Description wikipedia

The American gray flycatcher, American grey flycatcher, or just gray flycatcher (Empidonax wrightii) as it is known in North America, is a small, insectivorous passerine in the tyrant flycatcher family. It is common in the arid regions of western North America, especially the Great Basin. From sagebrush steppes to pinyon-juniper woodlands and ponderosa pine forests, this flycatcher forages for insects from shrubs or low tree branches. The American gray flycatcher is one of the many species in the genus Empidonax. These species are very similar in appearance and behavior, and they are notoriously difficult to differentiate. The best characteristics for distinguishing these species are voice, breeding habitat, and range. The American gray flycatcher, however, can be identified by a unique behavior, its downward tail wag. Other Empidonax species typically exhibit a rapid upward tail flick.