Rough-Winged Sparrow
617. Stelgidopteryx serripennis. 5½ inches.
This species is about the same size as the last, and similar, but with the throat and breast grayish in place of the white. The outer webs of the outer primaries are recurved, forming a series of hooks. It nests in holes of embankments or in the crevices of cliffs, or among the stones of bridges and buildings. Their eggs are four in number and are pure white (.75 ×.52). The range of these birds covers the whole of the United States, breeding from Mexico to British Columbia.