Variability in bird communities' composition in the Biosphere Reserve Montes Azules and adjacent areas, Chiapas, Mexico

In order to compare the bird communities' composition and their possible relationships, I sampled monthly from January to December 2002 in the Biosphere Reserve Montes Azules (REBIMA) and adjacent areas, Chiapas, Mexico. Data were obtained during 48 days of fieldwork in an area of 60 ha by site. I recorded 133 species, which represent 36% of the total number of species reported for the REBIMA. Highest species richness was found in the site 1 (well preserved forest with 113 spp). High similarity between the sites 1 and 4 were found (this last with 50% original vegetation, IS = 0.89). Approximately 80% of the species were residents; and insectivores were the best represented trophic guild (47 spp). All feeding guilds were represented in all sites showing differences in species richness and abundance. Variation in the richness and composition of bird communities among different sizes was due to the fact that some species may demonstrate a different response to the degree of forest fragmentation and habitat transformation. However, in spite of limited sampling efforts, the bird richness suggests that secondary habitats play an important role in the persistence of species in tropical ecosystems.

richness; similarity; tropical forest; Selva Lacandona