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Mahony's Toadlet (Uperoleia mahonyi)

Mahony’s toadlet is a small, endangered myobatrachid frog found only on coastal sand beds of New South Wales, from the northern Central Coast to Seal Rocks. It breeds in shallow, still swamps and swales on leached white sand, while adults use intact native vegetation around breeding sites, making clearing, hydrology changes and fragmentation important considerations on development sites.

Conservation status

Commonwealth, EPBC Act 1999: Endangered.

New South Wales, Biodiversity Conservation Act 2016: Endangered.

Breeding season

Mahony’s Toadlet breeds in two main windows, March and October to November, after suitable rainfall and inundation. Clearing can affect adults in native vegetation throughout the year, with the greatest risk around breeding, larval development and metamorphosis.

Reproductive mode: Egg laying. Eggs are laid singly.

Clutch size: Not recorded.

Incubation: Hatching occurred 5 to 6 days after laying in laboratory observations.

Size at hatching: Mean total length was 7.0 mm for hatchlings at stages 20 to 22.

Age at maturity: Estimated to be at least one year.

Nest or egg sites: Eggs are likely to attach singly to thin strands of submerged vegetation or substrate such as leaf litter in shallow, still water.

Breeding frequency: Breeding is documented in two seasonal windows each year, March and October to November, when water levels are suitable.

Confirm timing locally before works because calling, egg laying and tadpole survival depend on rainfall, water levels and temperature, and surveys should target waterbodies that are at least 70 percent full.

  • Calling: Calling is recorded during the October to March survey period. Breeding is documented in March and October to November, but no monthly calling peak has been established.
  • Egg laying: Egg laying is documented for March and October to November. Eggs are laid singly and are likely to attach to submerged vegetation or leaf litter.
  • Tadpoles: Tadpoles have been recorded in late March after autumn breeding and from October after spring breeding. Spring and summer larval development is likely to take 3 to 4 months, but the timing after autumn breeding is less certain.
  • Metamorphs: A stage 41 autumn tadpole metamorphosed six days later, supporting metamorphosis in late March or April. Tadpoles collected in October metamorphosed in December, and the likely 3 to 4 month larval period allows some metamorphosis into January or February.
  • Active period: No species-specific active season has been established. Adults are terrestrial outside breeding periods and have been recorded up to 400 m from standing water, so suitable native habitat may be used throughout the year, with movement likely to increase when rainfall produces suitable breeding conditions.
  • Highest clearing risk: Risk is highest in March and October to November, when calling adults, eggs or newly developing tadpoles may be present. Clearing, draining or dewatering can also affect tadpoles and metamorphs in the following months, and terrestrial adults may be harmed at any time within 400 m of breeding water.

Identification

Mahony’s toadlet is a small, compact frog that is usually detected by its call at suitable swamps and swales. It is cryptic on the ground, and visual searches alone are unreliable.

Adults are small and robust, with males reaching 30 mm and females 32 mm snout to vent length. The dorsum is variably patterned in pale, tan, chocolate, dark brown and grey, sometimes appearing almost uniform. Dorsal tubercles and parotoid glands may have yellow-orange to rust-orange tips.

Male size: Up to 30 mm snout to vent length.

Female size: Up to 32 mm snout to vent length.

Weight: Not reported in the supplied documents.

  • The tympanum is hidden beneath large parotoid glands.
  • The fingers and toes are unwebbed and slightly fringed.
  • Orange inguinal and femoral patches are present. The femoral patch is large, irregular and closer to the knee than the vent.
  • The underside is black with irregular off-white or bluish-white patches, producing a distinctive marbled pattern.

Identification: Call and field detection

The advertisement call is a single audible ‘squelch’ lasting about one third of a second. It is repeated at an average rate of 25 calls per minute, with an observed range of 15 to 33 calls per minute.

Call duration: About 0.33 seconds.

Call rate: Average 25 calls per minute; observed range 15 to 33.

Call frequency: Mean dominant frequency 2.37 kHz.

  • Calling males are normally located around flooded swamps, swales and ponds.
  • Calling individuals should be captured and examined to confirm identity because the call can be difficult to distinguish from calls of other Uperoleia species.
  • Visual searches are not recommended as the species is cryptic and has small eyes, which produce little visible eyeshine.
  • No tracks, scats, nests or sloughs are produced. Tadpoles may be found on sandy substrates among leaf litter in shallow water.

Identification: Distinguishing features

The completely black and white marbled underside is the most useful field character. Other eastern Uperoleia generally have more evenly speckled or stippled ventral pigmentation.

  • Mahony’s toadlet has maxillary teeth, unlike some similar Uperoleia species.
  • It lacks a colour patch below the knee.
  • Its toes are unwebbed.
  • The orange femoral patch is closer to the knee than the vent.
  • Tadpoles are difficult to separate reliably from those of other Uperoleia species. They have blotched tail pigmentation, a laterally positioned spiracle and a characteristic Uperoleia oral disc.

Distribution: National range

The species is endemic to a restricted section of coastal New South Wales. No records from other Australian states are provided in the supplied documents.

Mahony’s toadlet is known only from New South Wales, between Kangy Angy on the northern Central Coast and Seal Rocks at the northern end of the Myall Lakes sand bed system.

  • The known area includes coastal sand beds in the Port Stephens, Myall Lakes and northern Central Coast areas.
  • Recorded sites include Wyrrabalong National Park, Tomago, Oyster Cove, Nelson Bay, Fingal Bay, Seal Rocks and Kangy Angy.
  • Records are associated with the coastal sandplain systems of the NSW North Coast and Sydney Basin coastal areas, although formal bioregion names are not given in the supplied documents.

Distribution: Strongholds and population information

The species has been recorded from eight locations on sand beds in the Port Stephens, Myall Lakes and northern Central Coast areas. The type locality is an ephemeral swale on sand at Oyster Cove.

Extent of occurrence: 1,905 km².

Area of occupancy: 36 km², based on nine 2 km by 2 km grid cells.

Known locations: Eight locations reported in the NSW assessment.

Estimated abundance: Population size is unknown. Hundreds of individuals may occur at occupied waterbodies.

Population trend: A quantitative decline has not been established, but continuing decline is inferred from habitat loss, degradation and fragmentation.

  • Known sites include reserved and non-reserved land. Three of the eight known sites were reported to be in reserves at the time of the NSW assessment.
  • The species has also been recorded in a golf course dam, a sand mining swale and other disturbed sites where native vegetation remained around breeding habitat.

Habitat: Overall habitat

Mahony’s toadlet is a habitat specialist of coastal, nutrient-poor sand systems. It needs shallow, still water for breeding and intact native vegetation around those waterbodies for its terrestrial phase.

Records are concentrated in ephemeral and semi-permanent swamps and swales on leached, often white, nutrient-poor sand. Acid paperbark swamps are a common association.

Breeding waterbodies: Ephemeral or semi-permanent swamps, swales and ponds with limited or no apparent flow.

Recorded waterbody size: About 70 m by 20 m to 300 m by 500 m.

Recorded water depth: About 10 to 50 cm.

  • Wallum heath.
  • Swamp mahogany and paperbark swamp forest.
  • Heath shrubland.
  • Sydney red gum woodland.
  • Occasionally, artificial dams and sand mining swales where suitable native vegetation remains nearby.

Habitat: Vegetation and structure

Suitable sites generally retain intact native vegetation within and around the waterbody. Aquatic vegetation at breeding sites includes sedges and rush-like plants, including Schoenoplectus, Baumea and Lepironia, as well as broadleaf cumbungi Typha orientalis.

Recommended non-breeding habitat extent: Native swampy vegetation within 400 m of suitable breeding habitat.

Water chemistry reported from two sites: Salinity up to 0.1 parts per thousand; dissolved oxygen 4.53 to 6.24 mg/L.

  • Common terrestrial plant associations include Melaleuca quinquenervia, Eucalyptus robusta, Angophora costata, Acacia longifolia and Banksia species.
  • Native ground and shrub cover may include Persoonia, Isopogon, Dillwynia, bracken, Lomandra, Platysace, Acacia suaveolens, Blechnum, Hypolepis, Schoenus, Baloskion, Leptocarpus and Gahnia.
  • Maintain native vegetation buffers around breeding sites because adults use terrestrial habitat away from water.

Habitat: Climate and elevation

The species occurs in low elevation coastal areas of New South Wales. The supplied documents do not provide a precise elevation limit.

  • Coastal sand deposits and lowland wetlands are relevant habitat constraints.
  • Sites may be exposed to coastal inundation and sea level rise.

Foraging habitat: Adult foraging

The diet of Mahony’s toadlet has not been studied directly. Available information indicates that adults feed on small terrestrial invertebrates, while tadpoles feed on material associated with the pond floor.

Other Uperoleia species eat ants, pill bugs, springtails, beetles, termites and mites. These prey are likely to be taken from ground cover, leaf litter and low vegetation around breeding sites.

Likely adult prey: Ants, pill bugs, springtails, beetles, termites and mites, based on other Uperoleia species.

Recorded distance from water: Up to 400 m.

  • Retain leaf litter, logs, rocks and native ground cover around swamps and swales because these features support both shelter and invertebrate prey.
  • Adults forage in terrestrial habitat outside the breeding period and have been recorded up to 400 m from standing water.

Foraging habitat: Tadpole feeding

Tadpoles are pond adapted and bottom dwelling. Similar Uperoleia tadpoles feed on sediment and algae.

  • Tadpoles have been observed on sandy substrates among leaf litter, often in shallow water at the margins of a swale.
  • Avoid sediment disturbance and water quality changes that could remove or bury bottom food resources.

Breeding habitat: Breeding sites

Breeding occurs in shallow, still waterbodies in native vegetation on coastal sand. Calling males congregate around suitable water, while eggs and tadpoles develop in the waterbody.

Suitable breeding habitat consists of ephemeral and semi-permanent swamps and swales, and occasionally moderate-sized permanent or semi-permanent ponds with little or no water flow. Acidic, oligotrophic conditions on leached white sand are typical.

  • Maintain water levels sufficient for breeding and tadpole development. Survey guidance recommends that waterbodies are at least 70 percent full before survey.
  • Retain aquatic vegetation, leaf litter and natural sandy substrates.
  • Protect intact native vegetation within and around the breeding waterbody because adults use it outside the breeding period.

Breeding habitat: Breeding biology

Eggs are likely to be attached singly to thin strands of submerged vegetation or to substrate such as leaf litter. Field clutch size is unknown.

Breeding season: March, and October to November.

Clutch size: Unknown.

Egg deposition: Eggs are laid singly and are likely to attach to submerged vegetation or leaf litter.

Hatching: About 5 to 6 days after laying in laboratory observations.

Larval period: Likely about 3 to 4 months in spring and summer.

Age at maturity: Estimated to be at least one year.

Longevity: Unknown for Mahony’s toadlet. Five to 14 years has been estimated for Uperoleia martini.

  • Calling males should be confirmed by capture because calls can resemble those of other Uperoleia species.
  • Tadpoles may be almost fully grown by stage 28 and can reach about 35 mm total length.
  • Tadpoles collected at stage 41 metamorphosed six days later in autumn. Spring and summer larval life is likely to be about 3 to 4 months.

Sheltering habitat: Ground refuges

Outside the breeding period, adults are terrestrial and shelter close to breeding sites in native vegetation. The species can burrow in suitable sand but has limited ability to cross highly modified areas.

Suitable shelter includes burrows in appropriate sandy substrates, leaf litter, rocks and logs. Logs, rocks and leaf litter also support invertebrate prey.

  • Retain continuous native ground cover between breeding waterbodies and surrounding vegetation.
  • Avoid removing coarse woody debris, rocks and accumulated leaf litter from the breeding site buffer.
  • Inspect sandy ground, leaf litter, logs and other refuges before clearing where the species or suitable habitat is present.

Sheltering habitat: Terrestrial buffer

Adults have been recorded up to 400 m from standing water within intact native vegetation. This indicates that the area around the waterbody is used during non-breeding periods, not just the wet depression itself.

Recorded terrestrial distance: Up to 400 m from standing water.

Survey polygon guidance: Use aquatic habitat linked to the record and a 400 m buffer from the top of the breeding site bank, incorporating associated native vegetation.

  • Treat native vegetation within 400 m of a breeding waterbody as potential non-breeding habitat.
  • Do not assume that a cleared or highly urbanised gap is readily crossed. Uperoleia species are thought to have limited movement through urbanised areas.
  • Females of frogs generally may move farther from water than males, so clearing farther from the pond may still remove habitat used by breeding females.

Threats: Clearing and development

The main risks are loss and fragmentation of sandy swamp habitat, changes to water levels and water quality, and disturbance of native vegetation around breeding sites. The species’ restricted range and limited movement make recolonisation of isolated sites less likely.

Coastal urban and agricultural development has removed and fragmented habitat around Newcastle, Port Stephens, Hawks Nest, Tea Gardens, Tuggerah Lakes and Lake Macquarie. Historical clearing has removed an estimated 31 to 44 percent of potential habitat in relevant areas.

  • Avoid clearing ephemeral and semi-permanent swamps, swales and their native vegetation buffers.
  • Avoid clearing native vegetation within 400 m of occupied or suitable breeding waterbodies.
  • Sand mining is a particularly direct risk because it targets the sandy substrates used by the species.
  • Development can degrade retained habitat through altered drainage, runoff, weeds, lighting, noise and increased access.

Threats: Hydrology and water quality

Changes to water permanence, drainage and flow can reduce breeding success and tadpole survival. Urban and agricultural runoff may add nitrate, pesticides and other contaminants to naturally nutrient-poor wetlands.

  • Prevent sediment, nutrient, pesticide and chemical runoff from entering breeding waterbodies.
  • Avoid drainage, infilling, water extraction and road works that shorten or extend inundation in ways that reduce breeding suitability.
  • Assess indirect hydrology changes as well as direct clearing, including altered inflows, groundwater use and sand mine rehabilitation.
  • PFAS contamination has occurred in the Tomago area, but its effects on this species are unknown.

Threats: Fire, mining and industrial disturbance

Sand mining, clearing, fire and industrial fluoride fallout have altered vegetation and frog communities at Tomago. Mahony’s toadlet was absent from sites with high fluoride levels and was mainly recorded in later successional vegetation with established canopy cover.

  • Avoid clearing or burning native vegetation around breeding wetlands during periods when it is being used by adults or developing young.
  • Assess cumulative effects where fire, mining, clearing or industrial emissions have already reduced canopy and ground cover.
  • Retain established native vegetation around occupied swamps and swales.

Threats: Predators and disease

Potential predators include introduced red foxes, feral cats and plague minnow Gambusia holbrooki. Chytrid fungus susceptibility has not been confirmed for Mahony’s toadlet, but disease remains a potential risk.

  • Prevent the introduction or spread of Gambusia into breeding waterbodies.
  • Apply hygiene procedures between wetlands and avoid transferring water, mud or amphibians between sites.
  • Consider fox and cat predation where habitat is fragmented or construction increases access.

Threats: Coastal change and competition

The low elevation coastal range is exposed to sea level rise and infrastructure works that affect coastal sand deposits. More common frogs may also compete with Mahony’s toadlet or act as reservoirs for chytrid fungus.

  • Account for coastal inundation and the loss of inland refuge habitat when assessing project impacts.
  • Maintain connected native vegetation and suitable breeding wetlands so that occupied sites are not isolated by development.

Survey methodology: 1. Aural and capture surveys

Mahony’s toadlet is a cryptic, small frog of ephemeral and semi-permanent swamps and swales, usually on leached white sand. Surveys should target calling males at suitable breeding sites, with enough water present and with individuals captured for confirmation because calls can be confused with other Uperoleia species.

Survey potential breeding sites using aural surveys combined with capture of calling individuals for identification.

Walk or slowly inspect a 500 metre transect around suitable breeding habitat and listen for the species’ single ‘squelch’ call.

Use a suitably qualified frog surveyor to confirm records, because Mahony’s toadlet calls can be difficult to distinguish from calls of more common Uperoleia species.

Do not rely on call recorders as the primary survey method, because the NSW survey guide does not recommend them for this species.

Survey method: Aural and visual surveys, with capture of calling individuals for confirmation

Transect length: 500 metres of suitable breeding habitat

Total effort: 480 minutes per 500 metre transect

Repeat surveys: 4

  • Search temporarily flooded wetlands, swales, permanent or semi-permanent swamps and depressions within native vegetation.
  • Target sites on leached or white sand, particularly acid paperbark swamps, wallum heath and related heath or swamp vegetation.
  • Capture calling frogs for identification where this can be done safely and under the relevant animal ethics and wildlife authority requirements.

Survey methodology: 2. Timing and site conditions

Conduct surveys from October to March, covering the documented spring and autumn breeding periods.

Plan survey visits around suitable rainfall and water levels, because the NSW guide requires waterbodies to be at least 70 percent full before survey.

Record water level and acidity for each potential breeding site, as required for reporting in the Biodiversity Assessment Report.

Check reference sites where possible when setting survey timing, because breeding activity and detection can vary between sites.

Survey period: October to March

Required water condition: Waterbodies at least 70 percent full before survey

Recorded breeding periods: March and October to November

  • Give particular attention to March and October to November, when breeding has been recorded.
  • Do not treat an apparently suitable wetland as adequately surveyed if it is too dry to support calling or tadpole development.
  • Record the waterbody condition, water level, acidity, weather and survey date for every visit.

Survey methodology: 3. Detection and identification

Listen for a single audible ‘squelch’ of about one third of a second, repeated at an average of 25 calls per minute, with a reported range of 15 to 33 calls per minute.

Confirm the identity of captured frogs using the completely black and white marbled underside, orange inguinal and femoral patches, unwebbed toes and the absence of a colour patch below the knee.

Do not use visual searches alone to rule out presence, because the species is cryptic, has small eyes and has low visible eyeshine.

Inspect adjacent native vegetation as well as the waterbody, because adults have been recorded up to 400 metres from standing water.

Call duration: About one third of a second

Call rate: Average 25 calls per minute, observed range 15 to 33

Adult non-breeding movements: Recorded up to 400 metres from standing water

Typical breeding waterbodies: About 70 metres by 20 metres to 300 metres by 500 metres, and about 10 to 50 centimetres deep

  • Treat an aural record as provisional until a suitably qualified surveyor confirms the frog or the call is supported by an appropriate captured voucher or other accepted identification.
  • Search shallow water margins, submerged vegetation, leaf litter and nearby sandy native vegetation for adults, eggs and tadpoles.
  • Record co-occurring Uperoleia and other frog species, because sympatric species can complicate call identification.

Survey methodology: Minimum effort and reporting

  • Complete four aural and visual repeat surveys, with 480 minutes of effort per 500 metre transect, during October to March and when the waterbody is at least 70 percent full.
  • Use a suitably qualified frog surveyor and document the surveyor, dates, effort, transect length, weather, water level, acidity, survey conditions and detection results.
  • Map breeding habitat and non-breeding habitat when the species is detected, using the breeding site and associated native vegetation within 400 metres as the starting area for the species polygon.
  • Report all confirmed records, deaths, injuries, relocations and unexpected findings to the relevant NSW wildlife database and include the records in the project’s Biodiversity Assessment Report or equivalent approval report.
  • Check current state and Commonwealth survey, permit and reporting requirements before fieldwork, because the supplied survey guide is a minimum guide for NSW Biodiversity Assessment Method work.

Before habitat disturbance: Avoid and minimise habitat loss

Treat any suitable swamp, swale or adjacent native vegetation on leached white sand as potential Mahony’s toadlet habitat until targeted survey shows otherwise. The species has a restricted distribution and depends on both breeding waterbodies and nearby terrestrial vegetation.

Avoid clearing ephemeral and semi-permanent swamps, swales, depressions and acid paperbark wetlands.

Retain native vegetation within at least 400 metres of suitable breeding habitat where practicable, because adults have been recorded up to 400 metres from standing water and the NSW species polygon uses this distance.

Maintain intact vegetation around breeding sites, including wallum heath, swamp mahogany and paperbark swamp forest, heath shrubland and Sydney red gum woodland.

Keep breeding sites connected to retained native vegetation and avoid creating barriers through roads, compounds, stockpiles or cleared strips.

Non-breeding habitat planning distance: Native swampy vegetation within 400 metres of suitable breeding habitat

Known substrate: Leached, highly nutrient-impoverished white sand

Breeding habitat: Ephemeral and semi-permanent swamps and swales in native vegetation

  • Retain natural water levels, drainage paths and the absence of flow where those conditions support occupied breeding sites.
  • Avoid changes to runoff, water extraction, drainage, sediment movement and water quality that could alter water permanence or acidity.
  • Keep works, lighting, vehicle movement, spoil and chemicals away from the wetland and its surrounding terrestrial habitat.

Before habitat disturbance: Approvals and work planning

Check whether the proposed action requires Commonwealth assessment or referral because the species is listed under the EPBC Act, and check the applicable state threatened species and wildlife requirements before disturbance.

Obtain any required scientific, animal ethics, wildlife handling and relocation approvals before a fauna spotter catcher captures or relocates frogs.

Prepare a fauna management plan that identifies breeding sites, the 400 metre habitat area, exclusion zones, wet-weather controls, stop-work triggers, handling procedures and reporting responsibilities.

Stage clearing and construction so that breeding wetlands and their retained vegetation are protected before machinery enters the site.

  • Schedule ground disturbance outside periods of active calling and breeding where the project risk assessment and approvals allow, while still completing surveys in the required October to March period.
  • Include contingency measures for rain, rising water, unexpected frog records, sediment release, spills and altered drainage.
  • Brief machinery operators, supervisors and fauna personnel on the mapped exclusion zones before each work shift.

Before habitat disturbance: Pre-clearance preparation

Complete the targeted survey before finalising the clearing boundary, access tracks, drainage design and construction compound locations.

Mark breeding wetlands, swales, water margins, retained vegetation and the approved work limit on plans and on the ground.

Install exclusion fencing where it can prevent machinery and people entering retained wetland or terrestrial habitat, and inspect the fencing after rain and vehicle movements.

Remove or redesign proposed activities that would fragment the breeding site and its surrounding native vegetation.

  • Locate and protect logs, rocks, leaf litter and dense ground cover near breeding sites, because these features can provide shelter for frogs and their invertebrate prey.
  • Prevent sediment, nutrients, pesticides, hydrocarbons and other contaminants from entering breeding waterbodies.
  • Confirm who can identify, handle, hold and relocate frogs before work starts.

During habitat disturbance: Daily work controls

Mahony’s toadlet can shelter in terrestrial vegetation near breeding waterbodies and may be difficult to see. Work controls must protect wetlands, water quality and retained native vegetation, with a clear response if a frog is found.

Inspect exclusion fencing, wetland controls, drainage controls and access routes before machinery starts each day.

Keep machinery, vehicles, spoil, fuels, wash-down water and chemicals outside mapped breeding and retained habitat areas.

Stop work that causes sediment, contaminated runoff, dewatering or unexpected changes to water levels in an occupied or potential breeding site.

Use the fauna spotter catcher to check each active work area before clearing and to remain in communication with the operator while machinery is moving.

  • Move machinery slowly through approved clearing areas and keep the operator within direct sight or reliable communication of the fauna spotter catcher.
  • Do not allow night works near breeding wetlands during calling periods unless they are specifically assessed and approved.
  • Keep temporary lighting, noise, vibration and vehicle traffic away from calling sites where practicable.

During habitat disturbance: Fauna spotter catcher response

Stop the machine immediately when a frog, tadpole, egg mass or other animal is detected within the work area or on machinery.

Allow only an authorised and suitably qualified person to capture, handle or relocate the frog under the project approval and wildlife permit conditions.

Minimise handling time, keep the animal cool, shaded and moist using clean species-appropriate equipment, and do not use contaminated gloves, buckets or water between sites.

Relocate a healthy frog only to nearby retained habitat approved in the fauna management plan, with suitable native vegetation and access to an appropriate breeding wetland.

  • Do not move a frog across roads, cleared areas or drainage barriers unless the approved relocation procedure specifically addresses that risk.
  • Do not release a frog into a different catchment, an unoccupied waterbody or habitat that is not approved for relocation.
  • Send an injured or stressed frog to an authorised wildlife carer or veterinarian and record the transfer details.
  • Treat tadpoles, eggs and unidentified Uperoleia as potential Mahony’s toadlet material until identified by a qualified person.

During habitat disturbance: Stop work and records

Stop work in the immediate area if a Mahony’s toadlet is found, if multiple frogs are detected, or if eggs or tadpoles are found in a waterbody scheduled for disturbance.

Keep the area isolated until the fauna spotter catcher, project environmental officer and relevant approval holder agree on the response.

Record the date, time, GPS location, work activity, habitat, weather, water condition, identification, photographs, action taken and final outcome for every record.

Escalate any unexpected mortality, injury, chytrid concern, water pollution, wetland damage or breach of an exclusion zone to the project environmental officer and the relevant regulator or database.

  • Photograph the frog and habitat where this can be done without delaying release or increasing stress.
  • Record whether the frog was calling, gravid, in amplexus, associated with a breeding site or found in non-breeding habitat.
  • Update the site map after every confirmed record and revise exclusion zones before work resumes.

After habitat disturbance: Post-clearance checks

Post-work checks should confirm that breeding wetlands, water quality and retained native vegetation remain functional. The response should be measured through repeat observations, not only through completion of the clearing activity.

Inspect the cleared area, wetland margins, exclusion fencing, drainage controls and retained vegetation after each clearing stage and after major rainfall.

Search the edge of retained breeding habitat for stranded, injured or trapped frogs, particularly where temporary fencing, trenches, pits or stockpiles were used.

Remove temporary fauna hazards, including open pipes, uncovered pits, steep-sided excavations and fencing that could trap frogs, as soon as they are no longer required.

Repair erosion, sediment movement, drainage changes and damaged wetland margins before the next work stage.

  • Confirm that no spoil, mulch, chemical residue or construction waste has entered a swamp, swale or depression.
  • Check that water remains available in occupied breeding sites and that works have not introduced unwanted flow or altered water permanence.
  • Keep retained logs, rocks, leaf litter and native ground cover in place.

After habitat disturbance: Monitoring and reporting

Monitor occupied or affected breeding sites during October to March using the approved aural and visual method, with capture for confirmation where required.

Use the same transect, survey effort, timing and site condition measures where possible so that results can be compared with pre-work surveys.

Report confirmed records, mortalities, injuries, relocations, habitat damage and monitoring results to the approval holder, relevant regulator and relevant state wildlife database.

Retain survey sheets, photographs, GPS data, water level and acidity records, handling records and rehabilitation results with the project environmental records.

  • Use four repeat surveys and 480 minutes per 500 metre transect where the NSW survey guide applies.
  • Review monitoring results after each construction stage and trigger additional controls if calling activity, breeding evidence or habitat condition declines.
  • Obtain specialist advice if monitoring detects unexplained frog deaths, suspected chytrid disease or persistent loss of breeding water.

After habitat disturbance: Ongoing controls and offsets

Maintain wetland buffers, drainage controls, exclusion fencing and weed controls for as long as the approval or fauna management plan requires.

Prevent future clearing, sand extraction, water harvesting, chemical runoff and inappropriate fire within retained habitat.

Apply any approved offset, biodiversity credit, conservation agreement or rehabilitation commitment required by the Commonwealth or state approval.

Do not use an offset as a substitute for avoiding or minimising direct impacts on an occupied breeding site.

  • Review whether the project has caused habitat fragmentation or a loss of breeding locations and report the result through the approval process.
  • Keep the species polygon and retained habitat map current when new confirmed records are made.

Rehabilitation actions: Rebuild breeding and terrestrial habitat

Rehabilitation should restore shallow, low-flow wetland habitat on suitable sandy substrates and reconnect it with intact native vegetation. The aim is to recover breeding water, shelter and water quality rather than simply revegetate cleared ground.

Reinstate ephemeral or semi-permanent swales and shallow swamps where the original hydrology can be recovered and the activity is approved.

Design waterbodies to retain natural drainage and limited flow, with shallow margins suitable for egg deposition, tadpoles and submerged vegetation.

Use local native plants from the recorded habitat associations, including Melaleuca quinquenervia, Eucalyptus robusta, Angophora costata, Acacia longifolia and suitable Banksia species.

Re-establish sedges and aquatic plants recorded at breeding sites, including Schoenoplectus, Baumea, Lepironia articulata and Typha orientalis.

Restore native heath, paperbark swamp, swamp mahogany and other local ground and shrub vegetation around the wetland, extending into the 400 metre non-breeding habitat area where practicable.

Planning area around breeding habitat: Native vegetation within 400 metres

Reported aquatic plant associations: Schoenoplectus, Baumea, Lepironia articulata and Typha orientalis

Reported tree associations: Melaleuca quinquenervia, Eucalyptus robusta, Angophora costata, Acacia longifolia and Banksia species

  • Use clean, suitable sand and avoid adding nutrients or materials that change the oligotrophic and acidic conditions associated with the species.
  • Retain or reinstate leaf litter, fallen timber, logs, rocks and dense ground cover as shelter for frogs and prey.
  • Do not introduce fish, including Gambusia holbrooki, into restored waterbodies.

Rehabilitation actions: Manage threats during recovery

Control Bitou Bush, Boneseed and other weeds that can establish after nutrient enrichment or disturbed drainage.

Prevent runoff containing nitrate, fertilisers, pesticides, hydrocarbons or sediment from entering restored wetlands.

Manage foxes and feral cats in accordance with approved threatened species and site programs.

Prevent access by Gambusia holbrooki and other introduced predators to breeding waterbodies.

Use fire planning that protects established native vegetation and avoids short-term loss of canopy and late-successional habitat.

  • Do not undertake sand extraction or stockpiling on the leached sand habitat being restored.
  • Maintain natural water levels and prevent water harvesting or drainage that shortens the breeding period.
  • Inspect restored wetlands after rainfall, fire and construction maintenance to identify erosion, weeds, fish, pollution or altered water permanence.

Rehabilitation actions: Monitor recovery and success

Monitor water level, acidity, water permanence, vegetation cover, weeds, introduced predators and sediment condition at restored sites.

Survey restored breeding habitat during October to March using the NSW aural and visual method, with four repeat surveys and 480 minutes per 500 metre transect where that guide applies.

Use confirmed Mahony’s toadlet detections, calling activity, tadpoles or other breeding evidence as species-level measures of recovery, while recognising that absence from a survey does not by itself prove local extinction.

Set project-specific success criteria before rehabilitation begins and report results against the approved plan and any offset or consent requirements.

  • Compare post-rehabilitation results with the pre-disturbance survey records using the same survey locations and effort where possible.
  • Continue maintenance until native vegetation is established, wetland hydrology is stable and the site no longer presents construction hazards.
  • Escalate a failure to recover water levels, water quality or native vegetation to the project environmental officer and the relevant threatened species authority.

Sources