Body temperature and activity patterns of free-living laughing kookaburras: the largest kingfisher is heterothermic.

Cooper, Christine and Kortner, Gerhard and Brigham, Mark and Geiser, Fritz. 2008. Body temperature and activity patterns of free-living laughing kookaburras: the largest kingfisher is heterothermic.. Condor 110 (1): pp. 110-115.

Source Title

Condor

DOI

10.1525/cond.2008.110.1.110

ISSN

00105422

Faculty

School of Agriculture and Environment

Faculty of Science and Engineering

Department of Environmental Biology

Remarks

Published as Christine E. Cooper, Gerhard Kortner, Mark Brigham, and Fritz Geiser. Body temperature and activity patterns of free-living laughing kookaburras: the largest kingfisher is heterothermic. The Condor, 110 (1) : 110 - 115 © The Cooper Ornithological Society 2008. © 2008 by the Regents of the University of California / The Cooper Ornithological Association. Copying and permissions notice: Authorization to copy this content beyond fair use (as specified in Sections 107 and 108 of the U. S. Copyright Law) for internal or personal use, or the internal or personal use of specific clients, is granted by the Regents of the University of California / on behalf of The Cooper Ornithological Association for libraries and other users, provided that they are registered with and pay the specified fee via Rightslink® on Caliber (http://caliber.ucpress.net/) or directly with the Copyright Clearance Center, http://www.copyright.com.

URI

http://hdl.handle.net/20.500.11937/46212

Collection

Curtin Research Publications

Abstract

We show that free-ranging Laughing Kookaburras (Dacelo novaeguineae), the largest kingfishers, are heterothermic. Their minimum recorded body temperature (Tb) was 28.6°C, and the maximum daily Tb range was 9.1°C, which makes kookaburras only the second coraciiform species and the only member of the Alcedinidae known to be heterothermic. The amplitude of nocturnal body temperature variation for wild, free-living kookaburras during winter was substantially greater than the mean of 2.6°C measured previously for captive kookaburras. Calculated metabolic savings from nocturnal heterothermia were up to 5.6 ± 0.9 kJ per night. There was little effect of ambient temperature on any of the calculated Tb-dependent variables for the kookaburras, although ambient temperature did influence the time that activity commenced for these diurnal birds. Kookaburras used endogenous metabolic heat production to rewarm from low Tb, rather than relying on passive rewarming. Rewarming rates (0.05 ± 0.01°C min−1) were consistent with those of other avian species. Captivity can have major effects on thermoregulation for birds, and therefore the importance of field studies of wild, free-living individuals is paramount for understanding the biology of avian temperature regulation.