Veterinary and Husbandry Challenges of the Critically Endangered Mountain Pygmy Possum (Burramys parvus), a Small Marsupial Subniveal Hibernator
Mountain pygmy possum (Burramys parvus) from Mt Buller represent a separate Ecologically Sustainable Unit of a critically endangered species.1 The possum is an omnivorous, subniveal hibernator.2 Its body temperature will reduce to ambient during hibernation.3 The ambient temperature 30 cm below the surface in boulder fields at elevations between 1400–1800 m was measured as 0.5°C for 5 mo using 18, Onset Hobo H8 data loggers (Onset 470 MacArthur Blvd Bourne, MA, USA). To simulate this in captivity, refrigerated shipping containers (12 m x 2.5 m x 2.5 m) fitted with three phase 5.2 horsepower motors and reheat elements with a thermal range of -5°–30°C were used to house 20 individuals between 3–20°C.
The diet of the mountain pygmy possum in the wild is seasonal and was mimicked in captivity with emphasis on providing linoleic acid as this has been shown to affect the abdominal fat composition and hibernation duration of other mammals.4 All animals were anesthetized, a whole-body radiograph was taken and serum hematology and biochemistry values measured. The main ectoparasites collected were Ornithonyssus and Glycyphagus sp. Treatment of mites was successful using moxidectin (Cydectin Injectable, Fort Dodge Animal Health, Maitland Place, Baulkham Hills NSW, 2153) PO at 0.2 mg/kg concurrently with a substrate change and repeated after 2 wk if mites were seen. Daily urine free catch samples were used to determine the presence of oestrus. Mate choice selection trails based on the methods used in other dasyurids, were conducted to determine the order of mate introduction in this multiparous species.5
1. Mitovski, P., A. Heinze, L. Broome, A.A. Hoffmann, and A.R. Weeks. 2006. High levels of variation despite genetic fragmentation in populations of the endangered mountain pygmy-possum, Burramys parvus, in alpine Australia. Mol. Ecol. 5:395–397.
2. Mansergh, I.M. and D. Scotts. 1990. Aspects of the life history and breeding biology of the Mountain Pygmy possum, Burramys parvus (Marsupialia: Burramyidae) in alpine Victoria. Austral. Mammal. 13:179–191.
3. Geiser, F., H.S Sink, B.L. Stahl, I.M. Mansergh, and L.S. Broome. 1990. Differences in the physiological response to cold in wild and laboratory-bred mountain pygmy possums, Burramys parvus (Marsupialia). Austral. Wildl. Res. 17:535–539.
4. Geiser, F. and G.J. Kenagy (1987). 1987. Polyunsaturated lipid diet lengthens torpor and reduces body temperature in a hibernator. Am. J. Physiol. 36:473–481.
5. Parrot, M.L., SJ Ward, and P.D. Temple-Smith. 2007. Olfactory cues, genetic relatedness and female mate choice in the agile antechinus, Antechinus agilis. 2007. Behav. Ecol. and Sociobiol. 61;7:1075–1079.