QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

First published online January 19, 2006
Journal of Experimental Biology 209, 466-474 (2006)
Published by The Company of Biologists 2006
doi: 10.1242/jeb.02024

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Swanson, D. L. Articles by Liknes, E. T. Search for Related Content PubMed PubMed Citation Articles by Swanson, D. L. Articles by Liknes, E. T.

A comparative analysis of thermogenic capacity and cold tolerance in small birds

David L. Swanson^* and Eric T. Liknes

Department of Biology, University of South Dakota, 414 East Clark Street, Vermillion, SD 57069, USA

^* Author for correspondence (e-mail: dlswanso{at}usd.edu)

Accepted 1 December 2005

Small birds showing marked seasonal changes in cold tolerance also exhibit winter increases in summit metabolic rate (M_sum=maximum cold-induced thermogenesis or thermogenic capacity) relative to summer birds. However, some birds show modest seasonal changes in cold tolerance without winter increases in M_sum and others exhibit large seasonal changes in cold tolerance with only minor changes in M_sum. Thus, the degree of correlation between cold tolerance and M_sum is uncertain and no interspecific study has directly addressed this question. In this study, we measured cold tolerance and M_sum in summer- (21 species) and winter- (11 species) acclimatized birds from southeastern South Dakota. M_sum was measured as the maximum oxygen consumption attained during exposure of individual birds to a declining series of temperatures in 79% helium/21% oxygen (helox). Cold tolerance was measured as the temperature at cold limit (T_CL), which is the helox temperature that induced hypothermia in individual birds. Residuals from allometric regressions of logM_sum and logT_CL were significantly and negatively related for summer (R²=0.34, P=0.006) and winter (R²=0.40, P=0.037) birds. Data were also subjected to a comparative analyses with phylogenetically independent contrasts to remove potential confounding effects of phylogeny, and results were similar to the non-phylogenetic analyses, with significant negative correlations in both summer (R²=0.47, P<0.001) and winter (R²=0.40, P=0.049). Thus, birds with high M_sum tended to show reduced T_CL (i.e. high cold tolerance), suggesting that cold tolerance and summit metabolism are phenotypically linked in small birds.

Key words: thermogenesis, cold, bird, acclimatization, comparative analysis

This article has been cited by other articles:

				P. Wiersma, M. A. Chappell, and J. B. Williams Cold- and exercise-induced peak metabolic rates in tropical birds PNAS, December 26, 2007; 104(52): 20866 - 20871. [Abstract] [Full Text] [PDF]

				P. Wiersma, A. Munoz-Garcia, A. Walker, and J. B. Williams Tropical birds have a slow pace of life PNAS, May 29, 2007; 104(22): 9340 - 9345. [Abstract] [Full Text] [PDF]

				F. Vezina, K. M. Jalvingh, A. Dekinga, and T. Piersma Thermogenic side effects to migratory predisposition in shorebirds Am J Physiol Regulatory Integrative Comp Physiol, March 1, 2007; 292(3): R1287 - R1297. [Abstract] [Full Text] [PDF]

				F. Vezina, K. M. Jalvingh, A. Dekinga, and T. Piersma Acclimation to different thermal conditions in a northerly wintering shorebird is driven by body mass-related changes in organ size J. Exp. Biol., August 15, 2006; 209(16): 3141 - 3154. [Abstract] [Full Text] [PDF]