If you are refering to Vireo, the genus of birds, the answer is no they are not mammals. They are avians.
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.
Vireo Altricapilla.
vireo
The scientific or taxonomic name would be Vireo gilous.
The scientific or taxonomic name would be Vireo bellii.
Vireo
vireo
vireo
a small grayish bird
· Vanga · Vireo · Vulture
It is 4.5 inches long
Vireo