Abundance, temporal variation, and microhabitat use of the house sparrow, Passer domesticus (Passeriformes: Passeridae), in urban and anthropogenic environments in Northeastern Brazil

The increase in urbanization poses a significant threat to biodiversity, leading to the alteration of natural habitats and intensified competition between native and exotic species. The house sparrow, Passer domesticus (Linnaeus, 1758) is a globally widespread exotic and invasive species known for its environmental adaptability. However, recent studies have indicated that degrees of urbanization and microhabitat characteristics can influence house sparrow populations in diverse ways. In this study, we investigated the abundance, temporal variation, and microhabitat use of house sparrows across three areas with varying degrees of urbanization: urban areas (consisting of residential areas, paved streets, and squares), anthropic fields (including pastures and cultivated fields), and forests in Jacara & uacute;, Northeastern Brazil. From October 2017 to September 2018, we employed the point count method to compare the abundance of house sparrows among the different areas. A total of 1880 records of house sparrows were obtained, with 56.3% observed in urban areas, 43.7% in anthropic fields, and none in the forest, indicating significant variations among the study areas. Throughout the year, active birds were observed in both urban areas and anthropic fields. Although no variations in bird abundance were found among the months in urban areas, a significant difference was observed in March (higher abundance) and October (lower abundance) in anthropic fields. The most frequently utilized microhabitats by house sparrows were ground surfaces, man-made structures, and artificial perches, whereas trees were the least used microhabitats. Our findings confirm that both habitat and microhabitat characteristics play crucial roles in determining the abundance and distribution patterns of the species in Brazil. Furthermore, our results suggest that house sparrows avoid using forests, and these environments can act as barriers to the species' distribution. These findings enhance our understanding of the ecological dynamics of house sparrows in Brazil and provide valuable insights for management.