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Central Rock Rat (Zyzomys pedunculatus)

The central rock-rat is a nocturnal, ground-dwelling rodent of rocky ranges in central Australia. It is known from only a few isolated localities in the Northern Territory and is listed as Critically Endangered under the EPBC Act, so clearing, fire, predator control and habitat disturbance require careful assessment where rocky refuge habitat is present.

Conservation status

Commonwealth, EPBC Act 1999: Critically endangered.

Western Australia, Biodiversity Conservation Act 2016: Critically endangered.

Northern Territory, Territory Parks and Wildlife Conservation Act 1976: Critically endangered.

Breeding season

Breeding can occur in any month when conditions are suitable, and juveniles have been recorded in March, April, July and November. Population movement is driven by rainfall and resource availability rather than a regular annual migration.

Month values are ordered January to December. A value of 1 indicates that the activity can occur or risk is present; a value of 2 marks months with stronger evidence or likely peak concern. The species can undergo large rainfall-driven fluctuations, so conditions in the survey year should be considered.

  • Breeding: Breeding may occur throughout the year in suitable conditions. Captive litters contain 1 to 4 young.
  • Young: Wild juveniles have been recorded in March, April, July and November. These months are marked as peak evidence months, not as exclusive breeding months.
  • Movement and contraction: Numbers can increase after rainfall-driven resource pulses and contract into high elevation rocky refuges during dry periods. There is no regular seasonal migration.
  • Highest clearing risk: Clearing risk is present throughout the year because breeding may occur year round and dependent young have been recorded in March, April, July and November. These four months have the strongest direct juvenile evidence.

Identification

The central rock-rat is a stocky, medium-sized native rodent with a distinctive swollen, densely furred tail. It is difficult to detect because it is nocturnal, rare and strongly associated with rugged rocky country.

Adults have long, yellow-brown fur on the upper body and cream to white fur underneath. The body is strongly built, with large ears and prominent eyes. The tail is slightly longer than the head and body, densely furred, fattened at the base and has a distinctive tuft at the tip.

Older recovery material describes a rounded or Roman-like nose and a carrot-shaped tail. The species can lose tail skin, fur and even the tail readily when handled, so capture and restraint require care.

Body mass: 70 to 150 g

Body length: Up to about 14 cm

Tail: Slightly longer than the head and body, densely furred, swollen at the base and tufted at the tip

Activity period: Nocturnal

Identification: Similar species

The central rock-rat is one of five Australian Zyzomys species. The common rock-rat, Zyzomys argurus, is the most relevant potential confusion species where their ranges or habitats approach each other. The central rock-rat is generally larger, with a heavier body and larger feet, but field identification should use several characters together.

The 1996 recovery plan gives an adult central rock-rat mass of about 60 g at that time, compared with about 36 g for the common rock-rat, with common rock-rat masses reported from 26 to 55 g. It recommends confirmation from body weight, pes length, the pes to thenar pad ratio and, where necessary, skull and dental characters. Do not rely on a single photograph or a brief observation for a definitive record.

  • Treat any suspected record as significant and obtain clear photographs, location data and, where authorised, hair or other non lethal evidence.
  • Use an experienced mammal taxonomist or approved laboratory for confirmation where the animal, hair sample or other evidence cannot be identified confidently in the field.

Identification: Field signs and detection

Potential signs include tracks on sandy substrates near rocks, scats around rocks, caves or overhangs, and feeding remains such as chewed seeds or nuts. Hair may be collected using baited hair tubes or funnels and can be identified by a specialist. The species is included among mammals that can be distinguished from hair samples.

Shelter searches should focus on boulder fields, rock crevices, scree, cliffs, gorges, overhangs and other areas with exposed rock. No species-specific call, nest, burrow dimension, track dimension, eyeshine protocol or slough has been documented in the supplied sources.

For sites up to 5 hectares, recommended detection methods include daytime searches for habitat and signs, predator scat or owl cast searches, baited hair sampling and Elliott A trapping. Handle captured Zyzomys carefully because tail stripping is a known risk.

  • Search sandy substrates beside rocks and inspect caves, crevices and overhangs for tracks and scats.
  • Record chewed seeds, nuts and other feeding remains, but treat them as supporting evidence rather than a definitive identification.
  • Use peanut butter, rolled oats and honey, or sultanas, as bait for hair sampling devices where appropriate.
  • Use Elliott A traps only under an approved survey design and check and handle them in accordance with animal welfare requirements.

Distribution: Current range

The species was formerly widespread across rocky country in central Australia and inland Western Australia. Current records are restricted to a small number of isolated localities in the Northern Territory, while Western Australian records are historical or subfossil in the supplied material.

Current populations are known from the West MacDonnell Ranges and Haast's Bluff, west of Alice Springs in central Australia. Recent records are from higher elevation ridgetops in the western Chewings Range, including the Mt Giles area, the Heavitree Range around Counts Point, and west of Mt Edward on Haast's Bluff Aboriginal Land Trust.

The supplied documents do not assign the species to a formal IBRA bioregion. For project screening, describe the current range as the central Australian ranges, West MacDonnell Ranges and Haast's Bluff area, rather than assuming that all rocky habitat in central Australia is occupied.

Current state or territory records: Northern Territory only

Current localities: Western Chewings Range and Heavitree Range in Tjoritja, West MacDonnell National Park, and the Mt Edward area on Haast's Bluff Aboriginal Land Trust

Core refuge elevation: Generally above 950 m during contracted population phases; some sources refer to higher altitude ridges above 1,100 m

Extent of occurrence: Estimated at 906 km² using the 2007 to 2017 point record set

Area of occupied habitat: Less than 5 km², with an estimate of less than 500 ha in 2016

Distribution: Former range and subpopulations

Historical records or cave deposits indicate a much wider range, including Alice Springs, Illamurta in the James Range, Napperby Hills, Davenport Range, The Granites in the Tanami Desert, Mt Liebig, Uluru-Kata Tjuta National Park and parts of the MacDonnell Ranges. Subfossil records extend into Western Australia, including Cape Range.

At the time of the 2018 conservation advice, three current subpopulations were recognised: the western Chewings and Heavitree Ranges in Tjoritja National Park, and Mt Edward on Haast's Bluff. The species has not been detected at Mt Sonder since 2012 and appears to have been extirpated there.

Current subpopulations recognised in 2017: Three: western Chewings Range, Heavitree Range and Mt Edward

Distance between occupied sites: The species was unlikely to be recorded more than 5 km from the nearest occupied site in one occupancy analysis

Western Australia: Historical and subfossil records are documented, but no current living population is confirmed in the supplied sources

Distribution: Population size and trend

Reliable population estimates are not available because capture rates are low. Available estimates indicate fewer than 800, or fewer than 1,000, mature individuals.

The species underwent a population crash after the 2000 to 2002 increase associated with wet conditions. A comparison of suitable occupied area between the wet periods of 2000 to 2001 and 2010 to 2011 indicated a decline of at least 81 percent over 10 years. The long-term trend is decreasing, although numbers can fluctuate greatly after rainfall-driven resource pulses.

Estimated mature population: Fewer than 800 to 1,000 individuals

Estimated decline: At least 81 percent over 10 years in the assessment using the 2000 to 2001 and 2010 to 2011 wet periods

Population pattern: Large boom and bust fluctuations, with contraction into rocky refuge areas during dry periods

Habitat: Landforms and vegetation

The central rock-rat uses rocky landforms with open vegetation, but habitat use changes with rainfall and population phase. During dry or contracted phases, higher elevation quartzite ridges and peaks appear to provide the main refuge habitat.

Recorded habitats include tussock and hummock grasslands, low shrublands, low open woodlands, ridge tops, cliffs, scree slopes, hills and valley floors. Sites commonly have a high proportion of exposed rock and a very stony or shallow gravelly soil surface.

Contemporary refuge habitat is associated with quartzite mountains and ridge tops, rock crevices and mallee heath-like vegetation. Typical ground cover includes weeping or spike-flowered spinifex, with forbs and subshrubs. Common shrub and canopy elements include hill wallflower poison, yellow broom, desert buttercup, hill mulga, hakea and mallee eucalypts.

  • Look for exposed rock, boulders, scree, cliffs, steep slopes, shallow stony soils and connected rock crevices.
  • Prioritise quartzite ridges and peaks, especially at higher elevations, when assessing habitat during a dry or low population phase.
  • Record spinifex structure, subshrubs, forbs, mallee heath vegetation and the presence of hill mulga or cypress pine.

Habitat: Fire and habitat condition

In core refuge habitat, the species favours areas with a recent fire history, generally less than 10 years since fire, probably because important food plants are more abundant. However, extensive, frequent or intense fire can remove cover and food, and may increase predation risk.

Older recovery material also identifies fire shadow areas, rare plant assemblages and fire-sensitive vegetation patches as possible refuges during dry periods. The appropriate fire pattern is not fully resolved, so both recently burnt food-producing areas and unburnt refuge patches should be retained and assessed.

  • Map fire history and retain a mix of post-fire ages rather than treating all recently burnt or all long-unburnt vegetation as equivalent habitat.
  • Avoid clearing or burning rock crevice complexes, fire shadow patches and connected refuge vegetation without a species-specific assessment.
  • Assess buffel grass because it can increase fire frequency and intensity and may compete with preferred food plants.

Habitat: Climate and elevation

The species responds to rainfall-driven resource pulses, but rainfall alone does not reliably produce a population increase. During typical dry periods, it contracts into rugged, high elevation quartzite habitat.

Current core refuge records are from elevations above 950 m, with some descriptions referring to ridges above 1,100 m. The supplied documents do not establish a lower or upper climatic limit.

Core refuge elevation: Above 950 m in the 2018 conservation advice; higher altitude ridges above 1,100 m are also identified in the CITES proposal

Rainfall response: Numbers may increase after resource pulses, then contract during dry conditions

Documented climatic limit: No definitive temperature or rainfall threshold is provided

Foraging habitat: Diet

The central rock-rat feeds mainly on seeds and supplements these with leaves, stems and a small amount of invertebrate material. Food availability varies with rainfall, fire history and vegetation succession.

Seed is the main food, with leaf and plant stem material also important. Invertebrates form a low proportion of the diet. In one survey, identifiable faecal particles comprised approximately 72 percent seed, 21 percent leaf, 3 percent stem and 4 percent insects.

During dry conditions, seed use declines and plant stem material increases. Plants contributing important seed during an increase phase include Sida species, Solanum species and weeping spinifex, Triodia brizoides. Other recorded foods include Mt Sonder beard-heath, desert buttercup, broom ballart and butterfly bush.

Seed: About 72 percent of identifiable faecal particles in one diet study

Leaf: About 21 percent

Stem: About 3 percent

Invertebrates: About 4 percent

  • Inspect areas with seeding Sida, Solanum and spinifex, especially where these plants occur among rock outcrops and crevices.
  • Record seasonal seed availability and the abundance of subshrubs, forbs and spinifex when assessing habitat condition.
  • Treat food plant removal as a habitat impact even where the rocky landform remains intact.

Foraging habitat: Foraging areas and behaviour

The species forages at night on or around rocky landforms, spinifex communities, shrublands and open woodland. During resource-rich periods it has been found across a wider range of rocky landforms and vegetation types, including scree slopes, hills and valley floors.

No home range size or detailed movement distance has been established. Occupancy analysis found that records were unlikely more than 5 km from the nearest occupied site, but this is not a home range estimate and should not be used as a clearing buffer.

  • Survey both rocky refuge features and nearby seed-producing vegetation because feeding habitat may extend beyond the most obvious crevices.
  • Do not infer absence from a dry-season survey at a site that lacks recent records. Numbers and distribution can change markedly between wet and dry periods.
  • Do not use the 5 km occupancy relationship as a substitute for site-specific survey or impact assessment.

Breeding habitat: Breeding biology

Little is known about wild reproduction. Available evidence indicates that breeding can occur in suitable conditions throughout the year, with births and juvenile records spread across several months.

Captive females have produced litters of 1 to 4 young. Juveniles have been recorded in the wild in March, April, July and November, indicating that breeding may occur throughout the year when conditions are suitable.

Sex-specific field characters, a confirmed gestation period and a documented nest or birth site have not been provided in the supplied sources. Age at sexual maturity is estimated at 5 to 6 months from captive or congeneric information, and longevity is probably 2 to 3 years based on congeneric species.

Breeding season: Probably any month when environmental conditions are suitable

Litter size: 1 to 4 young in captivity

Gestation: Not reported in the supplied documents

Age at maturity: About 5 to 6 months

Lifespan: Probably 2 to 3 years, based on congeneric species

Generation length: Estimated at 1 to 2 years

Wild juvenile records: March, April, July and November

Breeding habitat: Breeding habitat

Specific birth or nest sites have not been described. The best-supported approach is to protect the rocky refuge habitat used by the species, including crevices, overhangs, scree, boulder fields and dense ground cover, together with nearby food plants.

Because juveniles can occur in several seasons and breeding may be year round in suitable conditions, clearing should not be scheduled on the assumption that the species has a single safe breeding season.

  • Treat occupied or potentially occupied rock crevices and dense spinifex cover as possible breeding habitat.
  • Avoid disturbing refuge features during all months unless surveys and approvals demonstrate that impacts can be managed.
  • If a captured female or juvenile is detected, stop work in the immediate area and follow the approved fauna handling and incident response procedure.

Sheltering habitat: Refuge features

Shelter is associated with rocky terrain rather than trees or constructed hollows. The species is likely to use crevices and other protected spaces among rocks, but the dimensions and internal structure of shelters are not known.

Core refuge habitat is characterised by exposed rock outcrop, shallow gravelly soils, quartzite ridges, rock crevices and rugged high elevation terrain. Earlier records include granite boulder fields, quartzite screes, eroded sandstone cliffs, gorges, hills and valley floors.

Fire shadow patches and vegetation protected from fire and grazing may provide refuge during dry or low population phases. Dense spinifex and nearby shrub cover can provide additional ground-level protection.

Shelter type: Rock crevices and other protected spaces in rugged rocky landforms

Shelter dimensions: Not documented

Tree hollows or nest boxes: Not identified as shelter requirements in the supplied sources

  • Inspect and map boulder fields, scree, cliffs, overhangs, gorges, caves and narrow rock crevices before clearing or earthworks.
  • Retain rock piles, natural crevice networks and connecting ground cover wherever practicable.
  • Include refuge features above and below the immediate work footprint where blasting, vibration, rock removal or access tracks could alter them.

Sheltering habitat: Dry-period refuge

When conditions are dry, populations contract to higher elevation, rugged quartzite ranges and peaks. The species can occupy broader habitat after rainfall-driven increases, so a site that is not occupied during one survey period may still be part of recolonisation or movement habitat.

The extent of the home range, daily movement and shelter-to-foraging distance is unknown.

  • Use recent records, fire history, elevation, geology, rock structure and food plant condition together when identifying potential refuge habitat.
  • Do not clear apparently empty rocky habitat solely because trapping or camera trapping did not detect the species on one occasion.
  • Maintain movement continuity between occupied or potentially occupied rocky sites where works affect ridges, scree or access routes.

Threats: Fire and invasive grasses

The principal documented threats are extensive fire and predation by feral cats. Habitat removal, fragmentation and construction effects are not quantified for this species, but clearing rocky refuge features or food-producing vegetation can directly remove the habitat on which the remaining subpopulations depend.

Extensive, frequent or intense fires can remove food and ground cover, alter vegetation and increase the vulnerability of rock-rats to cats. The interaction between wildfire and cat predation is a particular concern.

Buffel grass can increase fire frequency and intensity and may compete with preferred food plants. Fire management must retain adequate cover and a suitable mixture of post-fire ages.

  • Map existing fire scars, planned burns and fuel loads before works commence.
  • Prevent construction activities from increasing ignition risk, particularly near spinifex, buffel grass and dry rocky vegetation.
  • Protect fire shadow patches and retain post-fire cover around known or potential refuge habitat.
  • Include immediate and ongoing predator control after a fire where this is part of an approved management programme.

Threats: Predation

Feral cats are a known predator and central rock-rat remains have been found in cat scats. Approximately 33 percent of analysed feral cat scats contained rock-rat remains in the cited assessment. Cats may be especially effective predators after rainfall pulses or fire when rock-rat numbers are exposed and ground cover is reduced.

Fox predation is considered plausible but has not been demonstrated in core refuge habitat. Dingoes may help suppress cats, so predator control must avoid unintended impacts on native predators.

Cat scat evidence: About 33 percent of analysed scats contained central rock-rat remains

Foxes: Potential threat, but not demonstrated in the supplied evidence

  • Record feral cat activity, tracks, camera detections and scats during pre-clearance and monitoring surveys.
  • Do not introduce food waste, shelter or other attractants for feral cats around work areas.
  • Coordinate any cat control with the land manager and the approved recovery programme.

Threats: Clearing, fragmentation and construction

No quantified clearing threshold, road mortality rate or construction buffer is provided in the supplied documents. Even so, clearing of rocky ridges, scree, crevices, spinifex, subshrubs and food plants can remove refuge, foraging and possible breeding habitat.

The species occurs in small, isolated subpopulations and has a restricted occupied area. Access tracks, pads, blasting, rock extraction, drainage works and fragmentation can damage or disconnect the rocky habitat used during dry periods and limit recolonisation after resource pulses.

  • Undertake a targeted threatened mammal assessment before clearing in the species' current range, especially on high elevation quartzite ridges and rocky outcrops.
  • Avoid clearing rock crevices, boulder fields, scree, cliffs, dense spinifex and associated seed-producing vegetation wherever practicable.
  • Keep work areas, laydown areas, access routes and spoil away from mapped refuge features and occupied records.
  • Use fauna spotter catchers only under an approved method, because detection can be difficult and capture can injure the tail.
  • Do not treat a negative survey as proof that a dry rocky site is unoccupied.

Threats: Herbivores, climate and disease

Feral horses can cause erosion, soil compaction and vegetation damage, and may compete for grasses and forbs. Feral horses are reported at high density around the Mt Edward population, although they were not recorded on most higher elevation quartzite landforms in the cited assessment.

Climate change is expected to increase temperatures, heatwaves and drought risk, with fewer but more extreme rainfall events. This may lengthen dry periods, increase fire danger and reduce the frequency of resource pulses. Roundworms, lymphosarcoma and acute respiratory distress syndrome have been reported in captive animals, but their effects on wild populations are not established.

  • Control soil compaction, erosion and damage to food plants caused by vehicles, horses and other introduced herbivores.
  • Prevent spread of buffel grass and other invasive grasses through machinery hygiene and weed management where required by the project.
  • Report sick, injured or dead animals through the relevant wildlife authority and follow approved disease and hygiene procedures for any handling or translocation.

Survey methodology: 1. Search for habitat resources

The central rock-rat is a nocturnal, ground-dwelling rodent of rocky central Australian habitats. Surveys should target rocky ridges, scree, cliffs, boulder fields, rock crevices and nearby spinifex, shrubland, grassland and open woodland, with effort adjusted for rainfall and recent detections.

  • Search systematically for rocky outcrops, boulder fields, scree, cliffs, gorges, escarpments, caves, overhangs and crevices that could provide shelter.
  • Also record stony soils, spinifex hummocks and food plants, including Sida, Solanum, weeping spinifex, Goodenia, Ptilotus, Leucopogon sonderensis, Hibbertia glaberrima, Acacia macdonnellensis and Hakea grammatophylla.
  • For sites up to 5 hectares, search on transects spaced 50 to 100 metres apart, or in representative quadrats, with about 2 hours of searching for every hectare of stratified survey area.
  • Use aerial photographs, topographic maps, vegetation mapping and satellite imagery to plan transects, then ground-truth the habitat.
  • For areas larger than 5 hectares, replicate searches across each relevant habitat type or plant community.

Survey methodology: 2. Search for signs and remains

  • Search sandy substrates around rocks, caves and overhangs for tracks, scats, burrows and other signs of activity.
  • Inspect predator scats, owl casts, predator nests and dens for central rock-rat remains, where this can be done safely and lawfully.
  • Record the location, habitat, date, search effort, weather, recent rainfall and any fire history for every sign or suspected detection.
  • Treat the absence of signs as inconclusive because the species has very low detection rates and can contract to high elevation refuge habitat during dry periods.

Survey methodology: 3. Hair sampling devices

  • Use baited hair tubes or hair funnels in rocky habitat, along likely movement routes and near crevices.
  • Use peanut butter, rolled oats and honey, or sultanas, as the lure specified for this species.
  • Leave devices in place for several consecutive days, check them in accordance with the survey plan, and submit collected hair for specialist identification.
  • Use hair sampling where trapping access is difficult, including remote or scattered rocky sites, because central rock-rat hair can be distinguished from samples of several other listed mammals.

Survey methodology: 4. Elliott A trapping

  • Use Elliott A traps in suitable rocky habitat and along likely travel routes, following the survey guidelines for trap placement, baiting, checking and weather limits.
  • Schedule trapping during suitable nocturnal activity periods and check traps early enough to prevent exposure, overheating, dehydration or predation.
  • Handle Zyzomys species carefully because they are susceptible to tail stripping when trapped.
  • Record trap nights, trap locations, captures, non-target fauna, weather and trap failures, and stop trapping if welfare conditions cannot be maintained.

Survey methodology: 5. Survey timing and conditions

  • Prioritise surveys after rainfall-driven increases in food resources, while recognising that large rainfall events do not always produce an irruption of central rock-rats.
  • Repeat surveys across suitable seasons where practicable because population abundance can fluctuate greatly between wet and dry periods.
  • Include periods when juveniles may be detected, including April, June, July and November, but do not assume that breeding is restricted to these months.
  • Give particular attention to high elevation quartzite ridges above about 950 metres during dry or contracted population phases.

Survey methodology: Minimum effort and reporting

  • Use a stratified combination of habitat searches, sign searches, hair sampling and Elliott A trapping rather than relying on one method.
  • Document the searched area, transect spacing, search hours, trap nights, hair-device days, survey dates, weather, rainfall, fire history, habitat condition and detection results.
  • Use additional survey effort where habitat is fragmented, access is difficult, recent fire has altered detectability, or a nearby record is known.
  • Submit confirmed records, negative survey results of management significance and photographic or hair evidence to the relevant state or territory wildlife database and the Australian Government species information system.
  • Report any detection immediately to the project ecologist, environmental officer and the relevant wildlife authority before disturbance proceeds.

Before habitat disturbance: Avoid and minimise

Treat rocky habitat as potentially suitable even when the species is not detected. Current records are concentrated in the West MacDonnell Ranges and Haast's Bluff in the Northern Territory, but projects in former range areas should still check current state advice and records before clearing.

  • Redesign the project to retain occupied sites, rocky ridge tops, quartzite outcrops, scree, boulder fields, rock crevices and connected refuge habitat.
  • Retain nearby spinifex, mallee-heath, shrubland, tussock grassland and open woodland that provide food, cover and movement habitat.
  • Avoid creating isolated cleared patches between rocky habitat areas because occupied sites are localised and isolated within a wider area of suitable habitat.
  • Avoid clearing after extensive fire or during a period when animals are likely to be concentrated in remaining refuge habitat.
  • Do not set a generic buffer distance without site evidence, approval conditions and advice from the relevant wildlife authority.

Before habitat disturbance: Check approvals and plan the works

  • Check whether the proposed action may significantly impact the species and refer it under the EPBC Act if required.
  • Confirm the current state or territory listing, approval pathway, wildlife permits and handling requirements for the project location before work starts.
  • Prepare a species-specific fauna management plan covering survey results, no-go areas, clearing limits, fauna handling, relocation, injury response, stop-work triggers and reporting.
  • Stage clearing so retained rocky refuge habitat remains available and connected while works proceed.
  • Consult relevant Aboriginal organisations and land managers before work on Aboriginal land or near Haast's Bluff and other culturally significant areas.

Before habitat disturbance: Prepare the site

  • Complete the pre-clearance survey using the methods above and repeat it if conditions, fire history, rainfall or the work footprint changes.
  • Mark retained rocky habitat, crevices, boulder fields, spinifex patches, food plants and any detection locations before machinery enters the site.
  • Install exclusion fencing around approved no-go areas where fencing will not block animal movement or create a trapping hazard.
  • Brief machinery operators on the species' nocturnal habits, likely shelter sites, identification features and the requirement to stop when directed by the fauna spotter catcher.
  • Confirm an authorised wildlife carer or veterinarian, suitable transport equipment and the contact details for the relevant wildlife authority before clearing.

During habitat disturbance: Daily clearing controls

The fauna spotter catcher should control the sequence of clearing in the field and must be able to stop machinery immediately. Central rock-rats may shelter in rock crevices and can be difficult to detect, particularly during dry periods.

  • Inspect the work area each day before machinery starts, including rocks, crevices, boulder piles, spinifex hummocks, logs and other cover.
  • Clear progressively towards retained habitat so animals have an opportunity to move away from the active work area, unless the approved fauna management plan specifies another method.
  • Use a fauna spotter catcher who maintains direct communication with operators and has authority to stop work.
  • Keep machinery out of marked habitat, exclusion zones and retained movement routes.
  • Suspend clearing during excessive heat, heavy rain, smoke, poor visibility or any other condition that prevents effective inspection and safe fauna handling.

During habitat disturbance: Handle habitat features carefully

  • Inspect and dismantle removable rocks, boulder piles, logs and dense vegetation under spotter catcher supervision before removal.
  • Lift or roll rocks away from the operator and inspect the space beneath and between them before moving the next feature.
  • Do not insert hands into crevices, burrows or cavities without first checking for animals and using safe tools and approved handling methods.
  • Retain suitable rocks, logs, spinifex and native food plants within approved refuge areas where practicable.
  • Treat hollow-bearing trees, logs, burrows and other shelter features as fauna habitat even though this species is primarily associated with rocky shelter rather than tree hollows.

During habitat disturbance: If a central rock-rat is found

  • Stop work in the immediate area and keep people, vehicles and dogs away from the animal.
  • Do not chase, handle or relocate the animal unless the person is authorised under the relevant permit and project fauna management plan.
  • Confirm the identification using photographs or other approved evidence, because other Zyzomys species and small rodents may occur in Australia.
  • If authorised handling is required, use a qualified fauna spotter catcher and minimise restraint, heat exposure, noise and transport time.
  • Relocate an apparently healthy animal only to nearby retained habitat that is approved as suitable, connected to the disturbance area and outside the work zone.
  • Transport an injured or distressed animal in a secure, quiet, temperature-controlled container to the nominated veterinarian or wildlife carer, and notify the relevant authority.
  • Do not attempt to establish a new population or undertake a broader translocation as an incident response, because translocation requires risk assessment and an approved programme.

During habitat disturbance: Stop work and record the event

  • Stop work if a central rock-rat is detected, if an occupied refuge site is found, or if clearing enters an unmarked rocky habitat feature.
  • Also stop if the fauna spotter catcher cannot maintain safe visibility, if an animal cannot be accounted for, or if exclusion fencing creates an entrapment risk.
  • Record the date, time, precise location, photographs, habitat, fire history, weather, action taken, personnel, permit details and outcome.
  • Notify the project ecologist, environmental officer and relevant wildlife authority in accordance with approval conditions and the fauna management plan.
  • Review the clearing method and obtain written approval before restarting work in the affected area.

After habitat disturbance: Complete post-clearance checks

Post-clearance work must confirm that no animals or occupied refuge features remain in the disturbed area and that retained habitat controls are working. Monitoring should be scaled to the level of habitat disturbance and any detection made during the project.

  • Inspect the cleared footprint, access tracks, spoil areas and retained edges for animals, fresh signs, damaged crevices and displaced rocks after each clearing stage.
  • Check exclusion fencing, gates and culverts for gaps, trapped fauna and places where animals could enter the work area.
  • Remove temporary fauna hazards, including open trenches, uncovered pipes, unsecured spoil and materials that can trap small mammals.
  • Reinspect any retained refuge area that was exposed to vibration, dust, fire, altered drainage or increased predator access.

After habitat disturbance: Monitor retained habitat

  • Use repeat camera trapping, hair sampling, sign searches or Elliott A trapping where specified by the approval or fauna management plan.
  • Monitor occupancy, relative abundance, fire history, vegetation response, feral cat activity and the condition of retained rocky refuge habitat.
  • Use comparable methods and effort between monitoring periods so changes in detection can be interpreted.
  • Increase monitoring if a population is detected, if habitat is fragmented, or if construction causes fire, predator access or loss of food plants.

After habitat disturbance: Maintain controls and report

  • Keep no-go areas, fencing, access restrictions and fire controls in place for the period required by the approval and management plan.
  • Control weeds such as buffel grass where authorised, particularly where they increase fuel loads or compete with food plants.
  • Manage feral cats and other introduced predators in accordance with an approved programme and avoid impacts on dingoes and non-target fauna.
  • Report monitoring results, incidents, injuries, mortalities, relocations, habitat loss and corrective actions to the relevant approval holders and wildlife authorities.
  • Consider an offset only where required by the approval decision, and ensure it protects or improves habitat relevant to the central rock-rat rather than substituting for avoidance and minimisation.

Rehabilitation actions: Reinstate habitat structure

Rehabilitation should restore rocky refuge habitat, food resources and safe movement routes. It should also reduce the two main project-relevant risks identified for this species, inappropriate fire and predation by feral cats.

  • Retain or replace locally sourced rocks, boulders, scree and crevice-forming structures in approved rehabilitation areas.
  • Reinstate logs, coarse woody material and other ground cover where they occur naturally, without creating hazards or blocking animal movement.
  • Replant or encourage native food and cover plants suited to the local community, including spinifex, native forbs, subshrubs, Acacia macdonnellensis and other locally appropriate species recorded at the site.
  • Do not introduce plant species or soil material that could increase buffel grass spread or alter the local fire regime.
  • Restore connected habitat between retained rocky areas wherever the project has created barriers.

Rehabilitation actions: Manage fire, weeds and predators

  • Prepare and implement a fire management plan that maintains a mix of post-fire ages and protects refuge habitat from extensive, frequent or intense fire.
  • Use small-scale fire only where it is supported by the approved fire strategy and ecological advice, because fire can both promote food plants and remove cover and resources.
  • Control buffel grass and other invasive grasses where they increase fuel loads or compete with native food plants.
  • Provide immediate and ongoing predator control after fire where required by the approved management programme.
  • Monitor feral cat activity and the response of central rock-rats before and after predator control, while minimising effects on dingoes and other non-target species.

Rehabilitation actions: Monitor rehabilitation success

  • Set success measures for native plant establishment, rock and ground-cover retention, weed cover, fire history, predator activity and use of the rehabilitated area.
  • Use camera traps, hair devices, sign searches and approved trapping to test whether central rock-rats use restored habitat.
  • Monitor during both wet and dry conditions because abundance can increase after rainfall and contract to refuge areas during dry periods.
  • Continue monitoring for the period specified in the approval, and adapt fire, weed, predator and access management if habitat condition or detections decline.
  • Record rehabilitation methods, plant sources, rock placement, monitoring effort, detections and corrective actions in the project environmental records.

Sources