Willow flycatcher

The willow flycatcher is a small insect-eating, neotropical migrant bird of the tyrant flycatcher family. There are four subspecies of the willow flycatcher currently recognized, all of which breed in North America . ''Empidonax'' flycatchers are almost impossible to tell apart in the field so biologists use their songs to distinguish between them. The binomial commemorates the Scottish zoologist Thomas Stewart Traill.