SUMMARY
Bird species richness and composition vary along altitudinal gradients in response to differences in abiotic, e.g. temperature, and biotic factors, e.g. vegetation structure. A comparative analysis of two forest bird communities was made at Carlos Botelho State Park, southeastern state of São Paulo. Were selected for sampling areas where the forest was in the middle and late succession stages, located between 700 and 800 m in mountain forest and 70 and 200 m in submountain forest. The trails available were walked recording species observed or heard and sampling effort was the same in both areas, 360 hours. We recorded 177 species for mountain forest and 176 for submountain. Communities not differ significantly in any qualitative parameters evaluated, richness, and species with restricted distribution or threatened and species number per guild. However, they differed markedly in species composition. Results emphasize the importance of standardized sampling effort and evaluated habitat types in altitudinal gradients studies, and relevance of two forest physiognomies for Atlantic Forest bird conservation.Key words: altitudinal gradient, food guilds, Atlantic Forest