WATERBIRD ANNUAL ASSEMBLAGE IN A ZONE OF THE VENEZUELAN LLANOS REGION
DOI:
https://doi.org/10.58843/ornneo.v37i1.1419Keywords:
bird counts, boreal migrants, community structure and diversity, waterbird community composition, wetlandsAbstract
The Venezuelan Llanos is a floodplain region of global importance for waterbirds, but comprehensive surveys of waterbird assemblages that encompass the entire annual cycle are lacking. We conducted monthly fixed-point surveys of waterbirds at eight permanent lagoons within an agro-forestry landscape in the Llanos over an entire annual cycle, from April 2022 to March 2023. We recorded species richness and abundance and evaluated diversity, dominance, turnover patterns, and spatio-temporal variation to characterize assemblages and assess the conservation value of these wetlands. We recorded a total of 54 waterbird species, with greatest species richness and abundance at the largest Samancito lagoon. Month of the year significantly influenced species richness and abundance, peaking during the dry season. Structural traits (diversity, dominance, and species turnover) varied among lagoons, reflecting distinct ecological values and assemblages, with certain lagoons serving as functional hotspots for specific guilds, such as Gandaria lagoon for waders. Migratory species comprised a modest percent of species richness and total bird counts, peaking in the month of September (20% species richness; 12% abundance). Our findings underscore that wetlands within the Venezuelan Llanos were not functionally uniform, including also temporal dynamics of waterbird assemblages. Conservation and management strategies should recognize the complementary roles of different wetlands and account for seasonal variability in species use, thereby preserving permanent wetlands to support waterbird assemblages year-round, particularly during resource-scarce dry season.
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