Survey guidelines for Australia’s threatened non-flying mammals

Tasmanian devil

Sarcophilus harrisii

States and territories: Tasmania.

Regions: Widespread across Tasmania, excluding the Bass Strait and other offshore islands. Prior to European settlement this species was widespread on the Australian mainland but became extinct between 430 and 5000 years ago, possibly through competition with dingoes and increasing aridity (Jones 2008).

Habitat: Preferred habitats of the Tasmanian devil are open dry eucalypt forests, grassy woodlands and coastal scrub, with the highest populations occurring in a mosaic of grazing land and dry open forest and woodland in the medium to drier rainfall zone of the east, north and north-western parts of Tasmania (Jones & Barmuta 2000; Jones 2008). It avoids steep slopes and rocky areas and is present in lower densities in wet eucalypt forests, rainforests and buttongrass moorlands of the west and south-west parts of Tasmania (Jones & Barmuta 2000). The Tasmanian devil also occurs in modified habitats, such as forestry plantations, along roads, farmland and urban fringes, including rubbish tips. Dens may either be dug at a shallow angle and up to 15 metres in length or individuals may utilise common wombat Vombatus ursinus burrows. They may also shelter in logs, thickets of undergrowth such as tussock grass patches, caves, rock clefts and beneath buildings (Triggs 1996; Jones 2008).

Habit: Primarily ground dwelling.

Avg. body weight: 8 kg (males) and 6 kg (females).

Activity pattern: Predominantly nocturnal.

Diet: An opportunistic predator and a specialist scavenger, with social feeding (maximum number of 22 individuals) at the carcasses of larger prey (Jones 2008). Primary prey species are macropods, possums and wombats that are captured by a combination of ambush and short pursuit (Jones & Barmuta 2000). Cannibalism is considered fairly common in this species (Pfennig et al. 1998).

Breeding: The Tasmanian devil is promiscuous. It breeds once a year primarily between February and March, producing four young that are reared in dens (Guiler 1970; Jones 2008).

Description

The Tasmanian devil is an iconic species that is the world’s largest living marsupial carnivore. It can prey on species as large as wallabies and is an efficient scavenger leading to them being referred to as the ‘bush undertakers’. Although this species is wide ranging with movements of 50 kilometres recorded, there are two distinct subpopulations, with one subpopulation confined to the north-west of the state, west of the Forth River and south to Macquarie Heads (Jones et al. 2004). The first indication of their presence is often the presence of distinctive scats and screaming sounds enough to ‘raise the dead’ when mating or interacting at prey carcasses. In the last 10 years Devil Facial Tumour Disease, an infectious neuroendocrine cancer, has caused major population declines (locally up to 80 per cent) across two thirds of the species’ range (Tasmanian Department of Primary Industries, Water and Environment 2005), with newly infected populations continuing to be recorded. The largest declines have been recorded in areas which formerly supported high densities and, like other infectious diseases, it may not persist in or threaten low density populations.

Survey methods

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

• 
  daytime searches for scats (description of the survey technique and recommended effort is provided in Section 3.2.2). Scats are diagnostic, being grey in colour with large, sharp bone fragments intertwined with fine fur (Triggs 1996). Scats are often deposited in latrine sites, such as at track junctions and creek crossings. However, care must be taken not to confuse scats with those of the feral dogs, foxes and the spotted-tailed quoll Dasyurus maculatus, particularly when they are wet and misshapen
  
• 
  daytime searches for tracks on soft substrate (description of the survey technique and recommended effort is provided in Section 3.2.4) or using sand traps to identify the characteristic tracks of this species (refer to Section 3.3.2)
  
• 
  cage trapping, but instead of using cage traps (as described in Section 3.3.10) deploy PVC UV-resistant storm water pipe that can readily be cleaned and disinfected to avoid the spread of Devil Facial Tumour Disease, baited with any type of meat for three to five consecutive nights and having a trail of meat or fish oil leading to each trap site
  
• 
  spotlight surveys, particularly vehicle-based over a distance of 10 kilometres. This has been used as a standard since 1975 across much of the species’ range (see for example Hawkins et al 2006 and Hocking & Driessen 1992). This approach differs to the technique description and recommended effort provided in Section 3.3.3
  
• 
  identification of characteristic vocalisations, such as those uttered during feeding and breeding interactions (for example, Jones 2008)
  
• 
  deployment of hair tubes, particularly in areas with low densities (description of the survey technique and recommended effort is provided in Section 3.3.7)
  
• 
  use of remote cameras, particularly at deposited carcasses (description of the survey technique is outlined in Section 3.3.6)
  
• 
  community liaison to provide additional records, particularly on private land or urban areas.
  

Similar Species in Range

The Tasmanian devil is distinctive and unlikely to be confused with any sympatric species.

References

Guiler, E.R. 1970. Observations of the Tasmanian Devil, Sarcophilus harrisii (Marsupialia: Dasyuridae). II. Reproduction, breeding and growth of pouch young. Australian Journal of Zoology 18: 63-70.

Hawkins, C.E., Baars, C., Hesterman, H., Hocking, G.J., Jones, M.E., Lazenby, B., Mann, D., Mooney, N., Pemberton, D., Pyecroft, S., Restani, M. and Wiersma, J. 2006. Emerging disease and population decline of an island endemic, the Tasmanian Devil Sarcophilus harrisii. Biological Conservation. 131: 307-324.
Hocking, G.J. and Driessen, M.M. 1992. Tasmanian spotlight survey manual: a set of instructions and maps for conducting spotlight surveys in Tasmania. Department of Parks, Wildlife and Heritage, Hobart, Australia.
Jones, M. 2008. Tasmanian Devil Sarcophilus harrisii Pp. 78-80. In Van Dyck, S. and Strahan, R. (Eds.) The Mammals of Australia. Third Edition. Reed New Holland, Sydney.
Jones, M.E. and Barmuta, L.A. 2000. Niche differentiation among sympatric Australian dasyurid carnivores. Journal of Mammalogy 81: 434-447.
Jones, M.E. and Rose, R.K. 1996. Preliminary assessment of distribution and habitat associations of the Spotted-tailed Quoll (Dasyurus maculatus maculatus) and Eastern Quoll (D. viverrinus) in Tasmania to determine conservation and reservation status. Report to the Tasmanian Regional Forest Agreement Environment and Heritage Technical Committee, Tasmanian Public Land Use Commission, Hobart, Tasmania.
Jones, M.E., Paetkau, D., Geffen, E. and Moritz, C. 2004. Genetic diversity and population structure of Tasmanian Devils, the largest marsupial carnivore. Molecular Ecology 13: 2197-2209.
Pauza, M. Undated. Tasmanian Department of Primary Industries, Parks, Water & Environment. Personal communication regarding the Tasmanian Devil.
Pfennig, D.W., Ho, S.G. and Hoffman, E.A. 1998. Pathogen transmission as a selective force against cannibalism. Animal Behaviour 55: 1255-1261.
Tasmanian Department of Primary Industries, Water and Environment 2005. Tasmanian Devil Facial Tumour Disease (DFTD): Disease Management Strategy. Tasmanian Department of Primary Industries, Water and Environment, Hobart.
Triggs, B. 1996. Tracks, scats and other traces: a field guide to Australian mammals. Oxford University Press, Melbourne.