Torpor in free-ranging antechinus: does it increase fitness?

Title
Torpor in free-ranging antechinus: does it increase fitness?
Publication Date
2014
Author(s)
Rojas, A Daniella
Koertner, Gerhard
( author )
OrcID: https://orcid.org/0000-0001-8230-0709
Email: gkoertne@une.edu.au
UNE Id une-id:gkoertne
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
Springer
Place of publication
Germany
DOI
10.1007/s00114-013-1136-0
UNE publication id
une:16382
Abstract
Antechinus are small, insectivorous, heterothermic marsupial mammals that use torpor from late summer to early winter and reproduce once a year in late winter/early spring. Males die after mating, most females produce only a single litter, but some survive a second winter and produce another litter. As it is not known how these females manage to survive the second winter after the energetically demanding reproductive period and then reproduce a second time, we aimed to provide the first data on thermal biology of free-ranging antechinus by using temperature telemetry. Male 'Antechinus stuartii' and 'Antechinus flavipes' rarely entered torpor in autumn/early winter in the wild, expressing only shallow bouts of <2 h. Female 'A. stuartii' used torpor extensively, employing bouts up to 16.7 h with body temperatures as low as 17.8 °C. Interestingly, although first and second year females used similar torpor patterns, torpor occurrence was almost twofold in second year (93 % of days) than first year females (49 %), and the proportion of the overall monitoring period animals spent torpid was 3.2-fold longer in the former with a corresponding shorter activity period. Our study suggests that intensive use of torpor is crucial for second year females for autumn and winter survival and production of a second litter. We provide the first evidence of an age-related pattern in daily torpor expression in free-ranging mammals and show that torpor use is a complex process that is affected not only by the current energy availability and thermal conditions but also by the reproductive history and age of individuals.
Link
Citation
Naturwissenschaften, 101(2), p. 105-114
ISSN
1432-1904
0028-1042
Start page
105
End page
114

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