Patrones espaciales de distribución y diversidad de la avifauna en la provincia del Balsas

Abstract

The Balsas' province of southern Mexico has been defined as a natural unite based on its endemic taxa and environmental variables. It is recognized as a center of diversification, endemism and biogeographic transition. However, there are elements that allow us to distinguish 2 different biotic components within the province.We analyzed the distribution patterns of richness and beta diversity of birds, both total (migratory + resident) and resident. We used 2 coefficients of dissimilarity (1-Jclásicoy 1-Jmod.) to analyze beta diversity within the province. There are 3 areas with high species richness: 1) Northeastern; 2) Western and 3) in the center of the province of the Balsas. The beta diversity pattern suggests the existence of 2 components in the bird community that correspond to Eastern and Western sectors of the Balsas province. This is consistent with studies concerning the tendencies of the distribution of other taxa within the Balsas province. Therefore, we propose the division of the province into 2 faunal districts: Eastern and Western.