Sandy Inland Mouse (Pseudomys hermannsburgensis)

Conservation status

New South Wales, Biodiversity Conservation Act 2016: Vulnerable.

Breeding season

The supplied documents do not give fixed breeding months. Activity is nocturnal throughout the year, while breeding is most likely to increase after good rainfall, so clearing risk can occur in any month when suitable habitat is occupied.

Months are shown as a general planning guide only because the supplied sources describe rainfall-linked breeding rather than a fixed annual season.

• Breeding: Breeding is maximised after good rainfall, but no fixed months are documented.
• Young: Litters may follow rainfall-linked breeding. Young are naked at birth, furred at 15 days, open-eyed at 20 days and weaned at about 30 days; no fixed months are documented.
• Highest clearing risk: Risk may occur in any month because occupied burrows and dependent young can be present, with breeding increasing after good rainfall. The species shelters in shallow burrows during the day, so daytime clearing can still destroy shelter.

Identification

The Sandy Inland Mouse is a small, slender native rodent with sandy to grey-brown upperparts and white underparts. It is most likely to be encountered at night or detected from burrows and habitat signs during daytime site inspections.

Adults weigh 8 to 15 g. Head and body length is 55 to 85 mm, with NSW records of 55 to 80 mm. The tail is 70 to 90 mm and is slightly longer than the head and body. Ears are 12 to 15 mm and hindfeet are 16 to 20 mm.

Identification: Distinguishing features

The species is superficially similar to the introduced House Mouse, but is more slender and has relatively long ears and tail, more prominent eyes, and no musty House Mouse odour. Its dorsal fur is greyish-brown to sandy-brown and its underparts are off-white. The naked tail is bicoloured.

Identification: Field signs

Daytime shelter is provided by simple burrows up to 0.5 m deep and 1 m long, usually constructed around the base of shrubs or small trees. Four to five animals may occupy one burrow, and groups of up to 21 have been recorded.

• The supplied sources do not describe diagnostic tracks, scats, calls, nests or eyeshine for this species.
• Treat small rodent signs as unconfirmed unless supported by suitable trapping, camera or other targeted survey evidence and comparison with the House Mouse.

Distribution: National range

The Sandy Inland Mouse is widely but very sparsely distributed across arid and semi-arid inland Australia. The supplied records cover Western Australia, South Australia, the Northern Territory, Queensland and New South Wales, including some offshore islands.

The species occurs in western, central and central-eastern Australia. It is recorded from Western Australia, South Australia, the Northern Territory, Queensland and New South Wales, and from the offshore islands Dirk Hartog, Rosemary, Dixon and Hope.

Australian states and territories recorded: Western Australia, South Australia, Northern Territory, Queensland and New South Wales

NSW conservation status: Vulnerable

Commonwealth status: Not listed

Distribution: NSW distribution

In New South Wales, records are confined to the far north-west. Known localities include Fowlers Gap, Sturt National Park, Tibooburra, east of Enngonia, Mutawintji National Park, an area just east of Mutawintji National Park and near Kajuligah Nature Reserve north of Ivanhoe.

NSW known localities: Seven widely scattered localities are identified in the supplied profile

NSW subregions with known or predicted records: Barrier Range, Mootwingee Downs, Bulloo, Core Ranges, Sturt Stony Desert, Cuttaburra-Paroo, Nebine Plains, White Cliffs Plateau and South Olary Plain

Distribution: Population information

The supplied documents do not provide a national population estimate, local density, population trend or defined stronghold. Occurrence is described as widespread but very sparse, with scattered NSW localities.

• Do not infer absence from a negative result at one site, particularly where sandy habitat, spinifex or shrub cover is present.
• Use the NSW indicative distribution as a screening aid only, because the profile states that mapped areas may be restricted within each subregion and may contain errors or omissions.

Habitat: Vegetation and substrates

The species uses a broad range of open arid and semi-arid vegetation communities, usually where sandy substrates and ground cover provide food and burrow sites. It can also occur on cracking clay soils and gibber plains.

Recorded habitats include coolibah or Acacia woodlands, tall open shrublands, especially Mulga scrub, and hummock grasslands. The species occurs mostly on plains and dunes with sands or sandy loams, but also on cracking earth soils and gibber plains.

• Retain open woodland, shrubland and spinifex patches where they occur with sandy or sandy-loam ground.
• Include adjacent habitat in site assessments where clearing may remove shrubs, grasses, ground debris or burrow sites.

Habitat: Structural features

Important site features include understorey shrubs, Triodia spinifex, grasses through the full growth cycle, leaf and stick litter, tree and shrub bases, and ground debris. These features provide food, cover and locations for shallow burrows.

Habitat: Climate and elevation

The species is associated with arid and semi-arid inland Australia. No elevation limits are given in the supplied documents.

Foraging habitat: Diet

The Sandy Inland Mouse feeds mainly on plant material and seeds and forages primarily on the ground at night. It can also obtain food below ground and climb short distances into vegetation.

Seeds are the dominant food. Other foods include grass and green plant material, including shoots, roots, small tubers and, to a lesser extent, insects. The species has also been recorded eating fungi and invertebrates such as lepidopteran larvae.

Foraging habitat: Foraging places and methods

Foraging is mostly terrestrial. Some food is obtained underground, and animals may climb up to 1 m above the ground to obtain food.

• Retain seed-bearing grasses, Triodia, shrubs, litter and undisturbed sandy soil around proposed work areas.
• Avoid assuming that bare ground is unused, because the species can forage underground and may rely on food resources associated with litter and plant cover.

Foraging habitat: Water dependence

The species does not need access to free-standing water because it obtains most of its moisture from food.

• Limit creation of artificial standing water bodies near suitable habitat, because these can attract potential predators and competitors.

Breeding habitat: Breeding biology

Breeding is linked to rainfall and is maximised after good rainfall. Breeding animals use the same shallow burrow system that provides daytime shelter, with groups usually smaller during the breeding period.

Breeding is maximised after good rainfall. Four to five animals may occur in a burrow during the breeding period, compared with larger groups outside the breeding season. Females in breeding condition may be aggressive towards other individuals.

Breeding season: No fixed months are given; breeding is maximised after good rainfall

Litter size: 1 to 6 young, mean 4

Gestation: Not stated in the supplied documents

Age at maturity: Not stated in the supplied documents

Lifespan: Not stated in the supplied documents

Young development: Newborn young are naked and weigh about 2 g, are furred at 15 days, have open eyes at 20 days and are weaned at about 30 days

Breeding habitat: Breeding habitat features

Breeding habitat includes suitable burrows around the bases of shrubs or small trees, with nearby food resources and cover from grasses, spinifex, shrubs, litter and debris.

• Inspect burrows and dense ground cover before clearing, grading, trenching or vehicle access in suitable habitat.
• Retain connected patches of shrubs, grasses and ground debris around known or potential burrow areas.

Sheltering habitat: Burrows

The species shelters during the day in simple, shallow burrows. Burrows are associated with shrubs or small trees and may support several animals.

Burrows can be up to 0.5 m deep and 1 m long. They are constructed around the base of shrubs or small trees and are used as daytime refuges.

Maximum reported burrow depth: Up to 0.5 m

Maximum reported burrow length: Up to 1 m

Recorded group size in one burrow: Four to five commonly during breeding, with up to 21 recorded

• Search the bases of shrubs and small trees for burrow entrances before clearing or earthworks.
• Protect burrow areas from crushing by machinery, stock and repeated vehicle movements where practicable.

Sheltering habitat: Cover and refuge

Ground debris, leaf litter, understorey shrubs, grasses and Triodia provide shelter and should be retained in areas of likely habitat. The sources do not describe tree hollows, nests or above-ground roosts for this species.

• Retain litter, sticks, shrubs and mature grass structure through clearing and construction planning.
• Avoid removing all cover from a site at once, particularly after rainfall when breeding may be more likely.

Threats: Clearing and construction

The main risks on Australian development sites are removal of sandy or vegetated habitat, crushing of burrows, loss of ground cover, altered fire regimes and increased exposure to introduced predators and competitors.

Clearing trees, shrubs and grasses, removing ground debris and losing hollows can remove habitat, food resources and shelter. Fragmentation and heavy trampling can reduce movement between isolated mallee or suitable habitat areas.

• Retain understorey shrubs, grasslands, Triodia, leaf litter and sticks in and around the construction footprint where possible.
• Stage clearing so suitable habitat and food sources are not removed across a whole area at one time.
• Inspect shrub and small-tree bases for burrows before vegetation removal and ground disturbance.

Threats: Grazing and competition

Domestic stock, feral goats, rabbits and pigs can graze and trample habitat. Stock, rabbits, goats and House Mice can also compete for food and habitat resources.

• Control stock access and reduce grazing intensity where regeneration of food plants, cover or nest sites is needed.
• Manage rabbits, goats, pigs and House Mice around suitable habitat.

Threats: Predators, fire and pest control

Foxes and feral cats prey on the species. Frequent fires or altered fire regimes can remove habitat and food sources. Poisoning from 1080 baits is also identified as a threat.

• Plan fire regimes so that all habitat and food sources are not burned within a region at one time.
• Use alternatives to 1080 baiting where possible in pest control programs.
• Assess fox and feral cat control methods for effects on Sandy Inland Mouse populations.

Threats: Water and hydrology change

Artificial standing water can attract potential predators and competitors, even though the species does not require free-standing water for moisture.

• Limit artificial standing water bodies in areas of concern and assess the indirect effects of water points on predators, competitors and grazing pressure.

Survey methodology: 1. Nocturnal searches and spotlighting

Survey Sandy Inland Mice in suitable sandy or sandy loam habitat, including open coolibah or Acacia woodland, Mulga shrubland, hummock grassland, sand plains and dunes. The supplied documents do not provide a prescribed survey guideline or minimum effort, so the project ecologist must set effort in the survey plan and approvals, based on habitat, disturbance scale and likely detectability.

Sandy Inland Mice are terrestrial and nocturnal, and spend the day in shallow burrows. Use nocturnal searches and spotlighting as a general detection method in suitable habitat.

Search sandy ground, the bases of shrubs and small trees, grass tussocks, spinifex and the edges of dunes and sand plains. Look for animals, burrow entrances, tracks and other signs.

Record rainfall and recent conditions because breeding activity is reported to increase after good rainfall. Do not treat a negative search as proof of absence, particularly where the species is sparsely distributed.

Activity period: Nocturnal

Day shelter: Burrows up to 0.5 m deep and 1 m long, often around shrubs or small trees

• Survey all habitat types that will be cleared or disturbed, plus retained habitat that may receive relocated animals.
• Record the start and finish time, weather, recent rainfall, observers, route, search area and all observations using a map or GPS.

Survey methodology: 2. Burrow and habitat searches

Inspect likely shelter and foraging areas during daylight, when animals are expected to be in burrows. Search around shrub and tree bases, beneath ground debris, within grasslands and spinifex, and on sandy plains and dunes.

The species may occur in groups. Four to five animals may occupy one burrow, and groups of up to 21 have been recorded, so a burrow or sign record should be treated as evidence of potential group use.

Reported group size: Four to five individuals in a burrow, with up to 21 recorded

Foraging: Mostly terrestrial, with some underground feeding and occasional climbing to about 1 m

• Map burrows and record their position, substrate, dimensions where measurable, surrounding vegetation and whether they may be affected by access tracks, earthworks or machinery.
• Retain and flag nearby shrubs, small trees, grass tussocks, spinifex, leaf litter and sticks until the ecologist has assessed their value.

Survey methodology: 3. Trapping and targeted detection

Where presence or absence cannot be resolved by searches, the project ecologist should consider an approved small-mammal trapping program suited to the site and relevant animal ethics and wildlife requirements.

Place any traps or other equipment in the habitat types identified for the species, especially sandy substrates, stabilized dunes, sand fields, Mulga, Acacia or coolibah woodland, and hummock grassland.

Because the species is small and nocturnal, check equipment at the frequency required by the approved method and weather conditions, and provide appropriate shelter and protection from exposure. The supplied documents do not specify trap type, trap spacing, trap nights or a required number of trapping sessions.

Adult weight: 8 to 15 g in; 9 to 15 g in

Head and body length: About 55 to 85 mm

Tail length: 70 to 90 mm

• Obtain any required approvals before trapping, handling or marking animals.
• Identify Sandy Inland Mice using the diagnostic features in the field record, including the slender body, relatively long ears and tail, prominent eyes, sandy to grey-brown upperparts and off-white underparts.
• Record measurements and photographs only where authorised and where this will not increase handling risk; adults are reported to weigh 8 to 15 g, or 9 to 15 g in the NSW profile, with a head and body length of about 55 to 85 mm and a tail length of 70 to 90 mm.

Survey methodology: Minimum effort and reporting

• Set survey effort before works begin, document the rationale, and obtain project approval for the method; do not claim species absence from an unquantified search.
• Repeat surveys when initial conditions are unsuitable or when new habitat is exposed, particularly after good rainfall or when fresh signs are found.
• Submit verified records, including negative survey information where required, to the relevant state wildlife database and provide records to the project approval authority.
• Report the survey dates, methods, effort, conditions, personnel, detection results, habitat mapping, photographs, GPS data and any limitations.

Before habitat disturbance: Avoid and minimise

Treat sandy and semi-arid habitat as potential Sandy Inland Mouse habitat even where records are sparse. The NSW profile records the species from only seven widely scattered localities in far north-western New South Wales, so absence of a local record is not evidence that a site is unsuitable.

Avoid clearing sandy plains, dunes, sandy loams, Mulga scrub, Acacia or coolibah woodland, hummock grassland and associated shrub cover where practicable.

Retain shrubs and small trees with burrows at their bases, grass tussocks, Triodia, leaf litter, sticks, ground debris and hollows. These features provide shelter, food or both.

Maintain connected areas of suitable habitat between retained patches. Heavy grazing and trampling can reduce movement between isolated mallee areas, increase exposure to predators and reduce food resources.

• Keep construction access, laydown areas, vehicle movements and spoil outside retained habitat.
• Do not create artificial standing water in or beside retained habitat unless separately assessed, because standing water may attract predators and competitors.
• Avoid clearing or disturbing more habitat than is shown on the approved design.

Before habitat disturbance: Approvals and work planning

The species is listed as Vulnerable in New South Wales and is not listed under the EPBC Act in the supplied profile. Check the current Commonwealth and state listings before work starts, and assess whether other listed matters or project impacts require an EPBC referral or approval.

Confirm state wildlife permits, animal ethics requirements and any conditions applying to trapping, handling, relocation, vegetation clearing or rehabilitation.

Plan staged clearing so that animals can move into connected retained habitat before machinery enters each work area. Use a fauna management plan that identifies habitat, survey results, exclusion areas, controls, stop-work triggers and reporting responsibilities.

• Schedule works to avoid periods when fire, grazing or other disturbance would leave the remaining food and shelter resources concentrated in a small area.
• Have the fauna spotter catcher, clearing supervisor, machinery operators and site environmental officer agree on daily controls before clearing begins.
• Include contingency arrangements for unexpected records, injured animals, burrows and changes to the approved clearing footprint.

Before habitat disturbance: Site preparation

Complete the pre-clearance survey immediately before disturbance, with the timing and effort specified in the approved fauna management plan.

Mark the approved clearing boundary, retained shrubs, small trees, grassland, spinifex, litter, logs, burrows and other habitat features before machinery arrives.

Use exclusion fencing or other physical controls where they can keep machinery, vehicles and people out of retained habitat without blocking movement to connected areas.

• Brief all workers on the species' appearance, nocturnal activity, burrow habitat and the stop-work procedure.
• Inspect access routes and work areas for fresh burrows or animals on the day of clearing.
• Do not collapse, fill or drive over a potential burrow until it has been assessed by the fauna spotter catcher or project ecologist.

During habitat disturbance: Daily controls and spotter duties

Clear progressively and keep the fauna spotter catcher in direct contact with the clearing crew. The species shelters in shallow burrows and may be overlooked during daytime clearing, so rely on controlled, inspected work areas rather than visual clearance alone.

Inspect the work area each day before machinery starts, including burrow entrances, shrub bases, grass tussocks, spinifex, litter and recently exposed sandy ground.

Use staged clearing and direct machinery away from retained habitat and identified burrows. Keep vehicle speed, access and operating areas within the approved footprint.

The fauna spotter catcher must have authority to stop machinery, enter the exclusion zone when safe, and require an ecologist or other authorised person to assess an animal or habitat feature.

• Maintain exclusion fencing, flagging and signage, and replace or repair controls that are moved or damaged.
• Keep a clear communication link between the spotter catcher, operator, supervisor and environmental officer.
• Do not allow workers to chase, handle or remove an animal unless they are authorised and competent to do so.

During habitat disturbance: Habitat features and burrows

Protect burrows, shrubs, small trees, grass tussocks, Triodia, logs, sticks, leaf litter and hollows until they have been inspected and a handling decision recorded.

If a burrow, log, rock or other ground feature must be moved, inspect it first, move it slowly under the direction of the fauna spotter catcher, and check the surrounding ground for animals.

The supplied documents identify burrows, ground debris and hollows as relevant shelter or habitat features, but do not provide a species-specific procedure for dismantling or relocating them.

• Retain habitat features in place wherever possible.
• Place any approved salvaged feature in nearby retained habitat with similar substrate and vegetation, without blocking existing burrows or creating standing water.
• Do not burn, chip, bury or remove retained litter, shrubs, grasses or spinifex unless that action is approved and assessed for this species.

During habitat disturbance: Animal encounters and stop-work triggers

If a Sandy Inland Mouse is found, stop work in the immediate area and keep people, vehicles and predators away while the fauna spotter catcher assesses it.

Handle the animal only within the person's authorisation and competence, using the minimum handling needed for identification, health assessment or approved relocation.

If the animal is injured, stressed or unable to move normally, place it under approved care and arrange transfer to a veterinarian or wildlife carer authorised to receive native wildlife.

• Relocate a healthy animal only where authorised, and place it in nearby retained habitat with suitable sandy substrate, shrub or grass cover and connected shelter.
• Stop work if an animal is found in the active clearing area, if a burrow or occupied shelter is exposed, if the clearing boundary is exceeded, or if required fauna controls fail.
• Record the species, location, time, condition, action taken, release location, handlers, photographs and any mortality or injury.
• Escalate any death, injury, unapproved handling, unplanned habitat loss or repeated animal records to the project environmental officer and relevant approval authority.

After habitat disturbance: Post-clearance checks

Check the completed clearing area and retained habitat before demobilising the fauna crew. Use the records to confirm that controls worked and to identify any need for additional habitat protection or rehabilitation.

Inspect the cleared footprint, retained edges, access routes and nearby habitat for surviving animals, exposed burrows, trapped fauna, damaged exclusion fencing and unapproved clearing.

Repeat targeted searches where clearing has exposed sandy ground, collapsed burrows or isolated habitat features, using the project ecologist's approved method.

Check that relocated animals, if any, were released into nearby retained habitat and that release details are recorded.

• Remove temporary hazards such as open pits, unsecured pipes, spoil piles and machinery access points that could trap small mammals.
• Repair disturbed retained habitat boundaries and reinstate barriers where further construction activity will continue.
• Do not leave artificial water bodies or other new features that may attract predators or competitors.

After habitat disturbance: Monitoring and reporting

Monitor retained and rehabilitated habitat using repeat searches or other approved methods suited to the site. Focus on burrows, sandy substrates, shrub bases, grasslands and spinifex.

Record detections, signs, habitat condition, predator or competitor observations, fire impacts, grazing or trampling and any further disturbance.

Report clearing limits, survey effort, incidents, animal outcomes, rehabilitation actions and monitoring results to the relevant regulator, land manager and state wildlife database where required.

• Retain maps, GPS records, photographs, fauna registers, permits, approvals and spotter catcher daily records for the period required by the project approvals.
• Review the fauna management plan when monitoring identifies new records, repeated mortality, loss of connectivity or declining habitat condition.
• Apply offsets or other compensatory measures where required by an approval, assessment or state policy.

After habitat disturbance: Maintain retained habitat

Continue to protect retained shrubs, grass tussocks, Triodia, leaf litter, sticks, hollows and sandy ground from unnecessary grazing, trampling, clearing and fire.

Control foxes, feral cats and rabbits where this is approved and part of the site's management program. Consider competition from stock, goats and house mice when assessing habitat condition.

Use alternatives to 1080 baiting where possible, because the NSW profile identifies poisoning from 1080 baits as a threat.

• Keep any new fencing, drainage, lighting, water infrastructure and access arrangements under review for effects on movement, shelter, food and predator activity.
• Do not apply a fire regime that burns all habitat and food sources in the area at one time.
• Maintain records of pest control, grazing intensity, fire and habitat condition.

Rehabilitation actions: Restore vegetation and ground cover

Rehabilitation should rebuild the sandy, low-cover habitat structure used by the species and restore shelter and food resources over time. Base the design on the vegetation and substrate that occurred before clearing, with priority given to connected retained habitat.

Re-establish local forms of the habitat identified for the site, such as coolibah or Acacia woodland, Mulga shrubland, open shrubland, hummock grassland or Triodia.

Retain or reinstate grass tussocks, shrubs, leaf litter, sticks and other ground debris to provide food, cover and shelter.

Use local provenance seed or plant material where required by the rehabilitation plan, and avoid introducing vegetation that changes the sandy habitat structure.

• Stabilise disturbed sand and sandy loam without sealing or compacting the ground so that burrows and terrestrial foraging remain possible.
• Keep rehabilitation areas connected to retained habitat rather than creating isolated planted patches.
• Control weeds and grazing so that grass development can proceed through seed set and tussock formation.

Rehabilitation actions: Reinstate shelter features

Retain existing hollows, logs, sticks and leaf litter wherever practicable, because their loss is identified as a habitat threat.

Reinstate suitable salvaged logs, sticks, rocks and litter in arrangements that resemble the pre-clearing habitat and do not block existing burrows.

Do not install nest boxes as a substitute for all ground habitat; use them only where the ecologist identifies a site-specific need to replace lost hollows and the design is approved.

• Leave sandy areas and shrub bases available for burrow construction.
• Do not fill or compact potential burrow areas during follow-up works.
• Do not add artificial standing water as a rehabilitation measure, because the species obtains moisture from food and standing water may attract predators and competitors.

Rehabilitation actions: Fire, predators and monitoring

Apply a fire regime that retains unburnt habitat and food sources within the area at all times, and supports natural vegetation succession.

Manage foxes, feral cats and rabbits where approved, and reduce excessive stock or feral herbivore grazing that removes cover or food.

Monitor rehabilitation for vegetation establishment, retention of litter and shelter, burrow formation or use, connectivity and Sandy Inland Mouse detections.

• Set success measures before rehabilitation starts, including survival of planted or regenerating vegetation, retained ground cover, absence of damaging grazing or trampling, functioning habitat connections and results of fauna monitoring.
• Inspect rehabilitation after major rain, fire, grazing events and construction maintenance, and repair erosion, failed plantings, damaged fencing or loss of shelter features.
• Submit monitoring results and verified species records to the relevant state wildlife database and update management actions when results do not meet the approved success measures.

Sources

• Sandy Inland Mouse - profile, NSW Department of Climate Change, Energy, the Environment and Water: https://threatenedspecies.bionet.nsw.gov.au/profile.aspx?id=10688
• Pseudomys hermannsburgensis (Waite, 1896), treatment.plazi.org: http://treatment.plazi.org/id/1E30E27534A5FF14E1912853754F89BC