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Northern Hopping Mouse (Notomys aquilo)

The Northern Hopping-mouse is a small, nocturnal rodent of sandy habitats in northern Australia. It is listed as Endangered under the EPBC Act and is currently confirmed mainly from Groote Eylandt, where clearing, mining, roads, altered fire, feral cats and loss of ground cover can affect burrows and feeding habitat on development sites.

Conservation status

Commonwealth, EPBC Act 1999: Endangered.

Queensland, Nature Conservation Act 1992: Vulnerable.

Northern Territory, Territory Parks and Wildlife Conservation Act 1976: Vulnerable.

Breeding season

Breeding can occur in every month. The clearest seasonal signal is a higher influx of juveniles in June and July, which may coincide with grass seeding during the early dry season. Clearing risk therefore remains year round, with added concern during the juvenile peak.

Months are January to December. The species is not strictly seasonal, so pre-clearing surveys should consider active burrows and breeding use throughout the year.

  • Breeding: Breeding adults and juveniles have been recorded throughout the year; females may raise young alone in burrows.
  • Young: Juveniles have been recorded in all seasons, but the greatest influx was in June and July during the dry season.
  • Movement and dispersal: A greater influx of juveniles in June and July may coincide with improved conditions for dispersing young, including seasonal grass seeding. Individual movements can also extend outside the immediate trapping area.
  • Food availability: Eriachne stipacea, an abundant grass at one study site, mainly produced seed from March to August. This is a site-specific food phenology record, not a range-wide season.
  • Highest clearing risk: Active breeding and dependent young are possible in every month. Risk is highest in June and July because juvenile numbers are greater, but occupied burrows can be affected by clearing at any time.

Identification

The Northern Hopping-mouse is a small, sandy-brown hopping-mouse with a pale underside and a distinctive bipedal gait. It is difficult to capture in conventional traps, so identification on project sites should combine direct observations with verified camera records and carefully assessed burrow evidence.

Adults weigh about 30 to 40 g and have a head and body length of about 90 to 94 mm. The tail is about 156 to 165 mm long, partly tufted and much longer than the body. Large eyes and ears, narrow elongated hind feet and sandy-brown upperparts are characteristic.

Hind feet: Approximately 35 to 40 mm long.

Colour: Sandy-brown above and paler or white below.

Identification: Distinguishing features

The species has large eyes, large ears, very long hind feet and a long tail with a darker tuft. In the Top End it is the only confirmed hopping-mouse species, while the Spinifex Hopping-mouse, Notomys alexis, extends north only to the Barkly Tableland. The Delicate Mouse, Pseudomys delicatulus, can occur in the same sandy habitats and its spoil heaps cannot be reliably distinguished from Northern Hopping-mouse spoil heaps without camera confirmation or other reliable evidence.

  • Treat an apparent hopping-mouse record based only on a spoil heap as unconfirmed until checked with camera trapping or another reliable method.
  • Do not rely on poorly defined tracks alone, because hopping birds including the Great Bowerbird and Grey-crowned Babbler can leave similar-looking bipedal impressions.

Identification: Field signs and detection

The species constructs burrow systems and may leave spoil heaps, tracks and hairs in predator scats. Burrow entrances can be hidden by a thin layer of sand. Spoil heaps may remain visible for many months, but they can be old, weathered or made by the Delicate Mouse, so they do not by themselves confirm current occupancy or abundance.

Comparative detection: Camera trapping detection was five times higher than pitfall trapping in one study.

  • Use camera traps to validate suspected burrows or spoil heaps. Camera trapping detected the species more effectively than pitfall trapping in comparative work.
  • Record photographs and measurements of tracks, spoil heaps and burrow entrances, including a scale, and have uncertain signs checked by an experienced mammal ecologist.
  • Do not expect reliable detection from standard Elliott trapping alone. The species has shown little interest in conventional baits and can be difficult to trap.

Distribution: National range

The confirmed contemporary distribution is concentrated in the Northern Territory, particularly Groote Eylandt in the Gulf of Carpentaria. Historical mainland and Queensland records need careful qualification because some were based on unverified signs or doubtful provenance.

The species is currently confirmed from Groote Eylandt in the Northern Territory. Historical records include coastal and central Arnhem Land, including a collected specimen from the Cadell River area in 1973. The last confirmed mainland record was in 1973, and extensive later surveys have not confirmed persistence on the mainland.

EPBC Act status: Endangered, effective from 26 March 2021.

Northern Territory status in the supplied state listing: Vulnerable.

Queensland status in the supplied state listing: Vulnerable, although the Queensland occurrence is not supported by recent confirmed records.

  • Treat Northern Territory, especially Groote Eylandt and suitable sandy areas of Arnhem Land, as the relevant contemporary range for project screening.
  • The pre-1867 Queensland specimen from Cape York Peninsula has doubtful provenance, and the species has not been recorded there since.

Distribution: Strongholds and subpopulations

Groote Eylandt is considered possibly to hold the last remaining extant populations. Recent confirmed sites include inland woodland near the base of sandstone hills and coastal dune habitat in the Dalumba Bay area. Records are patchy, including within apparently similar vegetation.

2012 to 2015 survey: Detected at 3 of 32 locations on Groote Eylandt.

2018 to 2019 survey: Camera traps confirmed the species at 82 of 110 suspected spoil heaps on Groote Eylandt.

Mainland aerial survey: More than 2,800 km was surveyed in targeted mainland areas in 2018 to 2019 without detecting the species.

  • Give particular attention to sandy eucalypt woodland near sandstone hills, coastal dunes, heathland and grassland on Groote Eylandt.
  • Do not infer absence from a single negative survey, because the species is difficult to detect and its distribution is patchy.

Distribution: Population trend and evidence limits

Abundance and distribution on Groote Eylandt have declined substantially compared with observations from earlier decades. A total population size is not known. Historical records based only on tracks, burrows or spoil heaps are not directly comparable with recent camera-based records.

Known population size: Not reliably quantified.

Recent trend: Declining distribution and abundance on Groote Eylandt, based on comparison with earlier surveys.

Habitat: Habitat types

The Northern Hopping-mouse is associated with deep, stable sandy soils that allow it to excavate complex burrows. Suitable vegetation can occur in several communities, but ground-layer diversity and moderate ground cover are important features.

Recorded habitats include sandy eucalypt open forest and woodland, coastal heathland, grassland and vegetated dune systems. The species is generally associated with deep sandy soils, a diverse shrub and ground layer, and ground cover averaging about 5 to 30 percent.

Typical substrate: Deep sandy soils.

Reported ground cover: About 5 to 30 percent at characterised sites.

  • Map and ground-check sandy substrates before clearing, including vegetated dunes, sand plains and sandy woodland near the base of sandstone hills.
  • Include heathland, grassland and woodland habitat in targeted assessments where the soil is deep enough for burrowing.

Habitat: Vegetation and site structure

Preferred habitat includes floristically diverse heathlands or grasslands close to the coast and woodlands with a diverse understorey. Recent Groote Eylandt records include sand plain and coastal grassland with tussock grasses such as Chrysopogon oliganthus, Sarga plumosum and Triodia microstachya.

  • Retain diverse shrub and ground layers around suspected burrows and spoil heaps.
  • Assess adjacent open areas as well as denser vegetation, because tracked animals used open microhabitats more than expected from their availability.

Habitat: Substrate and climate limits

The available sources do not give a defined elevation range. Hard sandstone and laterite are thought to be unsuitable across large parts of Groote Eylandt because they are difficult to excavate. The species occurs in the monsoonal tropics of northern Australia.

Elevation limit: Not specified in the supplied sources.

Climate region: Northern Australia's monsoonal tropics.

Foraging habitat: Diet

The species forages at night on the ground, mainly in open areas within sandy woodland, heathland, grassland and dune habitat. Food availability is likely linked to the diversity and seasonal seeding of the ground layer.

The diet consists mostly of seeds and plant stems, with other vegetative material and invertebrates also taken. Grass seed availability may influence seasonal recruitment, with Eriachne stipacea producing much of its seed between March and August at one study site.

Main food: Seeds and plant stems.

Additional food: Other vegetation and invertebrates.

Example seed period: Eriachne stipacea mainly produced seed from March to August at one Groote Eylandt site.

  • Retain native grasses, seed-producing plants and diverse ground vegetation around occupied or potential habitat.
  • Avoid assuming that apparently sparse ground cover is unused, because the species often travels and forages in open areas.

Foraging habitat: Foraging areas and movement

Radio-tracked individuals used open microhabitats more than available habitat and preferred eucalypt woodland on sandy substrate over adjacent sandstone woodland and acacia shrubland. Individuals sometimes moved outside the trapping area, indicating that habitat use can extend beyond the immediate burrow site.

Recorded home ranges: 0.39 to 23.95 ha in nine radio-tracked individuals.

Alternative home-range estimate: 0.004 km² for a lactating female to 0.24 km² for a scrotal male.

  • Inspect sandy open areas and nearby woodland around burrow systems rather than restricting assessment to dense cover.
  • Maintain connected sandy habitat around burrows where practicable, including routes between woodland, grassland, heathland and dune patches.

Breeding habitat: Breeding biology

Breeding is not strictly seasonal, so occupied burrow systems may contain dependent young at any time of year. The species appears to breed in sandy burrow habitat where mothers can raise young away from surface disturbance.

Females with young are generally alone in burrows, suggesting that mothers raise young without assistance. Breeding adults and juveniles have been recorded throughout the year, with a greater influx of juveniles in June and July during the dry season.

Breeding season: Throughout the year, with more juveniles recorded in June and July.

Litter size: Up to five young.

Gestation: Approximately seven weeks.

Age at sexual maturity: Notomys species are reported to mature at about three to four months; a species-specific figure was not provided.

Maximum longevity: Around five years, used to estimate generation length.

Generation length: Estimated at 2.5 years.

  • Treat active burrow systems as potential breeding habitat in every month, including outside the June to July juvenile peak.
  • Avoid clearing, excavation and heavy vibration near occupied burrows until targeted survey and fauna management requirements have been addressed.

Breeding habitat: Breeding habitat features

Breeding occurs in complex burrow systems excavated in deep sand. Mothers with young generally remain alone in burrows, so individual burrow systems and their nearby foraging habitat can support a breeding female even where no animals are visible above ground.

  • Search sandy woodland, dune, heathland and grassland for burrows and spoil heaps before ground disturbance.
  • Keep a buffer around confirmed or suspected active burrows in accordance with the project fauna management plan and advice from the relevant authority or species ecologist.

Sheltering habitat: Burrow systems

The main refuge is a complex burrow system in deep sand. Surface shelter such as grass tussocks and shrubs is used occasionally, but burrows provide the principal daytime refuge and escape structure.

Northern Hopping-mice construct complex burrow systems with several hidden entry and exit holes. Burrows may be communally used and can extend up to 5 m. Vertical entrances may be obscured by a thin layer of sand, and spoil heaps can mark the original entrance.

Burrow length: Up to 5 m.

Entrances: Several hidden entry and exit holes may be present.

  • Inspect sand plains, dunes and sandy woodland for spoil heaps, small openings, fresh excavated sand and tracks before clearing.
  • Treat a suspected burrow as potentially occupied even when the entrance is covered or no animal is seen.

Sheltering habitat: Other cover

Individuals were rarely seen using woody debris or rocks as shelter. They sometimes crouched within grass tussocks or under shrubs, but spent much of the night travelling or foraging in open areas.

  • Retain grass tussocks, shrubs and ground cover around burrow systems where they do not conflict with immediate safety requirements.
  • Avoid compacting or grading sandy soil around burrows, because soil profile and compaction can remove the conditions needed for excavation.

Threats: Clearing and development

The main project risks are direct loss of sandy habitat, damage to burrow systems, increased access for predators and weeds, and fire or ground-cover changes. The species has a small confirmed range, so local disturbance can affect a significant part of a subpopulation.

Broad-scale clearing for mining, industrial or urban development can remove habitat and alter soil profile, compaction, hydrology and habitat connectivity. Mining, exploration, quarries, roads and associated infrastructure have occurred near Northern Hopping-mouse spoil heaps on Groote Eylandt.

Documented development risk: Mining and infrastructure disturbance can remove habitat, damage burrows and increase access for weeds, predators and fire.

  • Avoid clearing confirmed or potential sandy habitat where practicable, particularly occupied burrow systems and connected woodland, heathland, grassland and dune habitat.
  • Before clearing, map sandy substrates, spoil heaps, burrows, tracks and nearby open foraging areas.
  • Control the footprint of access tracks, laydown areas, borrow pits and temporary works, and rehabilitate disturbed ground using methods that retain sandy soil structure.

Threats: Fire and vegetation change

Frequent or intense fires can reduce food, vegetation structure and shelter, while extensive late dry season fires may reduce floristic diversity. Reduced cover can also increase exposure to feral cats. Very infrequent fire may reduce the range of food resources available through the year.

  • Use fire planning that maintains a patchwork of habitat ages, native ground cover and seed-producing vegetation, with Traditional Owner knowledge incorporated where appropriate.
  • Prevent construction activities and machinery movements from creating unmanaged ignition points or spreading high-biomass weeds.

Threats: Predators, herbivores and weeds

Feral cats are considered a very high threat and are known to prey on small mammals. Grazing and trampling by introduced herbivores can remove ground cover, alter plant composition, compact or erode soil and reduce shelter. Invasive weeds can displace native food plants and increase fuel loads, with Gamba Grass identified as a particular concern on Groote Eylandt.

  • Manage food, waste and site practices that could attract cats to work areas, and report or control feral cats under the approved management programme.
  • Clean vehicles and machinery before entering sensitive sandy habitat to reduce weed spread.
  • Prevent the establishment and spread of feral herbivores and pigs through site biosecurity and quarantine procedures.

Threats: Roads, fragmentation and other risks

Minor roads, tracks and exploration disturbance can fragment habitat, increase human access and facilitate weeds and altered fire. Disease may contribute to small mammal declines, but evidence for a species-specific disease threat is limited. The supplied sources do not identify a defined hydrology-change threat, although clearing-related changes to soil and drainage can degrade habitat.

  • Keep temporary and permanent roads away from burrow concentrations where practicable and restrict off-road access.
  • Inspect road verges, stockpiles and drainage works for burrows before construction and after major ground disturbance.
  • Do not treat the absence of visible animals as evidence that a site is unused, because the species is nocturnal and difficult to detect.

Survey methodology: 1. Desktop review and habitat search

Survey this species in suitable sandy habitat before disturbance, with methods selected to account for its low capture rate and cryptic, nocturnal behaviour. Camera trapping is the preferred broad-area method, while signs, spotlighting and trapping should be used as supporting methods and interpreted carefully.

Review recent and historic records, aerial imagery, vegetation mapping and proposed disturbance areas before fieldwork.

Prioritise deep sandy soils, stabilised dunes, coastal heathlands and grasslands, and eucalypt woodland with a diverse understorey. Look for complex burrow systems, spoil heaps and open foraging areas.

Search the full subject area and representative habitat units, rather than relying only on mapped preferred habitat. Hard sandstone and laterite substrates are generally less suitable because the species needs to dig burrows.

  • Walk systematic transects or sample representative quadrats across all potentially suitable habitat.
  • For sites up to 5 hectares, use one hectare survey sites and search potential habitat resources with about 2 hours of effort per hectare where practicable.
  • For larger or remote sites, replicate the survey across each relevant habitat type and plant community.

Survey methodology: 2. Camera trapping

Use motion-sensor camera traps as the primary detection method for broad-area surveys and to confirm suspected burrows or spoil heaps.

Place cameras at active-looking burrow systems, spoil heaps, sandy runways and other open areas within suitable woodland, heathland or grassland.

Camera trapping detected the species at substantially higher rates than pitfall trapping in comparative work, and confirmed occupancy at 82 of 110 spoil heaps during a 2018 to 2019 survey.

Recommended deployment used in project surveys: Cameras operated for a minimum of 28 days at 152 sampling sites.

Recent broad-area result: Northern Hopping-mice were confirmed at 82 of 110 spoil heaps on Groote Eylandt.

  • Run cameras for at least four weeks where site conditions and access allow, matching the minimum deployment used in a major targeted survey.
  • Use camera arrays across the disturbance footprint and adjoining retained habitat, not only at the largest spoil heaps.
  • Review images for Northern Hopping-mice and sympatric Delicate Mice, Grassland Melomys and other fauna, because similar spoil heaps can be misidentified.

Survey methodology: 3. Burrow, spoil heap and track searches

Inspect sandy ground for complex burrow systems, vertical or concealed entrances, tracks and fresh spoil heaps.

Treat spoil heaps, burrows and tracks as indicators requiring confirmation. Spoil heaps can remain visible after occupation has ceased, and weathered signs can remain when burrows are still in use.

Do not identify a Northern Hopping-mouse from a spoil heap or track alone. Spoil heaps made by the sympatric Delicate Mouse can be indistinguishable, and some bird tracks can resemble hopping-mouse tracks.

Persistence of spoil heaps: Spoil heaps may remain visible for many months after burrow completion.

  • Photograph each suspected sign with a scale and record its location, substrate, habitat, apparent age and condition.
  • Place a camera at suspected signs to confirm occupancy before disturbance.
  • Use experienced personnel for track identification and record uncertainty in the survey report.

Survey methodology: 4. Spotlighting and trapping

Conduct spotlighting at night when animals are active, concentrating effort in open areas, sandy woodland, heathland, grassland and along tracks or clearings.

Record the route, date, start and finish times, weather, moon or light conditions, observers and distance searched. The species is nocturnal and can be missed in dense vegetation.

Use Elliott traps and pitfall traps only where authorised and where the risk to this difficult-to-trap species is acceptable. Conventional trapping has often failed, while pitfall trapping detected fewer animals than camera trapping.

Published survey effort on Groote Eylandt: Approximately 224 search hours, 132 spotlighting hours and 870 opportunistic camera trap nights were completed across 32 locations between 2012 and 2015.

Historical mainland effort: Earlier surveys included about 200 spotlighting hours and 25,000 trap nights, but positive records were based on unreliable signs.

  • Do not treat a negative trapping result as evidence that the species is absent.
  • If trapping is used, check traps at the required frequency under the relevant animal ethics and permit conditions, provide suitable shelter and protection from weather, and stop if heat, flooding or animal welfare risks develop.
  • Use spotlighting, trapping and predator scat examination as supporting methods, not as substitutes for camera confirmation in suspected habitat.

Survey methodology: Minimum effort and reporting

  • Survey all suitable sandy habitat within the disturbance footprint and any retained habitat that may receive relocated animals.
  • Use camera traps for at least four weeks where practicable, and increase coverage when signs are present or habitat is patchy.
  • For sites up to 5 hectares, use stratified one hectare survey sites and aim for about 2 hours of daytime habitat and sign searches per hectare.
  • Where soil plots are used, establish at least two one metre wide plots per one hectare survey site and operate them for three consecutive nights, with daily track recording and raking.
  • Report effort by method, survey area, trap nights, camera nights, spotlight hours, search hours, dates, weather, habitat units, coordinates and detection or non-detection results.
  • Submit verified records, photographs and coordinates to the relevant Northern Territory or Queensland wildlife records database and provide records to the project regulator or approval authority.
  • Retain original photographs, camera files, field sheets and chain of custody information for any specimen or tissue record.

Before habitat disturbance: Avoid and minimise

Treat occupied sandy habitat as a high-risk feature before clearing, excavation, road construction or mining activity. Avoiding disturbance is preferable because the species is restricted in distribution and may occur in small, patchy groups that are difficult to detect.

  • Redesign the footprint to retain known occupied burrow systems, deep sandy soils, stabilised dunes, coastal heathlands, grasslands and diverse-understorey eucalypt woodland.
  • Retain connected areas of suitable sandy habitat around confirmed records and between occupied patches, rather than isolating individual burrow systems.
  • Avoid unnecessary clearing, soil compaction, sand extraction, drainage changes, road widening and storage of spoil on sandy habitat.
  • Keep construction traffic, laydown areas, lighting and temporary access routes out of retained habitat wherever practicable.
  • Do not assume that habitat outside a mapped record is unused, because the species has a patchy distribution and recent detection has been limited.

Before habitat disturbance: Approvals and work planning

  • Check whether the proposed action may significantly affect this EPBC Act Endangered species and obtain environmental advice on referral, approval and approval-condition requirements before works begin.
  • Check Northern Territory or Queensland threatened-species legislation, wildlife permits, animal ethics approvals and rehabilitation requirements before capture, handling, trapping or relocation.
  • Prepare a fauna management plan that identifies suitable habitat, confirmed signs, camera locations, no-go areas, clearing limits, stop-work triggers, authorised handlers and reporting pathways.
  • Stage clearing so that survey results can be reviewed before each work area is opened.
  • Schedule disturbance outside periods of extreme heat, heavy rain or active fire conditions, and avoid periods when burrows may be supporting young where this can be established from project monitoring. The species can breed throughout the year, so do not assume that a single closed breeding season will remove the risk.

Before habitat disturbance: Site preparation

  • Complete the targeted pre-clearance survey before machinery enters suitable habitat, using cameras and confirmation of suspected burrows or spoil heaps.
  • Mark confirmed occupied burrow systems, retained sandy habitat, access routes and no-go areas in the field and on construction drawings.
  • Install exclusion fencing where it can prevent machinery, vehicles and people entering retained habitat without blocking animal movement between connected retained areas.
  • Brief the fauna spotter catcher, supervisors and operators on the species' appearance, burrow signs, handling limits, exclusion zones and stop-work process.
  • Remove waste, food and materials that could attract cats or other predators to retained habitat, and check machinery and vehicles for weed seed and soil contamination before entry.

During habitat disturbance: Daily controls and machinery coordination

Use a daily control system led by the authorised fauna spotter catcher and site supervisor. The species is small, nocturnal and difficult to trap, so absence during a pre-clearance check does not remove the need for careful clearing controls.

  • Inspect exclusion fencing, no-go markers, access routes, burrow protection and retained habitat before work starts each day.
  • Hold a daily pre-start briefing with the fauna spotter catcher, machine operators and supervisor, including the day's clearing limits and stop-work triggers.
  • Keep the fauna spotter catcher in a position where the operator can stop immediately, and use agreed radio or hand signals.
  • Clear progressively in small sections, directing machinery away from retained habitat and towards already checked areas where this is safe and authorised.
  • Stop work during poor visibility, heavy rain, flooding, smoke, fire or any condition that prevents the fauna spotter catcher from seeing the work area.
  • Do not drive over burrow systems, fresh spoil heaps, marked sandy habitat or exclusion fencing.

During habitat disturbance: Habitat feature handling

  • Inspect burrows, spoil heaps, sandy embankments, grass tussocks, dense shrubs, logs, rocks and other ground cover immediately before disturbance.
  • Avoid collapsing or filling suspected burrows until they have been checked by the authorised fauna spotter catcher and the project ecologist.
  • Do not relocate spoil heaps, logs or rocks into retained habitat unless the fauna management plan identifies a suitable location and the movement can be completed without harming animals.
  • Keep excavations, trenches and stockpiles covered or ramped overnight where they could trap small ground-dwelling mammals.
  • Use clean machinery and defined access routes to limit soil compaction, weed spread and changes to the sandy substrate.

During habitat disturbance: Animal found or injured

  • Stop the immediate activity and establish a quiet exclusion area if a Northern Hopping-mouse is seen, trapped or exposed.
  • Only a person authorised under the relevant permit, animal ethics approval and project fauna management plan may capture, handle or relocate the animal.
  • Do not chase, corner, hand-feed or handle the animal unnecessarily. Keep handling time as short as practicable and follow the approved species-specific wildlife procedure.
  • Place an animal requiring care in a secure, ventilated container with suitable bedding and shelter, away from heat, noise, direct sun and predators.
  • Obtain veterinary or wildlife-carer assessment promptly for any injured, lethargic, heat-stressed or orphaned animal, using a person authorised to receive native wildlife.
  • If relocation is approved, release the animal into nearby retained sandy habitat that is connected to suitable cover and outside the active work area, at a time and place specified by the authorised ecologist.
  • Do not translocate animals to another site, island or mainland exclosure unless this is part of an approved conservation program.

During habitat disturbance: Stop-work triggers and records

  • Stop work if a Northern Hopping-mouse is detected inside the work area, if a suspected occupied burrow is exposed, or if exclusion controls fail.
  • Stop work if an animal is injured, trapped in an excavation, isolated from retained habitat or at risk from machinery, vehicles, fire or predators.
  • Notify the site supervisor and project ecologist, protect the location, and obtain regulator or approval-holder advice where required before restarting.
  • Record every detection, suspected sign, animal interaction, capture, relocation, injury, mortality, release location and work stoppage with coordinates, photographs, time, habitat and personnel.
  • Record negative results and the exact area, method and effort searched, because the species' detectability is low and historical sign records are difficult to compare.

After habitat disturbance: Post-clearance checks

Do not treat completion of clearing as the end of fauna management. Check disturbed and retained areas for animals, failed controls, new threats and changes to sandy habitat, then maintain monitoring and reporting for the period required by approvals.

  • Inspect the cleared area, retained habitat edges, exclusion fencing, trenches, stockpiles and access routes at the end of each work shift and after severe weather.
  • Check for exposed or collapsed burrows, trapped animals, fresh tracks, spoil heaps, carcasses, erosion, soil compaction and weed establishment.
  • Complete a final fauna inspection before removing temporary fencing, closing excavations or handing the area to the next contractor.
  • Repair fencing and close or modify construction features that could funnel animals into roads, pits, drains or machinery areas.

After habitat disturbance: Monitoring and reporting

  • Continue camera monitoring in retained occupied habitat and at the boundary of the disturbance area where required by the fauna management plan or approval conditions.
  • Use repeatable camera locations, deployment periods, habitat descriptions and image review rules so that results can be compared over time.
  • Report confirmed detections, mortalities, injuries, control failures, habitat loss, rehabilitation actions and monitoring results to the project environmental officer and relevant regulator.
  • Submit verified occurrence records to the relevant Northern Territory or Queensland wildlife database and update the project spatial records.
  • Review monitoring results before opening later work stages or removing no-go areas.

After habitat disturbance: Controls and offsets

  • Maintain retained-habitat fencing, cat controls, weed hygiene, fire controls and access restrictions for as long as the project risk remains.
  • Apply any approved offset, compensatory habitat or conservation payment requirements exactly as specified by the EPBC Act approval and state conditions.
  • Use offsets only after avoidance and minimisation measures have been applied, and document the area, habitat values, tenure, management actions and monitoring commitments.
  • Escalate any continuing decline in detections, new cat activity, frequent hot fire, weed invasion or loss of retained sandy habitat to the approval holder and regulator.

Rehabilitation actions: Restore habitat structure

Rehabilitation should restore the sandy ground structure, plant cover and shelter needed for burrowing, foraging and predator avoidance. Set targets around habitat function and confirmed use, not only plant establishment.

Preferred habitat structure: Deep sandy soils with a floristically diverse shrub and ground layer, with ground cover averaging 5 to 30 percent at studied sites.

  • Reinstate deep, uncompacted sandy substrates and stable dune or sand-plain surfaces where earthworks have altered them.
  • Re-establish locally appropriate native heathland, grassland and eucalypt woodland communities with a diverse shrub and ground layer.
  • Use local provenance seed or other approved local plant material where available, and include native grasses and shrubs that provide seed, stems, cover and open foraging areas.
  • Avoid creating hard-packed surfaces, continuous dense grass, bare eroding ground or abrupt edges between rehabilitation and retained habitat.
  • Reconnect rehabilitated sandy patches to retained habitat wherever the project footprint allows.

Rehabilitation actions: Burrows, shelter and site protection

  • Do not construct artificial burrows or move spoil heaps into habitat unless the design has been approved by the project ecologist and relevant authority.
  • Retain suitable natural ground cover, grass tussocks and shrubs that provide shelter between burrows and foraging areas.
  • Use logs, rocks or nest boxes only where they are appropriate to the local community and do not replace the species' normal sandy burrow habitat.
  • Control access, grazing, soil disturbance and construction traffic until the substrate and vegetation are stable.
  • Keep rehabilitated areas free of introduced herbivores and pigs, and maintain biosecurity controls against their establishment.

Rehabilitation actions: Weeds, cats and fire

Recorded fire pressure on Groote Eylandt: Annual area burnt has ranged from 1.5 to 40.1 percent, with some local areas burnt every year and extensive fires affecting about half the island every third or fourth year.

  • Control invasive grasses and other weeds before they increase fuel loads, displace native plants or alter ground cover.
  • Prevent weed spread through vehicle washdown, clean fill controls, machinery hygiene and inspection of rehabilitation areas.
  • Implement cat management around high-value retained and rehabilitated habitat, including control of feral cats and measures that reduce stray or owned cat access where authorised.
  • Develop a fire regime that avoids frequent extensive hot fires, retains protective ground cover and supports a varied supply of food plants.
  • Incorporate Traditional Owner knowledge and traditional burning practices into the Groote Eylandt fire management approach where relevant and authorised.

Rehabilitation actions: Monitoring and success measures

  • Monitor plant establishment, ground cover, substrate condition, weed cover, fire history, cat activity, burrow development and camera detections at rehabilitated sites.
  • Use the same camera methods and habitat descriptions as the baseline survey, with at least four weeks of deployment where practicable.
  • Treat confirmed Northern Hopping-mouse detections, repeated use of rehabilitated sandy habitat and functioning burrow systems as stronger success measures than spoil heaps alone.
  • Investigate a failure to detect the species alongside habitat condition, camera effort and nearby source populations before concluding that rehabilitation has failed.
  • Continue monitoring for the period required by approvals and adapt fire, weed, predator and access management when results show that habitat function is not being restored.

Sources