Cassin's Vireo

Scientific name: Vireo cassinii

The Cassin’s Vireo is the westernmost breeding member of the three species of vireos that were formerly considered to be a single species called the Solitary Vireo. Cassin’s Vireos have occurred as vagrants as far east as the East Coast.

Vireos as a group are very frequently parasitized by Brown-headed Cowbirds, and the Cassin’s Vireo is no exception. Despite this, the Cassin’s Vireo population has been increasing in recent years.