Willow flycatcher
The willow flycatcher (Empidonax traillii) is a small insect-eating, neotropical migrant bird of the tyrant flycatcher family native to North America. Taxonomy There are four subspecies currently recognized, all of which breed in North America (including three subspecies that breed in California). At one time, this bird and the alder flycatcher (Empidonax alnorum) were considered to be a single species, Traill's flycatcher.Their song is the only reliable method to tell them apart in the field. The binomial commemorates the Scottish zoologist Thomas Stewart Traill. Subspecies The subspecies are best distinguished from each other by their songs. In addition, the four subspecies have significant genetic differences based on mitochondrial DNA analysis. Their winter ranges have been elucidated using mitochondrial DNA genetic studies of 172 birds sampled in winter combined with plumage coloration and morphological differences. The four subspecies of the willow flycatcher are: E. t. brewsteri – Little willow flycatcher The little willow flycatcher (E.t. brewsteri) is the Pacific Slope subspecies of the willow flycatcher. Described by Oberholser in 1918, it breeds in California from Tulare County north along the western side of the Sierra Nevada, and in Oregon and Washington west of the Cascade range. E. t. adastus The Great