There are fifteen types of vireos in North America, nine of these vireos live or have been identified in Canada. These are the Bell's Vireo, Blue-headed Vireo, Cassin's Vireo, Hutton's Vireo, Philadelphia Vireo, Red-eyed Vireo, Warblering Vireo, White-eyed Vireo, and the Yellow-throated Vireo. The rest range mostly in the Southern States into Mexico. They are the Black-capped Vireo, Black-whiskered Vireo, Gray Vireo, Plumbeous Vireo, Thick-billed Vireo and the Yellow-green Vireo.

William J. Mattson has written:

'Shrub nesting of the red-eyed vireo in relation to structure of aspen forests' -- subject(s): Nest building, Aspen, Red-eyed vireo

a red-eyed vireo is a bird that ends in "o"

Vireo Altricapilla.

If you are refering to Vireo, the genus of birds, the answer is no they are not mammals. They are avians.