Diversity and activity of bird fauna in ephemeral river-created habitats in Amazonia

Abstract

ABSTRACT Seasonal changes in runoff and inundation create river-habitats that are considered key to the diversity of Amazonian bird species. However, studies on avifauna in different riverine habitats remain scarce. We used camera traps to survey the avifauna in river-created habitats along 39 km of river in the eastern Brazilian Amazon. We examined the number of bird species detected and species composition in islands and margin banks, evaluated species–area relationships in these two habitats, and examined if the most abundant bird species have differences in activity pattern between habitats. Cameras recorded 21 bird species from 13 families (Accipitridae, Ardeidae, Bucconidae, Caprimulgidae, Cathartidae, Columbidae, Cracidae, Hirundinidae, Icteridae, Scolopacidae, Thraupidae, Threskiornithidae, and Tyrannidae). Species composition did not differ between habitat types but we found a discernible area effect, explaining as much as 84% on the number of species detected across island sites. Overlaps of activity pattern of bird species were high between habitat types, but differences in activity peaks were found for Molothrus oryzivorus and Pitangus sulphuratus while examining islands and margin banks. River-created habitats are relevant to Amazonian bird diversity and studies on these habitats must be increased to better understand their value across the Amazon.