Plumbeous Vireo, Vireo plumbeus

Plumbeous Vireo, Vireo plumbeus. Photograph taken within a residential community in Alamos, Sonora, April 2018. Photograph and identification courtesy of David F Smith, Alamos, Sonora.

The Plumbeous Vireo, Vireo plumbeus plumbeus, is one of four subspecies of Plumbeous Vireo, three of which are permanent residents of Mexico. They are a member of the Vireonidae Family of Vireos, Shrike-Babblers and Erpornis, which has sixty-three members placed in eight genera, and one of thirty-three global members of the Vireo Genus. They are known in Mexico as vireo plomizo.

The Plumbeous Vireo is small in stature with short, rounded wings, with a long tail. Their head has a broad white stripe and eye ring. Their upperparts are a smooth neutral gray and their rump is a tinged olive green. Their underparts are near-white, the sides of breast smudged pale grayish olive, and their flanks are very pale sulfur yellow or dull white. Their wings and tail are blackish to neutral gray with two broad wing bars and edged in white. They have a black bill, bluish gray legs and a brown iris. The sexes have different plumages and size.

The Plumbeous Vireo is found within montane coniferous and mixed forests, deciduous riparian woodland at elevations between 920 m (3,000 feet) and 2,500 m (8,200 feet). They forage primarily on insects, spiders and crustaceans with their diets being supplemented during the winter with fruits and plant materials. They are highly migratory moving to southern locations during the winter. The Plumbeous Vireo are poorly studied, and their biology and behavioral patterns are not well documented.

The Plumbeous Vireo is found from the United States border south in the Central Highlands and along the Pacific Slope form Sinaloa to Oaxaca. The plumbeus subspecies is found in Western Mexico from within the Pacific Slope of Sonora south to Oaxaca.

The Plumbeous Vireo is difficult to distinguish from the Blue-headed Vireo, Vireo solitarius and Cassin’s Vireo, Vireo cassinii, in the areas with overlapping ranges.

From a conservation perspective Plumbeous Vireo is currently considered to be of Least Concern, with stable widely distributed populations.