Survey guidelines for Australia’s threatened non-flying mammals

Pilliga mouse

Pseudomys pilligaensis
Note that this species is now considered a southern population of the widespread delicate mouse P. delicatulus (Breed and Ford 2007; Ford 2008). Recent trapping in fauna surveys in northern NSW have revealed a continuous distribution of the delicate mouse to the Pilliga region. Under the EPBC Act this latest taxonomic change has not been formally recognised. Therefore, this species profile considers the Pilliga population of the delicate mouse.

States and territories: NSW.

Regions: Pilliga.

Habitat: Mixed Cypress-Eucalypt Woodland – dominant canopy trees include red stringy bark Eucalyptus macroryncha, scribbly gum Eucalyptus rossii and black cypress pine Callitris endlicheri. Paull (2009) found breeding sites to be correlated with a well-developed low shrub cover less than 50 cm high, mainly in broombush and kurricabah/bloodwood scrublands. The species showed a preference for early and late post-fire stages of vegetation and an avoidance of intermediate age habitats post fire (5–15 years old).

Habit: Ground-dwelling.

Avg. body weight: 11 g (Fox 1995).

Activity pattern: Nocturnal.

Diet: Herbivore: stem, seed and leaf material of grasses and forbs from the Pilliga scrub (Jefferys & Fox 2001).

Breeding: In captivity the breeding season extends from October to February, with a 24 day gestation period recorded to produce approximately three young (Fox & Briscoe 1980).

Description

The Pilliga mouse was regarded as exceptional among the Muridae as it was formerly considered to have a very small and isolated distribution, restricted to a small region within NSW (Dickman et al. 2000). It was only described in 1980 (Fox & Briscoe 1980) and since then has been detected in NPWS biodiversity studies and other trapping work in the Pilliga (Lim 1992, Paull 2004). However, recent genetic work has indicated that this species should now be considered a southern population of the delicate mouse rather than a separate species (Breed & Ford 2007, Ford 2008).

Survey methods

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

• 
  daytime searches for potentially suitable habitat resources such as shrubs where burrows might be associated (description of the survey technique and recommended effort is provided in Section 3.1)
  
• 
  daytime searches for signs for burrows, focussing on the habitat with bushes that may provide suitable cover for burrow entrances, and searching for signs of excavation of soil (description of the survey technique and recommended effort is provided in Section 3.2)
  
• 
  collection of predator scats, owl casts or remains in predatory bird/mammal nests/dens (description of the survey technique and recommended effort is provided in Section 3.2)
  
• 
  possibly hair sampling device surveys (description of the survey technique and recommended effort is outlined in Section 3.3.7), which have previously been used to detect the species’ presence (Lim & Johnson 1991). Note, however, that the Pilliga mouse is not included among those species known to be distinguishable from hair samples (Table 2)
  
• 
  Elliott A trapping surveys, following the technique and recommended effort described in Section 3.3.9, using a mixture of rolled oats, peanut butter and sultanas for bait. Traps should be adjusted to ensure the sensitivity will be light enough to be triggered by the small species (approximately 8 grams; Tokushima et al., 2008)
  
• 
  pitfall trapping surveys conducted according to the technique and recommended effort described in Section 3.3.8. It is not considered necessary to bait pitfall traps as the purpose of the trapping program outlined here is to detect the species and not maximise the number of captures. Furthermore, permission to bait pitfalls should be sought from the relevant animal care and ethics authority, as this is not standard for this technique.
  

Note that this species is eruptive. During extended dry periods (when it is likely to be present, but in low densities), either a higher sampling effort is required to determine the species’ presence or, if possible, sampling should be delayed until more favourable conditions arise.

Similar species in range

The common house mouse Mus musculus overlaps in range with the Pilliga mouse and so an experienced mammalogist must confirm the presence of this species in new localities. The two species can be distinguished by the larger eyes of the Pilliga mouse and usually (but not always) by the presence of a notch behind the front incisors of the house mouse.

Should hair or tissue samples be considered necessary for identification and/or molecular analysis, appropriate permission and licensing needs to be been granted by the relevant state or territory government organisation.

References

Breed, B. And Ford, F. 2007. Native Mice and Rats. CSIRO Publishing, Victoria.
Briscoe, D.A, Fox, B.J. and Ingleby, S. 1981. Genetic differentiation between Pseudomys pilligaensis and related Pseudomys. Australian Mammalogy 4: 89-92
Dickman, C.R., Lunney D., and Matthews, A. 2000. Ecological attributes and conservation of native rodents in New South Wales. Wildlife Research 27: 347-355.
Ford, F. 2008. Delicate Mouse Pseudomys delicatulus. In ‘The Mammals of Australia’ (Eds. S. Van Dyck and R. Strahan) pp. 623-624. (Reed New Holland: Sydney).
Fox B.J. 1995. Pilliga Mouse Pseudomys pilligaensis. In ‘The Mammals of Australia’ (Ed. R. Strahan) p. 616 (Reed Books: Sydney).
Fox, B.J and Briscoe D.A. 1980. Pseudomys pilligaensis, a new species of murid rodent from the Pilliga Scrub, northern New South Wales. Australian. Mammalogy 3: 109-126.
Jefferys, E. A. and Fox, B.J. 2001. The diet of the Pilliga Mouse, Pseudomys pilligaensis (Rodentia: Muridae) from the Pilliga Scrub, New South Wales. Proceedings of the Linnean Society of N.S.W. 123: 89-99.
Lim, T.L. 1992. "Conservation and biology of the rare Pilliga Mouse Pseudomys pilligaensis, Fox and Briscoe 1980 (Muridae: Conlurini)". Report to Zoological Parks Board of New South Wales.
Lim, L. and Johnson, B. 1991. The Pilliga Mouse Pseudomys pilligaensis, Fox and Briscoe 1980 (Rodentia: Muridae) and Fire management in the Pilliga Nature Reserve. Draft Report to Department of Planning.
Paull, D. (2003). University of New England. Personal communication regarding the Pilliga Mouse.
Paull, D.C. 2004. Habitat and post-fire selection of the Pilliga Mouse Pseudomys pilligaensis in Pilliga East State Forest. Pacific Conservation Biology 15: 254–267.
Tokushima, H. 2002. Population, resource and habitat ecology of the Pilliga mouse (Pseudomys pilligaensis). Ph.D. Thesis, University of New England, Armidale.
Tokushuma, H., Green, S.W. and Jarman, P.J. 2008. Ecology of the rare but irruptive Pilliga mouse (Pseudomys pilligaensis). I. Population fluctuation and breeding season. Australian Journal of Zoology. 56: 363-373.