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Northern Stuttering Barred Frog (Mixophyes balbus)

The Northern Stuttering Barred Frog is a large stream-breeding frog of moist forest in eastern Australia. It depends on permanent or near-permanent streams, intact riparian vegetation, shallow gravel or bedrock riffles for nesting, and pools that retain tadpoles for a long larval period. Clearing, sedimentation, altered stream flow and disturbance near streams can affect the species on development sites.

Conservation status

Commonwealth, EPBC Act 1999: Vulnerable.

New South Wales, Biodiversity Conservation Act 2016: Endangered.

Victoria, Flora and Fauna Guarantee Act 1988: Critically endangered.

Breeding season

Males call and breeding occurs mainly from September to April, usually after rain. Tadpoles can remain in pools or slow-flowing water for at least 12 to 15 months, so stream pools and nearby shelter habitat may remain sensitive to works throughout the year.

Reproductive mode: Egg laying with external fertilisation.

Clutch size: 130 to 1,025 eggs, with an average of 326 reported.

Incubation: Not recorded.

Size at hatching or birth: 2.8 mm hatchling length reported.

Age at maturity: Not recorded.

Nest or egg sites: Very shallow water in nests hollowed in gravel, wet leaf litter, rock shelves or shallow riffles beside rocky, flowing streams.

Breeding frequency: One clutch per year reported.

Confirm timing locally before works because rainfall, stream flow, temperature, elevation and the persistence of pools can shift calling, egg laying and metamorphosis across the species' range.

  • Calling: Males call from September to April, often after heavy rain. Calling is strongest in spring and summer, with some calling continuing through March and April.
  • Egg laying: Eggs are laid mainly from September to March, with breeding records extending to April. Females lay eggs in very shallow nests in gravel, wet leaf litter, rock shelves or shallow riffles beside rocky streams.
  • Tadpoles: Tadpoles occupy stream pools and slow-flowing or deeper water after eggs are deposited. Development takes about 12 months or at least 15 months, so tadpoles may be present in every month and can persist across more than one breeding season.
  • Metamorphs: No month-specific emergence period is recorded. Because tadpole development takes about 12 to 15 months, metamorphs may leave stream pools in any month, depending on when eggs were laid and local rainfall and water levels.
  • Active period: No species-specific month limit for adult activity is recorded. Adults are nocturnal and may move through forest-floor shelter and between breeding streams, especially during wet conditions; movement can extend hundreds of metres from a stream.
  • Winter inactivity: The species is not recorded as hibernating or entering formal winter dormancy. During cool or dry periods, adults may bury themselves under leaf litter and use dense vegetation, banks, logs and stream-floor cover, so winter sheltering is most relevant from June to August in temperate areas.
  • Highest clearing risk: Risk is highest from September to February, when calling adults, nests and newly developing larvae are most likely to be affected. Clearing, drainage and dewatering remain a risk in every month because tadpoles may persist for at least 12 to 15 months and adults use leaf litter, banks, logs and stream margins outside the calling period.

Identification

This is a large, ground-dwelling barred frog associated with flowing streams in rainforest and wet sclerophyll forest. Adults are well camouflaged on wet leaf litter, under banks and beside or above stream flow.

Adults have a brown to grey-brown back, with a darker longitudinal stripe or series of patches along the middle of the back.

A black stripe runs from the nostril past the eye, and a black triangular patch occurs at the tip of the snout.

The belly is white or yellow. The arms and legs have dark horizontal bars.

The pupil is vertical. The iris is dark brown with a blue crescent in its upper half.

Fingers are unwebbed and toes are about three-quarters webbed. Fingers and toes lack discs.

Maximum reported body length: Just over 8 cm

Typical description: Approximately 80 mm, yellow-grey to brown above, with barred limbs

Weight: Not provided in the supplied documents

Identification: Similar species

Mixophyes balbus can resemble the Southern Barred Frog, Mixophyes iteratus, and other barred frogs in areas of overlap.

It is generally smaller than M. iteratus and has a different eye colour from M. fasciolatus and M. iteratus, according to the supplied identification material.

It is also very similar to Mixophyes australis. The current account places M. australis south of the Macleay River and M. balbus north of the Macleay River. Records south of that boundary should therefore be checked against current taxonomy before attributing them to M. balbus.

Identification: Field signs and detection

Males call from beside streams, often under leaf litter, in holes, on dry parts of the stream floor, or on logs just above flowing water.

The call can be detected during nocturnal stream searches, and some males respond to call playback or a good imitation of the call.

Tadpoles are dark grey or nearly black and are bottom dwellers in pools or slowly moving water. They graze among stones and can be detected by repeated dip-net sweeps.

Eggs are laid in shallow water in nests hollowed by females in gravel, stream debris, bedrock or wet leaf litter beside rocky streams.

The species has no documented tracks, scats, sloughs, hollows or eyeshine field sign in the supplied documents.

  • Search wet leaf litter, stream margins, banks, shallow riffles, logs and the edges of pools.
  • Record the location of calling males, egg nests, tadpoles and adult frogs in relation to the stream channel.
  • Use clean equipment and follow frog hygiene procedures between sites.

Distribution: Current range

The current supplied distribution for Mixophyes balbus is in northern and north-eastern New South Wales. Older material describes a wider historical range extending through south-eastern Queensland, New South Wales and Victoria, but the 2023 taxonomic account separates southern frogs as Mixophyes australis.

The current species account places M. balbus from Boonoo Boonoo National Park in northern New South Wales south to the Macleay River.

The species occurs mainly along the ranges, with records also extending towards the coast in the Bellingen region.

The New England Tablelands, including the upper Styx River catchment, is a documented area where populations occur along streams.

States with current range documented in the supplied sources: New South Wales

Northern limit: Boonoo Boonoo National Park

Southern limit in the current account: Macleay River

Biogeographic areas named in the sources: New England Tablelands, northern New South Wales ranges and the Bellingen coastal area

Distribution: Taxonomic and state-listing issue

The supplied project brief lists the species as Vulnerable under the EPBC Act, Endangered in New South Wales and Critically Endangered in Victoria.

The current species account states that frogs formerly assigned to M. balbus in the southern part of the range were recognised in 2023 as Mixophyes australis. Victorian and southern New South Wales records therefore require taxonomic review before they are treated as M. balbus records.

Older survey guidance and historical material still describe M. balbus as extending to Victoria. Project assessments should identify which taxonomy and listing apply to each record.

Distribution: Population information

The supplied documents do not provide a national population estimate, total number of subpopulations or reliable density estimate.

The species was described as having reduced greatly in number, and the 1999 forest-practices review considered it unlikely to persist across the wider area despite amended prescriptions.

National population size: Not stated

Population trend: Reported decline or reduction, but no quantified national trend is provided

Documented monitoring area: Eleven streams in the Styx River catchment were monitored in 2007

Habitat: Forest and stream setting

Mixophyes balbus is a stream-dependent frog of generally undisturbed moist forest. Sites need both suitable stream habitat for breeding and moist forest floor habitat for adults outside the breeding period.

The species is usually associated with flowing streams in rainforest or wet sclerophyll forest.

It is also recorded in moist gullies, near permanent streams or springs, and in forest containing dense vegetation and leaf litter.

The species needs permanent water, or at least larger pools that retain water, because tadpoles may remain in the stream for at least 15 months.

  • Retain flowing streams, springs, larger pools and shallow riffles.
  • Retain riparian rainforest, wet sclerophyll forest and moist gully vegetation.
  • Avoid separating the stream from adjacent moist forest floor and leaf litter habitat.

Habitat: Structural features

Important stream features include shallow gravel or bedrock sections, riffles, stream debris, slowly moving pools and vegetated banks.

Important terrestrial features include wet leaf litter, dense ground vegetation, undercut banks, holes and logs beside or above the stream.

Males may call from the stream floor, banks or logs, so apparently dry margins and small raised structures beside the active channel can still be occupied.

Stream habitat: Flowing streams with shallow riffles, permanent pools or slowly moving water

Adjacent terrestrial habitat: Moist forest floor with leaf litter and dense vegetation

Habitat: Elevation and climate

The supplied documents do not define a numerical elevation limit or climatic envelope.

Detection and activity are favoured when the substrate and leaf litter are wet, usually after rain, but surveys should not be undertaken during heavy rainfall or excessive stream flow.

Foraging habitat: Adult feeding area

The supplied documents do not provide a confirmed diet or named prey list for Mixophyes balbus. They do show that adults use the moist forest floor and stream margins, while tadpoles feed in shallow stream pools.

Adults may range widely on the forest floor in moist conditions and may travel hundreds of metres from the breeding stream outside the breeding season.

For project planning, the likely adult feeding area should therefore include moist leaf litter, dense ground vegetation, stream banks and adjoining forest, not only the wetted channel.

No specific prey taxa or food plants are identified in the supplied documents.

Adult foraging range: May extend hundreds of metres from the breeding stream outside the breeding season

Known diet: Not specified in the supplied documents

  • Treat moist forest floor within and beside riparian habitat as potential adult foraging habitat.
  • Retain wet leaf litter and dense ground vegetation during clearing and construction planning.
  • Do not assume that forest beyond the stream bank is unused between breeding events.

Foraging habitat: Tadpole feeding habitat

Tadpoles are bottom dwellers in pools or slowly moving water. They graze among stones and on the stream substrate.

Maintaining clean substrate, pool habitat and suitable low-flow sections is therefore relevant to larval habitat.

Breeding habitat: Breeding biology

Breeding occurs beside flowing streams, especially where shallow riffles, gravel or bedrock and slower-flowing pools occur together. Females place eggs in shallow nests beside or within the stream, and larvae develop in pools or slowly moving water.

Males call beside streams during spring, summer and early autumn, with calling recorded from September to April.

Breeding generally follows rain. Females hollow nests in gravel, stream debris, bedrock or wet leaf litter in very shallow water beside rocky streams.

Tadpoles are bottom dwellers and may remain in pools or slowly moving water for at least 15 months. This long larval period means that breeding habitat must retain water beyond the initial rain event.

Breeding season: Spring to autumn, generally September to April

Peak calling period: Spring and summer, with calling sometimes continuing through March and April

Egg number or clutch size: Not provided in the supplied documents

Egg placement: Very shallow water in nests hollowed in gravel, stream debris, bedrock or wet leaf litter

Larval period: At least 15 months in captivity; tadpoles may be present for most of the year

Age at maturity: Not provided in the supplied documents

Lifespan: Not provided in the supplied documents

Breeding habitat: Breeding site features

Suitable sites contain shallow riffles or flat shallow stream sections for egg nests, together with deeper pools or slow-flowing water for tadpoles.

Breeding males may be hidden under leaf litter, under banks, on dry stream-floor surfaces or on logs just above flowing water.

Stream flow must be maintained because nests and larvae depend on the stream channel and its connected pools.

  • Protect shallow gravel and bedrock riffles from sediment deposition and physical disturbance.
  • Keep stream banks, overhanging vegetation, leaf litter, logs and undercut margins intact.
  • Prevent works from diverting, ponding, dewatering or rapidly concentrating flow through breeding habitat.

Sheltering habitat: Adult refuges

Adults shelter on the forest floor and beside streams rather than in tree hollows or burrows. Shelter habitat is closely linked to wet leaf litter, dense vegetation, banks and woody debris.

Adults may bury themselves under leaf litter during cool or dry periods and can then be difficult to detect.

Other refuges include dense vegetation, holes, undercut banks, dry parts of the stream floor and logs immediately beside or above flowing water.

The species may move hundreds of metres from its breeding stream, so shelter habitat can occur beyond the immediate riparian strip.

Known refuge type: Leaf litter, dense vegetation, holes, undercut banks, stream-floor cover and logs

Known refuge size: No specific refuge dimensions are provided

Movement from breeding stream: May extend hundreds of metres outside the breeding season

  • Retain continuous wet leaf litter and dense ground cover.
  • Retain logs, stream debris, undercut banks and natural holes beside the channel.
  • Inspect moist forest floor and stream margins before vegetation removal, including areas that appear to be outside the active channel.

Sheltering habitat: Larval refuge

Tadpoles shelter and feed on the bottom of pools or slowly moving stream sections, often among stones and substrate.

Larval habitat can persist for much longer than the adult calling period because tadpoles may take at least 15 months to metamorphose.

  • Avoid draining or infilling pools that retain water after breeding flows recede.
  • Prevent sediment, concrete washout, fuel and other pollutants from entering pools and slow-flowing stream sections.

Threats: Clearing and construction

The main project risks are loss or degradation of stream and riparian habitat, changes to flow and water quality, removal of moist forest-floor cover, and disturbance during the breeding and larval periods.

Removing riparian vegetation, leaf litter, logs or bank cover can remove calling, breeding and shelter sites and can dry the local microclimate.

The NSW forest-practices review identifies removal of vegetation cover and changes to compartment hydrology as threats to frog survival.

A historical species-specific prescription recommended protecting a recorded site with a 30 m buffer on each side of the stream for 200 m upstream and 200 m downstream. This is historical guidance and should not be treated as a substitute for current approval conditions.

Historical record-based protection: 30 m on each side of the stream, extending 200 m upstream and 200 m downstream

  • Map streams, springs, pools, riffles, wet gullies, dense leaf litter and connected forest before clearing.
  • Keep machinery, spoil, access tracks and stockpiles out of stream channels, banks and wet forest-floor refuges.
  • Use site-specific advice and current approval conditions wherever the species is recorded or suitable habitat is present.

Threats: Hydrology, sediment and water quality

The species depends on flowing streams, shallow riffles, permanent or persistent pools and suitable low-flow sections for egg laying and larval development.

Changes to stream flow, altered drainage, loss of riparian shade, sedimentation and pollution can affect nests, tadpoles and the moist forest-floor habitat used by adults.

The NSW review specifically identifies changes in compartment hydrology and riparian microclimate as risks.

  • Maintain natural stream flow and avoid concentrating runoff through occupied or potential breeding habitat.
  • Control sediment and prevent concrete, fuel, chemicals and contaminated water from entering streams or pools.
  • Keep stream crossings from altering stream flow where feasible.

Threats: Fire and vegetation removal

Fire, fuel-reduction burning and removal of vegetation cover can reduce leaf litter, ground shelter and riparian shade.

The supplied documents identify fire, vegetation-cover removal and altered hydrology as relevant risks for stream frogs, but do not provide a species-specific fire interval for M. balbus.

  • Avoid burning wet gullies, occupied riparian habitat and moist leaf-litter refuges.
  • Retain unburnt ground cover and streamside vegetation where the species or suitable habitat is present.

Threats: Predators, disease and roads

Introduced trout have been investigated as a possible pressure on stream-breeding frogs because fish can prey on amphibian larvae. In the Styx River study, M. balbus occurred in streams with and without trout, and no effect was demonstrated in the one season of demographic data, but the authors recommended further years of monitoring.

The supplied documents identify disease and predation by introduced species as recognised causes of amphibian decline generally, but do not establish a species-specific disease or predator impact for M. balbus.

Roads can provide access to suitable stream habitat and road transects can detect frogs after heavy rain, but the supplied documents do not quantify road mortality for this species.

  • Prevent the transfer of aquatic organisms and pathogens between streams by cleaning and disinfecting footwear, nets, traps and other equipment.
  • Avoid introducing or spreading fish into occupied or potential breeding streams.
  • Use fauna spotter catchers and project hygiene procedures during wet-weather works near streams.

Survey methodology: 1. Select habitat and timing

Survey this stream-dependent frog in suitable habitat before any clearing, excavation, access construction or changes to drainage. Use several methods because adults can be cryptic, males call only during part of the year, and tadpoles can remain in streams for an extended period.

Search generally undisturbed forest near moist gullies, permanent streams or springs, particularly riparian rainforest and wet sclerophyll forest.

Inspect shallow stream sections, riffles, gravel beds, stream debris, pools and slowly moving water. Check leaf litter, dense vegetation, banks, holes and logs beside the stream because adults may shelter away from open water.

Plan surveys from September to April, with the main calling period from September to March or April. Adults are most detectable when the substrate and leaf litter are wet, about one week after heavy rainfall, but surveys should not occur during heavy rain or high stream flow.

Tadpoles may be present for much of the year. They are bottom dwellers in pools or slowly moving water and may take at least 15 months to develop in captivity.

Recommended stream transect: At least 200 metres

Minimum survey nights: Two nights under suitable conditions, repeated on at least four separate occasions during the activity period

Calling period: September to April, with peak activity generally in spring to early autumn

Survey methodology: 2. Call and nocturnal searches

Walk a stream or creek transect at night using spotlighting and call detection. Search stream banks, dry parts of the stream floor, leaf litter, holes, banks and logs just above flowing water.

Use call playback or a good imitation of the call where permitted and where the surveyor is competent to identify the response. Record natural calls and responses separately from confirmed visual observations.

Give particular attention to periods after rain when stream levels are receding and riffle habitat is suitable for breeding. Do not treat a negative call survey as evidence that the species is absent, because non-calling frogs may be missed and adults can be concealed under leaf litter.

Survey conditions: Wet substrate and leaf litter, after rainfall, but not during heavy rainfall or high stream flow

Search method: Call playback, call detection and nocturnal spotlighting along a stream transect

  • Repeat the 200 metre stream transect on at least two nights and, for a high confidence survey, on at least four separate occasions during the activity period.
  • Record weather, rainfall history, stream flow, survey start and finish times, transect length, playback use, observers, call detections, visual detections and habitat conditions.

Survey methodology: 3. Tadpole and habitat searches

Dip-net suitable pools and slowly moving sections of the stream using multiple sweeps, while avoiding unnecessary disturbance to gravel beds, eggs and stream substrates.

Search shallow pools, gravel beds and stream debris for eggs and larvae. Tadpoles are dark and bottom dwelling, so inspect the substrate rather than relying only on surface observations.

Combine larval sampling with adult searches and call surveys. Larval detection can identify use of a stream when adults are not calling or are concealed.

Larval habitat: Pools or slowly moving water in permanent streams

Breeding habitat: Shallow water in gravel or stream debris nests, including flat shallow sections over bedrock or gravel

  • Survey all suitable pools along the transect where practicable, including larger permanent pools that may persist through dry periods.
  • Identify, photograph and release captured animals or larvae at the capture location unless a suitably authorised wildlife professional directs otherwise.

Survey methodology: Minimum effort and reporting

  • Do not rely on a single visit, a single method or a survey conducted outside the activity period to clear habitat for disturbance.
  • Use experienced frog surveyors who can distinguish this species from similar Mixophyes species and who can identify larvae with an accepted field key.
  • Check current taxonomy before finalising the survey target list because the southern part of the former range has been separated as Mixophyes australis.
  • Map the full stream reach surveyed, all records, breeding signs, tadpole pools, calling locations, refuge habitat and any nearby proposed impact area.
  • Submit confirmed records and important negative survey information to the relevant state wildlife database, and retain photographs, call recordings and field sheets with the project records.
  • Report any detection promptly to the project environmental officer and update the impact assessment, exclusion areas and fauna management plan before works proceed.

Before habitat disturbance: Avoid and minimise impacts

Treat permanent or semi-permanent streams, moist gullies and adjoining riparian forest as potential habitat until targeted survey and impact assessment show otherwise. The breeding stream and nearby forest floor both require protection.

Retain flowing streams, permanent pools, riffles, gravel beds, stream debris, banks, leaf litter, dense ground vegetation and riparian rainforest or wet sclerophyll forest.

Avoid altering stream flow, drainage, pool depth, stream bed structure, water quality or the moist microclimate of riparian zones.

Apply the NSW forestry protocol distance where it is relevant to the approval or management framework: protect a 30 metre buffer on each side of the stream for 200 metres upstream and 200 metres downstream of a record.

Also check general requirements for dams, ponds, wetlands, riparian buffers and habitat corridors. The reviewed NSW measures identify a 10 metre buffer for ponds and dams and recommend stronger protection around recorded stuttering frog habitat.

Species-specific protocol example: 30 metres either side of the stream for 200 metres upstream and 200 metres downstream of a record

General pond and dam buffer in reviewed NSW measures: 10 metres

  • Keep construction compounds, spoil, vehicle crossings, dewatering points and sediment controls outside retained stream and riparian habitat wherever practicable.
  • Design crossings so they do not alter stream flow, sediment movement or fish and frog passage.

Before habitat disturbance: Check approvals and plan the works

Confirm whether the proposed action is likely to have a significant impact on this EPBC Act vulnerable species and obtain advice on referral or approval requirements before work starts.

Check the current state listing, threatened species approval requirements, scientific licence conditions and wildlife handling requirements for the state or territory where the project occurs.

Prepare a fauna management plan covering survey results, exclusion areas, stream protection, fauna handling, stop-work triggers, incident reporting, rehabilitation and monitoring.

Stage clearing and construction to avoid the September to April survey and breeding period where the project risk assessment shows that timing can reduce harm. Do not use timing alone to justify disturbance of occupied habitat.

  • Give the fauna spotter catcher and machinery operators maps showing the retained stream, buffers, access routes, no-go areas and approved fauna handling process.
  • Include a stop-work process for a frog, tadpole, egg nest, unexpected breeding site, injured animal, stream damage, sediment discharge or unapproved clearing.

Before habitat disturbance: Prepare the site

Complete the targeted survey before clearing and repeat it if the approval, season, hydrology or proposed footprint changes materially.

Mark stream buffers, moist gullies, permanent pools, breeding pools, dense riparian vegetation, leaf litter refuges and access limits on the ground and in the construction plans.

Install exclusion fencing where it can prevent machinery, workers, stock or vehicles entering retained habitat without diverting frogs into roads or active work areas.

Brief all workers on the frog's appearance, habitat, reporting process and hygiene requirements before they enter the site.

  • Inspect and clean footwear, nets, waders, vehicles and other equipment between waterways under the project's frog disease hygiene procedure.
  • Plan clean water diversion, erosion control and sediment containment before disturbing soil near a stream.

During habitat disturbance: Daily controls and machinery coordination

Keep works outside retained stream and riparian habitat wherever possible. The fauna spotter catcher must have authority to pause work when the approved controls are not being met or when a frog or breeding site is found.

Complete a pre-start inspection of buffers, exclusion fencing, access routes, water controls and the work area each day.

Use a fauna spotter catcher during clearing and other high-risk activities where required by the approval or fauna management plan. The spotter catcher must remain able to see the active work area and communicate directly with the operator.

Clear vegetation in stages and at a controlled pace so the spotter catcher can inspect the ground, leaf litter, banks, logs, rocks, holes and wet areas before machinery moves into each section.

Keep machinery, spoil, concrete washout, fuels and temporary drainage out of streams, pools, wet gullies and retained riparian buffers.

  • Stop the relevant machine immediately when the spotter catcher gives the agreed stop signal.
  • Do not restart until the animal, breeding site, habitat issue or safety risk has been assessed and the environmental officer authorises restart.

During habitat disturbance: Habitat features and water protection

Leave stream banks, gravel beds, shallow pools, stream debris, leaf litter, dense ground vegetation and logs in place unless their removal is approved and unavoidable.

Do not block, divert, drain, fill or increase sedimentation in a stream or pool used by the species.

If a crossing is unavoidable, use the approved design and inspect it for changes to flow, scour, sediment deposition and passage during and after works.

Treat temporary dams, dewatering areas, trenches and sediment basins as potential frog habitat and inspect them before pumping, filling or backfilling.

  • Keep excavated material and sediment controls away from the channel and maintain clean water flow through the work area.
  • Do not handle or relocate logs, rocks, leaf litter or stream debris unless the fauna management plan specifies a safe method and the action is supervised by an authorised person.
  • Do not assume that hollow-bearing trees or nest boxes are a substitute for stream, pool and ground habitat for this species.

During habitat disturbance: Animal found, injury and stop-work response

Stop work in the immediate area if a stuttering frog, tadpole, egg nest or occupied breeding pool is found.

Keep workers, vehicles and machinery away from the animal and prevent it entering the active work zone, drains or traffic routes.

Only a person authorised under the relevant approval or permit may capture, handle or relocate the frog. Use the least handling necessary and follow the approved amphibian hygiene and handling procedure.

Relocate an animal only when necessary to prevent immediate harm, and place it in nearby suitable retained habitat approved by the fauna management plan, without moving it across roads or into unsuitable waterways.

Place an injured frog in a clean, secure, appropriately ventilated container and arrange prompt assessment by an appropriately licensed wildlife carer or veterinarian.

Escalate any record, injury, mortality, egg nest, tadpole concentration, stream damage, sediment release or breach of a buffer to the project environmental officer before work resumes.

  • Record the date, time, location, life stage, photographs, weather, habitat, action taken, handler, destination and outcome for every animal interaction.
  • Treat a confirmed breeding site or repeated record as a trigger to review the exclusion area, construction method and approval conditions.

After habitat disturbance: Post-clearance inspection

The environmental officer must confirm that controls remain effective after clearing and construction. Inspection should continue through wet weather, stream flow changes and the next suitable calling period.

Inspect the full work edge, retained buffers, stream crossings, pools, drainage lines and temporary work areas after clearing and after major rainfall.

Check for trapped frogs in trenches, pits, pipes, sediment basins, water tanks and other structures before covering, pumping or removing them.

Remove temporary fauna hazards as soon as they are no longer needed, or maintain daily inspection and escape measures until they are removed.

Repair damaged exclusion fencing, sediment controls, stream banks and riparian vegetation promptly.

  • Complete a documented post-clearance search of the retained habitat and work footprint before releasing the next construction stage.
  • Record any mortality, injury, displaced animal, habitat damage, sediment event or change to stream flow as an environmental incident.

After habitat disturbance: Monitoring and compliance

Monitor retained streams and riparian habitat during the next suitable calling period using the targeted methods in the survey plan.

Use at least 200 metre stream transects, call surveys, nocturnal searches and tadpole sampling where the approval or fauna management plan requires post-work monitoring.

Compare records with pre-work survey points and reference sites where feasible. Record calling males, adults, tadpoles, egg nests, pool condition, stream flow, riparian cover and water quality observations.

Maintain buffers, exclusion fencing, clean water controls and access restrictions until the environmental officer confirms that the relevant risk has ended.

  • Review monitoring results after each survey round and amend controls if frogs are detected in disturbed areas, if breeding habitat is degraded or if detection declines unexpectedly.
  • Submit required records, incidents and monitoring results to the regulator, approval holder and relevant state wildlife database.

After habitat disturbance: Offsets and corrective action

Apply any offset, restoration or compensatory habitat requirement imposed by the EPBC Act approval, state approval or project consent.

Do not use an offset to justify avoidable loss of occupied stream or riparian habitat.

If the project damages a stream, pool, breeding site or buffer, stop the relevant activity, stabilise the site, notify the approval authority where required and implement the approved corrective action.

Rehabilitation actions: Restore stream and riparian habitat

Rehabilitation should restore the features this frog uses for breeding, shelter and movement: permanent or persistent stream pools, shallow gravel margins, stable banks, moist leaf litter and shaded riparian vegetation.

Reinstate natural stream flow, shallow pools, riffles, gravel beds, stable banks and slowly moving water where construction has altered them.

Replant locally appropriate native riparian rainforest and wet sclerophyll species from nearby reference vegetation, and retain or restore the dense ground layer and leaf litter used for shelter.

Where the project is within the Dunn's white gum moist forest ecological community, consider the role of Eucalyptus dunnii and associated rainforest subcanopy trees and shrubs in restoring canopy and structural complexity.

Reconnect retained stream reaches with adjoining moist gullies and forest floor habitat rather than creating isolated wet areas.

  • Do not line or reshape restored channels in a way that removes gravel, shallow edges, leaf litter or natural variation in flow.
  • Keep rehabilitation works outside the species' calling and breeding period where practicable, and avoid working during heavy rainfall or high stream flow.

Rehabilitation actions: Ground features, weeds, predators and fire

Retain or reinstate coarse woody debris, logs, rocks, leaf litter and dense vegetation beside streams where these features provide refuge.

Do not install nest boxes as a substitute for the stream and ground habitat required by this frog.

Control weeds under an approved site plan without removing the moist ground cover needed for refuge or causing sediment to enter streams.

Apply approved feral predator controls where identified as a project risk, and prevent domestic animals from entering restored riparian habitat.

Manage fire so that restored riparian rainforest and moist ground habitat are not exposed to an increased fire frequency. Avoid burning retained moist gullies and buffers unless authorised fire planning identifies a safe and necessary treatment.

Rehabilitation actions: Success measures and follow-up

Set success measures for stable stream banks, functioning pools and riffles, persistent water in suitable pools, low sediment input, recovering riparian cover, retained leaf litter and absence of weed dominance.

Survey restored habitat during suitable conditions from September to April using call detection, playback, nocturnal searches and tadpole sampling.

Record calling males, adults, egg nests and tadpoles, and compare results with pre-disturbance data and nearby reference sites where feasible.

Continue inspections after heavy rainfall and repair erosion, scour, blocked flow, failed plantings, weed outbreaks or damaged habitat features.

Keep rehabilitation and monitoring records with the project environmental records and submit required results to the relevant regulator and state wildlife database.

Sources