Vireo cassinii ORDER: PASSERIFORMES FAMILY: VIREONIDAE
IUCN Conservation Status: Least Concern
© Brian E. Small
A common bird of the far western forests, the Cassin's Vireo is conspicuous for its constant singing. Formerly lumped as a "Solitary Vireo" with the Plumbeous and Blue-headed vireos, it is now considered a separate species.
Song a broken series of slightly burry whistled notes, inflected upwardly and then downwardly. Calls a series of short harsh notes.