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Greater Glider (Petauroides volans)

The Greater Glider is a large, nocturnal, tree dwelling marsupial of eastern Australia's eucalypt forests and woodlands. It depends on mature hollow bearing trees, connected native vegetation and suitable eucalypt foliage, so clearing, road construction, fire management and tree removal can cause direct mortality or remove habitat needed for shelter, feeding and breeding.

Conservation status

Commonwealth, EPBC Act 1999: Endangered.

Queensland, Nature Conservation Act 1992: Endangered.

New South Wales, Biodiversity Conservation Act 2016: Endangered.

Victoria, Flora and Fauna Guarantee Act 1988: Endangered.

Australian Capital Territory, Nature Conservation Act 2014: Endangered.

Breeding season

The following pattern is a general guide for the southern and central Greater Glider. Timing can vary between regions and individuals, and breeding activity can overlap with the period when young remain dependent.

Avoid relying on calendar timing alone. A live or dead hollow bearing tree may be occupied outside the main breeding period, and pre-clearing surveys should account for nocturnal activity and multiple den use.

  • Breeding and births: Breeding begins around March and females generally give birth to one young between March and June.
  • Young dependent: The young remains in the pouch until about September, then rides on the mother's back until November or December and becomes independent around January.
  • Local movement between dens: Animals use multiple den trees within their home range. The species has limited dispersal ability, and the supplied sources do not identify a distinct seasonal migration period.
  • Highest clearing risk: Clearing and tree removal are most likely to harm the species from March to September while breeding and pouch young are present, and from October to December while young may still be dependent. Hollow bearing trees can be occupied at any time of year.

Identification

The Greater Glider is the largest gliding possum in Australia. It is usually detected at night in the canopy or on large trees, and its dense fur, large furry ears and long non-prehensile tail are distinctive.

Adults have thick fur that may be dark grey, dusky brown, light mottled grey, cream or almost white. The underside is usually white or cream, the snout is short, and the ears are large and furred.

The gliding membrane extends from the forearm to the tibia. The long tail is furred but not prehensile, and is used as a rudder during gliding.

Identification: Size and sex

The southern Greater Glider has a head and body length of 35 to 46 cm, a tail length of 45 to 60 cm and a typical adult weight of 900 to 1700 g.

Females are larger than males. Male home ranges are generally larger, and males may hold largely separate home ranges while female ranges overlap.

Head and body: 35 to 46 cm

Tail: 45 to 60 cm

Adult weight: 900 to 1700 g

Identification: Field recognition and signs

A large, slow moving possum with a broad gliding membrane, very furry ears and a long non-prehensile tail is more consistent with a Greater Glider than with smaller gliding possums. The northern Greater Glider is generally more slender and has shorter ears and tail, but geographic range and habitat should also be considered because the two taxa are separated mainly through recent taxonomic work.

Useful field evidence includes a nocturnal animal in a eucalypt canopy, repeated use of large tree hollows, and direct observation of gliding between trees. Greater Gliders may use several den trees within a home range, and may line hollows with bark strips or leaves.

Tracks, scats and calls are not described in the supplied sources as reliable primary identification features. Spotlighting and inspection of hollow bearing trees should therefore be supported by experienced visual identification and suitable records of the tree and hollow used.

  • Record the animal's colour, body size, tail length, membrane position and ear shape.
  • Record the tree species, tree diameter, hollow entrance and height where a den or emergence is observed.
  • Do not rely on a single indirect sign to confirm presence.

Distribution

The Greater Glider occurs in a broad but discontinuous belt of eastern Australia. The current taxonomy recognises the northern Greater Glider, Petauroides minor, separately from the southern and central Greater Glider, Petauroides volans.

The southern and central Greater Glider occurs from around Proserpine in Queensland, through New South Wales and the Australian Capital Territory, to Wombat State Forest in central Victoria. It occurs from sea level to about 1200 m above sea level.

The northern Greater Glider occurs from around Townsville north to the Windsor Tablelands in north-eastern Queensland. Its range includes the Wet Tropics World Heritage Area and is very patchy in places.

States and territory: Queensland, New South Wales, Australian Capital Territory and Victoria for the southern and central form.

Southern and central elevational range: 0 to 1200 m above sea level.

Northern range: Townsville to the Windsor Tablelands in north-eastern Queensland.

Distribution: Strongholds and isolated populations

Important areas include taller, moist montane forests in the New South Wales and Victorian ranges, eastern Victorian forests, south-east Queensland eucalypt forests and woodlands, and the Wet Tropics and upland forests of north-eastern Queensland.

Known isolated northern populations include the Gregory Range and Gilbert Plateau west of Townsville, Blackbraes National Park and the Einasleigh Uplands. For the southern and central form, important areas include mature forest in the Central Highlands and East Gippsland of Victoria, forests of south-eastern New South Wales and the Australian Capital Territory, and connected forest near the range margins.

Distribution: Population size and trend

A reliable total population estimate is not available. Earlier assessments estimated more than 100,000 mature individuals for the taxon as then defined, but monitoring has recorded substantial local declines and loss of occupancy.

In Victoria's Central Highlands, occupancy declined by an average of 8.8 percent per year between 1997 and 2010. The southern and central form was estimated to have declined by 47 percent over 21 years, with a projected 53 percent decline when past and future decline were combined.

Earlier estimated mature population: More than 100,000 individuals, for the formerly broader taxon.

Central Highlands monitoring: Average occupancy decline of 8.8 percent per year from 1997 to 2010.

Southern and central estimated decline: 47 percent over 21 years, with 53 percent including projected future decline.

Habitat: Forest types and structure

Greater Gliders are forest dependent and are usually associated with eucalypt forests and woodlands that contain mature trees, abundant hollows and suitable browse. Presence can be patchy even where forest appears continuous.

Highest abundance is generally recorded in taller, wetter or montane eucalypt forest with relatively old trees and a high density of hollows. The species also occurs in drier eucalypt forest and open woodland, particularly in Queensland.

The Grey Box and Grey Gum Wet Forest ecological community in subtropical eastern Australia provides suitable shelter and forage, including hollows and crevices in mature eucalypts.

Important structural features include mature and senescent eucalypts, live and dead hollow bearing trees, high overstorey basal area, a range of eucalypt species and native forest connections between habitat patches.

Habitat: Climate and elevation

The species is associated with cool, wet or sheltered sites, including gullies, high elevation forest and south facing slopes. These areas can provide refuge from heat, drought and fire.

The southern and central form occurs from sea level to about 1200 m. The northern form is most abundant on higher elevation and wetter sites, but also occurs in open woodland and open forest.

  • Retain unburnt forest within or beside recently burnt areas.
  • Retain sheltered gullies, cool slopes and other areas likely to remain suitable during heat and drought.
  • Treat currently unoccupied forest as potential habitat where mature trees can provide future hollows and food resources.

Foraging habitat: Diet and food plants

Greater Gliders are specialised folivores that feed mainly in eucalypt canopies. Food availability depends on the species, age and condition of the trees, as well as seasonal foliage quality.

The diet consists mostly of eucalypt leaves, with buds and flowers also taken. The northern form has a distinct preference for young foliage and feeds from a restricted range of eucalypt species.

Preferred food trees vary regionally. Recorded examples include Mountain Ash, Cut-tail, Manna Gum, White Stringybark, Narrow-leaved Peppermint, Mountain Gum, white mahogany, lemon-scented gum and forest red gum.

A diverse range of eucalypt species supports seasonal changes in preferred browse. Leaves provide much of the animal's water intake, with the northern form estimated to obtain about 85 percent of its water from consumed leaves.

Foraging habitat: Foraging area and behaviour

Greater Gliders forage within relatively small home ranges, usually 1 to 4 ha, although ranges can reach 16 to 19 ha in lower productivity forest and open woodland. Males generally use larger areas than females.

They are nocturnal and arboreal. Their poor movement through cleared ground and limited dispersal ability mean that retaining connected native canopy is important for access to browse and for movement between den trees.

Typical home range: 1 to 4 ha

Larger recorded home ranges: Up to 16 to 19 ha in open or lower productivity habitat.

  • Retain preferred eucalypt food trees within and around the work area.
  • Avoid removing canopy links between mature trees where gliding or movement may occur.
  • Assess browse availability and tree species composition, not only the presence of hollows, when defining habitat.

Breeding habitat: Breeding biology

Breeding is slow, seasonal and produces few young. Mature forest with several suitable den hollows and reliable eucalypt browse is needed to support breeding females and dependent young.

Females generally produce a single young. The young remains in the pouch for several months, later rides on the mother's back and becomes independent during the following summer.

Sexual maturity is reached in the second year. The low reproductive rate increases the risk that small or isolated populations will not recover quickly after clearing, fire or other disturbance.

Breeding season: Breeding begins around March; births are generally recorded from March to June.

Litter size: One young.

Gestation: Not stated in the supplied sources.

Age at maturity: Second year, approximately 2 years.

Longevity: Estimated at about 15 years.

Generation length: Approximately 6 to 8 years.

Breeding habitat: Breeding habitat features

Breeding habitat includes mature eucalypt forest with multiple large hollows, suitable food trees and enough connected forest for the adult's small home range. In southern Queensland, at least 2 to 4 live den trees per 2 ha of suitable forest have been reported as necessary.

Each family group may use several den trees. In northern Queensland, individuals have been reported to use 4 to 6 dens per month, so removal of one apparently unused hollow can still reduce breeding habitat.

  • Retain live and dead hollow bearing trees, including trees that are not currently occupied.
  • Retain replacement trees that can develop hollows in future.
  • Avoid high noise, vibration, lighting and tree removal near occupied hollows during the breeding and dependent young period.

Sheltering habitat: Den trees and hollows

Greater Gliders shelter by day in tree hollows, usually in large old trees. Hollow loss is a direct habitat loss even where the surrounding forest canopy remains.

The species prefers large hollows in large, old trees. For the northern form, hollows with an entrance diameter greater than 10 cm are specifically reported as preferred.

Greater Gliders may use several hollows within a home range. They may line a hollow with bark strips or leaves, but the absence of visible nesting material does not show that a hollow is unused.

In Queensland, trees with a diameter at breast height greater than 30 cm can be used as a proxy for trees likely to contain hollows used by Greater Gliders, although ground based inspection may not detect all hollows.

Preferred hollow entrance for northern form: Greater than 10 cm diameter.

Queensland proxy for potential hollow trees: Trees greater than 30 cm diameter at breast height.

Den tree density reported in southern Queensland: At least 2 to 4 live den trees per 2 ha of suitable forest.

Northern form den use: About 4 to 6 dens per month in one study.

  • Inspect large live trees, dead standing trees, stags and trees with visible hollows before clearing.
  • Retain hollow bearing trees and suitable recruitment trees with buffers that protect the trunk, roots and surrounding access routes.
  • Check trees identified as hazardous with a suitably qualified person before removal.

Sheltering habitat: Movement and refuge features

Greater Gliders can glide up to about 100 m between trees. They are clumsy on the ground and disperse poorly through cleared or non-native vegetation.

Connected native forest, unburnt patches beside fire affected areas, sheltered gullies and cool slopes can provide refuge and support movement between den and feeding trees.

  • Maintain continuous or near continuous native canopy wherever practicable.
  • Protect unburnt forest and hollow bearing trees after fire from salvage clearing and clean-up operations.
  • Do not assume that a small isolated patch is low value because no animal is detected during one survey.

Threats: Clearing, fragmentation and infrastructure

The main risks on development and infrastructure projects are loss of mature trees, fragmentation of native forest, fire, heat and drought, and disturbance or mortality during tree and vegetation removal.

The species is absent from cleared areas and has limited ability to move between forest remnants through open ground. Clearing can remove den trees, food trees, gliding routes and the connected forest needed for recolonisation.

Roads, transport corridors, utility corridors and peri-urban expansion can divide habitat and increase edge effects. Roadside clearing has also removed hollow bearing trees that had been retained beside previous forestry areas.

Small remnants have lower persistence because Greater Gliders have low reproductive output, small home ranges and limited dispersal.

  • Avoid clearing mature eucalypts and hollow bearing trees wherever practicable.
  • Keep new roads, tracks, compounds and service corridors out of connected Greater Glider habitat where practicable.
  • Retain canopy connections and native forest links between retained patches.
  • Do not treat artificial glide poles, nest boxes or similar structures as a substitute for avoiding habitat loss.

Threats: Fire and tree removal

High intensity and frequent fire can cause direct mortality, remove browse and destroy hollow bearing trees. Recovery is slow because the species produces one young at a time and disperses poorly.

Planned burns, control lines, back burning, slashing, mulching and hazardous tree removal can damage den trees even when the main fire footprint is avoided.

  • Identify occupied and potential den trees before planned burning or fire access works.
  • Protect hollow bearing trees from direct flame, high heat, machinery and post-fire salvage operations.
  • Use lower intensity methods, mechanical treatment or seasonal timing where these reduce impacts and remain consistent with fire safety requirements.
  • Retain unburnt habitat within or beside recently burnt areas.

Threats: Climate, browse and hydrology

Greater Gliders are sensitive to high temperatures and low water availability because they rely on eucalypt foliage for food and much of their water. Heat and drought can reduce young, nutritious foliage, reduce reproduction and cause heat stress or mortality.

Changes in rainfall and soil moisture can reduce tree growth and browse quality. The supplied sources do not identify a separate direct effect from altered stream hydrology, so hydrology risks should be assessed through their effects on eucalypt health, soil moisture, fire behaviour and cool refuges.

  • Retain cool, sheltered and moist forest areas, including gullies and south facing slopes.
  • Avoid activities that reduce canopy cover or increase heat and drying around retained habitat.
  • Protect eucalypt species that provide regionally important browse.

Threats: Predators, fencing and disease

Powerful Owls and Sooty Owls prey on Greater Gliders. Predation risk may increase when hollow bearing trees are lost and animals must move between remaining hollows.

Feral cats and foxes may take gliders on the ground, particularly after fire when displaced animals are more exposed. Barbed wire fencing causes occasional entanglement.

Phytophthora root fungus can affect the health of eucalypts and may reduce the quality of habitat, although the supplied sources do not quantify its population level effect.

  • Avoid barbed wire in occupied habitat and replace the top strand of existing barbed wire with plain wire where practicable.
  • Reduce opportunities for gliders to reach the ground during clearing and retain canopy links between trees.
  • Apply hygiene and soil movement controls for Phytophthora where required by the relevant state or project procedures.

Survey methodology: 1. Spotlighting

Survey for Greater Gliders should target mature eucalypt forest and woodland with large hollow-bearing trees. Use repeatable night surveys, record habitat features as well as animals, and adjust effort for weather, fire history and recent disturbance.

Conduct nocturnal spotlighting along the proposed disturbance area and adjacent retained habitat. Greater Gliders are nocturnal and are often detected in tree crowns, on trunks or while gliding between trees.

Use a consistent route, observer team, spotlight and search speed on every survey night. Record the route length, start and finish times, weather, moon conditions, wind, rainfall, observer names and all detections.

Give particular attention to mature trees, large hollows, feeding trees, forest edges, gullies and connected native forest. The species can be patchy even where habitat appears suitable.

Activity period: Nocturnal.

Typical home range: About 1 to 4 hectares, increasing to as much as 16 hectares in lower-productivity forest and open woodland; up to 19 hectares has been reported for southern Greater Gliders in less fertile sites.

  • Survey in suitable weather, avoiding strong wind, heavy rain and conditions that reduce visibility or animal activity.
  • Record each animal's location, height, behaviour, direction of travel, estimated distance, habitat type and whether it is using a hollow-bearing tree.
  • Do not rely on a single negative spotlighting result, because detection probability can be low and the species may be absent from part of otherwise suitable habitat.

Survey methodology: 2. Habitat and den-tree assessment

Complete a daytime habitat assessment across the proposed clearing area and retained buffers. Greater Gliders shelter in tree hollows during the day and prefer large hollows in large, old trees.

Map hollow-bearing trees, trees with potential future hollows, connected native forest, feeding trees and any narrow vegetation links between retained patches. Ground-based hollow detection can be difficult, so inspect trunks, limbs and cavities from several viewpoints.

Preferred den hollow: Large hollows, including hollows with an entrance diameter greater than 10 cm in the northern advice.

Queensland proxy: Trees with diameter at breast height greater than 30 cm can be used as a proxy for hollows used by Greater Gliders.

Southern and central habitat patch modelling: Native forest patches of at least 160 square kilometres were predicted to support viable populations in one model.

  • Record tree species, diameter at breast height, approximate height, live or dead status, hollow entrance size, hollow position and evidence of use such as scratches, hair, staining or glider observations.
  • Use trees with a diameter at breast height greater than 30 cm as a Queensland proxy for potential hollow-bearing trees where the relevant regional advice applies.
  • Assess habitat beyond the clearing footprint because small home ranges, poor dispersal through cleared land and dependence on connected forest mean that indirect fragmentation effects can extend beyond the work area.

Survey methodology: 3. Repeat surveys and post-disturbance checks

Repeat surveys where the project may remove hollow-bearing trees, fragment forest, affect a known population or follow fire, drought or heatwave. Use the same routes and methods before and after the disturbance so changes can be detected.

Where possible, survey both the proposed clearing area and nearby retained habitat. Retained habitat may be used for relocation, recolonisation or comparison with disturbed sites.

Documented monitoring example: Victoria used 160 permanent 1 hectare sites across about 1,800 square kilometres, with annual monitoring from 1997 to 2010.

Recovery consideration: Recovery after major fire is slow because the species has small home ranges, low reproductive output and limited dispersal.

  • Survey known or previously occupied sites again when recent records, habitat modelling or local knowledge indicate that a single survey may understate use of the site.
  • Undertake follow-up surveys after clearing or a major disturbance to check for animals displaced into retained vegetation, injuries, mortality, loss of hollow use and changes in occupancy.
  • Use standardised, repeatable methods and retain georeferenced records so results can be compared with state monitoring programs.

Survey methodology: Minimum effort and reporting

  • Obtain the project-specific survey requirements from the relevant state or territory authority and the current Australian Government threatened mammal survey guidance before fieldwork begins.
  • State the survey area, route lengths, number of observers, number of nights, start and finish times, weather, visibility, survey limitations and all detection results in the report.
  • Report positive and negative results separately for the clearing footprint, retained habitat and any nearby reference sites.
  • Submit verified records and georeferenced habitat observations to the relevant state or territory wildlife database, and provide records required by the project approval or land manager.
  • Retain photographs, field sheets, GPS tracks, tree maps, animal handling records and injured-animal outcomes with the project environmental records.

Before habitat disturbance: Avoid and minimise

The preferred approach is to avoid clearing occupied habitat and retain the trees and forest connections that support denning, feeding and movement. Treat mature hollow-bearing trees as a project constraint from the first design stage.

Redesign the footprint to retain large, old hollow-bearing trees, surrounding forest, preferred food trees and connected native vegetation. The species is absent from cleared areas and disperses poorly through non-native vegetation.

Retain habitat patches and corridors that connect smaller patches to larger areas of native forest. Include unburnt refuges and cool, sheltered areas where they may support persistence during heat, drought or fire.

Den-tree requirement reported for southern Queensland: At least 2 to 4 live den trees for every 2 hectares of suitable forest habitat.

Home ranges: Usually 1 to 4 hectares, but up to 16 hectares in lower-productivity forest and open woodland.

  • Avoid removing hollow-bearing trees, large dead trees with usable hollows and trees needed for future hollow recruitment.
  • Avoid narrow clearing that removes the connection between den trees, feeding areas and nearby forest.
  • Avoid placing roads, tracks, utilities, compounds or spoil storage beside known den trees where construction noise, lighting, fire or tree removal could reduce habitat use.
  • If avoidance is not possible, document the alternatives considered and the residual loss of denning trees, food trees, connectivity and habitat area.

Before habitat disturbance: Approvals and project planning

Confirm the current national listing and whether the action requires referral or approval under the EPBC Act. Check the relevant state or territory threatened-species legislation, clearing controls, wildlife handling requirements and permit conditions.

Use the project environmental assessment to identify known records, modelled habitat, hollow-bearing trees, fire refuges, connectivity links and any state-specific prescriptions.

  • Obtain written approval for fauna survey, capture, handling, temporary containment, release and veterinary treatment before works begin.
  • Prepare a fauna management plan that identifies the fauna spotter catcher, authorised handlers, equipment, release sites, veterinary contacts, stop-work triggers, reporting lines and incident forms.
  • Include Greater Glider protection measures in the construction environmental management plan, clearing permit, vegetation management plan and contractor briefing.
  • Plan the work in stages so animals can move towards retained habitat before machinery enters each work area.

Before habitat disturbance: Pre-clearance and site preparation

Complete a pre-clearance inspection shortly before works, using the approved survey method and checking all trees, vegetation and ground features within the disturbance footprint and any nominated protection zone.

Mark every retained hollow-bearing tree, potential future hollow tree, habitat tree, retained forest patch and connectivity link on the ground and in the construction drawings.

Fence or otherwise clearly delineate retained habitat and tree protection areas before machinery, vehicles and materials enter the site.

Breeding period: Females generally give birth to one young from March to June.

Maturity: Sexual maturity is reached in the second year.

  • Brief all workers on the species, photographs, likely locations, exclusion areas, speed limits, lighting controls, reporting process and stop-work requirements.
  • Check trees proposed for removal from the ground and, where safe and authorised, inspect accessible hollows before felling.
  • Schedule tree removal and clearing for daylight, when animals are more likely to be located in hollows and can be managed before night activity begins.
  • Do not undertake pre-clearance checks so far in advance that animals can move into the work area before clearing.

During habitat disturbance: Daily controls and machinery coordination

A fauna spotter catcher must remain able to see the active work area and stop machinery before an animal or habitat feature is placed at risk. Clearing should proceed in small, controlled stages, with retained habitat protected throughout.

Inspect exclusion fencing, tree protection zones and access routes before work starts each day. Repair breaches before machinery enters.

Use a spotter catcher who can communicate directly with the machine operator and who has authority to stop work. Keep the spotter catcher in a safe position with a clear view of the work face.

Clear from the edge of retained habitat towards the retained area only where the approved fauna management plan shows that this will encourage movement away from the work zone and will not funnel animals into machinery or roads.

  • Stop work during poor visibility, unsafe wind, fire conditions or any event that prevents the spotter catcher from monitoring the clearing face.
  • Keep machinery, workers, vehicles, lighting and temporary structures out of marked tree protection zones unless the approval expressly allows access.
  • Prevent workers from climbing trees, entering hollows or handling animals unless they are authorised and trained for that task.
  • Control night lighting near retained habitat because Greater Gliders are nocturnal and may alter movement around illuminated work areas.

During habitat disturbance: Habitat feature handling

Treat hollow-bearing trees as high-risk habitat features. Do not fell, burn, limb or move them unless the action is approved and the fauna management plan specifies the method.

Where an approved removal is unavoidable, inspect the tree and accessible hollows before removal, use staged or supervised felling where safe, and check the felled tree and hollow sections immediately afterwards.

Hollow use: Greater Gliders use multiple den trees within their home range; the northern advice reports use of 4 to 6 dens per month in one Queensland population.

  • Retain logs, large limbs and other useful shelter features where they do not create a safety hazard, and place retained material in nearby suitable habitat where approved.
  • Protect retained trees from fire, machinery impact, soil disturbance, root damage, stock access and storage of materials.
  • Do not assume that an unoccupied hollow is unused, because Greater Gliders use multiple dens and may be inside a hollow during daylight.
  • Do not install nest boxes or artificial hollows as a substitute for avoiding mature hollow-bearing trees unless this is approved as a last-resort measure and followed by monitoring.

During habitat disturbance: Animal encounters, stop work and records

Stop work immediately if a Greater Glider is found in the clearing area, in a tree being removed, on the ground, injured, trapped, entangled or displaced into an unsafe area.

Keep people, dogs, vehicles and machinery away from the animal. Do not chase, corner or repeatedly spotlight it.

Only an authorised and trained wildlife handler should capture or handle the animal. Minimise handling, noise, heat and time in a container, and follow the approved fauna handling procedure.

  • If the animal is healthy and can move safely, allow it to move into nearby retained forest under supervision.
  • If relocation is authorised, release the animal into nearby retained habitat with suitable mature trees, hollows and connectivity, as close as practicable to the capture site and away from active works.
  • Place injured or heat-stressed animals in a quiet, ventilated container and arrange immediate assessment by a veterinarian or licensed wildlife carer.
  • Treat a dependent young found with a female or in a hollow as part of the same incident and seek specialist advice before release.
  • Record the date, time, exact location, condition, photographs, capture method, handler, temporary container, release location, veterinary outcome and any tree or work activity involved.
  • Use stop-work triggers for an animal encounter, unexpected hollow use, a breach of a tree protection zone, unapproved tree damage, mortality, injury or a clearing method that cannot be safely supervised.

After habitat disturbance: Post-clearance inspection

Post-clearance work should confirm that no animals, dependent young or usable habitat features remain at risk. Continue controls until the site is stable and the approval conditions have been met.

Inspect the cleared area, felled trees, hollow sections, retained trees, access routes and exclusion fencing after each clearing stage and again before the area is handed to construction crews.

Check for live animals, dependent young, carcasses, injured animals, entanglement, damaged hollows, fire damage and machinery impacts.

Review whether animals have moved into retained habitat or whether noise, lighting, barriers or loss of connectivity is affecting access to den trees and feeding trees.

  • Keep machinery out of the area until the spotter catcher has completed the inspection and signed off the clearing stage.
  • Notify the project environmental officer and relevant authority of any mortality, injury, unauthorised clearing, damaged hollow-bearing tree or release outside the approved location.
  • Repair exclusion fencing and replace tree protection markers before the next work stage.

After habitat disturbance: Monitoring and reporting

Monitor retained habitat and known Greater Glider records after disturbance where required by approval, where habitat loss was substantial, or where fire, heat, drought, logging or construction may affect occupancy.

Use the same repeatable spotlighting routes and habitat measures used before works so results can be compared over time.

Recovery after major disturbance: Recovery can be slow because of low reproductive output, small home ranges and limited dispersal.

  • Record post-work detections, den-tree use, mortality, injuries, signs of displacement, fire impacts, damaged trees and changes to connectivity.
  • Compare animal detections and hollow-bearing tree condition with pre-work results and investigate a sustained decline in occupancy.
  • Submit required monitoring reports, wildlife incident reports and verified records to the approval holder, relevant state wildlife database and regulating authority.
  • Keep monitoring data with the project spatial records so future works can account for the location of occupied habitat and den trees.

After habitat disturbance: Ongoing controls and offsets

Maintain tree protection zones, retained habitat, connectivity corridors, fire controls and lighting controls for the period specified in the approval or fauna management plan.

Where residual impacts remain, apply the approved offset, restoration or compensatory habitat measure. An offset does not replace avoidance of occupied habitat or retention of hollow-bearing trees.

  • Inspect offset or compensatory habitat for mature trees, hollow recruitment, connectivity and evidence of Greater Glider use.
  • Include management actions for fire, weeds, introduced predators, future clearing and hollow-tree retention in any conservation covenant or land management agreement.
  • Report whether each restoration or offset action was completed, its location, condition, monitoring results and any corrective action required.

Rehabilitation actions: Restore forest structure and food resources

Rehabilitation should rebuild connected eucalypt forest and protect the long-term supply of large hollow-bearing trees. It will not replace mature hollows quickly, so retain existing habitat wherever possible.

Re-establish locally appropriate eucalypt forest using a diverse mix of preferred regional food and den-tree species, based on the pre-clearing vegetation community and advice from the relevant state authority.

Prioritise continuous native vegetation and links between retained patches, rather than isolated planting blocks. Greater Gliders disperse poorly through cleared or non-native vegetation.

Protect planted and regenerating trees from browsing, grazing, machinery, weeds, drought and fire until they are established.

Food: The diet is mostly eucalypt leaves, supplemented by buds, flowers and regionally preferred foliage.

Water from food: Leaves provide a substantial part of the species' water requirements; the Victorian action statement reports about 60 percent, while the northern advice reports approximately 85 percent.

  • In Victorian habitats, consider locally appropriate Mountain Ash, Cut-tail, Manna Gum, White Stringybark, Narrow-leaved Peppermint and Mountain Gum where those species belong to the original forest type.
  • Retain and recruit trees that can develop hollows, including large live trees and suitable standing dead trees where safe.
  • Restore cool, sheltered gullies, wet forest and other locally suitable microclimates where they formed part of the original habitat.
  • Do not plant rainforest or non-local species into a eucalypt forest community unless required by the approved regional restoration design.

Rehabilitation actions: Hollows, logs and artificial structures

Retain fallen hollow limbs, logs and other shelter features where safe, and place salvaged habitat material in nearby retained or rehabilitated forest.

Use nest boxes or artificial hollows only where approved, where natural hollows are limiting, and as a last resort. Select designs and locations for Greater Gliders and monitor whether they are used.

Natural hollow limitation: Large hollows in large, old trees are a key shelter resource, and replacement habitat trees may take a very long time to develop.

  • Map each salvaged hollow-bearing section and record its placement, condition and protection status.
  • Do not count an artificial hollow as equivalent to a mature tree unless the approval or monitoring design expressly allows that assumption.
  • Monitor artificial hollows for occupancy, damage, competition and maintenance needs, and revise the design or placement if they are not used.

Rehabilitation actions: Fire, weeds, predators and success measures

Manage fire so rehabilitated and retained habitat is not exposed to unnecessary high-intensity or frequent burning. Protect hollow-bearing trees and unburnt refuge areas during planned burns and fire response.

Control weeds and introduced predators where they threaten establishment, movement or survival, especially after fire when displaced gliders may spend more time on the ground.

Recovery constraint: The species has a single young per year, reaches maturity in the second year and has an estimated generation length of about 6 to 8 years.

Fire response: A single fire in a ten-year period has been reported as capable of reducing Southern Greater Glider abundance by more than half.

  • Use survival of planted eucalypts, recruitment of future hollow trees, retention of existing hollows, canopy development and connectivity as vegetation success measures.
  • Use Greater Glider detections, den-tree use, occupancy and evidence of movement between patches as fauna success measures.
  • Undertake repeat spotlighting and habitat inspections at the intervals required by the approval, with additional surveys after fire, heatwaves or drought.
  • Investigate low detections or mortality before declaring rehabilitation successful, because the species can be difficult to detect and recolonisation may be slow.
  • Record fire frequency and intensity, weed cover, predator control, tree survival, hollow condition and corrective actions in each monitoring report.

Sources