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Great Cormorant (Phalacrocorax carbo)

The Great Cormorant is a large black waterbird found across most of Australia, wherever suitable fresh or salt water is available. It nests and roosts in groups, so clearing, construction, tree loss, noise and access near a colony can affect many birds at once. It is listed as least concern in Australia, but in Queensland it is a colonial breeder and interference with a breeding place requires a high risk species management program under the Nature Conservation (Animals) Regulation 2020.

Conservation status

Queensland, Nature Conservation Act 1992: Colonial breeder. Least concern in Queensland, but it breeds in colonies, so tampering with a breeding place needs a high risk species management program rather than the low risk program.

Breeding season

Great Cormorants are colonial breeders in Australia, with breeding recorded mainly from August to January. Breeding can occur at other times when food supply is favourable, so active colonies and breeding places need checking before clearing or construction, regardless of month.

Breeding mode: Colonial breeder. Both adults build or repair the nest, incubate the eggs and care for the young.

Clutch size: Usually 3 to 5 eggs. Other Australian accounts record 2 to 6 eggs.

Incubation: About 28 to 31 days.

Nestling and fledging period: Young remain in the nest for about 50 days after hatching. They can remain under adult care for about another 50 days after fledging.

Age at maturity: About 3 to 4 years.

Breeding places: Large stick nests occur in trees on islands, lake or river banks, and in trees over water. Coastal colonies may use cliff ledges, small islands and the ground on predator free rocky islands.

Colonies and active breeding places: Reported colonies range from a few birds to several thousand, with Australian colonies reported at about 2,000 birds and up to 20,000 birds. Up to 50 nests may occur in one tree. Reused sites, occupied stick nests, nest building, courtship, adult traffic, eggs or young indicate an active breeding place. Colonies can be damaged by disturbance, flushing and accumulated droppings, so plan works outside the nesting period where possible and obtain site specific ecological advice on buffers.

Timing can shift between years and regions with food supply, water conditions and colony history, so a colony inspection is needed before works even outside August to January.

  • Breeding and nesting: Breeding is most likely from August to January, but food supply can allow breeding at other times.
  • Eggs and nestlings: Eggs and nestlings may remain present after laying, with timing dependent on when the colony starts breeding.
  • Dependent young: Fledged young may continue receiving adult care for about 50 days, so active nests can remain sensitive after fledging begins.
  • Foraging and communal roost use: Great Cormorants use open water throughout the year and may gather at colonies or roosts near aquatic habitats.
  • Highest clearing risk: Risk is highest from August to January when colonies are most likely to contain eggs or dependent young, but active breeding places must be checked in every month because breeding is food dependent.

Identification: Appearance

The Great Cormorant is a large, mostly black waterbird with a long neck, heavy hooked bill and fully webbed feet. It is often seen swimming low in the water or perched with its wings spread to dry.

Adults are almost entirely black, with a grey bill and a white and yellow area around the face and chin. Breeding adults develop white patches on the thighs, head and upper neck.

The wings and body can show bronze, green or purple gloss in good light. Young birds are more dusky brown and may have paler underparts.

Adult field mark: Large black cormorant with a grey bill and a white and yellow facial patch.

Breeding field mark: White thigh patches and more white on the face and upper neck.

  • Length: about 70 to 90 cm.
  • Legs and feet: short, stout and dark grey.
  • Bill: long, stout and strongly hooked.
  • Feet: large and fully webbed between all four toes.
  • Tail: relatively long, with 14 feathers.

Identification: Calls and similar species

Great Cormorants are generally quiet away from colonies. They make guttural and raucous sounds at breeding sites, particularly during display and nest activity.

The Little Black Cormorant is the main similar species on Australian inland sites. The Great Cormorant is much larger and has a heavier bill and a distinctive white and yellow facial patch. Pied Cormorants and Australasian Darters may occur at the same colonies.

  • Check overall size before relying on plumage colour.
  • Look for the white and yellow facial patch and, in breeding birds, white thigh patches.
  • Do not confuse a darter's long thin neck and pointed bill with a cormorant.

Identification: Field signs

Look for large stick nests, accumulations of droppings and pale whitewash on branches, trunks, rocks, island margins and ground below nests. Droppings can build up heavily and may strip foliage or kill nesting trees over time.

A colony may also be detected by repeated guttural calls, birds flying to and from open water, fish remains, broken sticks and regular perching points. Strong odour and stained vegetation can occur where many birds roost or nest.

  • Large stick nests in low trees, island vegetation or on banks.
  • Whitewash on branches, trunks, rocks and the ground.
  • Black birds perched with wings spread to dry.
  • Repeated flight paths between a colony, roost and nearby water.
  • Concentrated droppings, fish remains and fallen nest material.

Distribution: Australian range

The Great Cormorant occurs across most of Australia and is recorded in all mainland states and territories, as well as Tasmania. It is widespread overseas and uses both inland and coastal water bodies.

The species is mapped in New South Wales, the Northern Territory, Queensland, South Australia, Tasmania, Victoria and Western Australia. It is more numerous in south eastern and south western Australia, but suitable open water is the main local requirement.

It breeds throughout much of the Australian continent except the central regions. Records can occur well away from the coast where permanent or productive freshwater is available.

Mapped Australian jurisdictions: NSW, NT, QLD, SA, TAS, VIC and WA

Local distribution: Most likely around extensive permanent water, productive wetlands, rivers, lakes, estuaries and coastal waters.

  • Freshwater lakes, rivers and wetlands.
  • Coastal inlets, estuaries and sheltered waters.
  • Islands, river banks and lake margins with suitable nesting trees or ground sites.

Distribution: Overseas range

The Great Cormorant is widespread across Europe, Africa, Asia, Australia and New Zealand. It occurs in both marine and freshwater settings across its global range.

  • Coastal waters, estuaries and inshore islands.
  • Large inland lakes and rivers.
  • Wetlands and other productive aquatic systems.

Distribution: Site assessment

A site record may represent a bird feeding locally, a bird commuting from a colony, or a seasonal or winter roost. Do not assume that an isolated bird is unrelated to a nearby breeding place.

Check connected waterways, islands, lake margins, river banks and tall trees within the broader works area. Search for regular flight paths and concentrated whitewash, not just birds on the water.

  • Review nearby wetlands and watercourses before clearing.
  • Inspect trees and structures over or close to water.
  • Ask landholders and site staff about regular roosting or nesting locations.
  • Record the direction and frequency of birds moving between water and trees.

Habitat: Waterbodies and wetland features

Great Cormorants need open water for swimming and diving, together with safe perches and suitable nesting or roosting places. They can use natural wetlands and modified water bodies, provided fish and relatively undisturbed banks, islands or structures remain available.

Look for the species on permanent freshwater systems, including lakes, rivers, ponds and wetlands. It also uses estuaries, coastal inlets and sheltered waters.

Productive or eutrophic waters can support high numbers of fish and may attract cormorants. Very low productivity or very turbid water may support fewer birds, although local conditions vary.

  • Open lakes and farm or park ponds.
  • River channels, backwaters and broad pools.
  • Permanent or semi permanent wetlands with fish.
  • Estuaries, coastal lagoons and sheltered bays.
  • Artificial wetlands and water storage areas.

Habitat: Vegetation and landform

On works sites, focus on mature or partially mature trees standing in water, on islands, or along lake and river banks. Also inspect exposed banks, rocky islands, cliff ledges and structures near water.

The species can use deciduous or coniferous trees and bushes for nests. A lack of dense canopy does not rule out a colony, because nests may occur on open islands, ledges or the ground.

  • Trees overhanging water.
  • Island and peninsula vegetation.
  • River forks and lake edges.
  • Rocky islands, cliffs and coastal stacks.
  • Quiet banks with clear flight access to open water.

Habitat: Landscape connections

Cormorants are central place foragers. Birds may travel 10 to 15 km from a colony to feed and can make daily flights approaching 50 km. A works site can therefore affect a colony even when the colony is outside the project boundary.

  • Map nearby waterways and fishable pools.
  • Trace regular flight paths between water and trees.
  • Consider indirect effects on connected wetlands, water levels and fish habitat.
  • Include offsite islands, banks and roost trees in the assessment where works may alter access or disturbance.

Foraging habitat: Foraging places

The Great Cormorant catches prey underwater by diving and pursuing fish with its feet. It may fish alone or in groups, and often returns to a colony or roost after feeding.

Search open water, river pools, lakes, estuaries and sheltered coastal waters. The species favours places with enough depth and visibility for underwater pursuit, although it can also feed in shallow water.

Cormorants may use several waterbodies within the same local area. Water turbidity, water level and fish availability can change where birds feed from day to day.

  • Open sections of lakes and ponds.
  • Deep or broad river pools and channels.
  • Wetland channels and permanent lagoons.
  • Estuaries and sheltered coastal waters.
  • Fish rich waters near aquaculture or managed wetlands.

Foraging habitat: Diet and feeding behaviour

The diet is mainly fish. Crustaceans, frogs and aquatic insects are also taken, particularly in freshwater. Fish are caught during foot propelled dives, with the bill used to seize prey.

Dives commonly last up to one minute in Australian field descriptions. Across the species range, dives of 1 to 3 minutes and depths up to 9.5 m have been recorded, with usual diving depths often 2 to 5 m.

  • Fish of different species and sizes, depending on local availability.
  • Crustaceans, frogs and aquatic insects.
  • Solitary fishing or coordinated group fishing.
  • Birds swimming low in the water, diving and resurfacing some distance away.

Foraging habitat: Works site risks

Works that reduce water depth, increase turbidity, remove fish habitat or block access between feeding water and a colony can affect birds without directly clearing a nest.

Plant, pump and vessel activity can cause repeated disturbance on feeding waters. Avoid unnecessary activity close to regular feeding areas, especially where birds are repeatedly diving or resting nearby.

  • Keep sediment and contaminated runoff out of feeding water.
  • Maintain access to open water and fish habitat where practicable.
  • Avoid sudden boat, vehicle and machinery movements near feeding flocks.
  • Record regular feeding areas before changing water levels or drainage.

Breeding habitat: Nest locations

Great Cormorants are colonial breeders. They usually nest near wetlands, rivers or sheltered coastal waters, and may use trees, islands, banks, cliffs or the ground where conditions are suitable.

Nests are large stick structures and may be in low trees over or beside water. Other sites include trees on islands, lake and river banks, cliff ledges, rocky islands and, less commonly, the ground.

Inland colonies may occur on islands, peninsulas, river forks and areas near lakes. Coastal colonies may occur on inshore islands, cliffs, stacks and boulders. Artificial structures can occasionally be used.

  • Low trees in or over water.
  • Trees on islands and lake margins.
  • River banks and river forks.
  • Cliff ledges and coastal rocky sites.
  • Ground sites on predator free or relatively secure islands.
  • Occasionally, artificial structures near water.

Breeding habitat: Breeding timing and nest use

Breeding is commonly recorded from August to January in southern Australia, but breeding can occur at other times when food supply is suitable. Both sexes build or repair the nest, and both adults incubate eggs and care for young.

Pairs may reuse the same nest site year after year. Colonised sites are often reused over many years, with nest numbers increasing until the site reaches a local limit.

  • Clutch size is commonly about 3 to 5 eggs.
  • Incubation takes about 28 to 31 days.
  • Young may remain in the nest for about 50 days and continue receiving care after fledging.
  • Inspect for fresh sticks, adults sitting low over nests, eggs, chicks and repeated adult visits.

Breeding habitat: Recognising an active breeding place

An active colony usually has multiple nests, adults arriving with sticks or food, birds sitting tightly on nests, chicks, fresh whitewash and regular movement between nests and nearby water. Guttural calls and display behaviour may increase when people or machinery approach.

A site can remain important even when only a few nests are visible. Check surrounding trees, islands, banks and ground because birds may spread to nearby sites if trees deteriorate or nests become exposed.

  • Fresh green or pale sticks in nest structures.
  • Adults carrying sticks or food.
  • Chicks, eggs or adults incubating.
  • Fresh droppings and whitewash below nests.
  • Repeated flights between nests and feeding water.
  • Multiple occupied nests in one tree, island or bank section.

Breeding habitat: Planning around nests

Treat an active colony as a high sensitivity work area. Keep clearing, tree trimming, piling, earthworks, lighting and high noise activities outside the nesting period where practicable, and retain a buffer around the colony until a suitably qualified ecologist confirms that breeding has finished.

There is no single species specific disturbance distance that suits every colony. Set the exclusion area using nest visibility, topography, noise, access routes, machinery type, flight paths and the number of nests. Increase the buffer if birds flush or repeatedly leave nests.

  • Do not clear occupied nesting trees or remove nest supporting vegetation.
  • Stage works away from the colony and avoid creating a new access route through it.
  • Use a fauna spotter catcher or ecologist to check the site before daily works near an active colony.
  • Stop and reassess if adults repeatedly flush, chicks are exposed, or birds abandon nests.

Sheltering habitat: Roost and perch features

Outside active nesting, Great Cormorants use trees, banks, islands, rocks and structures for resting, drying their feathers and communal roosting. Roosts may be close to water and can be used by many birds even when no nests are present.

Look for bare or lightly vegetated trees over water, dead branches, island trees, exposed banks, rocks, jetties and other structures with a clear view of the water. Birds commonly perch with their wings spread while drying after feeding.

Roosting colonies are generally on the banks of aquatic environments. Winter roosts can be particularly numerous and may contain more birds than a breeding colony.

  • Trees standing in or beside water.
  • Island vegetation and exposed branches.
  • Lake and river banks.
  • Rocky points, cliffs and coastal structures.
  • Jetties, posts, bridges or other structures near water, where present.

Sheltering habitat: How to recognise a communal roost

A roost may have many birds grouped on a few trees, rocks or structures, heavy whitewash below perches, stained bark and a strong odour. Birds may arrive together near dusk or leave in groups at first light, although timing varies with the site.

A communal roost is not a maternity roost. Great Cormorants are birds, so the relevant places are breeding colonies, communal roosts and nest trees rather than mammal maternity shelters.

  • Repeated use of the same perch or tree.
  • Many birds resting without obvious nests.
  • Heavy whitewash and droppings beneath perches.
  • Regular group arrival and departure flights.
  • Fish remains or fallen sticks beneath trees.

Sheltering habitat: Protection during works

Avoid removing roost trees, island vegetation or bank perches where practicable. Repeated disturbance can cause birds to abandon a roost and may force them to use less suitable or more exposed sites.

Maintain a quiet area around regular roosts during construction planning. If works must occur nearby, use staged activity, keep machinery and people on the opposite side of a visual barrier where possible, and monitor for repeated flushing.

  • Retain trees and structures used for regular perching.
  • Keep lighting directed away from water and roost trees.
  • Avoid sudden high noise near a roost.
  • Schedule high disturbance works for periods when the roost is not in use, where site observations support that approach.
  • Record roost use before removing vegetation or altering water levels.

Colonies and breeding places: What a colony looks like

A Great Cormorant colony can be a small group of nests in one tree or a large aggregation spread across islands, banks, cliffs or several nearby ponds. Colonies need special care because one disturbance event can flush many adults, expose eggs and chicks, damage nest trees and shift birds into less suitable areas.

Colonies range from a few birds to several thousand. About 2,000 birds have been reported at breeding colonies, and colonies of up to 20,000 birds have been reported. Nest density can be high, with up to 50 nests recorded in one tree, depending on the tree species.

A colony may be concentrated in one tree or distributed across several trees and islands. It may also include Pied Cormorants, occasional Little Black Cormorants, Australasian Darters or Australian White Ibis.

Typical scale: From a few birds to several thousand.

High density example: Up to 50 nests may occur in one tree, depending on tree species.

  • Many large stick nests in one or more trees.
  • Birds arriving with sticks or food.
  • Whitewash and bare branches below nests.
  • Guttural calls and repeated flight activity.
  • Several species nesting together.

Colonies and breeding places: Site fidelity and colony movement

Colonies and nest sites are often reused over many years. Pairs may use the same nest site year after year. Once established, a colony may grow until food, nest trees, space or disturbance limits it.

Birds can move within a wetland complex when trees deteriorate, nests become exposed or a colony is disturbed. In one documented example, tree degradation caused birds to spread from a former main colony to other ponds.

  • Inspect nearby ponds and islands if a known colony is disturbed.
  • Do not assume a vacant nest means the site has lost its value.
  • Map all occupied and recently used nest trees.
  • Retain alternative trees and quiet wetland areas where practicable.

Colonies and breeding places: Disturbance, flushing and buffers

Cormorants may flush from nests when people, vehicles, boats, machinery or aircraft approach. Repeated flushing can leave eggs and chicks exposed, increase predation risk and cause adults to abandon nests. Colonies are particularly vulnerable to disturbance because many nests are affected at once.

There is no universal species specific buffer distance. Establish a site specific exclusion zone around active nests and the wider colony, based on visibility, terrain, noise, machinery, access routes and observed bird behaviour. Extend it if birds flush or show repeated alarm.

  • Keep works outside the active nesting period where practicable, commonly August to January in southern Australia.
  • Keep clearing, construction traffic, cranes, lighting and high noise outside the colony buffer.
  • Use visual screening and keep people and machinery on the least intrusive side of the site.
  • Stop work and seek ecological advice if adults repeatedly leave nests or chicks are exposed.
  • Do not enter islands or approach nest trees to inspect them unless the inspection is planned and authorised.

Colonies and breeding places: Flooding and water management

Water level changes can affect island access, nest tree condition, bank stability, fish availability and the safety of ground nesting areas. Flooding may reduce access by people and predators, but it can also destroy nests, erode banks or alter feeding habitat.

Plan water releases, drawdowns, dewatering and drainage changes around the colony and its feeding areas. Keep water management gradual where practicable and inspect nest trees, islands and banks before changing levels.

  • Map nests, roosts, islands and feeding areas before water works.
  • Avoid sudden drawdown or inundation during active nesting where practicable.
  • Control sediment and polluted runoff entering colony or feeding water.
  • Retain island vegetation and stable bank features.
  • Monitor birds, nests, water levels and fish habitat during and after works.

Colonies and breeding places: Queensland approval context

In Queensland, the Great Cormorant is a least concern colonial breeder. Tampering with its breeding place requires a high risk species management program under the Nature Conservation (Animals) Regulation 2020, rather than the low risk program used for other least concern animals.

For project planning, confirm the current Queensland requirements before clearing, damaging, removing or materially disturbing a breeding place. A breeding place can support a large share of the local population, even when the broader species is common.

  • Identify active and recently used breeding places during pre clearance surveys.
  • Obtain the required approvals and management program before works begin.
  • Use qualified ecological advice to define the colony and its buffer.
  • Keep records of nests, activity, disturbance and mitigation outcomes.

Threats: Clearing and nest tree loss

The Great Cormorant is not listed as threatened in Australia, but local colonies and roosts can be sensitive to disturbance and habitat change. Development impacts are often cumulative because birds depend on connected water, trees, banks and flight paths.

Removing nest trees, island vegetation, bank trees or roost trees can eliminate a breeding place or force birds into nearby sites. Droppings can already weaken or strip colony trees, so loss of remaining suitable trees can accelerate colony movement.

Retain mature trees over or beside water, particularly trees with existing nests, old nests, whitewash or regular perching birds. Do not remove a nest tree without a site assessment and the required approvals.

  • Clearance of occupied or recently used nest trees.
  • Removal of island or bank vegetation.
  • Loss of alternative trees as a colony expands.
  • Felling trees that support a regular communal roost.

Threats: Noise, access and repeated disturbance

Construction noise, piling, drilling, vegetation burning, lighting, boats and frequent vehicle or pedestrian access can flush birds. Repeated disturbance is more harmful than a single brief observation because adults may stop returning to nests or abandon a regular roost.

Set exclusion areas before works begin. Brief all workers, mark buffers clearly and use a spotter catcher or ecologist to monitor activity near colonies and roosts.

  • Keep people and machinery outside active colony buffers.
  • Avoid sudden high noise and night lighting near roosts.
  • Use fixed access routes that do not pass through islands or nest banks.
  • Record flushing, alarm calls and nest attendance during works.

Threats: Water quality, hydrology and fish habitat

Sediment, contaminants, altered flows, dewatering and rapid water level changes can reduce fish habitat and affect the wetlands that support colonies. Changes to water clarity can also affect hunting success.

Protect connected waterways and manage runoff, erosion, dewatering and water releases. Check both the colony and its feeding waters when assessing a proposal.

  • Prevent sediment and contaminated runoff entering water.
  • Maintain fish habitat and open water access.
  • Avoid rapid drawdown, inundation or diversion near active colonies.
  • Monitor turbidity, water level and bird feeding activity during major water works.

Threats: Conflict and cumulative impacts

Cormorants can conflict with aquaculture and fisheries because they feed mainly on fish. Entanglement in fishing gear, reduced food availability and persecution are recognised risks in some regions.

Manage conflicts through non lethal measures and site based advice. Do not use exclusion, harassment or relocation around a colony without the required approvals and a qualified ecological assessment.

  • Keep discarded fishing line and netting away from water and roosts.
  • Use lawful, non lethal fishery protection methods where needed.
  • Consider the combined effect of several projects around one wetland.
  • Report injured or entangled birds to the appropriate wildlife authority or wildlife carer.

Survey methodology: 1. Desktop assessment

Great Cormorants are large, conspicuous waterbirds, but colonies and communal roosts can be missed when they are on nearby water or feeding away from the site. Survey both the proposed work area and connected open water, trees, islands, banks and structures that could support breeding or roosting.

Map all open water, including rivers, lakes, wetlands, farm dams, estuaries and coastal waters near the project. Check islands, peninsulas, lake and river banks, cliffs, bridges, culverts, artificial structures and mature trees over or beside water.

Review recent aerial imagery, local records, Atlas of Living Australia records, land manager information and reports from nearby fisheries, wetlands and reserves. Ask landholders and local rangers about regular colonies, roosts and seasonal movements.

Treat a group of perched cormorants, repeated flight paths to and from water, accumulated white droppings, fallen nest material or calls from trees as a reason for a targeted field inspection.

Australian range: Occurs across most of Australia, including NSW, NT, QLD, SA, TAS, VIC and WA.

Breeding period: Breeding is commonly recorded from August to January, but breeding can occur at other times when food conditions are suitable.

  • Map suitable nesting trees, reedbeds, lignum, sandbanks, islands, riverbanks, cliffs and structures.
  • Map nearby feeding water and likely flight paths between water and nesting or roosting places.
  • Identify works that could affect water levels, bank stability, vegetation, access, lighting or water quality.
  • Record whether the site is in Queensland and whether a colonial breeder management program may be required.

Survey methodology: 2. Field detection

Survey from a position that gives a clear view without approaching the water edge or nesting trees. Use binoculars or a telescope where available. Scan the water, shoreline, trees, islands, cliffs, bridges and other elevated structures systematically.

Repeat observations in suitable weather and light. Early morning and late afternoon checks can help identify birds leaving or returning to a colony or roost. Include observations when water levels and access conditions are representative of the site.

Look for large black cormorants with a yellow and white face, grey bill, black legs and webbed feet. Breeding adults may show white patches on the head, neck and thighs.

Nest placement: Nests may be in trees, on low vegetation, on lake or river banks, on small islands, on cliff ledges or, less commonly, on the ground.

Colony scale: Colonies can range from a few birds to several thousand. Australian colonies of about 2,000 birds and colonies of up to 20,000 birds have been reported.

  • Count birds on the water, in flight, perched, nesting and roosting.
  • Check whether birds carry sticks, visit a fixed nest, display, call, incubate, feed young or defend a nest site.
  • Inspect trees from a distance for large stick nests, whitewash, stripped foliage and broken branches.
  • Search likely islands and banks from the opposite shore or from a boat only where access is authorised and disturbance can be controlled.

Survey methodology: 3. Activity and effort records

Record enough information for another ecologist to relocate the observation and understand the level of risk. A single visit should not be treated as proof that a site is unused, particularly if water, weather or access conditions were poor.

Continue observations until all likely nesting and roosting places have been checked and flight paths are understood. Increase survey effort where birds are present, vegetation is dense, a colony is suspected, or works may affect water or shoreline habitat.

  • Record date, start and finish time, observers, weather, visibility, wind, water level and access method.
  • Record the number of birds, their behaviour, locations, flight direction and links to feeding areas.
  • Map each active nest, occupied tree, island, cliff, bank, roost and access track using coordinates and photographs where this can be done without disturbance.
  • Record signs of breeding, including nest building, incubation, adults feeding young, young in nests and recently fledged birds.
  • Record any other colonial waterbirds using the same place, including Pied Cormorants, darters or ibises.

Before habitat disturbance: 1. Confirm approvals and responsibilities

Plan works around the breeding place, not just around the footprint of clearing. A colony can occupy a small group of trees while depending on nearby water, flight paths, roosts and foraging areas.

Have the project ecologist check whether the action could affect a protected matter under the Environment Protection and Biodiversity Conservation Act 1999. Consider referral where a listed matter or other matter of national environmental significance may be affected.

In Queensland, treat the Great Cormorant as a least concern colonial breeder. If a breeding place is to be tampered with, obtain and follow the required high risk species management program under the Nature Conservation (Animals) Regulation 2020. Do not rely on the low risk program used for other least concern animals.

Check state and territory wildlife permits, vegetation clearing approvals, waterway or marine approvals, council requirements and land manager conditions before work starts. Keep approvals, permits and the approved management plan at the site.

Queensland requirement: Tampering with the breeding place of a least concern colonial breeder requires a high risk species management program, rather than the low risk program used for other least concern animals.

  • Nominate the project ecologist and the person authorised to stop work.
  • Confirm who can handle, capture, transport or treat injured wildlife.
  • Obtain written advice from the relevant state wildlife agency where a colony, active nest or breeding place may be affected.
  • Include permit conditions in the construction environmental management plan and subcontractor briefings.

Before habitat disturbance: 2. Complete a pre-clearance survey

Complete a targeted survey shortly before clearing or construction. Inspect all trees, islands, banks, cliffs, bridges, culverts, reedbeds and other structures that could support nests or roosts. Check nearby water and the airspace above the work area.

Have the ecologist define the active breeding place and associated disturbance area on a map. Include occupied nests, nest trees, access routes, roost trees, flight paths and water bodies used by the colony.

Do not assume a colony is inactive because adults are absent during one observation. Cormorants may be feeding, roosting elsewhere or travelling between the colony and water.

  • Mark no-go areas on plans and on the ground before machinery arrives.
  • Use a site-specific buffer around active nests, colonies and roosts. Set the distance according to visibility, terrain, machinery, noise, access, season and bird response.
  • Where a buffer cannot be maintained, redesign the work, change the method or obtain written agency and ecological advice before proceeding.
  • Recheck the site if works are delayed, the footprint changes, water levels change or birds begin using a new tree or structure.

Before habitat disturbance: 3. Schedule and design avoidance measures

Schedule vegetation removal, piling, blasting, high noise work and work over water outside the local nesting period where practicable. August to January is a useful precautionary period for planning, but breeding may occur outside these months when food supply is favourable.

Do not clear a colony or active breeding place to meet a program date. If urgent works are proposed, obtain specific ecological and regulatory advice first.

Retain nesting and roosting trees, islands, banks, cliffs and shoreline vegetation wherever possible. Protect nearby feeding water from sediment, pollutants, altered drainage and excessive turbidity.

Site fidelity: Pairs may reuse the same nest site year after year, and established colonies are often reused.

  • Keep works outside the nesting period where practicable.
  • Use physical exclusion fencing and signs to protect approved buffers. Do not use fencing that blocks normal flight paths or traps birds.
  • Avoid night lighting near colonies and roosts. Shield unavoidable lights away from trees, water and flight paths.
  • Use quiet plant, low disturbance access routes and staged work where complete avoidance is not possible.
  • Include a stop work trigger for any new nest, colony, roost or unusual concentration of birds.

Before habitat disturbance: 4. Induct the work crew

Give all workers, operators and subcontractors a short site induction before work starts. Show photographs and maps of the colony, roost, nests, buffers, access routes and stop work areas.

Explain that repeated flushing can expose eggs and chicks, cause nest abandonment and move birds away from a suitable breeding place. A large group taking flight is a warning that the work is too close or too disruptive.

  • Tell workers not to approach, feed, chase, photograph closely or handle cormorants.
  • Require workers to report any nest, injured bird, fallen chick, unusual bird behaviour or bird collision immediately.
  • Confirm the stop work authority of the fauna spotter catcher and project ecologist.
  • Place the wildlife rescue contact details and permit conditions in vehicles, crib rooms and supervisor folders.

During habitat disturbance: 1. Establish a controlled clearing sequence

Use a staged approach and keep a clear line of communication between the fauna spotter catcher, supervisor and ecologist. Work must stop when conditions differ from the approved plan or when birds show signs of unacceptable disturbance.

Start with low risk areas and retain the active breeding place, roost and access buffers. Progress only after the fauna spotter catcher has checked the next work area and the supervisor confirms that controls remain in place.

Use machinery that allows the spotter catcher to inspect trees, ground cover, banks and structures safely. Do not fell or dismantle a nest tree until the authorised ecologist has confirmed that it is outside the active breeding place and approved work area.

Keep sediment, fuel, concrete washout, rubbish and noisy activities away from water and colony access routes.

  • Fence and sign the exclusion area before clearing.
  • Clear away from the colony and toward retained habitat where this is safe and approved.
  • Stop work if birds repeatedly flush, circle, alarm call, fail to return to nests or abandon a roost.
  • Keep an updated map of cleared areas, retained habitat and areas not entered.

During habitat disturbance: 2. Respond to a colony, roost or active nest

Stop work immediately if an active nest, colony, communal roost or previously unknown breeding place is found within the work area or buffer. Move workers and machinery away without approaching the birds or blocking their flight path.

Contact the project ecologist and the relevant wildlife agency or permit holder. The ecologist must assess whether the place is active, define the required exclusion area and confirm whether work can lawfully continue.

Do not cut nest trees, remove nests, relocate eggs or chicks, disperse birds, use deterrents or destroy roost habitat unless the action is specifically authorised.

Nest density: Up to 50 nests may occur in one tree, depending on tree species. A single colony can therefore be much more sensitive than the number of visible adults suggests.

  • Record the location and condition of the breeding place from a safe distance.
  • Reinstate fencing and signs and brief the crew again before any work resumes.
  • Change the work method or sequence to avoid the place where possible.
  • If avoidance is not possible, obtain written approval and follow the high risk colonial breeder management program and any permit conditions.
  • Treat a mixed colony as one sensitive breeding place, even when Great Cormorants are nesting with other waterbirds.

During habitat disturbance: 3. Manage animals safely

Only authorised and trained wildlife personnel may capture, handle or transport a Great Cormorant. Cormorants have a strong hooked bill and can cause injury. Avoid handling unless it is necessary for welfare, safety or an approved management action.

Do not chase a healthy bird from water or attempt to make it fly. Give it space and allow it to leave naturally. Use a quiet approach and appropriate protective equipment when an authorised handler must intervene.

If a bird is injured, contained by works or unable to move, isolate the area, keep people and dogs away and contact the nominated wildlife carer, veterinarian or wildlife rescue service.

  • Do not give food or water unless directed by a veterinarian or wildlife carer.
  • Keep the bird cool, quiet and dark only when directed and safe to do so.
  • Record the location, apparent injury, photographs from a safe distance, time found and actions taken.
  • Do not release a rehabilitated bird without advice from the treating veterinarian or wildlife authority.

During habitat disturbance: 4. Maintain incident records

The site supervisor and fauna spotter catcher should maintain a daily wildlife log. Record normal observations as well as incidents, near misses and stop work events.

Report any breach of a permit, management program or exclusion area to the project manager and relevant authority as required.

  • Record date, time, location, species, number of birds and behaviour.
  • Record the activity underway, machinery involved, distance from birds and observed response.
  • Record nest, colony and roost status before and after the event.
  • Record who stopped work, who was notified, advice received and when work restarted.
  • Attach photographs, maps, permit references and rehabilitation or treatment records.

After habitat disturbance: 1. Complete post-clearance checks

Post-clearance checks confirm that no birds, nests or dependent young were overlooked and that retained habitat remains usable. Follow-up is also needed where work has changed water levels, vegetation, shoreline condition, noise or lighting.

Inspect the cleared area, retained buffers and nearby water after each clearing stage. Check felled trees, ground cover, banks, structures and debris for injured birds, eggs, chicks, nests or trapped animals.

Recheck the nearest retained trees, islands, cliffs and roosts for changes in bird behaviour. Watch for repeated flushing, abandoned nests, birds crowding into unsuitable trees or new nesting activity.

  • Have the fauna spotter catcher or ecologist sign off each cleared stage.
  • Check beneath nest trees and around machinery routes before the area is released.
  • Remove hazards such as exposed wire, netting, open pits, unsecured pipes and loose construction materials.
  • Keep exclusion fencing in place until the ecologist confirms that it can be removed.

After habitat disturbance: 2. Monitor retained habitat and birds

Monitor active or recently used colonies at a frequency set by the ecologist and approval conditions. Use distant observation and avoid repeated approaches to the colony.

Include water quality, water level, shoreline stability, tree condition, nest occupancy, roost use and flight paths in the monitoring design. Water management can affect fish availability and the suitability of waterbird colonies.

Colony condition: Accumulated droppings can damage nesting trees and strip foliage. Birds may move when nests become exposed or trees deteriorate.

  • Use consistent observation points, times and counting methods where practical.
  • Record adult numbers, nests, chicks, fledged young, roosting birds and signs of abandonment.
  • Record tree damage, accumulated droppings, loss of foliage, erosion, weed growth and changed access.
  • Compare results with the pre-work baseline and trigger additional controls if use declines or disturbance increases.

After habitat disturbance: 3. Close out incidents and relocated animals

Review every wildlife incident before the relevant work package is closed. Confirm that injured birds received appropriate care and that any authorised relocation or release was documented.

Do not describe a colony as successfully relocated merely because birds are seen nearby. Confirm that the new site is safe, suitable and accepted by the birds over an appropriate monitoring period.

Provide records to the regulator, land manager and project ecologist when required by permits or management programs.

  • Confirm the final disposition of each injured, captured or transported animal.
  • Record release location, date, authority, transporter, veterinarian and outcome where applicable.
  • Review whether buffers, timing, lighting, machinery or crew behaviour contributed to the incident.
  • Update the construction environmental management plan before similar work continues elsewhere on the project.
  • Retain survey, monitoring, photographs, maps and approval records for the required period.

Rehabilitation actions: 1. Restore water and shoreline habitat

Rehabilitation should restore functioning waterbird habitat rather than simply replace cleared trees. Great Cormorants need open water for feeding and suitable trees, islands, banks, cliffs or structures for nesting and roosting.

Protect and restore permanent or seasonally suitable open water, natural banks, islands and shoreline vegetation. Use local native species suited to the wetland and expected water regime.

Manage sediment, nutrients, pollutants and altered drainage. Maintain fish habitat and water quality without creating unsafe entanglement or access hazards.

Plan flooding and water level changes with the wetland manager. Sudden drawdown, prolonged inundation or loss of fish habitat can reduce the value of a colony and its feeding area.

  • Stabilise eroding banks with low disturbance methods and retain natural edges where practicable.
  • Replant native trees and shrubs around water while preserving clear flight and landing areas.
  • Control weeds without disturbing active nests or roosts.
  • Remove plastic, wire, fishing line, netting and other entanglement hazards.
  • Use weed control and maintenance methods that do not contaminate water.

Rehabilitation actions: 2. Replace lost nesting and roosting structures carefully

Retain mature trees and existing nests wherever safe. Great Cormorants build large stick nests in trees and can also nest on islands, banks, cliffs and the ground. They do not generally require mammal-style nest boxes.

Where an approved design requires replacement habitat, use artificial nest platforms, stable poles, island structures or other artificial nest sites only after advice from an experienced waterbird ecologist. Place them where birds have safe access to open water and people can maintain the site without entering a colony.

Bat boxes and standard terrestrial nest boxes are not suitable substitutes for Great Cormorant nests. A roost structure may suit a project only where it has been designed for this species and local conditions.

Nest material: A Great Cormorant nest is a large structure made mainly from sticks, with leaves and other plant material.

Nest use: Pairs may reuse the same nest site year after year, and established colony sites are often reused.

  • Base the design on the original nest type and the surrounding colony setting.
  • Use durable, non-toxic materials that will not entangle birds or shed contaminants into water.
  • Keep replacement structures away from powerlines, roads, machinery routes and uncontrolled public access.
  • Inspect platforms and structures for stability, occupancy, fallen material and accumulated droppings.
  • Do not install or maintain structures during active breeding without an approved method and ecological supervision.

Rehabilitation actions: 3. Manage lighting, access and disturbance

Design the completed site so that people, vehicles, dogs, boats and maintenance activities remain away from colonies and roosts. Keep unavoidable lighting shielded from water, trees, islands and flight paths.

Use signs, fencing, gates and access rules where public or operational activity could approach a breeding place. Avoid routine pruning, bank works and vegetation maintenance during the local nesting period.

Retain a quiet area around communal roosts, particularly where birds gather in large numbers outside the breeding season.

  • Direct lights down and away from habitat.
  • Use timers or motion controls where lighting is necessary and safe.
  • Keep maintenance routes outside approved buffers.
  • Prohibit fishing line, loose netting and other materials that can entangle birds.
  • Include colony and roost controls in the long-term asset maintenance plan.

Rehabilitation actions: 4. Monitor rehabilitation outcomes

Monitor restored water, vegetation, nesting structures and nearby colonies over multiple seasons. Use the same observation points and recording methods used during pre-construction surveys where practicable.

Success should be assessed by habitat condition, safe use by birds, nest occupancy, chick production where it can be observed without disturbance, and the absence of recurring injuries or conflict.

Adjust water management, weeds, lighting, access and structures when monitoring shows that the site is not supporting birds safely.

  • Record Great Cormorant and other colonial waterbird use of restored habitat.
  • Inspect restored trees, islands, banks and artificial structures after storms, floods and major water level changes.
  • Track weed cover, tree health, bank erosion, water quality and fish availability indicators.
  • Review monitoring results with the land manager and wildlife authority where approval conditions require it.
  • Keep monitoring long enough to cover establishment of vegetation and the return of seasonal or breeding use.

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