Beschreibung:
<jats:p> Landscape heterogeneity and annual flood pulses characterize the Brazilian Pantanal, the largest floodplain in South America. The objective of this work was to explain spatial and temporal variations in the trophic structure of a bird assemblage consisting of 316 species of terrestrial and aquatic birds, out of which 88 are visitors. The food items potentially consumed by these species were combined into 12 trophic guilds and were compared based on habitats (terrestrial or aquatic), periods of the year, and visitor or resident species. Nonmetric multidimensional scaling was used to determine which trophic guilds characterize the different habitats and months. The habitats were separated into a gradient of trophic guild similarity ranging from woodlands to purely aquatic, with swamps and floodable fields in intermediate positions. Species that consume invertebrates and plants predominate in the terrestrial habitats, whereas the consumption of terrestrial and (or) aquatic invertebrates, vertebrates, and plants predominate in the aquatic habitats. The monthly similarities in trophic structure vary with rainfall, and the period of receding waters is characterized by an increase in the number of species in guilds that consume nectar, invertebrates, vertebrates, and (or) plant parts obtained or captured in the drying landscape and terrestrial habitats. Visitor species do not exploit new resource types; instead they accommodate themselves in the pre-existing trophic guilds. </jats:p>