Activity patterns and torpor in two free-ranging carnivorous marsupials in arid Australia in relation to precipitation, reproduction, and ground cover

Title
Activity patterns and torpor in two free-ranging carnivorous marsupials in arid Australia in relation to precipitation, reproduction, and ground cover
Publication Date
2016
Author(s)
Koertner, Gerhard
( author )
OrcID: https://orcid.org/0000-0001-8230-0709
Email: gkoertne@une.edu.au
UNE Id une-id:gkoertne
Riek, Alexander
Pavey, Chris R
Geiser, Fritz
( author )
OrcID: https://orcid.org/0000-0001-7621-5049
Email: fgeiser@une.edu.au
UNE Id une-id:fgeiser
Type of document
Journal Article
Language
en
Entity Type
Publication
Publisher
Oxford University Press
Place of publication
United States of America
DOI
10.1093/jmammal/gyw113
UNE publication id
une:20780
Abstract
It is generally assumed that in unpredictable environments, the use of daily torpor and its interaction with daily activity are largely dependent on environmental thermal conditions and resource availability. Using temperature telemetry, we compared the thermal biology and activity patterns of 2 species of mulgaras ('Dasycercus blythi' and 'D. cristicauda') at 3 sites of different habitat types in central Australia. The work compared a dry period with a wet period (resource pulse). The most obvious functional difference among populations was observed in the timing of the onset of activity, which began significantly earlier in dense unburned spinifex (on average 17.7min before sunset) than in burned spinifex (4.6min after sunset) or on gibber plains (21.8min after sunset). However, although the seasonal expression of torpor differed significantly between males and females, torpor use as well as seasonal timing was similar among sites and periods despite differences in rainfall and habitat. It appears that predominantly reproductive activity governed torpor depth and duration in all measured populations and both species. Our data suggest that while the timing of activity is modulated by the amount of vegetation cover and thus protection from diurnal predators, torpor expression and winter reproduction in mulgaras are functionally linked and surprisingly more or less independent of apparent resource availability. Consequently, in mulgaras, daily torpor does not seem to be employed in response to immediate energy shortage but more likely to allow reallocation of energy and nutrients towards reproduction.
Link
Citation
Journal of Mammalogy, 97(6), p. 1555-1564
ISSN
1545-1542
0022-2372
Start page
1555
End page
1564

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