干旱区生态环境知识资源中心

We studied the bird community at a site in the Gran Chaco of Bolivia composed principally of gallery forest bordering the Parapeti River within a larger landscape of dry thorn forest. We present the first detailed analysis of local avian community diversity across seasons and habitats for the bolivian chaco, utilizing both observational and mist-net capture data. Of the 101 species recorded in dry and gallery forest, 20% were recorded exclusively in gallery forest-and 20% were recorded exclusively in dry forest; 60% were recorded in both habitats. Analysis of,species habitat affinities at the continental scale relative to their habitat occupancy at the study site revealed that species typical of lowland evergreen forest, which is not a chaco habitat, tend to be found in gallery forest at the site, while species associated with tropical deciduous forest/arid lowland scrub (habitats typical of the bolivian chaco) lire more likely to be found in the dry forest at the site. We examined species-habitat associations in more detail through mist-netting. Richness and diversity as measured by mist-netting were significantly higher in gallery forest than dry forest. When habitat associations were compared across wet and dry seasons, the dry forest in the dry season exhibited the lowest levels of species richness and diversity of any season-habitat combination. Overall, our results suggest that habitat differences in this region of the Gran Chaco play an important role in maintaining local avian community diversity.