Bird communities in a tropical dry forest at Mesa de Xeridas, Santander, Colombia

The characterization of bird assemblages constitutes key baseline information to guide plans of environmental land use and conservation. Here, we evaluated the composition and structure of understory bird communities in three micro-basins of Mesa de Xeridas, in the dry forest of Chicamocha Canyon, Colombia 's most extensive dry forest area. Bird assemblages were studied at different elevations and climatic seasons by means of mist netting. Based on 18,900 means of mist net/hour, we recorded 91 species of 29 families. The sub-basin diversity indexes were similar, but showing differences between altitudinal ranges and climatic season, with higher values in Totumera and during the transition season from dry to rainy. The structure of the communities, comparing rank/abundances, in all sub-basins by elevation and season, corresponded to a log-normal model. Temperature and humidity varied between most heights and climatic seasons, except in one of the three sub-basins, showing higher temperature values at lower elevations, as well as significantly lower relative humidity. Our results suggest that the studied bird assemblages are temporally stable, mainly due to a set of permanent core species. Given that this ecosystem is considered at high risk, knowing the composition of the community in different seasons and at various elevations, provides baseline information useful for decision-making in land use and conservation.