Avian Song Complexity is Associated With High Field Metabolic Rate

Abstract

Question: Is the production of bird song costly? Analyses of oxygen consumption during singing provided conflicting results. Data studied: Data on 28 passerine species with quantitative information on song complexity and field metabolic rate, which reflects energy requirements of wild birds. The phylogenetic relationship data came from molecular sources. Search method: Generalized least squares models to control for phylogenetic associations. First, we adjusted field metabolic rate to body size, and calculated the phylogenetic correlation between relative field metabolic rate and measures of song complexity. Second, we compared song complexity of birds inhabiting and and mesic environments. Conclusion: A measure of short-term song complexity, relative syllable repertoire size, is positively and significantly related to relative field metabolic rate. Species from and habitats have less complex songs than species from mesic habitats