Characterization and temporal variability of the avifauna in Petrel wetland, Libertador Bernardo O’Higgins region, Chile: Conservation needs

Abstract

Wetlands are habitats of high diversity and global importance that are suffering increasing anthropogenic pressure, especially riparian estuaries in urban areas. One of them in the Mediterranean area of Chile is the Petrel wetland. Bird diversity was evaluated through monthly monitoring between April 2020 and March 2023. The taxonomic diversity of the species (Rtp), the Shannon-Weaver community diversity index (H´) and the Pielou evenness index (J’) were determined. In addition, the effect of the sampling sites on richness, abundance and reproductive events was evaluated; and the effect of the seasonal period on richness and abundance, adjusting Poisson regression models. A total of 113 bird species were recorded, representing 57.1 % and 56.1 % of the orders and families described in Chile, respectively, observing a high diversity (2.49<H’<3.28) and evenness. (0.61<J’<0.81). Twenty-seven migratory species were recorded, of which 81.5 % were summer visitors. The sampling sites significantly affected richness, abundance and the number of reproductive events. The richness and abundance were significantly higher in the warm period. These results show that the Petrel wetland is a site of high diversity at the avifaunistic level in the central zone of Chile, it also constitutes a space that houses a significant number of migratory species. Our work provides key information to develop management and management plans, highlighting certain wetland sectors as priority areas for conservation.