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Saltwater Crocodile (Crocodylus porosus)

The Saltwater Crocodile is Australia's largest crocodilian and a top-order predator of northern coastal and inland waterways. On development sites, clearing or changing riparian vegetation, wetlands, floodplains and estuaries can remove habitat, alter nesting areas and increase movement into areas used by people, livestock and machinery.

Conservation status

Queensland, Nature Conservation Act 1992: Vulnerable.

Breeding season

Saltwater crocodiles mate and nest during the northern Australian wet season. Eggs remain in mound nests for about 80 to 98 days, so clearing risk extends from the start of courtship through hatching and early juvenile care.

Reproductive mode: Oviparous. Females lay eggs in mounded nests made from vegetation, mud and soil.

Clutch size: Usually 40 to 60 eggs. Clutches of up to 90 eggs have been recorded.

Incubation: About 80 to 98 days, with reported extremes of 75 to 106 days.

Size at hatching: About 30 cm long and approximately 70 g. Hatchlings are typically less than 0.6 m total length.

Age at maturity: Females mature at about 10 to 14 years. Males mature at about 16 to 17 years.

Nest or egg sites: Elevated mound nests of vegetation, mud and soil along freshwater swamps, rivers, watercourses and swamp margins, usually close to permanent water.

Breeding frequency: Usually one clutch per nesting season. Occasional double clutching has been recorded, and some females may nest in alternate years.

Confirm timing locally before works, because rainfall, flooding and nest temperature can shift courtship, nesting, incubation and hatching between catchments and across northern Australia.

  • Mating: Courtship and mating occur as the wet season approaches and during the wet season. Courtship is reported in September and October, or from October to November in Queensland, while mating generally occurs when water levels are high.
  • Gravid females: The sources do not define a separate gravid period. October to November is the best supported pre-laying window between courtship and egg laying, but females may carry developing eggs for part of the nesting season.
  • Egg laying: Females lay eggs mainly from November to March across the Australian range, with Queensland nesting reported from December to April. No narrower national peak is established.
  • Incubation: Eggs remain in mound nests for about 80 to 98 days, with incubation varying with nest temperature. Eggs laid from November to March may therefore remain in nests from November through June, and later Queensland nests may extend into July.
  • Hatchlings: Hatchlings emerge about 80 to 98 days after laying, giving a broad February to July emergence window from the documented November to April nesting period. Females may carry hatchlings to water and protect them for several weeks or months.
  • Active period: Adults remain active year round. Activity and time in the water are higher during the Australian summer, especially December to February, while winter animals are less active and spend more time basking. Timing is less seasonal in the tropical north.
  • Highest clearing risk: Risk is highest from November to April, when courtship, egg laying and early incubation overlap, particularly in freshwater swamps, river margins and floodplain vegetation. Risk remains in May to July because nests may still contain eggs or hatchlings may be using nearby water and cover; dry-season works can also affect crocodiles concentrated in permanent water.

Identification

The Saltwater Crocodile is a very large, heavily built crocodilian with a long, broad snout and a powerful tail. Identification in the field must be done from a safe distance because adults can attack people and domestic animals.

Size varies greatly with age. Hatchlings are typically less than 0.6 metres total length, juveniles are 0.6 to 1.8 metres, and animals over 1.8 metres are classed as adults for Northern Territory management purposes.

The species can reach at least 5.1 metres in free-ranging Australian samples. No reliable field estimate of body weight is provided in the supplied sources.

Hatchling size: Typically less than 0.6 metres total length

Juvenile size: 0.6 to 1.8 metres total length

Adult class: More than 1.8 metres total length for management purposes

Largest sampled animal: 5.1 metres total length

Identification: Similar species

The main Australian species requiring separation is the Freshwater Crocodile, Crocodylus johnstoni. It overlaps with Saltwater Crocodiles in northern rivers and some tidal reaches, and is generally smaller, but size alone is unreliable for hatchlings and juveniles.

Use clear photographs, body proportions, head shape, scute pattern and locality information where safe to obtain them. Do not approach, handle or enter crocodile water to confirm an identification.

  • Treat any unidentified crocodilian in northern Australia as a Saltwater Crocodile until a suitably experienced person confirms otherwise.
  • Record the waterbody, bank type, salinity or tidal influence if known, approximate total length, behaviour and direction of travel.
  • Use a qualified crocodile specialist for close identification, capture or relocation decisions.

Identification: Field signs

Crocodiles may be detected by direct sightings, slide marks and tracks on muddy or sandy banks, disturbance at nest sites, hatchling or juvenile sightings, and eyeshine during night spotlighting. The supplied documents do not provide diagnostic measurements for tracks, scats or nest mounds.

Nests are associated with temporarily flooded freshwater wetlands, swamps and floodplain vegetation. Nest surveys record nest locations, the number of eggs collected from each nest and egg viability, so nest disturbance should be treated as a significant fauna issue.

  • Inspect muddy banks, sandbars, creek margins and wetland edges from a safe vantage point for broad drag marks, tail traces and repeated entry points.
  • Do not approach a suspected nest, disturb vegetation around it or work from the water's edge without a crocodile risk assessment.
  • Use night spotlighting only under an approved method and site-specific crocodile safety procedure.

Distribution: Australian range

In Australia, Saltwater Crocodiles occur across the northern coast and connected inland waterways. Strongholds are associated with intact tropical coastal wetlands, estuaries and river systems, especially in the Northern Territory, northern Queensland and the Kimberley.

The Australian range includes coastal and inland waterways of the Northern Territory, northern Queensland and northern Western Australia. In Queensland, the largest populations are in coastal areas of the Gulf of Carpentaria and Cape York Peninsula.

In the Northern Territory, the species occurs across the Top End, including coastal rivers, creeks, floodplains, swamps, estuaries, near-coastal islands and freshwater reaches. The study area also included the East Kimberley in Western Australia.

  • Northern Territory: Top End coastal rivers, estuaries, floodplains, swamps and connected freshwater systems.
  • Queensland: Gulf of Carpentaria coast, Cape York Peninsula and other northern coastal rivers and wetlands.
  • Western Australia: Kimberley coastal rivers, creeks, islands and associated inland waterways.

Distribution: Strongholds and population units

The largest Queensland populations are in the Gulf of Carpentaria and Cape York Peninsula, where warm conditions, large intact coastal wetlands and estuaries provide suitable habitat.

Northern Territory management and genetic studies treat major hydrographic catchments, or groups of two or three adjacent catchments, as practical population management units. Populations are connected, but dry land and some saline areas reduce movement between river systems.

  • Important Queensland areas include coastal wetlands and estuaries between Cooktown and Townsville, and the Pormpuraaw area on western Cape York.
  • Important Northern Territory habitat includes the Adelaide, Daly, East Alligator, Mary, Victoria, Reynolds, Goyder and other Top End river systems.
  • No harvesting is permitted in Kakadu National Park under the Northern Territory program.

Distribution: Population size and trend

The species was heavily depleted by unregulated hunting in northern Australia before protection. Northern Territory populations have since recovered and are reported as stable, increasing in monitored rivers, or near natural carrying capacity.

A single national population estimate is not provided in the supplied documents. Northern Territory estimates are available and should not be applied to the whole Australian range.

Northern Territory wild population estimate: About 90,000 to 100,000 non-hatchling crocodiles

Migrants between catchments: Approximately 42 percent of sampled crocodiles

Common inferred movement distance: 150 to 200 kilometres

Long movements recorded: Up to 600 to 700 kilometres in the genetic study

Habitat: Waterway and wetland habitat

Saltwater Crocodiles use a wide range of aquatic habitats, but breeding depends on suitable freshwater wetlands and floodplain vegetation. They are most abundant where waterways, banks, wetlands and nesting areas remain connected and relatively intact.

Adults and juveniles may occupy estuaries, tidal rivers, coastal lagoons, beaches, inshore waters, non-tidal rivers, creeks, lakes, floodplains, swamps and freshwater wetlands.

The species is physiologically adapted to salt water, but occurs at higher density in brackish and freshwater habitats. Open sea is less favoured for residence and connectivity than brackish or freshwater habitat.

  • Retain permanent pools, deep river channels, tidal creeks, billabongs, floodplain channels and wetland connections.
  • Treat muddy banks, sandbars, mangrove margins, freshwater swamps and creek mouths as potential crocodile habitat.
  • Assess both the waterbody and its connected floodplain because crocodiles shift between habitats as wetland extent changes.

Habitat: Vegetation and physical structure

Core breeding habitat includes perennial freshwater wetlands and swamps with Melaleuca, Eucalyptus or Pandanus open forest and mixed grasses and sedges. Species recorded in associated wetland vegetation include Chrysopogon, Xerochloa, Oryza and Eleocharis.

Non-breeding habitat includes permanent waterbodies suitable for residence, with adjacent temporary waterbodies and coastal areas forming marginal habitat. Dry land is a strong movement barrier compared with aquatic habitat.

  • Map riparian vegetation, mangroves, freshwater swamps, wetland margins, floodplain grass and sedge communities before clearing.
  • Keep machinery, access tracks, spoil and stockpiles out of wetland depressions and nest-supporting vegetation.
  • Maintain aquatic connections between breeding wetlands and permanent water where practicable.

Habitat: Climate and elevation

The Australian range is tropical and monsoonal, with a wet season from November to April and a dry season from May to October. Wetlands expand during the wet season and temporary waterbodies contract or dry during the dry season.

The supplied documents do not provide a specific elevation limit. Habitat assessment should therefore focus on hydrology, tidal influence, wetland persistence and connection to occupied waterways rather than elevation alone.

Foraging habitat: Feeding areas

Saltwater Crocodiles are top-order predators and feed in and beside water. The supplied documents do not give a complete prey list, so project assessments should focus on access to productive waterways and safe movement between feeding areas.

Crocodiles forage in estuaries, rivers, creeks, floodplains, swamps, wetlands, lakes, beaches and inshore waters. Brackish and freshwater areas support higher densities than open marine areas.

Potential feeding habitat includes deep pools, channel margins, tidal creek mouths, muddy banks, floodplain waterholes and wetland edges used by fish, aquatic animals, birds and terrestrial animals.

  • Retain access to permanent pools and channel margins during the dry season.
  • Avoid blocking creek mouths, wetland connections or floodplain channels with roads, bunds, culverts or spoil.
  • Manage food waste, livestock access and fish-processing waste because these can attract crocodiles to work areas and increase safety risks.

Foraging habitat: Foraging range and movement

The species can move long distances between river systems. Genetic evidence found a common movement distance of 150 to 200 kilometres and some movements of 600 to 700 kilometres. Individuals may also use ocean currents when moving between coastal waterways.

During the dry season, crocodiles tend to move back towards permanent water as temporary wetlands contract. This can concentrate animals near remaining pools, crossings, boat ramps and construction access points.

Common inferred movement distance: 150 to 200 kilometres

Maximum movement reported in the study: 600 to 700 kilometres

Breeding habitat: Breeding biology

Breeding habitat is concentrated in temporarily flooded freshwater wetlands and swamps, rather than in open marine habitat. Nesting areas require suitable wetland vegetation, seasonal flooding and enough isolation from people, predators and machinery.

Breeding is highly seasonal and occurs during the wet season. Females nest in wetland vegetation and hatchlings emerge after incubation, but the supplied documents do not provide a confirmed incubation period, clutch size, age at maturity, lifespan or sex-specific size data for use in this profile.

Nest survival is affected by flooding and predation. At Pormpuraaw, research found high levels of nest mortality from these causes.

Breeding and nesting season: Wet season, generally November to April in northern Australia

Clutch size: Not specified in the supplied documents

Incubation period: Not specified in the supplied documents

Age at maturity: Not specified in the supplied documents

Lifespan: Not specified in the supplied documents

Hatchling size: Typically less than 0.6 metres total length

Breeding habitat: Nest habitat

Core breeding habitat consists of temporarily flooded freshwater wetlands and swamps, including Melaleuca, Eucalyptus and Pandanus open forest with mixed grasses and sedges. Suitable nesting areas may be within or beside broader floodplain wetland systems.

Annual nest surveys in the Northern Territory record nest locations, eggs collected from each nest and egg viability. Any nest, nest mound or concentrated hatchling activity found during site works should be protected until assessed.

  • Before clearing, inspect freshwater swamps, wetland margins, floodplain depressions and dense grass or sedge vegetation for nests.
  • Maintain a site-specific no-go area around suspected nests until a crocodile specialist and the relevant authority have assessed it.
  • Do not burn, slash, grade, drain or flood nest-supporting vegetation during the wet season without a species-specific approval and method.

Sheltering habitat: Aquatic refuges

Crocodiles shelter in water and along banks rather than in tree hollows or terrestrial burrows. They may use permanent pools, deep channels, muddy banks, dense wetland vegetation and drying mud during seasonal water loss.

Permanent waterbodies are the main non-breeding refuge, especially when temporary wetlands contract during the dry season. Crocodiles may also remain in deep river channels, tidal creeks, lagoons, billabongs and other waterholes.

The species may aestivate in drying mud when early wet-season rains are delayed. This behaviour means apparently dry or partly dry wetland margins cannot be assumed to be free of crocodiles.

  • Inspect water edges, mudflats, deep pools and creek bends from a safe distance before machinery or people enter.
  • Do not use waterway access points, boat ramps or wetland crossings without crocodile exclusion and worker-safety controls.
  • Retain permanent pools and avoid isolating them from connected channels.

Sheltering habitat: Bank and vegetation cover

Crocodiles use riverbanks, muddy margins, sandbars, mangrove edges and dense floodplain vegetation for resting, concealment and access between waterbodies. Specific refuge dimensions are not provided in the supplied documents.

Large animals can travel over broad areas and may use habitat outside the immediate construction footprint. A fauna assessment should therefore include connected waterways and likely access routes, not only the area proposed for clearing.

Threats: Clearing and habitat change

The main development risks are loss or alteration of wetland and riparian habitat, disturbance or destruction of nests, hydrology changes and increased human access to crocodile habitat. Saltwater Crocodiles also present a serious workplace and public safety risk.

Clearing riparian vegetation, wetlands and floodplain vegetation can remove shelter, movement routes and nesting habitat. Urban, rural residential, agricultural and infrastructure development are identified threats in Queensland.

Roads, crossings, bunds, drains, levees, culverts and hardstand areas can fragment waterways, restrict movement, alter flood patterns or concentrate crocodiles at remaining pools.

  • Avoid clearing freshwater wetland, floodplain and riparian vegetation where practicable.
  • Map permanent and temporary waterbodies, tidal channels, wetland connections and suspected nest areas before design finalisation.
  • Design crossings and drainage so they do not create isolated pools, block movement or direct crocodiles towards work areas.

Threats: Hydrology and climate

Changes to flooding, drainage, water depth, salinity and wetland persistence can affect nesting success, hatchling survival, prey availability and movement. Storm surges and flooding can increase egg and juvenile mortality.

Climate change may alter nesting temperatures and sex ratios, increase egg and juvenile mortality, and change the species' distribution.

  • Assess changes to wet-season inundation, dry-season water retention, tidal exchange and floodplain connectivity.
  • Prevent uncontrolled sediment, contaminated runoff and dewatering impacts in occupied waterways.
  • Treat unusual concentrations of crocodiles around dewatering ponds, culverts or retained pools as a safety and ecological issue.

Threats: Direct mortality and disturbance

Accidental mortality can occur in commercial and recreational fish netting in estuaries. Deliberate killing, illegal shooting and disturbance of nests are additional risks.

Feral predators and weed incursions can reduce nesting success. Construction traffic, night lighting, noise and repeated access can disturb crocodiles and increase encounters with people.

  • Remove or secure fish nets, wire, snare-like materials and other entanglement hazards from work areas and access routes.
  • Control invasive weeds and feral predators where they affect mapped nesting habitat, subject to approval.
  • Use crocodile-aware exclusion zones, spotters and access controls around water during all clearing and construction activities.

Threats: Safety and project controls

Saltwater Crocodiles are top-order predators and can attack people, livestock and domestic animals. Removing or relocating a crocodile is a regulated activity and may require state or territory authority.

In Queensland, crocodiles are protected and the species is Vulnerable. In the Northern Territory, the species is protected wildlife and take, keeping, movement and trade require authority.

  • Complete a crocodile risk assessment before workers enter or work beside any waterbody in northern Australia.
  • Keep workers, dogs and livestock away from the water's edge unless a crocodile specialist has approved the method.
  • Stop work and notify the project ecologist and relevant wildlife authority if a crocodile, nest or hatchling group is found within the work area.
  • Do not attempt capture, harassment, feeding, relocation or euthanasia without the required authority and qualified personnel.

Survey methodology: 1. Daytime habitat assessment

Saltwater Crocodiles use estuaries, rivers, wetlands, beaches, inshore waters and some freshwater areas. Survey design must protect workers from a large, dangerous predator and avoid entering water or banks where crocodiles may occur without a site-specific risk assessment and authorisation.

Inspect the project area from a safe land-based position and map permanent and temporary waterways, tidal reaches, wetlands, floodplain channels, mangroves, freshwater swamps and likely nesting areas.

Record connections between waterways because Saltwater Crocodiles can disperse between catchments, with approximately 42 per cent of sampled crocodiles originating from a different catchment and recorded movements commonly spanning 150 to 200 kilometres, with some movements of 600 to 700 kilometres.

Give particular attention to freshwater wetlands with suitable nesting vegetation, because nesting females and embryos require access to freshwater and high quality breeding habitat is concentrated in freshwater wetlands.

Breeding season: Breeding and nesting are highly seasonal during the wet season, generally November to April.

Preferred breeding habitat: Freshwater wetlands and swamps with vegetation such as Melaleuca, Eucalyptus and Pandanus open forest, mixed with grasses and sedges.

  • Do not enter water, mud, dense bank vegetation or isolated wetland habitat during the assessment unless the activity has been specifically authorised and the crocodile risk has been assessed.
  • Use binoculars, photographs, drone imagery where authorised, and distant observation points to identify basking animals, tracks, slide marks, nests, hatchlings and likely access points without approaching the water edge.

Survey methodology: 2. Spotlighting and night observation

Use spotlighting from a boat, vehicle or safe bank position only where the method has been approved in the project risk assessment and the operators are trained for crocodile work.

The supplied management documents identify spotlight surveys of selected river systems as the standard monitoring method for Northern Territory populations, but they do not prescribe a universal number of nights, hours, transect length or detection distance for project surveys.

Do not treat a failed spotlight survey as evidence that crocodiles are absent. Density varies between waterways and crocodiles may be in submerged, vegetated or connected habitats.

Reported sighting density range: 0.1 to 15 crocodiles sighted per kilometre of river in northern Australian waterways.

Typical movement distance: 150 to 200 kilometres between source and destination waterways, with some recorded movements of 600 to 700 kilometres.

  • Survey in the dry season where this is the approved local monitoring period, while separately assessing wet season access, flooding and nesting risk.
  • Record the waterway, survey route, start and finish times, weather, water level, observer effort, number of animals seen, estimated size, location and direction of travel.
  • Use the same route, observers, timing and observation method for repeat surveys so that changes in detection are interpretable.

Survey methodology: 3. Nest and wetland inspection

Inspect potential nesting habitat from a safe distance and use remote observation where possible. Do not search nests by walking through wetland vegetation unless the activity is authorised, the crocodile risk is controlled and the survey is conducted by suitably experienced personnel.

Where a project may affect nesting habitat, engage a crocodile specialist and the relevant state or territory wildlife authority to set the survey method, timing and access controls.

Record nest locations, habitat type, evidence of flooding or predation, and any observed hatchlings without handling eggs or approaching a guarding female.

Annual monitoring used for licensed egg harvest: Population counts are conducted from July to August, with nest surveys recording nest locations, eggs collected and egg viability.

  • Do not use snorkelling, wading, seine nets, traps or similar aquatic methods in waterways occupied by Saltwater Crocodiles unless specifically authorised and supported by a crocodile safety plan.
  • Treat temporary freshwater pools, floodplain channels and tidal reaches as potential crocodile habitat even when no animals are seen.

Survey methodology: 4. Minimum effort and reporting

The supplied documents do not provide a single Australia-wide survey effort standard for construction or clearing projects. Set effort from the area and habitat affected, the waterway network, seasonal conditions, project risk and the requirements of the relevant wildlife authority.

  • Prepare a survey plan that states the area searched, accessible and inaccessible habitat, survey dates, start and finish times, observers, method, weather, water level, limitations and safety controls.
  • Repeat surveys when flooding, high turbidity, dense vegetation or unsafe access is likely to have reduced detection.
  • Submit verified records, photographs and spatial data to the relevant state or territory wildlife database and wildlife authority.
  • Report all sightings, nests, hatchlings, tracks, carcasses, captures, relocations and injuries to the project fauna management records.
  • Retain records of any consultation, permits, risk assessments, spotter catcher qualifications and stop-work events.

Before habitat disturbance: Avoid and minimise

Plan the project around the presence of a large, mobile aquatic predator and the habitat features that support breeding and dispersal. The absence of a sighting does not remove the need for controls near connected waterways.

Habitat connectivity: Genetic evidence indicates extensive dispersal between catchments, so local works can affect animals using connected waterways outside the project area.

  • Avoid clearing freshwater wetlands, swamps, nesting vegetation, riparian cover, mangroves and permanent water connections wherever practicable.
  • Retain connected waterways and riparian vegetation so animals can move between feeding, breeding and refuge areas.
  • Avoid blocking channels, isolating wetlands, filling floodplain depressions or creating temporary water bodies that could attract crocodiles to active work areas.
  • Keep workers, machinery, camps, access tracks and spoil stockpiles away from the water edge and likely crocodile haul-out or nesting areas.

Before habitat disturbance: Approvals and project planning

Queensland conservation status: Vulnerable reptile under the Queensland framework.

EPBC considerations: The species is a listed marine species and listed migratory species under the EPBC Act, although it is not identified in the supplied material as an EPBC threatened species.

  • Check the current EPBC Act status, state or territory conservation status and project approval requirements before works begin.
  • Obtain all required wildlife, animal welfare, capture, movement and relocation permits before any person attempts to capture, handle, move or interfere with a crocodile.
  • Use the Queensland vulnerable species controls where the project is in Queensland, including wildlife authorities for keeping, using, moving or dealing with crocodiles.
  • Prepare a fauna management plan that identifies crocodile habitat, exclusion zones, access controls, emergency contacts, stop-work triggers, safe observation points and the authorised response to a sighting.
  • Stage works so that habitat disturbance is limited to the smallest practicable area and the retained habitat remains connected throughout construction.

Before habitat disturbance: Pre-clearance preparation

  • Complete the approved pre-clearance habitat assessment and crocodile survey before vegetation or wetland disturbance.
  • Mark retained waterways, wetlands, riparian vegetation, nesting habitat, access restrictions and exclusion zones on plans and on the ground.
  • Fence or barricade work areas where this can safely prevent people and machinery from reaching crocodile habitat, but do not create barriers that trap an animal between water and the work area.
  • Brief all workers on crocodile recognition, safe distances, reporting, no-go areas, water-edge hygiene and the requirement not to feed, approach or photograph an animal from an unsafe position.
  • Confirm that the fauna spotter catcher has the authority, equipment and experience required for this species, and that a crocodile specialist and wildlife authority contact are available before works start.

During habitat disturbance: Daily controls

Use a stop, assess and respond approach. A fauna spotter catcher must not improvise a capture or relocation of a Saltwater Crocodile.

  • Inspect exclusion fencing, gates, drains, culverts, water-retaining depressions and access points before work starts each day.
  • Confirm the daily work area, water levels, weather, flooding, visibility and any new crocodile reports during the pre-start briefing.
  • Keep workers and machinery out of waterways and wetland margins unless the method is authorised and the crocodile safety controls are in place.
  • Do not allow workers to fish, swim, wash, feed animals or store food near crocodile habitat.
  • Maintain a clear communication system between the fauna spotter catcher, operator, supervisor and emergency contact.

During habitat disturbance: Working with machinery

  • The fauna spotter catcher must inspect the work zone before machinery enters and must remain in a safe position with a clear retreat route.
  • Stop machinery immediately when the spotter catcher identifies a crocodile, nest, hatchling, carcass or fresh evidence that may indicate an animal is close to the work area.
  • Keep the machine operator stationary until the fauna spotter catcher has confirmed the animal's location and the authorised crocodile specialist or wildlife authority has provided direction.
  • Do not use machinery to chase, herd, pin, block, lift or relocate a crocodile.
  • Do not place a fauna spotter catcher between a crocodile and water or between an animal and a likely escape route.

During habitat disturbance: Animal response and stop-work triggers

Problem crocodile response: Management programs generally remove problem crocodiles rather than release them elsewhere because transport and handling can cause stress and released animals may return.

  • Stop work and withdraw people and machinery if a crocodile is seen, if a nest or hatchling is found, or if an animal is reported in a drain, excavation, temporary pond or other work area.
  • Establish a safe exclusion zone from outside the animal's likely approach route and contact the authorised wildlife authority, crocodile specialist or licensed removal contractor.
  • Do not handle, restrain, transport or relocate the animal unless the person is authorised, the method is approved and the required permits are in place.
  • If an authorised relocation is required, move the animal only to suitable nearby retained habitat approved by the wildlife authority, with consideration of connectivity and the risk that it will return to the capture site.
  • Do not relocate a crocodile as a routine response to a public safety risk without authority, because released problem crocodiles may return rapidly to the capture site.
  • Treat an injured or stressed animal as an emergency and contact the relevant wildlife authority, veterinarian or licensed wildlife carer; do not provide treatment or transport without direction.
  • Resume work only after the authorised person has confirmed that the animal has left the work area or has been lawfully dealt with and that controls have been reinstated.

During habitat disturbance: Habitat features and records

Size information: The species is the largest living crocodilian; the supplied documents do not provide a safe approach distance or a project handling size threshold.

  • Avoid disturbing nests, freshwater wetland vegetation, riparian cover, mangroves, floodplain channels and permanent water refuges unless the approved plan specifically allows the disturbance.
  • Do not apply generic hollow-bearing tree, log, rock or burrow procedures to crocodile habitat without first assessing whether the feature forms part of a wetland, bank, nest or movement route.
  • Keep excavations, trenches, sumps and culverts closed, ramped or inspected so they cannot trap a crocodile or create an unsafe encounter.
  • Record the date, time, location, observer, animal size estimate, behaviour, habitat, photographs, action taken, permits, people involved and time work stopped.
  • Report incidents, captures, injuries, mortalities and suspected breaches to the project manager and relevant wildlife authority within the timeframe set by the approval or permit.

After habitat disturbance: Post-clearance checks

Controls must continue after active clearing because connected waterways can allow crocodiles to enter restored, flooded or newly disturbed areas.

  • Inspect the cleared area, drains, culverts, excavations, wetland edges and retained habitat for crocodiles, nests, hatchlings, carcasses and evidence of entrapment before demobilisation.
  • Check that temporary fencing, gates, ramps, covers and warning signs remain effective after rainfall, flooding and earthworks.
  • Remove or redesign temporary ponds, open drains and other water-holding structures that could attract crocodiles or trap wildlife.
  • Keep access restrictions and water-edge controls in place until the site is stable and the responsible authority agrees that they can be removed.

After habitat disturbance: Monitoring and reporting

Monitoring response trigger in the Northern Territory program: A catastrophic decline is defined there as a 50 per cent or greater decline in density in one river system in one year, subject to distinguishing the result from natural environmental variation.

  • Repeat safe, land-based or approved spotlight monitoring where the project has affected wetlands, waterways, nesting habitat or movement connections.
  • Compare post-work observations with pre-work records, including sightings, location, estimated size, habitat use and movement direction.
  • Report verified records to the relevant state or territory wildlife database and provide the approval authority with the required fauna monitoring and incident reports.
  • Investigate any decline in observations only with an appropriate survey design, because detection varies with habitat, water level, weather and access.
  • Record whether mitigation measures were installed, maintained and effective, and document any corrective action.

After habitat disturbance: Offsets and residual impacts

  • Assess residual impacts on freshwater wetlands, nesting habitat, riparian vegetation and waterway connectivity under the project approval.
  • Apply any required offset, rehabilitation or conservation measure in accordance with the approval and the relevant state or territory framework.
  • Do not treat a financial offset as a substitute for avoiding disturbance to occupied crocodile habitat where avoidance is practicable.

Rehabilitation actions: Wetland and riparian restoration

Rehabilitation should restore connected aquatic habitat, wet season nesting opportunities and safe refuge areas. It should not create new crocodile hazards for workers, visitors or nearby communities.

Northern Territory high quality habitat: High quality Saltwater Crocodile habitat was estimated at 41,154 square kilometres in the Northern Territory, with suitable nesting habitat limited mainly to freshwater wetlands.

  • Reinstate natural water levels, drainage patterns and connections between permanent water, floodplain channels and freshwater wetlands where the project has altered them.
  • Replant locally appropriate native wetland and riparian vegetation, including vegetation communities that provide nesting structure such as Melaleuca, Eucalyptus and Pandanus where those species are part of the local reference community.
  • Use local reference sites and advice from the relevant land manager or wildlife authority to set planting composition, wetland depth, bank profile and seasonal inundation targets.
  • Keep restored habitat connected to retained waterways and avoid creating isolated pools that dry rapidly or trap crocodiles.

Rehabilitation actions: Habitat structure and site safety

  • Retain or reinstate stable banks, shaded riparian cover, natural woody debris and other aquatic refuge features where they occur in the local reference habitat.
  • Do not install hollow logs, nest boxes, artificial burrows or rock piles as a generic crocodile measure unless they are supported by a site-specific design and wildlife authority advice.
  • Make culverts, drains, fencing and wetland edges passable for wildlife while preventing animals from entering active work areas, public swimming areas or confined infrastructure.
  • Design public access, viewing points and warning signs so people cannot approach or feed crocodiles.

Rehabilitation actions: Weeds, predators and fire

Documented threats: Threats include habitat destruction, feral pests and weeds in nesting habitat, deliberate killing, accidental net mortality and climate-related flooding, storm surge and altered nesting temperatures.

  • Control weeds that degrade wetland and nesting vegetation, using methods that do not contaminate water or disturb nests and shelter areas.
  • Manage feral predators and other causes of nest and hatchling loss where this is included in the approved rehabilitation plan.
  • Use fire planning that protects freshwater wetland vegetation, nesting cover and riparian corridors, and obtain advice on the local wet season and dry season fire pattern.
  • Prevent erosion, sediment release and altered runoff from reducing water quality or damaging wetland and nesting habitat.

Rehabilitation actions: Monitoring and success measures

Northern Territory monitoring approach: Population surveys, harvest information and environmental conditions are considered together when assessing whether management intervention is needed.

  • Monitor restored wetlands and waterways through the wet season and dry season for water retention, vegetation establishment, bank stability, connectivity, nests, hatchlings and crocodile use.
  • Use repeatable land-based counts or approved spotlight routes and record the same effort and conditions at each visit.
  • Set success measures for restored wetland area, native vegetation cover, functioning water connections, absence of wildlife traps, and safe separation between crocodile habitat and public or work areas.
  • Review the rehabilitation design if monitoring identifies a decline, unsafe animal concentration, repeated entrapment, nest loss or a new conflict with people or livestock.

Sources