Survey guidelines for Australia’s threatened non-flying mammals

Greater bilby

Macrotis lagotis

States and territories: Queensland, Northern Territory and Western Australia, and reintroduced to South Australia.

Regions: Deserts of central Australia:

• 
  Western Australia (from the Northern Territory border to Broome and south to Warburton)
  
• 
  Northern Territory in the Tanami Desert
  
• 
  South-western Queensland (Johnson 1995), and
  
• 
  Reintroduced to areas within South Australia (Roxby Downs, Venus Bay Conservation Park, Thistle Island, and Yookamurra Sanctuary), Western Australia (Dryandra Woodland, Peron Peninsula), Queensland (Currawinya National Park), and NSW (Scotia Sanctuary) (Pavey 2006).
  

Habitat: Acacia scrubland and hummock grasslands (Western Australia and Northern Territory), clay stony downs in channel country (Queensland).

Habit: Ground-dwelling (burrowing).

Avg. body weight: 1750 g (males) and 950 g (females) (Johnson 1995).

Activity pattern: Nocturnal.

Diet: Omnivore: insects, larvae, seeds, bulbs, tubers and fungi (Gibson 2001). Opportunistic feeding strategy selecting dietary items in accordance with their abundance (Gibson & Hume 2004).

Breeding: Capable of breeding throughout the year in captivity but is probably mediated by environmental conditions, with one to three offspring per litter (Southgate et al. 2000).

Description

The greater bilby is a distinctive Peramelid that had a former distribution which covered up to 70 per cent of the Australian mainland, mostly in arid and semi-arid environments (Southgate 1990a). This range has contracted and now the species’ range is restricted to only the most arid parts of the former distribution, including parts of the Tanami Desert, a small area north-east of Alice Springs, the Gibson Desert, northern Great Sandy Desert, the inland Pilbara, the southern Kimberley, and a small area in the channel country in south-western Queensland (Southgate 1990b).

The greater bilby is found in hummock grassland habitats, predominantly comprising Spinifex, with an overstorey of Acacia and Melaleuca. The species feeds on a variety of food sources within their arid habitat, including insects, seeds, bulbs and fungi with preference related to availability (Gibson 2001). Signs of foraging and digging occur around the base of overstorey trees, where greater bilbies dig holes up to 250 millimetres in depth in search of food (Gibson 2001).

Greater bilbies emerge from burrows after dark to forage at night, and during the day they shelter in a relatively extensive burrow system that is up to 3 metres in length and 1.8 metres deep (Johnson 1995). A burrow can shelter one or more adults and newly weaned offspring have also been observed to remain for a short time in their maternal burrow (Johnson 1995).

The main reason for the decline of the greater bilby appears to be predation by feral cats and foxes, with predation by dingos possibly contributing (Southgate 1987). Competition with rabbits and livestock through grazing and modified fire regimes are also likely to have contributed to the decline (Johnson 1995).

Survey methods

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

• 
  daytime searches for potentially suitable habitat resources, such as hummock grassland in arid regions (description of the survey technique and recommended effort is outlined in Section 3.1)
  
• 
  daytime searches for signs of activity, including burrows, tracks, scats and diggings (description of the survey technique and recommended effort is outlined in Section 3.2)
  
• 
  collection of predator scats, owl casts or remains, targeting predatory bird/mammal nests/dens (description of the survey technique and recommended effort is outlined in Section 3.2)
  
• 
  soil plot surveys conducted according to the description of the technique and the recommended effort provided in Section 3.3.2.
  

Should confirmation of the species’ presence be required after detection of signs, then spotlight surveys conducted at the entrances of burrows after dusk would be a more time and cost efficient manner to directly observe the species rather than conducting a trapping survey. Such observational surveys are similar in principal to stagwatching surveys. The recommended survey effort for this technique has been outlined in Section 3.3.4.

Similar species in range

There are no similar species.

References

Finlayson, G.R., Vieira, E.M., Priddel, D., Wheeler, R., Bentley J. and Dickman, C.R. 2008. Multi-scale patterns of habitat use by re-introduced mammals: a case study using medium-sized marsupials. Biological Conservation 141(1): 320-331

Gibson, L.A. 2001. Seasonal changes in the diet, food availability and food preference of the greater bilby (Macrotis lagotis) in south western Queensland. Wildlife Research 28: 121-134.
Gibson, L.A. and Hume, I.D. 2000. Seasonal field energetics and water influx rates of the greater bilby (Macrotis lagotis). Australian Journal of Zoology 48: 225-239.
Gibson, L.A. and Hume, I.D. 2004. Aspects of the ecophysiology and dietary strategy of the greater bilby Macrotis lagotis: a review. Australian Mammalogy 26:179-183.
Johnson, K.A. 1995. Bilby Macrotis lagotis. In ‘The Mammals of Australia’. (Ed. R. Strahan). pp.186-188. (Reed Books: Sydney).
Johnson, K.A. 2008. Bilby Macrotis lagotis. In ‘The Mammals of Australia’. (Eds. S. Van Dyck and R. Strahan). pp.191-193. (Reed New Holland: Sydney).
Paltridge, R. 2002. The diets of cats, foxes and dingoes in relation to prey availability in the Tanami Desert, Northern Territory. Wildlife Research 29: 389-403.
Parks and Wildlife Commission of the NT. Unknown date of document made public on the Parks and Wildlife Commission of the Northern Territory website (www.nt.gov.au/ipe/pwcnt/docs/management_program_for_the_bilby.pdf)
Pavey, C. 2006. National Recovery Plan for the greater bilby Macrotis lagotis. Northern Territory Department of Natural Resources, Environment and the Arts.
Southgate, R.I. 1987. Conservation of the Bilby. Wildlife Fauna Department, Northern Territory Conservation Commission. Unpublished report to World Wildlife Fund.
Southgate, R. I. 1990a. Distribution and abundance of the greater bilby Macrotis lagotis Reid (Marsupialia: Peramelidae). In ‘Bandicoots and Bilbies’. (Eds. J.H. Seebeck, P.R. Brown, R.L. Wallis and C.M. Kemper). (Surrey Beatty and Sons: Sydney).
Southgate, R. I. 1990b. Habitat and diet of the greater bilby Macrotis lagotis Reid (Marsupialia: Peramelidae). In ‘Bandicoots and Bilbies’. (Eds. J.H. Seebeck, P.R. Brown, R.L. Wallis and C.M. Kemper). (Surrey Beatty and Sons: Sydney).
Southgate, R.I., Christie, P. and Bellchambers, K. 2000. Breeding biology of captive, reintroduced and wild greater bilbies Macrotis lagotis (Marsupialia: Peramelidae). Wildlife Research 27: 621-628.
Southgate, R.I., McRae, P. and Atherton, R. 1995. Trapping techniques and a pen design for the greater bilby Macrotis lagotis. Australian Mammalogy 18: 101-104.
Southgate, R.I., Paltridge, R., Masters. P. and Carthew, S. 2007. Bilby distribution and fire: a test of alternative models of habitat suitability in the Tanami Desert, Australia. Ecography 30(6): 759-776