Davies' Tree Frog (Dryopsophus daviesae)

Conservation status

Commonwealth, EPBC Act 1999: Vulnerable.

Breeding season

Davies’ tree frog breeds in streams, with calling recorded from late winter to autumn and strongest calling in November and December. Eggs hatch after 6 to 10 days, and tadpoles take 3 to 4 months to develop, so clearing near streams can affect several life stages across spring to winter.

Reproductive mode: Eggs are laid in a single cluster.

Clutch size: One egg cluster; the number of eggs is not recorded.

Incubation: 6 to 10 days until hatching.

Size at hatching or birth: Not recorded. Tadpoles can reach up to 4.5 cm.

Age at maturity: Estimated at 3 to 4 years for females.

Nest or egg sites: The egg cluster is attached to a plant or rockface just below the water surface, in shaded, slowly flowing parts of pools or mid-stream.

Breeding frequency: Not recorded.

Confirm timing locally before clearing, particularly after rainfall and at sites where stream temperature or seasonal rainfall may extend calling, spawning or tadpole development.

• Calling: Males call from January to May, may call in August, and call from September to December. Calling peaks in November and December. Calling occurs during the day and night, increases during or after light rain, and males may call from ferns or broad-leaf shrubs 0.5 to 1.5 m above the water.
• Egg laying: Egg laying is expected during the documented spring to early summer breeding period, from September to December. Another source describes breeding more broadly as spring to early autumn, so egg laying may extend into January to April at some sites.
• Tadpoles: Tadpoles develop for 3 to 4 months after hatching. They occur in shallow, slowly flowing stream sections, on sand and among rocks or leaf litter, so cohorts from spring and early autumn spawning may remain in water from September into winter and, for later cohorts, into July.
• Metamorphs: The documents do not give a month for juvenile emergence. Based on the 3 to 4 month tadpole period, metamorphs may occur from about December to August following spring to early autumn spawning, with timing varying between breeding events.
• Active period: A species-specific activity season is not recorded. Calling records support activity from August to May, while the documented breeding and monitoring period extends from spring into summer and, in one account, to March.
• Winter inactivity: No winter inactivity, brumation or hibernation is recorded for this species. As general practice for a stream frog in temperate southern Australia, inspect sheltered streamside cover carefully from June to August rather than assuming frogs are absent.
• Highest clearing risk: The highest risk is from September to December, when spring and early summer breeding, peak November and December calling, eggs and early tadpoles overlap. Risk can extend from January to April where breeding continues into early autumn, and from winter into July where tadpoles from later spawning remain in streams.

Identification

Davies' tree frog is a medium-sized tree frog with variable golden-brown, brown and sometimes green upper surfaces. It is associated with vegetated streams and rivers in upland New South Wales.

The upper surface is usually golden brown with darker brown patches. Some individuals also have green patches. A narrow brown stripe runs from the nostrils through the eye towards the groin, broadening towards the rear before becoming intermittent. A green band runs below the eye to the shoulder, and a thin white line borders the upper lip.

The underside has fine granulations. The species has slightly bumpy skin rather than smooth skin.

Male snout to vent length: Up to 53 millimetres

Female snout to vent length: Up to 63 millimetres

Upper colour: Usually golden brown with darker brown patches, sometimes with green patches

Identification: Similar species

Davies' tree frog is very similar to the New England tree frog. Davies' tree frog is larger, less green and has slightly bumpy rather than smooth skin.

Identification: Field signs

The source material does not provide a diagnostic call, egg, tadpole, nest, track, scat, slough, eye-shine or other field sign. Positive identification should therefore rely on the frog's morphology, location and streamside habitat, with expert confirmation where the New England tree frog may also occur.

Distribution: National range

Davies' tree frog is endemic to New South Wales. The documented range is restricted to the eastern side of the Great Dividing Range, from north of the Hunter River to the Hastings River drainage.

The species is known only from New South Wales, Australia. Records occur in a number of separate locations over about 150 kilometres between north of the Hunter River and the Hastings River drainage.

States recorded: New South Wales only

Range extent described in the source: About 150 kilometres

Geographic setting: Eastern side of the Great Dividing Range

Distribution: Bioregions and strongholds

The source does not identify IBRA bioregions, named strongholds, population boundaries or subpopulation sizes. It describes occurrences in deep gullies, tableland streams and other streamside sites above 400 metres.

Area of occurrence: Less than 20,000 square kilometres

Population size: Not provided

Population trend: Not provided

Habitat: Habitat types

Davies' tree frog occurs near streams and rivers with well-vegetated banks at elevations above 400 metres. The surrounding vegetation varies from wet forest in deep gullies to tea tree, ferns and grass tussocks in tableland woodland and heathland.

Recorded habitat includes subtropical or tropical dry forest, subtropical or tropical moist lowland forest, dry shrubland, rivers and stream margins. In the documented New South Wales range, deep gullies may contain wet sclerophyll forest and rainforest.

Habitat: Streamside structure

Tableland stream margins are described as having tea tree, ferns and grass tussocks. These streamside plants form the main documented structural features associated with the species.

Known elevation limit: Above 400 metres

Key habitat feature: Well-vegetated banks beside streams and rivers

• Retain vegetated stream and river banks during site planning and clearing.
• Treat deep gullies, wet sclerophyll forest, rainforest, woodland, heathland and vegetated tableland stream margins as potential habitat where they occur above 400 metres.

Foraging habitat: Diet and feeding

The source material does not state what Davies' tree frog eats, how it captures prey or how far it travels while foraging. Its documented association with vegetated stream and river margins indicates that these areas should be retained as potential activity habitat during works.

Diet, prey types, feeding method and foraging range are not provided in the source material.

Diet: Not provided

Foraging range: Not provided

Foraging habitat: Site implications

Because the species is found near streams and rivers with well-vegetated banks, clearing assessments should include streamside vegetation and adjoining forest, woodland or heathland habitat rather than considering only the active channel.

• Inspect vegetated stream and river margins for frogs before clearing where the species may occur.
• Avoid unnecessary removal of tea tree, ferns, grass tussocks and other streamside vegetation in tableland habitat.

Breeding habitat: Breeding biology

Davies' tree frog breeds in streams according to the source material. The source does not provide breeding dates, clutch size, egg development, maturity or lifespan.

The species breeds in streams. Some breeding streams have been stocked with exotic fish, which may feed on the tadpoles.

Breeding habitat: Streams

Breeding season: Not provided

Clutch size: Not provided

Gestation or incubation: Not provided

Age at maturity: Not provided

Lifespan: Not provided

Breeding habitat: Features to retain

Retain streams and their well-vegetated banks, including habitat in deep gullies and tableland areas. Preventing exotic fish access or stocking in breeding streams is relevant because trout, carp and mosquitofish may eat tadpoles.

• Keep clearing and construction activities out of stream channels and vegetated banks where practicable.
• Manage sediment, barriers and other changes that could affect stream breeding habitat, using project-specific aquatic fauna controls.
• Check whether nearby streams contain introduced trout, carp or mosquitofish before works begin.

Sheltering habitat: Documented shelter context

Specific refuge sites, shelter dimensions and daytime retreat behaviour are not described in the source material. The species is associated with well-vegetated stream and river banks and with forest, woodland and heathland settings.

The source identifies well-vegetated banks beside streams and rivers, wet sclerophyll forest, rainforest, tea tree, ferns and grass tussocks as habitat settings. It does not identify particular hollows, burrows, rocks, logs, leaf litter or refuge sizes.

Known refuge size: Not provided

Specific refuge type: Not provided

Sheltering habitat: Clearing controls

Retain streamside vegetation and ground cover where possible, because the species is recorded beside vegetated streams and rivers. A fauna spotter catcher should check suitable stream margins and adjacent vegetation before clearing.

• Do not clear vegetated stream banks without an approved fauna management process.
• Retain tea tree, ferns, grass tussocks and other streamside cover where these occur in potential habitat.
• Move any captured frog to suitable nearby habitat in accordance with the project fauna handling procedure.

Threats: Habitat loss and fragmentation

Davies' tree frog has a restricted range and is uncommon. The documented threats are forest clearance for agriculture and exotic fish in breeding streams, which may consume tadpoles.

Forest clearance for agriculture threatens the species. Clearing or breaking up streamside vegetation on infrastructure and construction sites may remove habitat within its restricted range.

Area of occurrence: Less than 20,000 square kilometres

Status: Vulnerable under the EPBC Act

• Avoid clearing stream and river banks and adjoining wet forest, rainforest, woodland and heathland habitat where practicable.
• Map and protect vegetated stream margins before access tracks, compounds and services are established.

Threats: Predation by introduced fish

Some breeding streams have been stocked with exotic trout, carp and mosquitofish. These fish may feed on Davies' tree frog tadpoles.

• Identify introduced fish in streams near the work area before modifying aquatic habitat.
• Do not introduce or spread exotic fish through project water movements or aquatic works.

Threats: Other project risks

The source material does not specifically document road mortality, fire, disease, hydrology change, fragmentation effects or predation by terrestrial animals for this species. These risks should be assessed through the project-specific impact assessment because works occur in or near stream habitat.

• Assess changes to stream flows and water quality where construction or infrastructure crosses potential breeding habitat.
• Use the species' restricted distribution and stream association to set survey and clearing controls even where no frog is found during a single inspection.

Survey methodology: 1. Night searches and spotlighting

Davies' tree frog is a restricted-range stream-associated frog from eastern New South Wales. Survey effort should focus on vegetated streams and rivers above 400 metres elevation, including wet sclerophyll forest, rainforest gullies, tableland woodland and heathland. No species-specific survey guideline is provided in the source material, so the methods below are general practice for stream-associated frogs.

Search stream margins, river banks, pools, overhanging vegetation and nearby wet forest after dark, when frogs are more likely to be detected.

Target sites with well-vegetated banks, tea tree, ferns and grass tussocks, particularly where the watercourse passes through tableland woodland or heathland.

Record weather, recent rainfall, air temperature, start and finish times, search length, searchers, route and all frog observations.

Use a quiet approach and avoid entering the water unless the survey method and site conditions permit it.

A medium-sized frog may measure up to 53 millimetres from snout to vent for males and 63 millimetres for females, so inspect small vegetation and the stream edge carefully.

Known elevational range: Above 400 metres

Maximum snout to vent length: 53 millimetres for males and 63 millimetres for females

• Repeat searches on more than one suitable night where the project may affect occupied habitat.
• Do not treat a failed search as evidence that the species is absent, particularly where access, weather or water conditions were unsuitable.

Survey methodology: 2. Call and habitat searches

Listen from the stream bank and nearby wet vegetation for calling frogs, then inspect the area with a torch to confirm identity where possible.

Search in deep gullies containing wet sclerophyll forest or rainforest, and along tableland watercourses bordered by tea tree, ferns and grass tussocks.

Document calling locations as point records and map the occupied or potentially occupied stream reach.

• Conduct call surveys during suitable frog activity conditions selected by the project ecologist, such as warm, humid or recently wet periods, rather than relying on a single daytime inspection.
• Minimise noise, vehicle movement and handling during listening periods.

Survey methodology: 3. Aquatic searches for eggs and tadpoles

Inspect shallow pools, stream margins and other slow-water areas for tadpoles and other breeding evidence where access is safe and permitted.

Use aquatic sampling methods approved for the project and clean and disinfect equipment between waterways to reduce disease transmission.

Record the waterbody, search area, method, effort, water conditions and photographs or voucher material where authorised.

Consider fish presence when assessing breeding habitat, because trout, carp and mosquitofish are identified threats to tadpoles.

• Do not release captured aquatic fauna into another waterway or move water, sediment or aquatic equipment between catchments.
• Obtain any required authority before collecting, retaining or transporting frogs, tadpoles or other aquatic material.

Survey methodology: 4. Daytime habitat assessment

Walk the proposed clearing footprint and adjoining retained areas to map streams, rivers, wet gullies, dense streamside vegetation and likely movement routes.

Inspect the bank condition, canopy and understorey cover, leaf litter, rocks, logs and pools that may provide shelter or breeding habitat.

Extend the assessment beyond the immediate footprint where works could affect drainage, sediment movement, water quality or streamside vegetation.

Record whether the site is above 400 metres elevation and whether it lies within the known eastern New South Wales range, from north of the Hunter River to the Hastings River drainage.

Known distribution: Separate locations over about 150 kilometres, from north of the Hunter River to the Hastings River drainage

Known habitat setting: Near streams and rivers with well-vegetated banks

• Use the habitat assessment to select night survey locations and identify areas requiring retention, fencing or additional approval review.

Survey methodology: Minimum effort and reporting

• Prepare a site-specific survey plan that states the number of survey nights, search hours, search area, aquatic sampling effort, weather limits and detection constraints before fieldwork starts.
• Use additional repeat surveys where habitat is suitable but detection conditions were poor or the species may be affected by the works.
• Record positive and negative results, photographs, coordinates, habitat condition, survey conditions and the identity and experience of surveyors.
• Have records reviewed by the project ecologist and submit confirmed records to the relevant New South Wales wildlife database or other relevant state wildlife database.
• Assess whether the record or proposed impact requires an EPBC Act referral and any state approval, permit or threatened species authorisation before disturbance.

Before habitat disturbance: Avoid and minimise

Plan the project around the species' streamside habitat and its EPBC Act vulnerable listing. The source identifies habitat loss, agricultural clearing and introduced fish as threats, so avoid removing vegetated banks and avoid changes that affect breeding water.

Retain streams, rivers and their well-vegetated banks within and beside the work area.

Retain wet sclerophyll forest, rainforest gullies, tea tree, ferns, grass tussocks, woodland and heathland adjoining suitable watercourses.

Avoid clearing or filling pools, seepage areas, wet gullies and streamside shelter used by frogs.

Maintain connected vegetated movement routes between the watercourse and retained wet forest, woodland or heathland.

Design drainage, crossings and sediment controls so that runoff, sediment and contaminants do not enter breeding or shelter habitat.

• Keep the smallest practicable disturbance footprint and place compounds, access tracks and stockpiles away from streams and wet gullies.
• Do not introduce trout, carp, mosquitofish or other exotic fish into project waterbodies.

Before habitat disturbance: Approvals and work planning

Confirm the project footprint against the known eastern New South Wales distribution and the species' EPBC Act vulnerable listing.

Obtain ecological and legal advice on whether an EPBC referral, state threatened species approval, scientific licence or fauna handling authority is required.

Schedule clearing and construction to avoid periods selected by the ecologist as having high frog activity or breeding risk, based on local weather, rainfall and water conditions.

Stage works so that retained streamside habitat and escape routes remain available while each work area is cleared.

Include species-specific controls, stop-work rules, survey requirements, fauna handling arrangements and incident reporting in the fauna management plan.

National listing: Vulnerable under the EPBC Act

State listing supplied: No state listing provided

• Do not begin habitat disturbance until approvals, survey results, contractor inductions and fauna management procedures are in place.

Before habitat disturbance: Site preparation

Complete a pre-clearance survey of the footprint and adjoining streamside habitat using the approved survey plan.

Mark no-go areas, stream buffers, wet gullies, retained vegetation and access routes before machinery enters the site.

Install exclusion fencing where it can keep machinery and people out of retained streamside habitat without blocking frog movement between water and shelter.

Brief operators to stop and contact the fauna spotter catcher if a frog, tadpole, occupied shelter area or unexpected wet habitat is found.

Check that erosion, sediment, dewatering, lighting and waterway crossing controls are installed before clearing.

• Keep fencing, signs and marked exclusion areas visible and intact for the duration of the works.
• Do not rely on fencing as a substitute for retaining suitable streamside habitat and safe drainage.

During habitat disturbance: Daily controls and spotter catcher procedure

Use daily controls to keep machinery away from retained streamside habitat and to detect frogs before vegetation or ground disturbance begins. A fauna spotter catcher should have authority to pause work where a frog or suitable habitat is encountered.

Inspect exclusion fencing, no-go markers, sediment controls and waterway protections before work starts each day.

The fauna spotter catcher should walk the immediate work area ahead of machinery, check wet vegetation and stream margins, and remain in communication with the operator.

Use staged clearing from the disturbed edge towards retained habitat so animals have an opportunity to move into suitable retained cover, where this is safe and approved.

Keep machinery, personnel, spoil, fuels and washdown water out of retained streams, rivers, wet gullies and vegetated banks.

Stop work for heavy rain, flooding, unsafe water conditions, uncontrolled sediment movement or any other condition that could move contamination into frog habitat.

• Operators must stop immediately on the spotter catcher's instruction and must not recommence until the area has been checked and released.
• Keep night lighting, noise and vehicle movements away from retained streamside habitat as far as practicable.

During habitat disturbance: Finding and handling a frog

Stop the relevant activity and establish a quiet exclusion area if a Davies' tree frog is found.

Only a person authorised under the project approvals and relevant wildlife permit may capture, handle or relocate the frog.

Confirm identification using photographs or other approved methods and record the location, time, habitat, condition and action taken.

If relocation is approved, place the frog in nearby retained habitat with suitable moist vegetation and a connection to the stream or river, as directed by the ecologist and approval conditions.

Keep handling to the minimum necessary, use clean wet gloves or other approved hygiene controls, and do not move the frog across a road, into a different catchment or into unsuitable dry habitat.

Send an injured frog to an authorised wildlife carer or veterinarian under the project's fauna management procedure.

• Do not handle frogs, tadpoles or aquatic material without the required authority.
• Do not keep a frog in custody longer than necessary to obtain advice or transport it for treatment.

During habitat disturbance: Habitat features and stop-work triggers

Treat stream banks, wet gullies, pools, dense tea tree, ferns, grass tussocks, logs, rocks and leaf litter as potential shelter or breeding habitat until assessed by the ecologist.

Do not remove, bury or relocate logs, rocks, vegetation or wet substrate from retained habitat without approval and a documented handling method.

Manage dewatering, trenching and waterway crossings so that frogs and tadpoles are not stranded and water quality is maintained.

Stop work if a frog is found, if tadpoles or suspected breeding activity are detected, if an unmarked stream or wet area is exposed, or if approved exclusion controls fail.

Stop work if machinery enters a no-go area or if clearing begins before the fauna spotter catcher has inspected the work zone.

• Release the work area only after the fauna spotter catcher and project ecologist have applied the approved response and documented the decision.
• Treat repeated frog records as evidence that the work method, timing or exclusion controls need review.

During habitat disturbance: Records and incident reporting

Maintain daily records of inspections, weather, rainfall, work locations, habitat disturbed, fauna observations, captures, relocations, injuries, mortalities and stop-work events.

Record all confirmed sightings with coordinates, photographs where appropriate and the habitat features present.

Report threatened species incidents, injuries, deaths, unauthorised habitat disturbance and approval breaches to the project environmental officer and the relevant regulator as required.

Submit validated occurrence records to the relevant state wildlife database.

• Retain records with the project environmental file and include them in the completion report.

After habitat disturbance: Post-clearance checks

Post-clearance work should confirm that no frogs remain in disturbed areas, that streamside controls are functioning and that retained habitat has not been degraded. Monitoring should focus on the watercourses and vegetated banks that define the species' known habitat.

Have the fauna spotter catcher or ecologist inspect the cleared footprint, stream margins, wet gullies and retained vegetation after each clearing stage.

Check trenches, pits, machinery areas, sediment basins and dewatered areas for trapped or stranded fauna before they are closed or refilled.

Inspect stream banks and downstream areas for sediment, erosion, altered flow, fuel, concrete washout or other construction impacts.

Repair exclusion fencing, no-go markers and erosion and sediment controls immediately when damage is found.

• Repeat checks after rainfall, flooding, major earthworks or any event that changes flow or exposes new wet habitat.
• Document the condition of retained habitat with photographs and mapped observations.

After habitat disturbance: Monitoring and reporting

Use the approved survey methods to monitor retained streamside habitat where the project approval or fauna management plan requires it.

Compare records with pre-clearance survey results, including frog detections, tadpole observations, habitat condition and waterway impacts.

Investigate any decline in detections alongside changes in water quality, vegetation cover, stream flow, introduced fish or construction disturbance.

Report monitoring results, incidents, corrective actions and any confirmed Davies' tree frog records to the approval holder, project environmental officer and relevant regulator.

• Continue monitoring for the period required by approvals and do not remove controls solely because no frogs were detected after clearing.
• Assess whether additional habitat protection, rehabilitation or offset action is required where approved impacts were exceeded.

After habitat disturbance: Offsets and approval compliance

Check whether the approved action requires an offset, conservation measure or contribution for residual impacts to vulnerable habitat.

Ensure any offset or conservation measure protects suitable streamside habitat within the species' known range and addresses the documented threats of habitat loss and introduced fish.

Close out the project only after approval conditions, rehabilitation commitments, fauna incidents and database submissions have been recorded and verified.

• Do not describe an offset as a replacement for avoiding and minimising impacts to occupied or suitable streamside habitat.

Rehabilitation actions: Restore streamside habitat

Rehabilitation should restore connected, vegetated stream margins and protect the water conditions used by the species. The source identifies wet forest, rainforest gullies, tea tree, ferns, grass tussocks, streams and rivers as relevant habitat features.

Reinstate stable, vegetated stream banks and reconnect disturbed sections to retained wet sclerophyll forest, rainforest, woodland or heathland where appropriate to the site.

Use locally appropriate native plants that match the pre-disturbance community, including tea tree, ferns and grass tussocks where they formed part of the original streamside vegetation.

Restore ground cover, leaf litter, small shelter features and shaded moist conditions without blocking frog movement or concentrating runoff.

Remove temporary crossings, hardstand and spoil from the riparian area when no longer required, and stabilise the site with methods that do not release sediment into the watercourse.

• Do not plant species or use soil, mulch or water that could introduce weeds, pathogens, contaminants or aquatic pests.
• Do not create isolated ponds or wet areas that disconnect from the site's natural drainage or become a source of polluted runoff.

Rehabilitation actions: Waterways and shelter features

Reinstate natural stream form, pools, banks and flow paths where they were altered by the project, subject to the design and approval requirements.

Retain or replace naturally occurring logs, rocks, leaf litter and low vegetation where these features provided cover, using material from the same site only when approved and hygienically safe.

Do not install nest boxes as a substitute for this frog's streamside and wet forest habitat unless a project ecologist identifies a specific approved purpose.

Prevent trout, carp, mosquitofish and other exotic fish from entering rehabilitated breeding water, and remove or manage introduced fish only under the relevant authority.

• Design crossings and drainage outlets to avoid scour, barriers to movement and sudden changes in flow.
• Keep rehabilitation works outside retained stream banks wherever practicable.

Rehabilitation actions: Weeds, predators and fire

Control weeds that replace tea tree, fern, grass tussock or other native streamside cover, using methods that protect frogs, tadpoles and water quality.

Prevent construction waste, food and other attractants from increasing predator pressure around rehabilitated habitat.

Develop fire controls with the land manager so that planned burning does not remove moist streamside refuges or expose banks to erosion.

Manage sediment and runoff during weed control, fire preparation and follow-up earthworks.

• Do not use chemicals near water or occupied frog habitat unless the product, method and timing have been assessed and approved.
• Record weed treatment, fire events, fish management and any fauna impacts.

Rehabilitation actions: Monitoring and success measures

Monitor plant establishment, stream-bank stability, water quality, aquatic habitat, weed cover, introduced fish and the condition of connected moist vegetation.

Use repeat frog and tadpole surveys under suitable conditions and compare results with pre-disturbance records.

Set project-specific success measures for native vegetation cover, stable banks, functioning drainage, absence or control of introduced fish, and no ongoing sediment input.

Continue corrective works where rehabilitation remains dry, eroded, weed-dominated, disconnected from the stream or unsuitable for moist streamside shelter.

• Submit rehabilitation and monitoring results with the project's threatened species and approval reporting.
• Do not close rehabilitation obligations until the agreed success measures and monitoring period have been met.

Sources

• Davies' tree frog - Wikipedia, en.wikipedia.org: https://en.wikipedia.org/wiki/Ranoidea_daviesae
• Litoria daviesae - Species Profile, frogid.net.au: https://www.frogid.net.au/frogs/litoria-daviesae/
• THREATENED SPECIES SCIENTIFIC COMMITTEE, environment.gov.au: http://www.environment.gov.au/biodiversity/threatened/species/pubs/78964-conservation-advice-15032023.pdf