Survey guidelines for Australia’s threatened non-flying mammals

Long-nosed potoroo (south east mainland)

Potorous tridactylus tridactylus

States and territories: Queensland, NSW, Victoria and South Australia.

Regions: Fragmented distribution along the east coast mainland, including south-eastern Queensland, north-eastern, central and south-eastern NSW, north-eastern Victoria, and three isolated regions in western Victoria, including a remnant population near the South Australian border.

Habitat: Coastal heath, and dry or wet sclerophyll forests with thick ground-cover and understorey habitats (Bennett 1993; Johnston 1995).

Habit: Ground-dwelling.

Avg. body weight: 1180 g (males) and 1020 g (females) (Johnston 1995).

Activity pattern: Nocturnal.

Diet: Omnivore: roots, tubers, fungi, insects and their larvae (Johnston 1995).

Breeding: Breeds throughout the year with peaks in late winter/early spring and late summer (Johnston 1995).

Description

The long-nosed potoroo consists of two subspecies: P. t. tridactylus from the south-eastern Australian mainland and P. t. apicalis from the Bass Strait islands and Tasmania (Johnston 1995). The mainland subspecies is listed as vulnerable under the EPBC Act.

Long-nosed potoroos are medium-sized nocturnal mammals that shelter in dense vegetation during the day and forage by digging for fungi, prey or tubers at night. The species’ range has become fragmented and restricted by land use changes on the mainland. The extent and abundance of the long-nosed potoroo within its range is not well known because of the difficulties in trapping and detecting the species’ presence.

Survey methods

The following survey techniques are recommended to detect the presence of the long-nosed potoroo in areas up to 5 hectares in size:

• 
  daytime searches for potentially suitable habitat resources, such as areas with a dense understorey (description of the survey technique and recommended effort is outlined in Section 3.1)
  
• 
  daytime searches for signs of activity, however observers should be aware that long-nosed potoroo diggings are usually indistinguishable in the field from those of sympatric species like bandicoots (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 and mammal nests and 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. However, where the long-nosed potoroo occurs in sympatry with the long-footed potoroo or small wallaby species, tracks cannot be distinguished, or may be difficult to distinguish between species
  
• 
  baited camera traps using universal bait (peanut butter and rolled oats) with added truffle or walnut oil (description of the survey technique and recommended effort is outlined in section 3.3.6).
  

An integrative approach is recommended for this species, whereby direct detection surveys like spotlighting (Section 3.3.3), cage trapping (3.3.10) or hair sampling surveys (3.3.7) should be conducted in concert with searches for traces like diggings, scats and tracks, baited camera traps and predator scat surveys etc. Also, given the mixed results of past trapping efforts, different techniques may work better in some locations than others and a variety of methods should be attempted for any given survey program.

To help distinguish the tracks of different species in the field, NSW State Forests have prepared foot casts of potoroos and bandicoots (S Ingleby pers. comm.) although as indicated above, there are difficulties associated with identifying tracks of this species.

Similar species in range

The long-nosed potoroo occurs in sympatry with the long-footed potoroo in parts of north-eastern Victoria and south-eastern NSW. If captured, the two species can be distinguished by the longer snout and the generally larger size of the long-nosed potoroo. These species also differ genetically, with long-footed potoroos having 24 chromosomes and the long-nosed potoroo 12 (females) or 13 (males) (Seebeck 1995).

The long-nosed potoroo is sympatric with several Perameles species. However, tracks made by potoroos differ to those made by bandicoots by the presence of five clawed digits on the forepaws of potoroos, compared with three clawed digits on the forepaws of bandicoots.

References

AMBS 2002. Fauna Underpass Monitoring Stage Two, Episode Five Bulahdelah to Coolongolook. Unpublished report for NSW Roads and Traffic Authority.

Bennett, A.F. 1993. Microhabitat use by the long-nosed potoroo, Potorous tridactylus, and other small mammals in remnant forest vegetation of south-western Victoria. Wildlife Research 20: 267-285.
Catling, P.C., Burt, R.J. and Kooyman, R. 1997. A comparison of techniques used in a survey of the ground-dwelling and arboreal mammals in forests in north-eastern New South Wales. Wildlife Research 24: 417-432.
Catling, P.C., Coops, N.C and Burt, R.J. 2001. The distribution and abundance of ground-dwelling mammals in relation to time since wildfire and vegetation structure in south-eastern Australia. Wildlife Research 28: 555-564.
Capararo, S.M and Beynon, F. 1996. Survey of the Long-nosed Potoroo (Potorous tridactylus) in Red Rocks nature Reserve. Unpublished report prepared for the NSW National Parks and Wildlife Service Nowra District.
Claridge, A.W. and Barry, S.C. 2000. Factors influencing the distribution of medium-sized ground-dwelling mammals in southeastern mainland Australia. Austral Ecology 25: 672-688.
Ingleby, S. (2003). Australian Museum. Personal communication regarding the Long-nosed Potoroo.
Johnston, P.G. 1995. Long-nosed Potoroo Potorous tridactylus. In Mammals of Australia (Ed. R. Strahan) pp. 301-302 (Reed Books: Sydney).
Johnston, P.G. 2008. Long-nosed Potoroo Potorous tridactylus. In Mammals of Australia (Eds. S. Van Dyck and R. Strahan) pp. 302-304 (Reed New Holland: Sydney).
Mason, R. 1993. Report on the Long-nosed Potoroo (Potorous tridactylus) at Cobaki. Unpublished report prepared for the NSW National Parks and Wildlife Service.
Mills, D. J., Harris, B., Claridge, A. W. and Barry, S. C. 2002. Efficacy of hair-sampling techniques for the detection of medium-sized terrestrial mammals. I. A comparison between hair-funnels, hair-tubes and indirect signs. Wildlife Research 29: 2002: 379-387.
Qld CRA/RFA Steering Committee 1998. Systematic vertebrate fauna Survey Project: Stage 1 - Vertebrate Fauna in the southeast Queensland Bioregion. Prepared by the Sustainable Forest Science Unit (SFSU), Forestry and Wildlife Division, Natural Resource Sciences of the Queensland Environmental Protection Agency, Indooroopilly, Queensland.
Seebeck, J.H. 1995. Long-footed Potoroo Potorous longipes. In Mammals of Australia (Ed. R. Strahan) pp. 298-299 (Reed Books: Sydney).
Triggs B. 1998. Tracks, Scats and other Traces: A Field Guide to Australian Mammals. (Oxford University Press: Melbourne).