Altitudinal Distribution of Birds in the Sierra Madre Del Sur, Guerrero, Mexico

Altitudinal patterns of distribution, diversity, and species turnover in the avifauna of the Sierra de Atoyac, Sierra Madre del Sur, Guerrero, México, were studied along a transect from the tropical coastal plain to high-altitude coniferous forests. Species richness is highest at low elevations and declines with increasing altitude. Richness is relatively uniform within habitat types, but high levels of species turnover are found at habitat ecotones. Altitudinal ranges of congener species pairs overlap more frequently than predicted by null models, suggesting that competition may not have played a dominant role in structuring the community. Patterns of diversity, endemism, and habitat destruction are discussed in terms of conservation priorities.