Fauna Spotters logo

Many-lined Delma (Delma impar)

The Striped Legless Lizard is a small, cryptic, legless pygopodid restricted mainly to temperate grasslands and nearby grassy woodland in south-eastern Australia. It is listed as Vulnerable under the EPBC Act and is highly relevant to development sites because it can occupy small grassland remnants, roadsides, rail reserves, construction areas and modified pastures, where clearing and ground disturbance can remove shelter and breeding habitat.

Conservation status

Commonwealth, EPBC Act 1999: Vulnerable.

New South Wales, Biodiversity Conservation Act 2016: Vulnerable.

Victoria, Flora and Fauna Guarantee Act 1988: Endangered.

South Australia, National Parks and Wildlife Act 1972: Endangered.

Australian Capital Territory, Nature Conservation Act 2014: Vulnerable.

Breeding season

Many-lined Delma breeds during spring and early summer. Adults are most active from September to April, with timing varying between Victoria and the ACT. Clearing can harm eggs in soil cavities, gravid females, hatchlings and animals sheltering during winter, so timing alone does not remove the need for pre-clearance searches and salvage planning.

Reproductive mode: Egg laying

Clutch size: Usually two eggs; communal clutches of up to 36 eggs have been recorded

Incubation: About 35 to 60 days, with published records of 38 to 47 days

Size at hatching: About 40 to 45 mm snout-vent length and 0.5 to 0.75 g

Age at maturity: Males 2 to 3 years; females 3 to 4 years

Nest or egg sites: Soil cavities, including arthropod burrows, and under or beside rocks

Breeding frequency: Females are thought to be capable of breeding each year after maturity, depending on environmental conditions

Confirm timing with local records and a qualified ecologist, because rainfall, temperature, soil moisture and regional conditions can shift activity, breeding and shelter use.

  • Mating: Mating is associated with increased spring and early summer movement. Timing may be earlier in Victoria, mainly September and October, and later in the ACT, mainly November and December.
  • Gravid females: Gravid females are recorded mostly from late November to early January. Capture rates decline through January and February, so November and December are the strongest supported months.
  • Egg laying: Females usually lay two eggs in December and January. Assessment information places deposition mainly in mid to late December.
  • Incubation: Eggs laid in December and January remain in soil cavities or under rocks for about 35 to 60 days. Incubation therefore extends mainly from December to February, with January the most likely month for eggs to be present.
  • Hatchlings: Hatching occurs in January and February, with hatchlings reported to emerge in February. Hatchlings are about 40 to 45 mm snout-vent length and may have faint or absent stripes.
  • Active period: The general active period is September to April. Detection is highest in spring and early summer, particularly October to December, while Victoria may have an earlier peak in September and October and the ACT a later peak in November and December.
  • Winter inactivity: Animals enter winter torpor or brumation and shelter in soil cavities, cracks, under or beside rocks, and tussock bases. Surface detection is low from May to September, with the strongest winter sheltering period generally June to August.
  • Highest clearing risk: There is no reliably low-risk month. Risk is highest from October to February because adults are breeding or moving, eggs are present from December to February and hatchlings emerge in January and February; clearing from May to August can destroy animals sheltering in winter refuges.

Identification

The Striped Legless Lizard looks like a small snake but is a lizard with external ear openings and vestigial hind-limb flaps. It is cryptic in dense grass and may be missed even when present.

The body is long and thin, with an intact tail about twice the length of the body. The dorsal surface is usually pale grey-brown and the underside is white or cream. Dark and light brown lateral and dorsolateral stripes run from the neck along the body and become diagonal bands on the tail. Stripes may be faint or absent in juveniles.

The head is usually darker than the body, particularly in juveniles, and the side of the face commonly has a yellow flush between the posterior infralabial scales and the tympanum. Some individuals have salmon-pink colouration on the flanks. The species has small vestigial hind limbs expressed as flaps near the vent.

Maximum total length: About 300 mm

Typical adult snout to vent length: About 90 to 110 mm

Tail: About twice the body length when unbroken

  • Check for a visible external ear opening, a broad fleshy tongue, small hind-limb flaps and an intact tail longer than the body.
  • Record the head-scale pattern and photograph both sides of the head before release. Head markings can help identify individuals.
  • Handle animals only as required for identification, and use an appropriately licensed and experienced fauna handler.

Identification: Similar species and sexing

The closest similar species mentioned in the supplied material is the Olive Legless Lizard, Delma inornata. Striped Legless Lizards are generally smaller and striped, but colour and scale characters can vary. The nasal and first supralabial scales are not fully reliable on their own, so difficult records should be checked by an experienced herpetologist.

Juveniles can be confused with the Pink-tailed Worm Lizard, Aprasia parapulchella, in the ACT and NSW. Positive identification may require magnification and, for uncertain new records, a tissue sample in accordance with permit and animal welfare requirements.

The sexes are externally similar. Adult males may have a small rounded cloacal spur beneath each hind-limb flap. Females are generally larger, with adult females averaging about 87.1 mm snout to vent length and adult males about 78.1 mm in one western Victorian study.

Adult female snout to vent length in one study: 72 to 100 mm, mean 87.1 mm

Adult male snout to vent length in one study: 70 to 91 mm, mean 78.1 mm

Observed sex ratio: Approximately 1:1 among adults in the cited western Victorian survey

Identification: Field signs

The species may leave sloughed skins beneath roof tiles and other artificial refuges. Twenty-six sloughed skins were recorded during one western Victorian roof-tile survey, which also recorded 156 individuals.

There are no reliable species-specific tracks, scats or nests described in the supplied documents. A captured animal may emit a high-pitched squeak. Individuals are more likely to be found under grass tussocks, rocks, roof tiles, timber, asphalt or in soil cracks than in open view.

Searchers should treat a snake-like animal with visible ears or hind-limb flaps as a lizard and avoid assuming that a lack of surface sightings means absence.

Useful field sign: Sloughed skin beneath artificial or natural refuges

Call when handled: High-pitched squeaking vocalisation may occur

Eyeshine: Not described as a survey feature in the supplied sources

Distribution

The species has a fragmented distribution across south-eastern Australia. Records extend across South Australia, Victoria, New South Wales and the ACT, with many historical sites lost or no longer occupied.

In South Australia, records are from the south-east, including Bool Lagoon Game Reserve and a nearby site east of Naracoorte. Recent records are scarce, and the supplied survey guidance notes that the Bool Lagoon specimens were collected before 1970.

In Victoria, the known range includes the western volcanic plains and central and western plains, with records near Hamilton, Ballarat and Melbourne and some isolated north-eastern records. In NSW, records are concentrated in the Southern Tablelands and nearby areas, including the Goulburn, Cooma, Yass, Sutton and Tumut to Batlow regions. In the ACT, records occur in the Gungahlin and Belconnen area, Majura Valley, central Canberra near Yarramundi Grassland and the Jerrabomberra Valley.

The species is associated with IBRA regions containing lowland temperate grasslands and grassy woodlands, including the South Eastern Highlands and Southern Tablelands, the Victorian Volcanic Plains and other central and western Victorian plains regions. The supplied documents do not provide a complete current IBRA range map.

  • Use current state and territory databases, recent survey records and local recovery planning documents before defining the potential range for a project.
  • Treat historical records as a trigger for habitat assessment, not as evidence that the species is absent or still present at the same location.

Distribution: Strongholds and subpopulations

Important ACT areas include the Crace, Gungaderra and Mullanggari grassland reserves, Kenny, Majura Training Area, Majura West and grasslands in the Jerrabomberra Valley. The ACT populations are separated by geographic and human-made barriers and may include genetically distinct subpopulations.

In Victoria, many occupied sites are small, including road reserves and other narrow remnants. The species also occurs on private land, conservation reserves, rail reserves and other government land. In NSW, the supplied recovery plan recorded only a small number of known sites, with Kuma Nature Reserve near Cooma the principal protected site identified at that time.

Gungahlin reserves: Crace, Gungaderra and Mullanggari together exceed 500 ha

Estimated ACT reserve populations: At least 1,000 individuals were estimated in each of the three Gungahlin reserves in surveys cited by the ACT action plan

Kenny, ACT: About 250 ha of grassland, estimated to contain 1,000 or more individuals

Known Victorian sites: About 70 sites were reported in the ACT action plan, many small, with about 10 in conservation reserves

Known NSW locations: Seven locations were reported in the ACT action plan, all within 100 km of the ACT

Distribution: Population trend

The species is believed to have declined throughout its range and disappeared from many former sites. The main cause is the loss and degradation of temperate grassland, of which about 99.5 per cent was estimated to have been destroyed or drastically altered after European settlement.

Population abundance is not available for the national range. ACT estimates show that some reserves and grassland clusters support large populations, but many Victorian and NSW sites are small and isolated.

Broad trend: Declining, with local extinctions documented or suspected across the former range

Temperate grassland loss: About 99.5 per cent estimated to have been destroyed or drastically altered since European settlement

Large population benchmark used in the ACT action plan: 500 or more individuals occupying a habitat patch of 50 ha or more

Habitat

The Striped Legless Lizard is a grassland specialist. It is most often associated with structurally complex tussock grassland, but can also occur in grassy woodland margins, secondary grassland and some exotic pastures near native grassland.

Typical habitat is lowland natural temperate grassland dominated by perennial tussock grasses such as Kangaroo Grass, Themeda triandra, Wallaby Grasses, Austrodanthonia species and Spear Grasses, Austrostipa species. The species may also occur in grassland with scattered Eucalyptus trees, provided the canopy is not dense, and in grassland derived from cleared woodland.

Records also come from degraded or exotic-dominated grasslands containing Phalaris aquatica, Cocksfoot, Dactylis glomerata, Serrated Tussock and other pasture plants. Such records are commonly near primary grassland, and presence in exotic grassland does not establish that the habitat can support a population indefinitely.

  • Map native grassland, secondary grassland, grassy woodland edges and nearby exotic pasture as potential habitat where the species is known or likely to occur.
  • Retain connected grass cover and avoid assuming that a site has low value because native plant diversity is poor.
  • Assess habitat within at least the surrounding movement area because individuals can move tens of metres over days or weeks.

Habitat: Structure and site conditions

Grass structure appears more important than plant composition alone. Occupied sites commonly have intermediate biomass, a mixture of tussocks and inter-tussock spaces, and a well-developed grass thatch. In ACT studies, higher detection was associated with tussock leaf heights of about 20 to 50 cm and projected tussock foliage cover of about 35 to 80 per cent.

Very short, uniformly grazed or slashed grass can remove cover. Very tall and dense grass can also reduce structural diversity. In western Victoria, higher roof-tile occupancy was associated with shorter maximum vegetation height and particular grass covers, showing that habitat requirements vary between sites.

Common ACT tussock height at higher detection sites: About 20 to 50 cm

Common ACT projected tussock foliage cover at higher detection sites: About 35 to 80 per cent

Important ground features: Dense tussocks, thatch, inter-tussock spaces, rocks and cracking clay soils, depending on region

Habitat: Climate, soils and elevation

The Southern Tablelands natural temperate grassland community occurs mainly between 560 and 1,200 m elevation in valleys, broad plains and lower slopes influenced by cold-air drainage. Western Victorian study sites were at elevations from 0 to 300 m, with annual rainfall of about 500 to 750 mm.

Victorian and Cooma populations often occur on basaltic rocks and cracking clay soils. ACT sites may have little rock or soil cracking, so tussock bases are likely to provide the main shelter. Some occupied sites are poorly drained and waterlogged in winter.

Southern Tablelands grassland elevation: About 560 to 1,200 m

Western Victoria study-site elevation: 0 to 300 m

Western Victoria annual rainfall in the cited study: About 500 to 750 mm

Foraging habitat

The species feeds on small grassland invertebrates and is thought to be an active forager, although it may also use ambush feeding. Foraging occurs through tussocks, thatch and near the soil surface.

The diet includes spiders, crickets, Lepidopteran larvae and cockroaches. Grasshoppers, butterflies, moths, beetles and flies are also eaten. Slaters, ants and true bugs were rarely recorded in the diet despite being common in grassland.

Prey availability was not identified as a limiting factor in ACT native or non-native grasslands in the cited study. The main habitat requirement for foraging is therefore likely to be a structurally suitable grass sward that supports prey and provides cover.

Preferred prey groups: Spiders, crickets, caterpillars and cockroaches

Other recorded prey: Grasshoppers, butterflies, moths, beetles and flies

Rarely eaten groups: Slaters, ants and true bugs

  • Retain tussocks, thatch and inter-tussock spaces that support invertebrate prey and allow movement beneath ground cover.
  • Avoid unnecessary soil compaction, broad-spectrum pesticide use and removal of coarse ground cover in occupied or potential habitat.

Foraging habitat: Foraging movements

Individuals have been recorded moving at least 20 m in one day and up to 50 m over several weeks. Recapture studies recorded movements from 2.5 to 62.5 m over periods of up to nine days, with one individual moving 60 m in two days.

Roof-tile recaptures often occurred at the same tile, but some individuals moved 80 m. A reasonable generalisation from the cited ACT data is a home-range area of about 25 to 100 square metres, although this varies between individuals and sites.

Recorded movement in one day: At least 20 m

Recorded movement over several weeks: Up to 50 m

Reported recapture movement range: 2.5 to 62.5 m over up to nine days

Generalised home-range area from ACT data: About 25 to 100 square metres

Breeding habitat: Breeding biology

Breeding occurs in warm-season grassland, with eggs placed in sheltered sites such as soil cavities and possibly beneath rocks. Breeding information remains incomplete, so occupied tussocks, rocks and suitable soil refuges should be retained during works.

Mating and increased movement are thought to occur mainly in November and December. Females usually lay two eggs, probably each year. Communal clutches of up to 36 eggs have also been observed, so a clutch site may support more than one female.

Eggs are laid in December and January and hatch in January and February. Published captive incubation periods were 35 to 60 days, including a reported range of 38 to 47 days. Eggs may be laid beneath rocks or in soil cavities, including cavities associated with arthropod burrows.

Mating and increased adult activity: Mainly November and December

Typical clutch size: Two eggs

Observed communal clutch size: Up to 36 eggs

Egg-laying period: December and January

Hatching period: January and February

Incubation: About 35 to 60 days; captive records include 38 to 47 days

Estimated age at maturity: Males 2 to 3 years; females 3 to 4 years

Estimated lifespan: About 10 to 20 years, with adults recaptured after almost seven years and captive animals held for up to 12 years

Breeding habitat: Breeding habitat on projects

Breeding habitat includes structurally complex grassland with tussock bases, thatch, inter-tussock spaces, rocks and suitable soil cavities. In Victoria and the Cooma region, cracking clay and basalt rocks provide potential egg-laying and refuge sites. In the ACT, where rocks and cracks may be scarce, tussock bases and underground cavities may be more important.

Do not remove rocks, collapse soil cavities, strip tussocks or heavily compact the soil in occupied habitat during the breeding and hatching period. Where clearing cannot be avoided, a species-specific salvage and handling plan must be approved by the relevant authority and implemented by licensed personnel.

Sheltering habitat

Shelter is central to persistence because the lizard is small, cryptic and vulnerable when ground cover is removed. Refuge use varies between regions and includes vegetation, soil features and surface debris.

The species shelters mainly in grass tussocks and other dense ground cover. It also uses soil cracks, especially in Victoria, and shelters under or beside rocks at Victorian and Cooma sites. Other records include a spider burrow, arthropod burrows, timber, asphalt and artificial roof tiles.

During winter the species enters torpor. Victorian animals overwinter mainly in soil cracks, under or beside rocks and in tussock bases. In the ACT, tussock bases are likely to be the main winter refuge because many sites have little rock cover or soil cracking. Animals may shelter underground where suitable cavities are available.

Main refuge types: Grass tussocks, tussock bases, soil cracks, rocks, burrows, timber, asphalt and roof tiles

Known underground features: Soil cracks and spider or arthropod burrows

Winter refuge pattern: Cracks, rocks and tussock bases in Victoria; mainly tussock bases in the ACT

  • Retain intact tussock bases, grass thatch, rocks, soil cracks, burrows and coarse ground debris in work areas.
  • Do not turn or remove rocks, lift artificial refuges or disturb burrows repeatedly unless this is part of an approved survey or salvage method.
  • Place refuge materials only where approved by the project ecologist. Artificial refuges are survey tools and are not automatically equivalent to natural tussock shelter.

Sheltering habitat: Torpor and disturbance response

Animals are rarely observed in outdoor enclosures from May to September and may be torpid during the cooler months. They have nevertheless been found under rocks during cooler months, so winter absence from surface searches should not be treated as evidence of absence.

The species may persist after some short-term disturbance if nearby refuges remain. It can be eliminated by extended intense grazing, ploughing, drought or other heavy disturbance, and recolonisation probably depends on nearby undisturbed refuge areas.

Likely low-detection period: May to September

Important refuge principle: Nearby undisturbed refuges may support survival and recolonisation after short-term disturbance

Threats: Clearing and fragmentation

The main threats are the loss, fragmentation and degradation of temperate grassland. Clearing and earthworks can remove both the grass sward and the small refuges used for shelter, foraging and egg laying.

Clearing for urban, industrial, infrastructure and agricultural development is the primary threat across the range. Small remnants, roadsides and rail reserves may still support the species, so narrow or degraded grassland should not be excluded without appropriate survey and habitat assessment.

Fragmentation isolates populations and reduces access to nearby refuge areas. Habitat loss can also remove the connected grass cover needed for movement between tussocks and adjacent patches.

  • Before clearing, map native grassland, secondary grassland, grassy woodland edges, exotic pasture near native grassland and all rocks, cracks, burrows and dense tussocks.
  • Keep machinery, laydown areas, access tracks and spoil outside occupied or potential habitat where practicable.
  • Fence retained habitat and prevent accidental entry, soil compaction, mowing, slashing and storage within the exclusion area.

Threats: Ground disturbance and management

Extended intense grazing, pasture improvement, ploughing, drought, inappropriate mowing or slashing and heavy disturbance can remove the grass structure and refuges needed by the species. Very short grass can reduce cover, while heavy grazing can expose animals to predators.

Fire can cause direct mortality. Recently burnt habitat may also expose surviving animals to predation. The species has persisted after some fires, but intense and widespread fires are expected to have greater effects than small, patchy, low-intensity burns.

Weed invasion and replacement of native grassland by exotic species modify vegetation structure. Some exotic grasslands can be occupied, but their ability to support populations in the long term is uncertain.

  • Schedule slashing, mowing, grazing and burning to avoid the most sensitive periods and retain unburnt refuge patches.
  • Use patchy, low-intensity fire only where it is consistent with the approved ecological management plan.
  • Prevent weed spread through clean-down procedures and avoid broad disturbance of tussock bases and soil refuges.

Threats: Predators, roads and climate

Predation by native birds and snakes is likely, although its extent is not quantified. Foxes may prey on the lizards, and domestic or stray cats may affect populations beside suburban areas. Fence posts, power poles and other perches may increase predation pressure. Loss of ground cover can also make animals more exposed.

Road and infrastructure projects create direct clearing, barriers and repeated disturbance. The supplied documents do not quantify road mortality for this species, but road reserves and rail reserves can contain occupied habitat and should be assessed before widening, trenching or construction.

Warmer and drier conditions, more extreme weather and increased fire risk may reduce habitat quality. Drying of soil and increased evaporation may affect eggs in soil cavities. The supplied documents do not identify a specific disease threat for this species, so disease controls should follow the project fauna hygiene plan and current authority advice.

  • Control domestic and feral cats around retained grassland where this is authorised and practical.
  • Avoid adding unnecessary perches next to occupied habitat and retain ground cover beneath unavoidable infrastructure.
  • Treat changes to drainage, soil moisture and waterlogging as habitat risks requiring site-specific assessment.

Survey methodology: 1. Roof-tile artificial refuges

Delma impar is a cryptic grassland specialist. A negative result does not demonstrate absence, so surveys must target its seasonal activity period and its refuges in tussocks, soil cracks, rocks and other ground cover.

Install artificial refuges in suitable grassland before the main survey period and allow them to settle before repeated checks.

Use roof-tile grids where the objective is to detect presence, compare occupancy or monitor a known population. A Western Victorian study used grids of 50 tiles and checked 13,900 tiles across 278 grid surveys between 28 September 2005 and 22 January 2006.

Check tiles during spring and early summer, with the highest detection rates generally reported from October to December. Record the date, time, weather, temperature, relative humidity, vegetation structure and whether each tile is occupied.

Lift each tile carefully and replace it in the same position. Check the ground beneath and immediately around it for lizards, sloughed skins, soil cracks and escape routes.

Treat tile occupancy as a detection measure, not a direct population estimate. Recaptures can inflate counts unless individuals are marked and the survey design supports mark and recapture analysis.

Example grid size: 50 roof tiles per grid

Example survey period: 28 September 2005 to 22 January 2006

Example survey effort: 278 grid surveys and 13,900 tile checks

Survey methodology: 2. Pitfall trapping with drift fencing

Use pitfall trapping as a targeted method in suitable grassland, especially where ground cover, tussocks and movement pathways are present.

Run trapping in the active period, particularly October to November and more broadly late spring to summer. The species is much less detectable in cooler months, although individuals may shelter under rocks or in other refuges from April to August.

Use escape-safe traps, suitable shade and shelter, and check traps at an interval that prevents heat stress, drowning, predation and prolonged confinement. The supplied guidelines identify pitfall trapping as a method for this species but do not provide a single nationally prescribed trap layout or checking interval.

Record trap location, trap nights, weather, ground cover, bycatch, lizard condition and all release or treatment actions. Close traps and remove drift fencing as soon as the survey is complete.

Most productive period reported: October to November

Broader recommended season: Late spring to summer

Survey methodology: 3. Targeted refuge searches

Search likely refuges by carefully inspecting dense perennial tussocks, grass thatch, soil cracks, rocks, logs and other ground debris. This species is generally difficult to detect by visual observation of active animals in dense vegetation.

Search during warm conditions in spring and early summer, when activity and pitfall captures increase. Include a search of retained habitat beside the impact area so that animals displaced by works can be detected and protected.

Do not repeatedly turn the same rocks or disturb the same refuges without a survey reason. Repeated disturbance can temporarily reduce subsequent captures.

Use experienced reptile surveyors and verify unusual or juvenile records. Delma impar can be confused with other Delma species and with the Pink-tailed Worm Lizard in parts of New South Wales and the Australian Capital Territory.

Typical active period: Spring and summer, particularly October to December

Reported movement: Up to 20 metres in one day, with recapture movements recorded up to 62.5 metres over several days

Survey methodology: Minimum effort and reporting

  • Map the study area, adjoining grassland, vegetation condition, tussock structure, soil cracks, rocks and other potential refuges before selecting survey methods.
  • Survey during the active period and use more than one method where habitat is suitable, because this cryptic species may remain undetected when present.
  • Report the method, dates, start and finish times, personnel, weather, survey area, trap nights, tile checks, refuge searches, raw detections and non-detections.
  • Photograph and record the location of each detection, including the habitat feature used and the direction of movement.
  • Have suspected records confirmed by an experienced reptile identifier, and obtain a tissue sample for positive identification where required by the relevant authority, especially for juveniles or records outside the known range.
  • Submit confirmed records and associated survey data to the relevant state or territory wildlife database, and provide records to the Australian Government where required by approval conditions.

Before habitat disturbance: Avoid and minimise habitat loss

Plan the work around the species' grassland habitat and seasonal activity. The preferred outcome is to avoid disturbing occupied grassland, refuges and connections between retained patches.

Recorded movement: Up to 20 metres in one day, with longer movements recorded between captures

Associated habitat: Native grassland, grassy woodland with low tree cover, secondary grassland and some nearby exotic pasture

  • Retain native and secondary grassland with dense, structurally varied tussocks, grass thatch, soil cracks, surface rocks and other shelter.
  • Keep adjoining grassland and nearby refuge areas connected where practicable, because animals can move tens of metres and may recolonise disturbed grassland from nearby undisturbed refuge.
  • Avoid unnecessary removal of rocks, logs, dense tussocks, soil structure and ground debris from retained habitat.
  • Avoid creating short, uniform grassland in retained habitat. The species is associated with intermediate grass biomass and structurally complex swards, rather than very short or very dense uniform growth.
  • Keep construction access, spoil, vehicle parking and storage outside retained grassland and outside mapped refuge areas.

Before habitat disturbance: Approvals and project controls

National status: EPBC Act vulnerable

State status supplied: ACT vulnerable, New South Wales vulnerable, South Australia endangered, Victoria endangered

  • Check the current EPBC Act listing before works start. Delma impar is listed as vulnerable nationally, so refer the action if it may significantly affect the species or its habitat.
  • Check the relevant state or territory threatened species legislation, survey requirements, scientific licences, animal ethics requirements and fauna handling permissions.
  • Include a species-specific fauna management plan in the construction environmental management plan where suitable habitat or a known population may be disturbed.
  • Define the authorised fauna spotter catcher, reptile specialist, site supervisor, environmental officer and stop-work decision maker before mobilisation.
  • Include procedures for pre-clearance surveys, daily inspections, animal handling, relocation, injury response, unexpected finds, records and reporting.

Before habitat disturbance: Timing and site preparation

  • Schedule ground disturbance outside the main activity period from spring to early summer where practicable, while recognising that animals may still be present in refuges during cooler months.
  • Complete a targeted pre-clearance survey before vegetation removal, with particular attention to tussock bases, soil cracks, rocks, logs and dense grass thatch.
  • Mark all retained habitat, no-go areas, refuge features, access routes and relocation areas on plans and on the ground.
  • Install exclusion fencing where it can keep machinery and people out of retained habitat, and inspect the fencing daily for gaps, trapped animals and maintenance failures.
  • Brief all workers on the species' appearance, snake-like body form, visible ear opening, small hind-limb flaps, reporting requirements and the instruction not to handle it unless authorised.

During habitat disturbance: Daily work controls

Treat each work front as a controlled fauna operation. The spotter catcher must have enough time and authority to inspect refuges before machinery enters and to stop work when an animal or occupied habitat is found.

  • Inspect exclusion fencing, work limits, access routes and the active work area at the start of each shift.
  • Use a fauna spotter catcher ahead of clearing machinery, with the spotter catcher positioned where the operator can stop safely and immediately.
  • Clear in small stages towards retained habitat only where this direction does not push animals into machinery, traffic or other hazards.
  • Keep machinery at low speed near tussocks, rocks, logs, cracks and other potential refuges, and stop before disturbing each feature.
  • Do not burn, slash, grade, plough, roll or stockpile grassland material within the approved work area unless the fauna management plan specifically allows it.

During habitat disturbance: Handling and relocation

  • Stop the relevant activity if a Delma impar is seen, trapped, injured or found within the work area.
  • Allow only an appropriately authorised and experienced fauna handler to capture or move the animal, using the approved reptile handling procedure and avoiding tail restraint or unnecessary handling.
  • Place an uninjured animal in nearby retained, suitable grassland with dense tussocks and available ground refuge, at a location approved by the project ecologist and relevant authority.
  • Keep the relocation point within or immediately beside connected retained habitat unless the approval or fauna management plan specifies another location.
  • Do not relocate an animal across roads, into isolated habitat, into unsuitable short grass or into an area that will soon be disturbed.
  • Place an injured animal in a secure, ventilated container and transfer it promptly to an authorised wildlife carer, veterinarian or other approved facility.
  • Do not commence salvage or translocation beyond immediate construction avoidance without an agreed protocol and the required government approvals.

During habitat disturbance: Refuge features and stop-work triggers

  • Inspect rocks, logs, soil cracks, tussock bases and dense thatch before moving or destroying them, and retain these features wherever possible.
  • Replace retained rocks and logs in their original position and orientation if they must be moved temporarily.
  • Treat an occupied refuge, repeated detection area, unexpected concentration of animals, injured animal, damaged exclusion fence or unapproved habitat disturbance as a stop-work trigger.
  • Stop work and obtain ecological advice if clearing reveals a previously unmapped grassland patch, a connected refuge area or evidence of repeated use by Delma impar.
  • Do not treat a lack of detections during a single inspection as proof that the area is unoccupied.

During habitat disturbance: Records and incident reporting

  • Record every detection, non-target capture, injury, relocation, mortality, refuge feature removed, stop-work event and fence inspection.
  • For each animal, record the date, time, coordinates, habitat feature, condition, photograph, sex or life stage if known, handler, destination and authority reference.
  • Report deaths, injuries, escapes, repeated detections and any breach of the approved clearing limits to the project environmental officer and relevant regulator.
  • Update the project map each day so that machinery operators and supervisors know where animals and retained refuges have been found.

After habitat disturbance: Close-out checks

Post-clearance work must confirm that no animals or occupied refuges remain in the disturbed area and that retained grassland is still functioning as habitat.

  • Complete a post-clearance inspection of the entire work area, edges, access tracks, spoil areas and retained habitat beside the disturbance.
  • Inspect remaining tussock bases, cracks, rocks, logs and other ground refuges for animals, sloughed skins and signs of disturbance.
  • Remove temporary traps, drift fencing and artificial refuges when the approved survey or management program ends, unless they form part of an ongoing monitoring design.
  • Repair damaged exclusion fencing and close gaps that could allow machinery, stock or uncontrolled access into retained habitat.

After habitat disturbance: Monitoring and success measures

  • Monitor retained and rehabilitated grassland during spring and early summer using the same method, grid locations and reporting units used for the pre-clearance survey where comparison is required.
  • Use roof tiles or other approved artificial refuges only under a documented monitoring design, and check them consistently for season, time of day and weather.
  • Track detections, occupancy, vegetation height, tussock cover, weed cover, soil refuge condition and evidence of grazing, fire, predation or vehicle damage.
  • Treat continued use of retained habitat, stable or increasing detections where monitoring is appropriate, and recovery of suitable tussock structure as project success measures.
  • Do not interpret zero detections as local extinction without repeated, adequately timed surveys and advice from the relevant threatened species authority.

After habitat disturbance: Reporting and offsets

  • Submit the post-clearance report to the approval holder, project environmental officer and relevant regulator within the timeframe set by the approval.
  • Provide confirmed records to the relevant state or territory wildlife database and retain the spatial data, photographs and handling records with the project environmental record.
  • Check whether residual impacts require an approved offset, habitat protection measure or additional conservation action under the EPBC Act or state approval.
  • Maintain all fencing, no-go areas, weed controls, grazing controls and fire controls for the period specified in the fauna management plan.

Rehabilitation actions: Restore grassland structure

Rehabilitation should restore the structure and shelter resources of temperate grassland, not simply establish a short grass cover. Retain and rebuild the ground refuges that allow Delma impar to shelter, overwinter and move through the site.

Reported preferred vegetation structure: Intermediate biomass and structurally complex grass swards

Common associated grasses: Themeda triandra, Austrodanthonia species and Austrostipa species

  • Use locally appropriate native perennial tussock grasses, including Themeda triandra, Austrodanthonia species and Austrostipa species where suitable for the site.
  • Establish a structurally varied sward with tussocks, intertussock spaces and ground thatch rather than a uniformly short or uniformly dense cover.
  • Retain or reinstate suitable surface rocks, logs, coarse ground debris and dense tussock bases as shelter features.
  • Protect soil structure and retain existing cracks where they are a natural feature of the site, especially in Victorian and Cooma region habitat where cracking clay and basalt rocks are used as refuges.
  • Do not plant trees or shrubs into treeless core grassland unless the approved ecological restoration design requires them, because the species is associated mainly with open grassland and low tree cover.

Rehabilitation actions: Manage weeds, grazing and fire

Reported suitable tussock height in ACT studies: About 20 to 50 centimetres

Reported tussock projected foliage cover: About 35% to 80%

  • Control Serrated Tussock, African Lovegrass, Phalaris, Cocksfoot, St John's Wort and other weeds that alter grassland structure or replace native tussocks.
  • Use grazing only under a site-specific regime that maintains shelter and avoids extended intense grazing, pasture improvement and loss of ground cover.
  • Avoid slashing that leaves a uniformly short sward, particularly where no alternative refuge is available.
  • Use patchy, low-intensity fire only where it is consistent with the approved grassland management plan, and retain unburnt refuge areas beside any planned burn.
  • Avoid widespread intense fire because fire can cause direct mortality and recently burnt habitat can expose animals to increased predation.

Rehabilitation actions: Monitor rehabilitation outcomes

Known ACT large-population benchmark: 500 or more individuals occupying habitat patches of 50 hectares or more

Known ACT medium-population benchmark: 200 or more individuals, where the large-population criteria are not met

  • Inspect rehabilitation areas at least during spring and early summer while Delma impar is most detectable, and repeat surveys at the frequency required by the approval or management plan.
  • Measure native tussock establishment, vegetation height, tussock cover, ground cover, weed cover, soil refuge condition and the presence of rocks, logs and dense thatch.
  • Use the same tile, pitfall or refuge-search design before and after rehabilitation where a detection comparison is required.
  • Investigate any failure of tussock establishment, increased weed cover, severe grazing, fire damage, predation signs or loss of ground refuges, and adjust management.
  • Document whether the area is being used by Delma impar and other grassland species, while recognising that a negative survey result alone does not demonstrate absence.

Sources