The hypothesis that the metabolic rates of birds are convergent and depend on functional adaptations was tested as an alternative that taxonomic affiliations sufficiently account for variation in metabolism. Basal metabolic rates (BMR) of 122 species from six families (Corvidae, Emberizidae, Fringillidae, Muscicapidae, Nectariniidae, and Parulidae) of passerine birds were taken from literature and compared with data on their life history traits: food habits, climate, habitat, biotope, type of nest and migrations. Using factor analysis and clustering procedures different strategies were distinguished according to assortment of traits - food strategies: nectarivc rous, insectivorous, granivorous, omnivorous; environmental strategies: terrestrial, tropical, boreal and strategies based on analysis of food and remaining traits together: group 1, group 2, group 3. These sets are only partly congruent with taxonomic classification. All groups demonstrate similar dependence of BMR on body weight but granivorous have a significantly higher BMR than nectarivorous and tropical has lower BMR than terrestrial and boreal. In contrast, Fringillidae have significantly higher BMR than Muscicapidae, Emberizidae, Nectariniidae and Parulidae. Analysis of residuals within ANCOVA for strategies and for families indicates that taxonomic affiliation exerts greater influence on BMR values than adaptive strategy.