Data from: Using river color to predict Amazonian floodplain forest avifauna in the world’s largest black-water river basin

Despite the importance of rivers in Amazonian biogeography, avian distribution patterns in river-created habitats (i.e., floodplain forest) have been sparsely addressed. Here we explore geographic variation in floodplain forest avifauna, specifically regarding one of the most striking aspects of the Amazon: the diversity of river “colors” (i.e., types, based on the color of the water). We sampled the avifauna at 30 sites, located in 17 different rivers (nine black- and eight white-water), in the Rio Negro basin, northwestern Brazil. Our sampling comprised ten 15-min point-counts per site, distributed every 500-1000m along the river. We recorded a total of 352 bird species, many of which occurred in both river types. Although bird species richness was similar among rivers, we found significant differences in species composition. Nearly 14 percent of the species were significantly associated with one of the two river types. Most floodplain forest specialists occurred predominantly in white-water rivers, whereas species that are typically associated with white-sand habitats occurred in black-water. Despite significant distinctions between river types, occurrence patterns and levels of habitat association differed among indicator species and may vary in the same species throughout its global distribution. There were also “intermediate” avifaunas in some of our sites, suggesting continuous parameters that characterize river types are structuring species turnover. The water color-based classification of Amazonian rivers represent a simple and powerful predictor of the floodplain forest avifauna, offering a stimulating starting point for understanding patterns of floodplain avian distributions and for prioritizing conservation efforts in these overlooked habitats