Structure of the Wetland‐Dependent Bird Assemblages in the Pequenos Lençóis Maranhenses, in Maranhão, Brazil

ABSTRACT Wetland‐dependent birds play crucial ecological roles and are highly influenced by local environmental factors such as depth, salinity and microhabitat availability. Although the importance of these environments for biodiversity is already recognized, studies on the spatiotemporal dynamics of these assemblages in Maranhão remain scarce. Here, we investigated the structure of bird communities in two lakes in the Pequenos Lençóis Maranhenses, evaluating the influence of area, perimeter, depth and salinity. With a total sampling effort of 45 h, being accumulated over the 15 months of the study period, we recorded 1588 individuals, distributed across 40 species and 16 families, with the larger and shallower lake exhibiting higher abundance, richness and taxonomic diversity. Our findings indicate that extensive and shallow lakes enhance habitat heterogeneity, thus supporting higher foraging opportunities for wetland‐dependent species. Furthermore, we recorded seven migratory bird species, including the globally near‐threatened Calidris pusilla , reinforcing the importance of these sites as wintering and migratory stopover areas. This pattern suggests that environmental gradients, particularly depth and area, act as key drivers shaping bird assemblages in the Pequenos Lençóis. This study was the first quantitative analysis of wetland‐dependent avifauna in the Pequenos Lençóis Maranhenses, and the results provide baseline information for wetland management and migratory bird conservation in northern Brazil.