Basking and diurnal foraging in the dasyurid marsupial Pseudantechinus macdonnellensis
Chris R. Pavey A B and Fritz Geiser AA Centre for Behavioural and Physiological Ecology, Zoology, University of New England, Armidale, NSW 2351, Australia.
B Corresponding author. Present address: Biodiversity Conservation, Department of Natural Resources, Environment, and the Arts, Alice Springs, PO Box 1120, Alice Springs, NT 0871, Australia. Email: chris.pavey@nt.gov.au
Australian Journal of Zoology 56(2) 129-135 https://doi.org/10.1071/ZO08032
Submitted: 21 March 2008 Accepted: 13 August 2008 Published: 13 October 2008
Abstract
Several mammal species bask to passively rewarm during arousal from torpor, a strategy that can decrease energetic costs. Nothing is known about basking behaviour in these species or the trade-offs between energetic benefits of basking and potential costs associated with changes in activity patterns and increased predation risk. We assessed basking during winter in Pseudantechinus macdonnellensis, an Australian arid-zone marsupial that belongs to a family (Dasyuridae) that is typically nocturnal. Animals were implanted with temperature-sensitive transmitters to assess body temperatures and to assist in visually locating animals active during the day. Tagged animals regularly exhibited diurnal foraging. Foraging bouts occurred throughout the day; however, most bouts were observed within 3 h of sunset. By comparison, basking occurred much more frequently in the morning. Basking and a shift towards diurnal foraging in winter is associated with a decrease in richness and abundance of predators. P. macdonnellensis appears to compensate for the occurrence of torpor during the active phase (i.e. night) in winter by changing activity patterns such that foraging commences during what is usually the rest phase. These activity patterns are not expected to occur during the remainder of the year.
Acknowledgements
We thank Nicola Goodship for field assistance throughout the study. Michael Barritt, Silke Beckedorf, Karen May, and Parks and Wildlife Service of the Northern Territory staff based at Ormsiton provided assistance and logistic support during the study. We thank Gavin Bedford and Greg Fyfe for expert advice on predatory reptiles in the study area. We are grateful to R. Mark Brigham, Ed Heske and an anonymous reviewer for comments on the manuscript. Permits were provided by the Animal Ethics Committee of the University of New England and the Parks and Wildlife Service of the Northern Territory. The research was supported by grants from the Australian Research Council and the Faculty of Sciences, The University of New England.
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