Basal metabolic rate, food intake, and body mass in cold- and warm-acclimated Garden Warblers.
We address the question of whether physiological flexibility in relation to climate is a general feature of the metabolic properties of birds. We tested this hypothesis in hand-raised Garden Warblers (Sylvia borin), long-distance migrants, which normally do not experience great temperature differences between summer and winter. We maintained two groups of birds under cold and warm conditions for 5 months, during which their body mass and food intake were monitored. When relatedness (siblings vs. non-siblings) of the experimental birds was taken into account, body mass in cold-acclimated birds was higher than in warm-acclimated birds. BMR, measured at the end of the 5-month temperature treatment, was also higher in the cold- than the warm-acclimated group. Migrant birds thus seem to be capable of the same metabolic cold-acclimation response as has been reported in resident birds. The data support the hypothesis that physiological flexibility is a basic trait of the metabolic properties of birds.
Klaassen
Marcel
M
Netherlands Institute of Ecology (NIOO-KNAW), Centre for Limnology, Department of Plant-Animal Interactions, P.O. Box 1299, 3600 BG Maarssen, The Netherlands. m.klaassen@nioo.knaw.nl
Oltrogge
Martina
M
Trost
Lisa
L
D000064:Acclimatization / Q000502:physiology*; D000704:Analysis of Variance; D000818:Animals; D001481:Basal Metabolism / Q000502:physiology; D001837:Body Weights and Measures; D003080:Cold Temperature; D004435:Eating / Q000502:physiology; D020308:Songbirds / Q000378:metabolism* / Q000502:physiology*; D013696:Temperature