This medium sized sparrow is 5-6 inches in length and has a wingspan of 9 inches. Identifying characteristics are dark streaking on a light brown back, a white eye ring, orange shoulder patch, and white outer tail feathers that flash in flight. A white mustache line extends back from the base of the rather small conical beak.
Vesper sparrows favor rather dry grassy habitats of prairies, meadows, shrubby fields and pastures, where they spend a lot of time foraging on the ground. In New Mexico these sparrows are found outside the breeding season in the central and southern counties and in the north and west during spring and summer. The wider breeding range extends up through the western states and Midwest, up into the prairies of Canada. Winter range is the southern border states and into Mexico.
They take a variety of ground invertebrates, including grasshoppers, beetles, bugs, moths, spiders and others. They also feed on grass seeds. The open cup nest is built on the ground out of grasses and animal hair. The 2-6 eggs and nestlings are vulnerable to predators and the female will flutter and attempt to divert potential predators away from the nest, in the same manner as is familiar in Killdeers. Two broods are produced per year.
While populations have declined in recent year in the upper Midwestern states due to losses of grassland habitat, the Audubon Society reports that the species is still abundant in the West.