The Willow Flycatcher is a small, insectivorous songbird in the tyrant flycatcher family (Tyrannidae) that breeds in riparian habitats across much of North America, including Arizona. It is one of the more challenging species to identify in the genus Empidonax, as its plumage is generally grayish-olive above and whitish below, with indistinct wing bars and a faint eye ring. Identification is most reliable by voice: the species gives a sharp “fitz-bew” song.
In Arizona, the Southwestern Willow Flycatcher (Empidonax traillii extimus), a subspecies, is of particular conservation importance. This population is federally listed as endangered due to significant loss and degradation of riparian habitats, especially those dominated by willow (Salix spp.) and cottonwood (Populus fremontii). Historically widespread along rivers such as the Colorado, Gila, Salt, and San Pedro, the species now occurs in fragmented breeding populations at sites like Roosevelt Lake, the San Pedro River, and along the lower Colorado River.
Breeding typically occurs from May through August, with nests placed in dense riparian vegetation near surface water. The birds feed primarily on flying insects, which they sally out to catch from perches. Migration takes them south into Mexico, Central America, and northern South America for the winter months.
Conservation efforts in Arizona focus on protecting and restoring riparian habitats, managing water use, and monitoring breeding populations of Empidonax traillii extimus. These efforts are essential to prevent further declines of this subspecies, which remains one of the most imperiled songbirds in the American Southwest.
