Survey guidelines for Australia’s threatened non-flying mammals

Leadbeater’s possum

Gymnobelideus leadbeateri

States and territories: Victoria.

Regions: Confined to the montane ash forests of the Central Highlands of Victoria. However, there is a small resident colony in a lowland swamp forest at Yellingbo State Nature Reserve (Smales 1994; Harley et al. 2005). Additionally, specimens were collected in the 1860s from the edge of the Koo-wee-rup Swamp on the western Gippsland Plain and from Mt Wills in the Eastern Highlands (Menkhorst & Lumsden 1995).

Habitat: Montane ash forests, dominated by mountain ash Eucalyptus regnans, alpine ash E. delegatensis or shining gum E. nitens. However, recent records include observations of animals sheltering in snow gum E. pauciflora stumps in the Victorian Alps (Jelinek et al. 1995). The population at Yellingbo occurs in forest dominated by mountain swamp gum E. camphora (Menkhorst & Lumsden 1995). Critical habitat requirements for this species include numerous dead stags or live hollow-bearing trees, a dense canopy or secondary tree layer, an understorey with Acacia spp. well-represented and an abundance of loose bark (Smith & Lindenmayer 1988; Lindenmayer et al. 1991).

Habit: Arboreal.

Avg. body weight: Varies between an average of 122 g in spring and an average of 133 g in autumn (Smith & Harley 2008).

Activity pattern: Nocturnal.

Diet: Acacia gum, sap of paperbarks and tea-tree, eucalypt nectar and manna, honeydew and a variety of arthropods (Smith & Harley 2008).

Breeding: May breed twice a year (winter and spring), with a maximum of two young per litter in the highlands and breed year-round in the lowlands (Smith & Harley 2008).

Description

Leadbeater’s possum is one of the faunal emblems for Victoria. It is a small, fast-moving possum with grey to greyish-brown fur above and paler below, with a dark mid-dorsal stripe from the nose to the base of its club-shaped tail. A black stripe runs between the cheeks and the throat (Menkhorst & Knight 2004). Colonies have a matriarchal social structure and the species is polyoestrus, with breeding success related to food supply (Smith 1984).

Until 1961, Leadbeater's possum was only known from five specimens, with no records between 1909 and 1960. Since then, the species has been recorded at more than 300 sites, although some of these sites have subsequently been logged and no longer support this species (Menkhorst & Lumsden 1995). Its distribution is dependent on vegetation structure, food availability and nest-tree abundance. The possums prefer nesting in living or dead trees with short, thick trunks (2 metres diameter at breast height) and which contain numerous hollows (Lindenmayer et al. 1991). Trees which are estimated to be around 200 years in age, surrounded by young regenerating or mixed-aged mountain ash forest is considered optimal habitat in the Central Highlands as it provides nesting and foraging sites.

The occurrence of this species in lowland swamp forest is poorly understood, with only one remnant population remaining. It is unlikely that additional populations occur due to the extensive fauna surveys conducted in remnant vegetation on the Gippsland Plains. However, the possibility of rediscovery in additional localities cannot be ruled out given the cryptic nature of this possum. Similarly, targeted surveys have been undertaken in the Mt Wills area without relocating the species. However, any survey in this region of the Eastern Highlands should target this species and ensure that all sugar gliders detected are identified with certainty.

Management measures for conservation of Leadbeater’s possum are outlined in the species’ recovery plan (Macfarlane et al. 1997) in line with current understanding of the species’ ecological needs and vulnerability to loss of habitat. Processes such as fire and selective logging help to maintain a mosaic of ecological successional states; however, high-intensity fire and clear felling in some areas can render them unsuitable for periods of up to 200 years (Macfarlane et al. 1997).

Survey methods

On the basis of previous surveys, the following survey techniques are recommended to detect the presence of Leadbeater’s possum in areas up to 5 hectares in size:

• 
  daytime searches for potential den sites in short and thick-set (minimum two metre diameter at breast height) mature hollow-bearing trees/stags (description of the survey technique and recommended effort is outlined in Section 3.1)
  
• 
  daytime searches for signs of activity, such as scratches on tree trunks, or scats on the ground below trees, particularly those considered potential den sites (description of the survey technique and recommended effort is outlined in Section 3.2.6 and 3.1.2)
  
• 
  stagwatching surveys at potential den sites (description of the survey technique and recommended effort is outlined in Section 3.3.4)
  
• 
  spotlight surveys on foot along transects, tracks or roads (description of the survey technique and recommended effort is outlined in Section 3.3.3). Spotlighting surveys from a vehicle are considered less effective (M Schulz pers. comm.)
  
• 
  arboreal hair sampling device survey, consistent with the methods described in Section 3.3.7
  
• 
  if the species is not detected during the application of the aforementioned, then a cage trapping program (Section 3.3.10) or nest box survey (Section 3.3.6) is recommended.
  

Similar species in range

Leadbeater’s possum is distinguishable from the sympatric sugar glider by the absence of a gliding membrane and its club-shaped tail, which is broader near the tip than at the base (Menkhorst & Knight 2004). This species can readily be confused with sugar gliders by inexperienced observers, a factor likely to be responsible for its only relatively recent discovery in the lowland forests at Yellingbo.

References

Beyer, G.L. and Goldingay R.L. 2006. The value of nest boxes in the research and management of Australian hollow-using arboreal marsupials. Wildlife Research 33: 161-174.

Harley, D. K. P. 2004. Patterns of nest box use by Leadbeater’s possum (Gymnobelideus leadbeateri): applications to research and conservation. In ‘The Biology of Australian Possums and Gliders’. (Eds. R. L. Goldingay and S. M. Jackson.) pp. 318–329. (Surrey Beatty, Sydney.)
Harley, D.K.P., Worley, M.A. and Harley, T.K. 2005. The distribution and abundance of

Leadbeater’s possum Gymnobelideus leadbeateri in lowland swamp forest at Yellingbo Nature Conservation Reserve. Australian Mammalogy 27: 7-15.

Jelinek, A., Cameron, D., Belcher, C. and Turner, L. 1995. New perspectives on the ecology of Lake Mountain: the discovery of Leadbeater’s possum Gymnobelideus leadbeateri McCoy in sub-alpine woodland. Victorian Naturalist 112: 112-115.
Lindenmayer, D.B., Cunningham, R.B., Tanton, M.T. and Smith, A.P. 1991. The conservation of arboreal mammals in the montane ash forests of the central highlands of Victoria, south-east Australia: II. The loss of trees with hollows and its implications for the conservation of Gymnobelideus leadbeateri McCoy (Marsupialia: Petauridae). Biological Conservation 54: 133-145.
Lindenmayer, D.B., Cunningham, R.B., Donnelly, C.F, Incoll, R.D., Pope, M.L., Tibolet, C.R., Viggers, K.L. and Welsh, A.H. 2001. How effective is spotlighting for detecting the greater glider (Petauroides volans). Wildlife Research 28: 105-109.
Lindenmayer, D. B., MacGregor, C. I., Cunningham, R. B., Incoll, R. D., Crane, M., Rawlins, D., and Michael, D. R. 2003. The use of nest boxes by arboreal marsupials in the forests of the central highlands of Victoria. Wildlife Research 30: 259–264.
Macfarlane, M., Smith, J. and Lowe, K, 1997. Leadbeater's Possum (Gymnobelideus leadbeateri) Recovery Plan. Department of Natural Resources and Environment Victoria.
Menkhorst, P. and Knight, F. 2004. A Field Guide to the Mammals of Australia 2^nd edition. (Oxford University Press: Melbourne, Australia).
Menkhorst, P. and Lumsden, L.F. 1995. Leadbeater’s Possum Gymnobelideus leadbeateri. In ‘Mammals of Victoria: distribution, ecology and conservation’ (Ed. P.W. Menkhorst) pp. 104-107 (Oxford University Press: Melbourne).
Schulz, M. 2009. Personal communication regarding Leadbeater’s Possum.
Smales, I.J. 1994. The discovery of Leadbeater’s Possum Gymnobelideus leadbeateri McCoy resident in lowland swamp woodland. Victorian Naturalist 111: 178-182.
Smith, A.P 1984. Demographic consequences of reproduction dispersal and social interaction in a population of Leadbeater’s Possum. In ‘Possums and Gliders’ (Eds. A.P Smith and I.D Hume) pp 359-373(Surrey Beatty and Sons: Sydney).
Smith, A.P. and Harley, D.K.P. 2008. Leadbeater’s Possum Gymnobelideus leadbeateri. In ‘The Mammals of Australia’ (Ed. S. Van Dyck and R. Strahan) pp. 226-228 (Reed New Holland: Sydney).
Smith, A.P. and Lindenmayer. D., 1988. Tree hollow requirements of Leadbeater’s Possum and other possums and gliders in the timber production Ash forests of the Victorian Central Highlands. Australian Wildlife Research 15: 347-362.
Smith, A.P, Lindenmayer, D.B., Begg, D.B., Macfarlane, M.A., Seebeck, J.H. and Suckling G.C. 1989. Evaluation of the stagwatching technique for census of possums and gliders in tall open forest. Australian Wildlife Research 16: 575-580.
Van der Ree, R. and Loyn, R.H. 2002. The influence of time since fire and distance from the fire boundary on the distribution and abundance or arboreal marsupials in Eucalyptus regnans - dominated forest in the Central Highlands of Victoria. Wildlife Research 29: 151-158.