caa a22 4500 463176189 CHVBK 20180406164826.0 cr unu---uuuuu 170326e20071001xx s 000 0 eng 10.1007/s10336-007-0205-6 doi (NATIONALLICENCE)springer-10.1007/s10336-007-0205-6 Heterothermy in an Australian passerine, the Dusky Woodswallow ( Artamus cyanopterus ) [Elektronische Daten] [Tracy Maddocks, Fritz Geiser] Information regarding passerine heterothermy and torpor is scant, although many species are small and must cope with a fluctuating food supply and presumably would benefit from energy savings afforded by torpor. We studied whether insectivorous Dusky Woodswallows (Artamus cyanopterus; ∼35g) enter spontaneous torpor (food ad libitum) when held outdoors as a pair in autumn/winter. Woodswallows displayed pronounced and regular daily fluctuations in body temperature (T b) over the entire study period. The mean T b ranged from ∼39°C to 40°C (photophase, day time) and ∼33°C to 36°C (scotophase, night time). However, on 88% of bird nights, nocturnal T b minima fell to<35°C. The lowest T b observed in air was 29.2°C. However, when a bird fell into water its T b dropped further to ∼22°C; this T b was regulated for several hours and the bird survived. Our observations suggest that heterothermy is a normal part of the daily thermal regime for woodswallows to minimise energy expenditure. Spontaneous nocturnal torpor in captive woodswallows suggests that torpor in the wild may be more pronounced than recorded here because free-living birds are likely challenged by both low food availability and adverse weather. Dt. Ornithologen-Gesellschaft e.V., 2007 Air nationallicence Body temperature nationallicence Energy conservation nationallicence Shallow torpor nationallicence Water nationallicence Maddocks Tracy Centre for Behavioural and Physiological Ecology, Zoology, University of New England, 2351, Armidale, NSW, Australia aut Geiser Fritz Centre for Behavioural and Physiological Ecology, Zoology, University of New England, 2351, Armidale, NSW, Australia aut Journal of Ornithology Springer-Verlag 148/4(2007-10-01), 571-577 0021-8375 148:4<571 2007 148 10336 https://doi.org/10.1007/s10336-007-0205-6 text/html Onlinezugriff via DOI 1 brief-communication jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10336-007-0205-6 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Maddocks Tracy Centre for Behavioural and Physiological Ecology, Zoology, University of New England, 2351, Armidale, NSW, Australia aut NATIONALLICENCE 700 1- Geiser Fritz Centre for Behavioural and Physiological Ecology, Zoology, University of New England, 2351, Armidale, NSW, Australia aut NATIONALLICENCE 773 0- Journal of Ornithology Springer-Verlag 148/4(2007-10-01), 571-577 0021-8375 148:4<571 2007 148 10336 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer