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Cape Barren Goose (Cereopsis novaehollandiae)

The Cape Barren Goose is a large, mostly grey grazing goose of offshore islands, coastal grasslands and mainland pasture in southern Australia. It is listed as Vulnerable under the EPBC Act and in Western Australia, so clearing, earthworks and disturbance near island or coastal grassland habitat require careful timing and survey planning.

Conservation status

Commonwealth, EPBC Act 1999: Vulnerable.

Western Australia, Biodiversity Conservation Act 2016: Vulnerable.

Breeding season

Timing varies across the range. The south-western population is concentrated on the Recherche Archipelago for breeding from May to November, while the species is also reported to breed mainly from July to September and to use mainland pasture during summer.

Survey timing and clearing controls should be adjusted to the local population. The supplied guidance identifies April as an effective survey month for Recherche islands because birds are less often on the mainland and breeding disturbance can be avoided.

  • Breeding: Pairs establish territories in autumn. Breeding in the south-western population occurs from May to November, with July to September reported as the main breeding period for the species.
  • Young: Young are associated with the breeding territories through spring, and young have been recorded up to December.
  • Mainland movement and dispersal: During summer, many non-breeding birds leave islands for mainland improved pasture. Some birds remain on islands and some move between islands.
  • Island concentration: In the Recherche Archipelago, birds congregate on islands for breeding from April to November. April is also identified as a useful survey period before the breeding season.
  • Highest clearing risk: Clearing and disturbance are most likely to harm the species during the breeding period and while young remain dependent. The highest risk is expected from July to September, with risk extending through November and into December where young are present.

Identification

Cape Barren Geese are large, pale grey geese that are conspicuous in open country and in flight. They are usually straightforward to identify, but staff should record the distinctive bill, wing and leg features rather than relying on size alone.

The species is a very large, pale grey goose with a relatively small head. The short, triangular bill is largely concealed by a prominent greenish-yellow cere, the fleshy skin above the bill. The legs are pink to deep red and the feet are black.

Rows of large dark spots form lines across the shoulder feathers and wing coverts. In flight, the bird shows dark wingtips and a dark trailing edge to the wings.

Body length or height: 75 to 100 cm

Plumage: Pale grey overall, with dark spotted shoulders and wing coverts

Bill: Short triangular bill with a prominent greenish-yellow cere

Legs and feet: Pink to deep red legs and black feet

Identification: Sexes and calls

Males and females have a similar appearance. The female has been described as producing a distinctive pig-like grunt, while the male produces a more typical goose-like call. Another description records the male as giving a harsh, trumpeted 'ark, ark-ark' call, especially in flight.

The species is generally quiet on the ground unless alarmed or displaying, but becomes more vocal in flight. Calls, repeated alarm responses and territorial displays can help locate birds in open grassland where visual detection is usually good.

Identification: Field signs and similar species

The species is unmistakable on the ground and in the air according to the threatened bird survey guidelines. It is most likely to be confused with another large goose at a distance, so confirm the pale grey plumage, yellow-green cere, pink or red legs, black feet and dark wing margins.

Nests are shallow ground nests in grass tussocks or at the base of bushes. They are lined with down and other nearby vegetation. Searchers should avoid walking through likely nesting areas during the breeding season.

  • Record direct sightings, flight direction, flock size, calls and any territorial behaviour.
  • Search open grassland, tussock bases and low scrub edges for ground nests rather than looking for tree hollows or burrows.
  • Treat an agitated pair, repeated calling or persistent guarding behaviour as an indication that a nest or young may be nearby.

Distribution: Australian range

The Cape Barren Goose occurs in southern Australia, with island populations and seasonal use of nearby mainland pasture. The supplied documents do not provide a complete state by state or bioregional inventory, but they identify the main regions and the south-western subspecies range.

The nominal subspecies occurs across south-eastern Australia, the Bass Strait islands and Tasmania. The species also occurs on the south-eastern coast, in south-eastern Victoria and along the southern coast of Western Australia.

The south-western subspecies, Cereopsis novaehollandiae grisea, occurs in the Recherche Archipelago and on the adjacent mainland coast. The Recherche Archipelago is the named Western Australian stronghold in the supplied threatened bird survey guidance.

  • Prioritise island and adjacent coastal mainland records in Tasmania, Victoria and Western Australia.
  • Check local records for offshore islands, coastal grasslands, tussock country, low heath and mainland pasture before clearing or construction.
  • The supplied documents do not name Australian bioregions, so bioregional assignment should be made from the project location and current spatial datasets.

Distribution: Population and subpopulations

The species has island and mainland components. Many birds remain on offshore islands throughout the year because they can drink salty or brackish water, while non-breeding birds may disperse to mainland pasture in summer.

The south-western population in the Recherche Archipelago is treated as a distinct subspecies in the survey guidance. The broader species population was described as stabilised after historical declines, but it remains one of the world's rarest geese.

Reported population estimate: Approximately 15,000 to 20,000 individuals

Named south-western population: Cereopsis novaehollandiae grisea in the Recherche Archipelago and adjacent mainland coast

Historical trend: Numbers were very low by the 1950s, followed by increases associated with conservation initiatives

Habitat: Core habitat

Cape Barren Geese use open, low-growing habitats on islands and nearby mainland areas. Habitat suitability is linked more clearly to vegetation structure and pasture availability than to elevation in the supplied documents.

The species occurs mainly on offshore islands, usually on granite islands, with pasture, tussock grass or low heathy scrub. It also uses open grassland, glades in scrub and succulent mats, including pigface communities.

In the Recherche Archipelago, islands with the highest counts had a high proportion of grassy or herbaceous vegetation. Coastal mainland pasture is used particularly outside the breeding period.

  • Map open grassland, tussock grass, low heath, scrub glades and succulent mats before site disturbance.
  • Treat island pasture and coastal grassland as potential habitat even where no birds are present during a single visit.
  • Include adjacent mainland pasture in habitat assessments where birds may move seasonally from islands.

Habitat: Structural features

The preferred structure is low, open vegetation that allows birds to walk, feed and detect approaching people or predators. Dense forest is not identified as core habitat in the supplied documents.

Nesting habitat occurs within open grassland, at the base of bushes and among grass tussocks. The species also uses beaches and the margins of lakes and lagoons.

Key vegetation: Tussock grass, pasture, herbs, succulents and low heathy scrub

Important open features: Grassland, scrub glades, succulent mats, beaches and lake or lagoon margins

Elevation and climate limits: No elevation limit is provided in the supplied documents

Foraging habitat: Diet and feeding sites

Cape Barren Geese are primarily terrestrial grazers. They feed in short or open vegetation on islands and move to improved mainland pasture when seasonal conditions and food availability favour dispersal.

The diet consists mainly of common island tussock grass, Poa poiformis, spear grass, herbs, succulents, pasture grasses, barley, clover and other legumes. The birds eat stems, leaves, seeds and grass tufts, as well as aquatic plants.

Foraging occurs in island grassland, open scrub glades, succulent mats and mainland pasture. The species may also use the margins of lakes and lagoons.

Main food plant: Common island tussock grass, Poa poiformis

Other recorded foods: Spear grass, herbs, succulents, barley, clover, legumes and aquatic plants

Feeding method: Grazing and cropping vegetation

  • Inspect tussock grassland, improved pasture, herb-rich areas, succulent mats and low scrub openings for grazing birds and droppings.
  • Retain access between island or coastal grassland habitat and nearby mainland pasture where seasonal movement is known or likely.
  • Avoid assuming that a bird-free island is unused if the survey is conducted after birds have dispersed to the mainland.

Foraging habitat: Seasonal foraging movement

During summer, non-breeding geese generally leave the islands for mainland improved pasture. Some birds remain on islands all year, and some move between islands or between islands and the mainland.

No foraging range distance is provided in the supplied documents. Project assessments should therefore use local records and habitat connectivity rather than applying an unverified fixed radius.

Breeding habitat: Breeding biology

Cape Barren Geese form long-term pairs and defend breeding territories in open island and coastal grassland. Breeding habitat must provide suitable tussocks or low bushes for a ground nest and enough open vegetation for the pair to feed and guard the territory.

Pairs establish and defend territories in autumn or before the winter breeding period. The nest is built on the ground by the male and lined with down. The female incubates, while the male defends the nest and both parents brood and protect the young.

Breeding timing varies between the broader species range and the south-western subspecies. The south-western population breeds from May to November, while the Australian Museum gives July to September as the breeding season for the species. Young may be present until December.

Breeding season: Generally autumn to winter; May to November in the south-western population, with July to September also reported for the species

Clutch size: Four to six eggs

Incubation: Approximately 32 to 35 days

Pairing: Monogamous, with life-long pair bonds reported

Young: Both parents brood and protect the young; young may be seen until December

Age at maturity: Not provided in the supplied documents

Lifespan: Not provided in the supplied documents

  • Treat open tussock grassland, bush bases and scrub glades as potential nesting habitat from autumn through late spring.
  • Use quiet observation from the edge of habitat where possible, because pairs defend territories noisily and may be disturbed by people approaching nests.
  • Plan searches before the main breeding period where feasible, while recognising that breeding can occur from May to November in the Recherche population.

Breeding habitat: Nest habitat

Nests are placed in tussocks of open grassland, at the base of bushes or among grass tussocks. The nest is a shallow ground structure made from small branches and other plant material collected nearby, with an inner lining of down.

Breeding pairs maintain all-purpose territories. Reported territory sizes for the species include a mean of 0.33 hectares on Big Green Island, Tasmania, and 0.52 hectares on poorer pasture on Maria Island.

Reported mean territory size: 0.33 ha on Big Green Island, Tasmania; 0.52 ha on poorer pasture on Maria Island

  • Search tussock bases, bush bases and sheltered edges within open grassland for shallow nests and down lining.
  • Keep machinery, vehicles and foot traffic out of active territories where practicable.
  • Use the reported territory figures as local examples only, not as a universal exclusion distance.

Sheltering habitat: Nests and ground cover

The supplied documents provide most detail on nesting cover rather than roosting or refuge structures. Cape Barren Geese are ground-nesting birds that use low vegetation and open habitat, and they may enter water during moulting or when protecting young.

Nests are shallow ground structures in tussocks of open grassland, at the base of bushes and among grass tussocks. They are lined with down, which helps conceal the eggs and retain heat during incubation.

The birds favour low vegetation and are readily seen when walking or flying up in response to an approaching boat or person. Dense overhead cover is not identified as a required refuge.

Nest type: Shallow ground nest

Nest materials: Small branches, nearby vegetation and down

Nest locations: Tussocks, open grassland and the base of bushes

Known refuge dimensions: No nest or refuge dimensions are provided

  • Inspect tussock bases, low bushes and grassland edges before slashing, grading or vehicle access.
  • Mark and protect active nests and the surrounding defended territory in accordance with project fauna procedures.
  • Do not rely on the absence of tree hollows, burrows or caves as evidence that habitat is unsuitable.

Sheltering habitat: Water and seasonal shelter

The species does not generally swim, but may enter water during moulting, when flight ability is reduced. It may also enter water while protecting young from threats from the mainland.

Many birds remain on offshore islands because they can drink salty or brackish water. Beaches and lake or lagoon margins may therefore form part of the habitat used around shelter, feeding or movement areas.

Threats: Documented pressures

The supplied documents identify historical persecution, hunting and the loss or protection of island habitat as the main documented pressures. On development sites, the immediate risks are destruction of ground nests and territories, loss of open feeding habitat, and disturbance during the breeding period.

The species was heavily persecuted by farmers because it grazed in cultivated areas. Limited hunting concessions still exist in Tasmania.

Historical declines were followed by population increases after conservation initiatives and the protection of some Australian islands as nature reserves. The species remains Vulnerable and rare.

  • Check whether the project occurs near protected islands, coastal grassland or known island populations.
  • Do not treat grazing conflict or hunting history as evidence that a population is secure at the project site.
  • Record any deliberate disturbance, persecution or shooting risk through the appropriate project and wildlife reporting channels.

Threats: Clearing and construction risks

Clearing or grading open grassland, tussock, low scrub and succulent mats can remove feeding habitat or ground nests. Works near the base of bushes and within tussock grass can disturb incubating birds and dependent young.

The species is highly visible and vocal, but birds may move between islands and mainland pasture. A single absence survey does not establish that seasonal habitat is unused.

  • Complete targeted searches of open grassland, tussock bases, bush bases and low scrub before clearing.
  • Avoid clearing and high-disturbance works during the local breeding period where practicable, especially May to November in the Recherche population.
  • Maintain access between island or coastal breeding areas and mainland pasture where the project affects both habitat types.
  • Use onshore vantage points, boat-based island surveys or area searches as appropriate to the site, following the threatened bird survey guidance.

Threats: Other risks and evidence gaps

The supplied documents do not provide species-specific evidence on road mortality, fragmentation, fire, disease, introduced predators or hydrology change. These risks should be assessed from the project design and local site conditions rather than assumed to be absent.

Changes to lakes, lagoons, beaches or coastal pasture may affect habitat used for feeding or movement. Any such effects should be considered alongside direct clearing.

  • Assess vehicle access routes for disturbance or collision risk where roads pass through open habitat or between feeding and breeding areas.
  • Assess fire and hydrology changes where they alter tussock grassland, succulent mats, pasture, lake margins or lagoon margins.
  • Seek local records and advice from the relevant state agency for known colonies, seasonal movements and site-specific threats.

Survey methodology: 1. Plan the survey around habitat and season

Survey effort must reflect the Cape Barren Goose’s open island habitat, high visibility and seasonal movements. The published effort guide is specifically for the south-western subspecies, also called the Recherche Cape Barren Goose, so apply it directly in the Recherche Archipelago and use it as the closest species-specific guide elsewhere.

Search offshore and nearshore islands with open grassland, tussock grass, low heathy scrub, grassy glades and succulent mats, especially where vegetation is predominantly grassy or herbaceous.

Include adjacent mainland pasture and coastal areas because non-breeding birds may disperse from islands to the mainland during summer.

Schedule island surveys in April where practicable. This is before the main breeding period, when birds are less often recorded on the mainland and weather is more likely to be calm.

Treat May to November as the main breeding period for the south-western subspecies and avoid interrupting territorial birds, nests or broods.

Detectability: Highly visible and vocal in flight, and easily seen in open habitat.

South-western subspecies breeding period: April to November, with young recorded to December.

Survey methodology: 2. Circumnavigate islands by boat

Use an inshore boat to circumnavigate suitable islands, because birds favour low vegetation and tend to walk or fly up when approached by a vessel or people.

Survey areas up to 50 hectares using 10 hours of inshore boat observation spread over 5 days.

Record all birds, pairs, territorial behaviour, nests, broods, landing sites and movements between islands or between islands and the mainland.

Keep the boat and observers far enough away to avoid flushing birds repeatedly or interrupting territorial behaviour.

Recommended effort: 10 hours over 5 days for areas up to 50 hectares.

Best timing: April.

Survey methodology: 3. Search from land and the air

Conduct land-based area searches for nests in open grassland, grass tussocks and at the base of bushes.

Use 20 hours of land-based area searches over 4 days for areas up to 50 hectares.

Use an aerial survey where access is difficult or the site is extensive. Fly around the outside of the island first, then over the top, using transects close enough to detect birds and nests.

Allow 4 hours over 2 days for the aerial survey method, or as much time as is needed to complete sufficiently close transects over the area of interest.

Use onshore vantage points and telescopes where boat access or landing is unsuitable. Record birds on the mainland as well as on islands.

Land search effort: 20 hours over 4 days for areas up to 50 hectares.

Aerial survey effort: 4 hours over 2 days, with additional time if needed for sufficiently close transects.

Nest location: On the ground at the base of bushes and among grass tussocks.

Survey methodology: Minimum effort and reporting

  • Use the method that matches the site, and combine boat, land and aerial methods where terrain, access or proposed disturbance could leave detection gaps.
  • Record the survey date, time, weather, tide or access conditions, observer names, method, effort, survey area, locations, flock size, breeding behaviour, nests and photographs where permitted.
  • Map all sightings, nests, territories, feeding areas, movement routes and proposed disturbance areas in project plans.
  • Submit confirmed records and suitable negative survey results to the relevant state wildlife database and to the project’s environmental records system.
  • Retain the survey data with the approval and fauna management documentation.

Before habitat disturbance: Avoid and minimise habitat loss

Treat open grassland, tussock and low scrub on islands and adjacent coastal areas as potential habitat. Before clearing or construction, identify where birds feed, breed, roost and move between retained areas.

Retain rocky islands and coastal areas with open grassland, tussock grass, low heathy scrub, grassy glades and succulent mats wherever practicable.

Retain stands of island tussock grass, including common island tussock grass, Poa poiformis, and other native grasses, herbs and succulents used for grazing.

Maintain connected areas between feeding habitat, nesting habitat, shoreline access points and nearby retained pasture or coastal habitat.

Establish site-specific no-go areas around active nests, broods, territorial pairs and regularly used feeding areas before work starts.

Do not create a generic buffer distance where the documents provide no species-specific distance. Have the ecologist set the buffer from the nest, activity, terrain, machinery reach and risk of repeated disturbance.

Before habitat disturbance: Check approvals and plan the works

Confirm whether the action may affect the EPBC Act listed vulnerable species or the south-western subspecies and obtain project-specific advice on referral requirements before work begins.

Check the relevant state or territory wildlife, land access and disturbance requirements, including any permit requirements for handling, relocation, nest disturbance or work in protected areas.

Schedule ground disturbance outside the main breeding period where practicable, particularly May to November in the Recherche Archipelago.

Stage clearing so that birds can move towards retained habitat without being surrounded by machinery or temporary works.

Prepare a fauna management plan that identifies survey methods, exclusion areas, spotter catcher authority, stop-work triggers, handling procedures, emergency contacts and reporting requirements.

National status in the survey guideline: Vulnerable under the EPBC Act.

South-western breeding period: May to November in the detailed account, with breeding activity recorded from April to November.

Before habitat disturbance: Prepare and mark the site

Complete a pre-clearance survey using the most appropriate combination of boat, land and aerial searches before finalising the clearing footprint.

Mark active nests, broods, territorial areas, feeding areas, movement routes and retained habitat on the ground and in the construction drawings.

Install exclusion fencing where it can prevent machinery entry without blocking movement to retained feeding or nesting habitat.

Brief all operators on the goose’s appearance, its high visibility and vocal flight behaviour, the exclusion areas, the spotter catcher’s authority and the stop-work procedure.

Inspect proposed access tracks, laydown areas, stockpile sites and temporary drainage works as well as the permanent clearing area.

During habitat disturbance: Daily controls and machinery interface

The fauna spotter catcher must control the interface between birds and machinery. Work must stop whenever continued activity could injure a bird, destroy a nest or isolate birds from retained habitat.

Complete a daily pre-start inspection of the work area, exclusion fencing, access routes, retained habitat and any known nest or territory.

Have the fauna spotter catcher inspect the active work zone immediately before clearing, excavation, vehicle movement and delivery of materials.

Use a slow, staged approach to vegetation removal so birds can leave towards retained habitat before machinery enters each section.

Keep machinery outside marked exclusion areas unless the ecologist or authorised fauna spotter catcher has cleared the area for entry.

Require operators to stop immediately on the fauna spotter catcher’s instruction, and do not resume until the animal, nest or hazard has been assessed and the spotter catcher gives clearance.

During habitat disturbance: Ground nests and habitat features

Inspect grass tussocks, the base of bushes and open grassland for ground nests before slashing, grading, excavation or vehicle access.

Treat a nest, eggs, brood or incubating bird as an active exclusion trigger and prevent people, vehicles and machinery from entering the area until the ecologist has set the control measures.

Retain low vegetation and succulent mats around active territories where practicable, because the species uses open grassy and herbaceous habitat for breeding and feeding.

Do not assume that hollow-bearing trees, logs or rocks are the primary nesting features for this species. The documented nest site is on the ground among tussocks and at the base of bushes.

Inspect wetlands, lagoons, shorelines and drainage areas before disturbance because the species may use water edges and can drink brackish or salty water.

Documented nest sites: At the base of bushes and among grass tussocks.

Recorded water use: The species can drink salty or brackish water and may remain on offshore islands year round.

During habitat disturbance: If a bird is found

Stop the nearby activity and give the bird a clear route to retained habitat if it is mobile and uninjured.

Do not chase, catch or relocate a bird unless the person is authorised under the applicable approval or wildlife requirements and the fauna management plan allows it.

Use a quiet, low-disturbance approach and keep people and machinery away from the bird’s escape route, nest, eggs or brood.

Relocate an animal only to suitable nearby retained habitat selected by the ecologist, and avoid moving it away from its territory, nest, brood or established feeding area unless required for welfare or authorised management.

Have injured birds assessed promptly and transfer them to an appropriately authorised wildlife carer or veterinarian in accordance with state requirements.

Stop work and notify the site environmental officer and project ecologist if a nest, egg, brood, injured bird, dead bird, repeated territorial defence or unexpected concentration of birds is found.

Record the location, time, activity, bird condition, photographs where permitted, handling or treatment, destination and the names and authorisations of people involved.

After habitat disturbance: Complete post-clearance checks

Post-clearance checks must confirm that no nest, brood or bird has been trapped or isolated and that retained habitat remains usable. Keep controls in place until the project ecologist confirms that the risk has ended.

Inspect the cleared area, retained grassland, exclusion boundaries, access routes and temporary works after each clearing stage.

Check for injured, dead or trapped birds, abandoned eggs, damaged nests and birds unable to reach retained habitat.

Recheck disturbed island edges, pasture, shorelines and water points because birds may move between islands and the mainland or congregate in open feeding areas.

Remove temporary fencing only after the fauna spotter catcher and ecologist confirm that it will not expose birds to machinery, pits, traffic or construction hazards.

After habitat disturbance: Monitor and report

Monitor retained habitat and known territories during the next suitable breeding period, with effort set by the project ecologist according to the disturbance risk and approval conditions.

Record whether birds continue to use retained grassland, tussock, low scrub, succulent mats, feeding areas and movement routes.

Report nests, broods, injuries, deaths, relocations, stop-work events, breaches of exclusion areas and changes to habitat condition to the project environmental officer and approval authorities where required.

Submit verified occurrence records to the relevant state wildlife database and retain the monitoring data with the project file.

After habitat disturbance: Offsets and residual impacts

Assess residual impacts after avoidance, retention, staging and rehabilitation measures have been applied.

Apply any approved offset, conservation payment or compensatory habitat measure required by the EPBC Act, state approval or project condition.

Do not treat an offset as a substitute for retaining active nests, breeding territories or suitable open island habitat within the project area.

Rehabilitation actions: Restore feeding and nesting habitat

Rehabilitation should restore the open, low-growing habitat used for grazing, nesting and movement. The target is functional habitat, not simply revegetated ground.

Re-establish open grassland and tussock cover using locally appropriate native species, including Poa poiformis where it is suitable for the site.

Include native spear grasses, herbs and succulents where they formed part of the pre-disturbance community.

Restore low heathy scrub and grassy glades without allowing dense regrowth to replace the open vegetation structure used by the species.

Reform disturbed ground so it does not create pits, steep edges or barriers between feeding habitat, nests and retained coastal areas.

Do not install nest boxes as a default measure, because the documented nest is on the ground among tussocks and at the base of bushes.

Rehabilitation actions: Manage water, weeds and disturbance

Reinstate natural drainage and shallow water edges where they were disturbed, while preventing erosion, pollution and sudden loss of access to feeding areas.

Control weeds that displace native tussock, grasses, herbs and succulents, using methods that do not disturb active nests or broods.

Control domestic, feral and introduced predators where required by the approved management plan and relevant land manager arrangements.

Keep construction traffic, public access and night lighting away from restored breeding and feeding areas during establishment and the breeding period.

Set fire controls with the land manager to prevent unplanned fire from removing tussock and low scrub habitat. The supplied documents do not specify a prescribed fire interval for this species.

Rehabilitation actions: Monitor rehabilitation success

Inspect restored areas after establishment and during the next breeding period for tussock cover, native grass and herb recovery, weed invasion, erosion and barriers to bird movement.

Use repeatable photographs, mapped vegetation condition and records of goose presence, feeding, territorial behaviour, nests and broods to measure recovery.

Treat continued use by geese, successful access to feeding habitat and reoccupation of suitable nesting areas as key biological outcomes.

Repair failed plantings, erosion, fencing or drainage promptly and continue monitoring until the project ecologist and approval authority accept the rehabilitation outcome.

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