Padrões espaciais em comunidades de aves amazônicas

Abstract

Amazonia houses the world´s richest avifauna. To understand the processes that originated and have maintained this diversity, are required detailed studies concerning spatial variation of major patterns of bird assemblages as well as comparisons among them across different spatial scales. In addition, it is essential to use an approach that takes in to consideration different factors that can be acting on and influencing these patterns. This thesis is composed of three chapters. In the first chapter, the composition, ecological characteristics and vulnerability patterns of the avifauna at the Ferreira Penna Scientific Station (ECFPn), Eastern Amazonia, are described. An updated species list to that area, with information on the abundance, trophic guilds and habitat type is presented. Vulnerability for each species was determined by using rarity patterns. In the second chapter, the avifauna of ECFPn is compared with other sites representing the different areas of Amazonian bird endemism. Different taxonomic and ecological categories were considered in several comparisons to evaluate if patterns of distribution are different among these categories and determine which factors can influence the patterns observed. Finally, the third chapter presents an analysis of the spatial variation of richness, abundance and similarity across six 100-ha sites located within a homogeneous landscape dominated by upland forests. Variation in species composition was then correlated with geographical distance and vegetation structure of these sites. The combination of theses studies increases our knowledge about the area of endemism Xingu and uses for the first time several different approaches to investigate distribution patterns bird assemblage in Amazonia at different spatial scales.