Cassin's vireo Vireo cassinii

Identification Tips:

• Length: 4.75? inches
• White spectacles
• Dark eye
• White wing bars
• Dull gray head contrasting slightly with olive back
• Whitish underparts with dull olive flanks
• Thick bill with hooked upper mandible
• Sexes similar
• Juveniles similar to adults
• Formerly conspecific with Blue-headed and Plumbeous Vireos

Similar species:

The bold white spectacles of the Cassin's Vireo are shared by the Blue-headed and Cassin's Vireos. Blue-headed Vireo has brighter yellow flanks and more contrast between the head and back. Plumbeous Vireo is duller with little contrast between the head and the back and has grayer flanks. Black-capped Vireo also has white spectacles but it has a black, not gray, head. Yellow-throated and White-eyed Vireos have yellow spectacles. The Gray Vireo lacks spectacles and has faint wing bars.

Length and wingspan from: Robbins, C.S., Bruun, B., Zim, H.S., (1966). Birds of North America. New York: Western Publishing Company, Inc.