Wyulda squamicaudata 

Scope: Global
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Mammalia Diprotodontia Phalangeridae

Scientific Name: Wyulda squamicaudata Alexander, 1919
Common Name(s):
English Scaly-tailed Possum, Ilangurra , Yilangal
French Possum à queue écailleuse

Assessment Information [top]

Red List Category & Criteria: Near Threatened ver 3.1
Year Published: 2016
Date Assessed: 2014-03-16
Assessor(s): Burbidge, A.A. & Woinarski, J.
Reviewer(s): Hawkins, C. & Johnson, C.N.
Contributor(s): Doody, J.S., Legge, S., Pearson, D., Runcie, M. & Tuft, K.

The Scaly-tailed Possum is assessed as Near Threatened because its area of occupancy may be <2,000 km2 and may be declining, but not at a rate of 30% in 12 years (three generations). Recent records are from a small number of location. Survey effort of the remote area where it occurs has been insufficient to estimate the actual number of locations, but this is probably >10.

Previously published Red List assessments:

Geographic Range [top]

Range Description:

The Scaly-tailed Possum is restricted to the Kimberley, Western Australia: most records are from near-coastal, high-rainfall north-western Kimberley from Kalumburu south to Yampi Peninsula. The type specimen came from Violet Valley, near Warmun, east Kimberley in 1917. It was rediscovered in east Kimberley at Emma Gorge, Cockburn Range, El Questro Station in June 2010 (Doody et al. 2012). The East Kimberley population may be separated from that of the north-west Kimberley (Doody et al. 2012), but survey effort in areas between has been low. It occurs on Augustus (190 km2), Bigge (171 km2) and Boongaree (42 km2) Islands (Burbidge and McKenzie 1978; Gibson and McKenzie 2012). A 1970 sight record from Broome reported by Ride (1970) was possibly a translocated animal as Broome is considered unlikely on habitat grounds. It is known to have disappeared from some sites (Lochman and Lochman 2003). The species is reasonably widespread in some parts of the Kimberley, such as the Artesian Range (R. Hohnen pers. comm. 2016). There has been too little survey effort to determine the total number of locations at which it occurs but this is highly likely to be grater than 10 (R. Hohnen pers. comm. 2016).

Countries occurrence:
Australia (Western Australia)
Additional data:
Estimated area of occupancy (AOO) - km2:1500Continuing decline in area of occupancy (AOO):Yes
Extreme fluctuations in area of occupancy (AOO):NoEstimated extent of occurrence (EOO) - km2:32500
Continuing decline in extent of occurrence (EOO):YesExtreme fluctuations in extent of occurrence (EOO):No
Continuing decline in number of locations:Yes
Extreme fluctuations in the number of locations:No
Range Map:Click here to open the map viewer and explore range.

Population [top]


There is no robust estimate of population size. It is locally common at some sites in the north-west Kimberley and on Bigge Island; but is apparently uncommon in the east Kimberley. A 2003 survey demonstrated persistence in Prince Regent National Park and at Mitchell Plateau (Start et al. 2007). Recent surveys (2011, 2012) by the Australian Wildlife Conservancy have recorded Scaly-tailed Possums as locally common in the Artesian Range south of the Prince Regent (Sarah Legge pers. comm.). It has been recently recorded on Augustus Island via camera trapping.

Current Population Trend:Decreasing
Additional data:
Number of mature individuals:5000-10000Continuing decline of mature individuals:Yes
Extreme fluctuations:NoPopulation severely fragmented:No

Habitat and Ecology [top]

Habitat and Ecology:

The Scaly-tailed Possum occurs in rugged sandstones with adjacent open woodland or closed forest, sometimes with rainforest elements. It forages mainly in trees but may venture into open areas to feed on flowers, fruits, seeds and leaves. In captivity it also eats nuts and insects. It shelters in rock piles, under rock slabs and in underground crevices. Females give birth mainly in the dry season between March and August, although breeding may extend later in the dry season. A single juvenile is carried in the pouch for 150-200 days and is weaned after eight months. Females are sexually mature at two years (Humphreys et al. 1984; Runcie 1999; Burbidge and Webb 2008).

Continuing decline in area, extent and/or quality of habitat:Yes
Generation Length (years):4
Movement patterns:Not a Migrant

Threats [top]

Major Threat(s): Major threats are inappropriate fire regimes (too frequent, extensive and hot) and predation by feral cats. Information on the effects of these threats is limited.

Conservation Actions [top]

Conservation Actions:

National Parks within its range are managed by the Department of Parks and Wildlife. Aboriginal lands, most of which are Indigenous Protected Areas, are managed by the Wunambal Gaambera Aboriginal Corporation and the Dambimangari Aboriginal Corporation. Artesian Range Sanctuary is managed by the Australian Wildlife Conservancy. Emma Gorge is within the El Questro pastoral lease. There is regional fire management in the western parts of its range, intensive management of fire at Artesian Range, and regional fire management immediately to the east of the main distribution through the EcoFire Project. A research project on Scaly-tailed Possums at Artesian Range (Australian Wildlife Conservancy / University of Tasmania) began in late 2012, aimed at describing the impacts of fire patterns and feral Cats on their ecology and survival.

Classifications [top]

1. Forest -> 1.5. Forest - Subtropical/Tropical Dry
suitability:Suitable season:resident major importance:No
2. Savanna -> 2.1. Savanna - Dry
suitability:Suitable season:resident major importance:No
0. Root -> 6. Rocky areas (eg. inland cliffs, mountain peaks)
suitability:Suitable season:resident major importance:Yes
1. Land/water protection -> 1.1. Site/area protection
2. Land/water management -> 2.1. Site/area management
2. Land/water management -> 2.2. Invasive/problematic species control
4. Education & awareness -> 4.3. Awareness & communications
6. Livelihood, economic & other incentives -> 6.1. Linked enterprises & livelihood alternatives

In-Place Research, Monitoring and Planning
  Action Recovery plan:No
  Systematic monitoring scheme:Yes
In-Place Land/Water Protection and Management
  Conservation sites identified:Yes, over part of range
  Occur in at least one PA:Yes
  Percentage of population protected by PAs (0-100):91-100
  Area based regional management plan:No
  Invasive species control or prevention:No
In-Place Species Management
  Harvest management plan:No
  Successfully reintroduced or introduced beningly:No
  Subject to ex-situ conservation:No
In-Place Education
  Subject to recent education and awareness programmes:No
  Included in international legislation:Unknown
  Subject to any international management/trade controls:Unknown
7. Natural system modifications -> 7.1. Fire & fire suppression -> 7.1.1. Increase in fire frequency/intensity
♦ timing:Ongoing ♦ scope:Whole (>90%) ♦ severity:Slow, Significant Declines ⇒ Impact score:Medium Impact: 7 
→ Stresses
  • 1. Ecosystem stresses -> 1.2. Ecosystem degradation
  • 2. Species Stresses -> 2.1. Species mortality

8. Invasive and other problematic species, genes & diseases -> 8.1. Invasive non-native/alien species/diseases -> 8.1.2. Named species [ Felis catus ]
♦ timing:Ongoing ♦ scope:Whole (>90%) ♦ severity:Slow, Significant Declines ⇒ Impact score:Medium Impact: 7 
→ Stresses
  • 2. Species Stresses -> 2.1. Species mortality

1. Research -> 1.2. Population size, distribution & trends
1. Research -> 1.3. Life history & ecology
1. Research -> 1.5. Threats
2. Conservation Planning -> 2.1. Species Action/Recovery Plan
2. Conservation Planning -> 2.2. Area-based Management Plan
3. Monitoring -> 3.1. Population trends
3. Monitoring -> 3.4. Habitat trends

Bibliography [top]

AnAge. 2012. The animal aging and longevity database. Available at:

Burbidge, A. A. and McKenzie, N. 1978. The islands of the North-west Kimberley Western Australia. Wildlife Research Bulletin of Western Australia 7: 1-47.

Burbidge, A.A. and Webb, M.J. 2008. Scaly-tailed Possum, Wyulda squamicaudata. In: S. Van Dyck and R. Strahan (eds), The Mammals of Australia. Third Edition, pp. 277-278. Reed New Holland, Sydney.

Doody, J., Rhind, D., Castellano, C. and Bass M. 2012. Rediscovery of the Scaly-tailed Possum (Wyulda squamicaudata) in the Eastern Kimberley. Australian Mammalogy 34: 260-262.

Gibson, L.A. and McKenzie, N.L. 2012. Occurrence of non-volant mammals on islands along the Kimberley coast of Western Australia. In: L.A. Gibson, S. Yates and P. Doughty (eds), Biodiversity values on selected Kimberley islands, Australia. Western Australian Museum Records Supplement No. 81, pp. 15-39.

Humphreys, W. F., How, R. A., Bradley, A. J., Kemper, C. M. and Kitchener, D. J. 1984. The biology of Wyulda squamicaudata Alexander 1919. In: A. Smith and I. Hume (eds), Possums and Gliders, pp. 162-169. Surrey Beatty and Sons and Australian Mammal Society, Sydney, New South Wales, Australia.

IUCN. 2016. The IUCN Red List of Threatened Species. Version 2016-1. Available at: (Accessed: 30 June 2016).

Jones, K.E., Bielby, J., Cardillo, M., Fritz, S.A., O'Dell, J., Orme, C.D.L., Safi, K., Sechrest, W., Boakes, E.H., Carbone, C., Connolly, C., Cutts, M.J., Foster, J.K., Grenyer, R., Habib, M., Plaster, C.A., Price, S.A., Rigby, E.A., Rist, J., Teacher, A., Bininda-Emonds, O.R.P., Gittleman, J.L., Mace, G.M. and Purvis, A. 2009. PanTHERIA: a species-level database of life history, ecology and geography of extant and recently extinct mammals. Ecology 90: 2648.

Lochman, J., and Lochman, M. 2003. Expressions of concern about the welfare of north-west Kimberley mammals. Wilderness News 163: 12–13.

Ride, W.D.L. 1970. A guide to the native mammals of Australia. Oxford University Press, Melbourne.

Runcie, M. J. 1999. Movements, dens and feeding behaviour of the tropical scaly-tailed possum (Wyulda squamicaudata). Wildlife Research 26: 367-373.

Start, A.N., Burbidge, A.A., McKenzie, N.L . and Palmer, C. 2007. The status of mammals in the North Kimberley, Western Australia. Australian Mammalogy 29: 1-16.

Citation: Burbidge, A.A. & Woinarski, J. 2016. Wyulda squamicaudata. The IUCN Red List of Threatened Species 2016: e.T23091A21950421. . Downloaded on 22 April 2018.
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