Seasonality in the Brazilian Pantanal influences avian functional diversity

Abstract

ABSTRACT Seasonality significantly affects environmental changes in the Pantanal, especially during wet and dry periods. Inundation and drought impact the onset of flowering and fruiting and the occurrence of insects. Because such resources may vary across seasons, it is expected that avian functional diversity also changes. We examine how functional diversity changed over time, as measured by functional richness and functional divergence. For functional richness, we observed a functionally overdispersed bird community over the seasons, whereas for functional divergence, two different patterns were found: (1) functionally overdispersed bird communities during the wet and receding seasons and (2) functionally clustered avian communities in the dry and rising seasons. The diversity of functional groups did not significantly vary across the seasons, as expected, but varied between forests and savannas. The environment has restricted resources in certain seasons, benefiting species with specific functional characteristics, however, bird species in the Pantanal are often generalists adapted to using a wide variety of food resources. Although the habitat turnover rate is an important factor that influences bird species composition across seasons, the changes in species composition still allowed the maintenance of certain functional characteristics, contributing to conservation of the existing functional groups in the ecosystem.