Thermoregulation under semi-natural conditions in speckled mousebirds: the role of communal roosting

Author(s)
McKechnie, Andrew E
Koertner, Gerhard
Lovegrove, Barry G
Publication Date
2007
Abstract
<p>Mousebirds (Coliiformes) exhibit well-developed communal roosting behaviour as well as a pronounced capacity for facultative hypothermic responses. We recorded body temperature (T<sub>b</sub>)) in speckled mousebirds (<i>Colius striatus</i>) under semi-natural conditions in outdoor aviaries, and examined interactions between behavioural and metabolic thermoregulation by experimentally manipulating food availability and communal roosting behaviour. When food was available <i>ad libitum</i>, mousebirds roosting in a cluster maintained approximately constant rest-phase T<sub>b</sub>, with 32°C < T<sub>b</sub> < 42°C. By contrast, rest-phase T<sub>b</sub> in single mousebirds decreased at 0.5°C/hr and minimum rest-phase T<sub>b</sub> was significantly lower than when clustering. When food availability was restricted, the mousebirds exhibited facultative hypothermic responses that were less pronounced in clustering groups (minimum rest-phase T<sub>b</sub> = 33.3°C, circadian amplitude of T<sub>b</sub> = 9.5°C) compared to single birds (minimum rest-phase T<sub>b</sub> = 30.7°C, circadian amplitude of T<sub>b</sub> = 11.8°C). When clustering, rest-phase T<sub>b</sub> was highly synchronized among individuals. Our data reveal that communal roosting has profound consequences for rest-phase thermoregulation in <i>C. striatus</i>, and provide further insights into the potential role of physiological constraints in the evolution of avian sociality.</p>
Citation
Africian Zoology, 41(2), p. 155-163
ISSN
1562-7020
Link
Publisher
South African Bureau for Scientific Publications
Title
Thermoregulation under semi-natural conditions in speckled mousebirds: the role of communal roosting
Type of document
Journal Article
Entity Type
Publication

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