, nests or dependent young remain at risk and that retained lignum and wetland habitat are still protected. Continue controls until construction no longer threatens the habitat.

Complete a fauna spotter catcher inspection of the cleared area, adjoining retained lignum and access edges after each staged clearing event.

Check disturbed areas for birds, nests, injured fauna and habitat damage that was not recorded during clearing.

Reinspect areas where dense vegetation, flooding or machinery access prevented a reliable pre-clearance inspection.

  • Keep exclusion fencing and no-go zones in place until the supervisor and project ecologist confirm that the construction risk has ended.
  • Repair damaged fencing, sediment controls and wetland protection measures promptly.
  • Report any Grey Grasswren detection after clearing as a project fauna incident and reassess the remaining works.

After habitat disturbance: Monitoring and reporting

Monitor retained lignum, canegrass, sedges, samphire and nearby wetland areas for damage, weed invasion, altered flooding and continued habitat use.

Where the approval or fauna management plan requires species monitoring, use repeat area searches and broadcast surveys and keep the effort and method consistent between monitoring events.

Report construction impacts, survey results, fauna incidents, habitat loss, rehabilitation progress and any required corrective actions to the relevant approval authority.

  • Submit confirmed records to the relevant state wildlife database and update the project spatial register.
  • Retain maps, photographs, observer details, survey data, handling records and authority notifications with the project environmental records.
  • Escalate evidence of changed flooding patterns, loss of lignum density or continuing disturbance to the project ecologist and approval holder.

After habitat disturbance: Offsets and residual impacts

Reassess residual impacts where clearing, hydrological change, fire, grazing or pest control has affected suitable Grey Grasswren habitat.

Apply any Commonwealth or state offset, restoration or compensatory habitat requirement specified by the project approval.

Do not use an offset as a substitute for avoiding and minimising damage to existing dense lignum wetland habitat.

  • Document the area and condition of habitat lost, retained, restored or protected.
  • Confirm that any offset or compensatory site supports the same habitat features used by the species, including dense lignum and associated floodplain vegetation.
  • Continue management commitments for the period specified in the approval or fauna management plan.

Rehabilitation actions: Restore habitat structure

Rehabilitation should rebuild dense, structurally diverse wetland vegetation and restore the flooding conditions that support Grey Grasswren habitat. The immediate target is functional lignum habitat, not simply groundcover on a disturbed surface.

Protect natural regeneration of lignum in swamps, overflow channels and flood pans wherever the soil and hydrology remain suitable.

Re-establish or protect associated sandhill canegrass, sedges and samphire, and retain nearby Old Man Saltbush where it forms part of the habitat mosaic.

Maintain dense patches with enough mature structure for shelter, roosting, feeding and nests 30 to 75 centimetres above ground.

Nest structure to support: Lignum or canegrass between 30 and 75 centimetres above ground

Habitat features: Dense, tall lignum with associated canegrass, sedges or samphire in wetland floodplain areas

  • Remove spoil, compacted fill and temporary infrastructure that prevents wetland vegetation from regenerating.
  • Use locally appropriate provenance and methods approved by the project ecologist or land manager where planting or direct seeding is needed.
  • Prevent stock and feral herbivores from entering recovering lignum and canegrass until vegetation has regenerated and can withstand grazing pressure.

Rehabilitation actions: Restore hydrology and manage threats

Restore natural or approved flooding patterns where construction has altered water movement, because hydrological changes can alter the structure and value of Grey Grasswren habitat.

Control cattle, rabbits, goats, pigs and other introduced herbivores where they reduce lignum density, damage canegrass or degrade groundcover.

Control foxes and cats where required under the approved recovery or pest management programme, because predation is a recognised threat although its effects are not fully known.

  • Keep drainage, culverts, crossings and water regulation structures from concentrating flows or drying retained wetland habitat beyond the approved design.
  • Manage weeds so they do not replace lignum, canegrass, sedges or samphire.
  • Prepare a fire plan that avoids burning all habitat and food resources in a region at one time.
  • Retain unburnt refuge habitat and allow vegetation to complete seed set, germination, establishment and growth to maturity.

Rehabilitation actions: Success measures and monitoring

Set rehabilitation success measures around the return and persistence of dense lignum habitat, associated wetland vegetation, suitable flooding patterns and reduced grazing or pest damage.

Monitor vegetation density, regeneration, weed cover, signs of grazing, hydrological condition and fire impacts at agreed intervals.

Use area searches and broadcast surveys to test whether Grey Grasswrens use rehabilitated or retained habitat once vegetation has recovered sufficiently.

Indicative group size to record: 15 to 40 birds outside the breeding season

Indicative foraging territory: 10 to 100 hectares, with a reported mean of 57 hectares

  • Record the area and condition of rehabilitated lignum, canegrass, sedges and samphire using repeat photographs and mapped monitoring points.
  • Investigate failed regeneration, continuing grazing, altered flooding or habitat fragmentation and implement corrective action.
  • Record Grey Grasswren detections, calls, nests, group size and habitat use, and submit confirmed records to the relevant state wildlife database.
  • Continue monitoring until the project ecologist and approval authority agree that the habitat is stable and the required success measures have been met.

Sources