Cassin’s Vireo, Vireo cassinii

Cassin’s Vireo, Vireo cassinii. Bird photographed in the greater Los Cabos area of Baja California Sur, December 2019. Photograph courtesy of Dr. Tom Bartol, Carlsbad, California.

Cassin’s Vireo, Vireo cassinii. Photograph taken within the Resrerva-Monte Mojino, Alamos, Sonora, January 2019. Photograph and identification courtesy of David F Smith, Alamos, Sonora.

The Cassin’s Vireo, Vireo cassinii, is a member of the Vireonidae Family of Vireos, Shrike-Babblers and Erpornis. They are small in stature. In Mexico they are a year-round resident of the Sierra de la Laguna Mountains of the greater Los Cabos area of Baja California Sur. They are also found during the winter months within the Pacific Slope from Northern Sonora south to Oaxaca and in the interior from Durango, Southeast Coahuila and central Nuevo León to south-central Oaxaca at elevations between 120 m (400 feet) and 2,400 m (7,900 feet). From a conservation perspective Cassin’s Vireo is currently considered to be of Least Concern with stable, widely distributed populations. They are found in coniferous, mixed coniferous/deciduous and deciduous forests in mountains and foothills. They consume primarily insects and spiders and limited amounts of seasonal fruits and berries.