The Vesper Sparrow (Pooecetes gramineus) is a medium-sized sparrow and the lone member of the genus Pooecetes.
Adults are light brown on top, lighter underneath. Throughout their plumage is darker streaking. They have a white eye ring and a long dark brown tail which shows white outer feathers in flight.
They can be found in open grassy areas across most of North America and they build their open cup nests on the ground, usually under a clump of grass.
These birds winter in southern and central United States and Mexico.
These birds forage on the ground for insects and seeds. When not breeding they will often feed in small flocks.
To indicate territory the male sings from a higher perch, such as a shrub or fencepost. The musical song begins with two pairs of repeated whistled notes and ends in a series of trills, somewhat similar to that of the Song Sparrow.
This bird’s numbers are declining in the eastern parts of its range due to habitat loss.