The vesper sparrow (Pooecetes gramineus) is a medium-sized New World sparrow. It is the only member of the genus Pooecetes.
Adults have light brown upper-parts and light under-parts, both with darker streaking. There are three features that are unique to the Vesper Sparrow. The first is the presence of a small, white ring surrounding the eyes. The second is the flash of white tail feathers that occurs during flight. The third is the presence of a chestnut patch on the shoulder. However, this is usually not visible to an observer. Another notable characteristic is that some Sparrows, especially west of the Cascades, tend to have a more pinkish hue. They also do not have a bold eyeline found in some sparrows.