Black or white? Physiological implications of roost colour and choice in a microbat

Title
Black or white? Physiological implications of roost colour and choice in a microbat
Publication Date
2016
Author(s)
Doty, Anna C
Stawski, Clare
Currie, Shannon
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
Elsevier Ltd
Place of publication
United Kingdom
DOI
10.1016/j.jtherbio.2016.07.015
UNE publication id
une:20068
Abstract
Although roost choice in bats has been studied previously, little is known about how opposing roost colours affect the expression of torpor quantitatively. We quantified roost selection and thermoregulation in a captive Australian insectivorous bat, 'Nyctophilus gouldi' (n=12) in winter when roosting in black and white coloured boxes using temperature-telemetry. We quantified how roost choice influences torpor expression when food was provided ad libitum or restricted in bats housed together in an outdoor aviary exposed to natural fluctuations of ambient temperature. Black box temperatures averaged 5.1 °C (maximum 7.5 °C) warmer than white boxes at their maximum daytime temperature. Bats fed ad libitum chose black boxes on most nights (92.9%) and on 100% of nights when food-restricted. All bats used torpor on all study days. However, bats fed ad libitum and roosting in black boxes used shorter torpor and spent more time normothermic/active at night than food-restricted bats and bats roosting in white boxes. Bats roosting in black boxes also rewarmed passively more often and to a higher skin temperature than those in white boxes. Our study suggests that 'N. gouldi' fed ad libitum select warmer roosts in order to passively rewarm to a higher skin temperature and thus save energy required for active midday rewarming as well as to maintain a normothermic body temperature for longer periods at night. This study shows that colour should be considered when deploying bat boxes; black boxes are preferable for those bats that use passive rewarming, even in winter when food availability is reduced.
Link
Citation
Journal of Thermal Biology, v.60, p. 162-170
ISSN
1879-0992
0306-4565
Start page
162
End page
170

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