House Sparrow (Passer domesticus) populations have been negatively affected in various regions of the world because of the urbanization process, although in Brazil the factors involved are still poorly understood. Through standardized sampling, our study aimed to assess the effects of an urbanization gradient on the abundance of House Sparrows in the city of Campo Grande, in central-western Brazil. We recorded House Sparrow and Saffron Finch (Sicalis flaveola) abundance and the percentage of urbanized area (impervious surface) in 61 hexagons of 16 ha each. We surveyed sparrows by using fixed-radius (50 m), 10-min point counts (4 points/hexagon). We recorded 897 House Sparrows and 408 Saffron Finches in all sampled hexagons, with abundance ranging from 0 to 68 House Sparrows/hexagon (∼1 individual/ha) and from 0 to 22 Saffron Finches/hexagon (0.42 individual/ha). We found a significant relationship between House Sparrow abundance and the proportion of hexagon impervious surface according to a quadratic equation, as well as more birds in areas that exhibit moderate to high urbanization than in low urbanization. Multilevel Structural Equation Models showed that House Sparrows were negatively (but nonsignificantly) affected by buildings and trees >5 m in height, positively affected by buildings <5 m in height (houses), and Saffron Finch abundance had a positive but nonsignificant effect in House Sparrow distribution. Even for a bird considered common and adapted to urban conditions, cities seem to have barriers for the establishment of House Sparrows. Simple urban architectural considerations, such as the establishment of roof openings or the management of town squares and vacant lots that allow the growth of seed grasses, could help these birds to continue using urban landscapes.

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