Cercartetus nanus (Diprotodontia: Burramyidae)

Abstract

Cercartetus nanus (Desmarest, 1817) is a burramyid commonly called the eastern pygmy-possum. It is 1 of 4 species in the genus Cercartetus, which together with Burramys parvus form the marsupial family Burramyidae. This species is endemic to southeastern Australia and occupies a range of vegetation types, but Banksia woodland is probably preferred habitat. This species is notable for its longevity, ability to hibernate, and its likely role as an important pollinator of a range of large-flowered plants. This species is of conservation concern in several Australian states, where it is threatened by habitat loss, inappropriate fire regimes, and introduced predators.

Sex and age differences in tree cavity dependence in a small arboreal marsupial

“…But are other age and sex classes cavity dependent? Eastern pygmy-possums are known to shelter in shallow depressions within a tree, disused bird's nests, burrows in the ground, and also sites under the leaf skirts of certain plants (Laidlaw & Wilson, 1996;Tulloch & Dickman, 2006;Harris, 2008), which does not suggest tree cavity dependence. The small horizontal pipe refuges installed here were intended to mimic any narrow shelter site.…”

“…Predatory reptiles will be inactive in that period but other predators will be in abundance. Pygmy-possums have been observed to occasionally shelter in disused open-cup nests of the New Holland honeyeater (Phylidonyris novaehollandiae) (Harris, 2008). Nest failure in this bird can be as high as 48% during April-September with 38% of that (i.e., 18% overall) being due to predation (Armstrong & Pyke, 1991).…”

“…I investigated whether maternal cavity dens were used by the eastern pygmy-possum (Cercartetus nanus), an Australian marsupial that is listed as threatened across part of its geographic range and shows partial dependence on tree cavities. It is known to use a wide range of shelter sites, from holes in the ground, disused bird nests, and accumulations of dead leaves, through to cavities in trees and logs (Ward, 1990;Tulloch & Dickman, 2006;Harris, 2008;Law et al, 2013a). Females with large dependent young are described as requiring 'more substantial nest sites' (Ward, 1990).…”

Cercartetus lepidus (Diprotodontia: Burramyidae)

“…1) is distinguished from other pygmy-possums by its size, coloration, tail length, and dentition. Specifically, it differs from C. concinnus (Harris 2009) by having gray rather than white belly fur, and from C. nanus (Harris 2008) by its smaller size and the presence of a 4th molar (Fig. 2).…”

“…The longest period of dormancy recorded is 6 days and animals may become dormant at any time of the year (Geiser 1987;Hickman and Hickman 1960). It has been suggested that C. lepidus should be considered a true hibernator (Geiser 1985), and although this may well be justified, torpor is not as prolonged or deep as that in C. nanus (see Harris 2008), and arousal rates (0.03uC/min) may be slower (about 20 min to normothermia) in the smaller C. lepidus (Green 1973;Hickman and Hickman 1960;Wallis 1979). In one study, body temperature of dormant C. lepidus was within 1uC of ambient temperature, that is, body temperature was recorded as 15uC; however, body temperature was not measured below an ambient temperature of 15uC.…”