Survey guidelines for Australia’s threatened non-flying mammals

Fluffy glider, yellow-bellied glider (Wet Tropics)

Petaurus australis unnamed subsp.

States and territories: Queensland.

Regions: Western slopes of the wet tropics of north-eastern Queensland, north from the Lumholtz National Park to the Mt Windsor tableland at altitudes above 700 m (Van Dyck 2000; Goldingay 2008).

Habitat: Tall open wet eucalypt forest adjacent to rainforest, with red stringybark Eucalyptus resinifera a well represented canopy species (Van Dyck 2000; Bradford & Harrington 1999).

Habit: Arboreal.

Avg. body weight: 498 g (sexually dimorphic) (Goldingay et al. 2001).

Activity pattern: Nocturnal.

Diet: Sap of E. resinifera (80 per cent of feeding observations), nectar and pollen of eucalypts and banksias, arthropods and honeydew (Quin et al. 1996; Goldingay 2008).

Breeding: Seasonal breeding with 62 per cent of births (n=21) recorded between June and late August (Goldingay et al. 2001).

Description

The fluffy glider, Petaurus australis unnamed subspecies, is confined to the western slopes of the Wet Tropics region of north-eastern Queensland, separated by a distribution gap of over 300 kilometres from the south-eastern Australian subspecies of the yellow-bellied glider (Goldingay 2008). A recent phylogeographic study indicates that the northern subspecies is an evolutionarily distinct unit and is restricted from moving between other populations by unsuitable habitat, with a major biogeographic break at the Burdekin Gap (Brown et al. 2006). The two species are difficult to distinguish by appearance, with separation of the northern subspecies based on fur characteristics being contentious (Brown et al. 2006). In addition, Goldingay and colleagues (2001) reported a typical transition from white to yellow fur as juveniles matured to become adults among the northern subspecies.

The species is readily distinguished by a number of distinctive calls, including a loud high-pitch shriek followed by a low-pitch rattle audible over 500 metres away (Goldingay 2008). The species is the most vocal of all marsupials and calls are characteristic of the species across its range. Regular calling may facilitate communication between individuals which live in small social groups that occupy exclusive territories of approximately 50 hectares, or it may act as a form of territorial defence (Goldingay et al. 2001). The number of females and males per group is not uniform, but typically a group comprises three to six individuals, which may indicate that a range of mating systems (monogamy, polygyny and possibly polyandry) exist within the social system (Goldingay et al. 2001).

Yellow-bellied gliders use specially adapted incisor teeth to make distinctive V-shaped marks in the trunks and larger branches of suitable trees to access the sap on which they feed. In northern Australia, the yellow-bellied glider feeds exclusively on the red stringybark, Eucalyptus resinifera (Quin et al. 1996; Bradford & Harrington 1999) and uses only E. grandis trees for den sites (Russell 1984). Bradford and Harrington (1999) found that 99 per cent of sap-feeding scarred E. resinifera trees were within 500 metres of mature E. grandis trees.

Survey methods

On the basis of previous surveys, the following survey techniques are recommended to detect the presence of the fluffy glider in areas up to 5 hectares in size:

• 
  investigation of the presence of key eucalypt species, E. resinifera and E. grandis through examining fine-scale vegetation mapping (where available), aerial photography and ground truthing
  
• 
  daytime searches for potential den sites in hollow-bearing trees, particularly E. grandis (description of the survey technique and recommended effort is outlined in Section 3.1);
  
• 
  daytime searches for signs of activity, in particular the characteristic V-shaped sap-feeding scars on E. resinifera trees, (description of the survey technique and recommended effort is outlined in Section 3.2.6)
  
• 
  stagwatching surveys at potential den sites (description of the survey technique and recommended effort is outlined in Section 3.3.4)
  
• 
  call playback surveys (Note: for best results use pre-recorded calls of the fluffy glider rather than those of the south-eastern Australian subspecies) conducted according to the method outlined in Section 3.3.5, including playback of the rufous owl call, which has had better results in call-playback surveys than fluffy glider calls in some cases (M Schulz pers. comm.) It is recommended that care should be taken conducting call playback surveys during the species’ breeding season (NSW Agriculture 1998) so if possible avoid or limit the use of this survey technique between June and August (consult appropriate Queensland government organisations for advice)
  
• 
  spotlight surveys (including listening for vocalisations) along transects, tracks or roads using the method described in Section 3.3.3. (Note: since this species is difficult to detect using spotlighting, listening for vocalisation is a primary technique for detection. It is therefore strongly recommended that spotlighting surveys are not conducted from a vehicle).
  

An arboreal cage trapping program consistent with the method outlined in Section 3.3.9 could also be employed if permission and licensing is approved by relevant Queensland government authorities; however, this technique is time-consuming, and the abovementioned techniques, if employed thoroughly, should normally be sufficient for detecting the species if present.

An important point to consider in the design of surveys to detect this species is that social groups are known to range over areas (possibly territories) approximately 50 hectares in size (Goldingay et al. 2001). Therefore, a 5 hectare site represents approximately one tenth of the total area that a group utilises in the course of their home-range movements, and therefore surveys may need to be either conducted on adjacent land or conducted at different times of the year to determine if the species is likely to potentially occur on the site.

Similar species in range

The fluffy glider can be distinguished from all other potentially sympatric glider species by its larger size, diagnostic vocalisations and characteristic feed marks on the trunks and larger branches of E. resinifera. Further, it can be distinguished from the sugar glider P. breviceps and the squirrel glider P. norfolcensis by the buff yellow belly colouration, larger size and lacking the distinctive white underbody.

Distinguishing between the northern subspecies of the yellow-bellied glider and southern populations should not be necessary as the north-eastern Queensland subspecies is geographically isolated by more than 300 kilometres from other populations in mid-eastern Queensland (Brown et al. 2006).

References

Bradford, M.G. and Harrington, G.N. 1999. Aerial and ground survey of sap trees of the yellow-bellied glider (Petaurus australis reginae) near Atherton, north Queensland. Wildlife Research 26: 723-729.

Brown, M., Cooksley, H., Carthew, S. M. and Cooper, S. J. B. 2006. Conservation units and phylogeographic structure of an arboreal marsupial, the Yellow-bellied Glider (Petaurus australis). Australian Journal of Zoology 54: 305-317.
Goldingay, R.L. 2008. Yellow-bellied Glider Petaurus australis. In ‘The Mammals of Australia’ (Ed. S. Van Dyck and R. Strahan) pp. 228-230 (Reed New Holland: Sydney).
Goldingay, R.M., Quin, D.G. and Churchill, S. 2001. Spatial variability in the social organisation of the yellow-bellied glider (Petaurus australis) near Ravenshoe, north Queensland. Australian Journal of Zoology 49: 397-409.
McCabb, M. 1983. Observations on the numbers, distribution and habitat characteristics of the Yellow-bellied Glider Petaurus australis (Shaw) in part of the Otway National Park, Victoria. Unpublished Report.
NSW Agriculture. 1998. Guideline 10-Animal care guidelines for wildlife surveys. Animal Welfare Unit, NSW Department of Agriculture, Orange.
Quin, D., Goldingay, R., Churchill, S. and Engel, D. 1996. Feeding behaviour and Food availability of the yellow-bellied glider in north Queensland. Wildlife Research 23: 637-646.
Russell, R. 1984. Social behaviour of the Yellow-bellied Glider Petaurus australis reginae in north Queensland. In ‘Possums and Gliders’ (Eds. A.P Smith and I.D. Hume) pp. 343-353 (Surrey Beatty and Sons and Australian Mammal Society: Sydney).
Schulz, M. 2009. Personal communication regarding the Yellow-bellied Glider.
Van Dyck, S. 2000. Other mammals. In ‘Wildlife of Tropical North Queensland’ (Ed. Ryan, M. And Burwell, C.) pp. 329-353 (Queensland Museum: South Brisbane).