Small flycatcher, extremely similar to several other species. Prefers clearings and boggy areas, often with patches of alders. Grayish-olive above and pale below with thin white eyering. Wings dark with bold white wingbars. Nearly identical to Willow Flycatcher; once considered the same species. Also compare with Least Flycatcher, which is very similar but has slightly shorter wingtips and a bolder eyering. Best identified by voice: song is a rolling, rough "freeBEER;" call is a clear "pip." Silent birds, especially in migration, often best left unidentified.