Distribution, habitat and conservation status of the eastern pygmy-possum Cercartetus nanus in Victoria.

Abstract

We review the distribution, habitat and conservation status of the eastern pygmy-possum (Cercartetus nanus) in Victoria. Data on the habitat occurrences and rates of detection were gleaned from 133 published and unpublished fauna surveys conducted from 1968 to 2003 in Gippsland; northern Victoria; the Melbourne area and south-western region. C. nanus was reported from a broad range of vegetation communities, which predominantly included a dense mid-storey of shrubs rich in nectar-producing species such as those from the families Proteaceae and Myrtaceae. Survey effort using a range of methods was immense across surveys: 305,676 Elliott/cage trap-nights, 49,582 pitfall trap-nights, 18,331 predator remains analysed, 4424 spotlight hours, and 7346 hair-sampling devices deployed, 1005 trees stagwatched, and 5878 checks of installed nest-boxes. The surveys produced 434 records of C. nanus, with Elliott/cage trapping, pitfall trapping and analysis of predator remains responsible for the vast majority of records (93%). These data and those from the Atlas of Victorian Wildlife indicate that although C. nanus has a widespread distribution in Victoria, it is rarely observed or trapped in fauna surveys. Only 11 (8%) of the surveys we reviewed detected >10 individuals. C. nanus is likely to be sensitive to several recognised threatening processes in Victoria (e.g., feral predators, high frequency fire, feral honeybees). There is also evidence of range declines in several regions, which suggests that the species is vulnerable to extinction. Therefore, we recommend that it be nominated as a threatened species in Victoria.

Cercartetus nanus (Diprotodontia: Burramyidae)

“…The oldest fossil bones of C. nanus are from Cathedral Cave in the Naracoorte Caves National Park World Heritage Site where dates as old as 528,000 years 6 41,000 SD have been established. Comparison of prehistoric and modern distribution records for C. nanus indicates a slight eastward contraction at the range periphery in Queensland (Harris et al 2007b). …”

“…Use of nest boxes and livetrapping within trees probably represent the most efficient census methods employed for this species in tall or densely wooded habitats (Bladon et al 2002;Harris and Goldingay 2005a;Turner 1985;Ward 1990). However, pitfall trapping would be expected to be more successful in heathlands and open woodlands (Harris and Goldingay 2005b;Tulloch and Dickman 2006;van Weenen and Harris 2006).…”

“…3) from southeastern Queensland (Harris et al 2007b), through New South Wales (Bowen and Goldingay 2000), Australian Capital Territory (Dickman and Happold 1988) and Victoria (Harris and Goldingay 2005b), and into southeastern South Australia (van Weenen and Harris 2006). The elevational range is from sea level to about 1,800 m (Green and Osborne 1994).…”

“…Space use.-Across its range, C. nanus is a midstory specialist inhabiting shrubby components of a variety of habitats including rain forest, sclerophyll forest, shrubland, heathland, and woodland (Bowen and Goldingay 2000;Harris et al 2007bHarris et al , 2008Harris and Goldingay 2005b;Turner 1985;van Weenen and Harris 2006). Despite this breadth of habitat, this species is patchily distributed and generally in low abundance.…”

“…Known predation records are by barn owl (Tyto alba), masked owl (T. novaehollandiae), sooty owl (T. tenebricosa), barking owl (Ninox connivens), brown antechinus (Antechinus stuartii), spotted-tailed quoll (Dasyurus maculates), Tasmanian devil (Sarcophilus harrisii), dingo and dog (Canis lupus), fox (Vulpes vulpes), cat (Felis catus), Stephen's banded snake (Hoplocephalus stephensii), and rough-scaled snake (Tropidechis carinatus-see Bladon et al 2002;Fitzgerald et al 2004;Harris and Garvey 2006;Harris and Goldingay 2005c;Harris et al 2007b). These records indicate that C. nanus is an important prey item for a range of avian, mammalian, and reptilian predators.…”