Effects of nest use, huddling, and torpor on thermal energetics of eastern pygmy-possums
Sae Namekata A and Fritz Geiser A BA Centre for Behavioural Physiology and Ecology, Zoology, University of New England, Armidale, NSW 2351, Australia.
B Corresponding author. Email: fgeiser@une.edu.au
Australian Mammalogy 31(1) 31-34 https://doi.org/10.1071/AM08114
Submitted: 18 October 2008 Accepted: 8 December 2008 Published: 7 April 2009
Abstract
Eastern pygmy-possums (Cercartetus nanus) are known to be conservative with energy use probably because they rely on food that varies in availability. We quantified how nest use, huddling, and torpor contribute to a reduction of energy expenditure in C. nanus during mild cold exposure. In comparison to normothermic resting C. nanus at the same ambient temperature, nest use reduced energy expenditure on average by ~17%, huddling as a pair in a nest by ~50%, whereas torpor, which was employed by all seven individuals, lowered energy expenditure by >95%. Our study shows that while all energy-conserving strategies employed by these possums can contribute significantly to reducing energy expenditure, torpor is by far the most effective because it not only reduces thermoregulatory energy costs, but also energy expenditure required for maintenance processes.
Acknowledgements
We thank Mike Fleming, Gerhard Körtner, and Simon Ward for constructive comments on the manuscript, and the Australian Research Council for financial support.
Bladon, R. V. , Dickman, C. R. , and Hume, I. D. (2002). Effects of habitat fragmentation on the demography, movements and social organization of the eastern pygmy-possum (Cercartetus nanus) in northern New South Wales. Wildlife Research 29, 105–116.
| Crossref | GoogleScholarGoogle Scholar |
Harris, J. M. (2008). Cercartetus nanus (Diprotodontia: Burramyidae). Mammalian Species 815, 1–10.
| Crossref | GoogleScholarGoogle Scholar |
