11 Birds That Are So Round They'll Roll Straight Into Your Heart

You'd Be Forgiven If You Thought The Term Plumbeous Referred To The Roundness Of This Bird: The Plumbeous Vireo is matte gray above and white below—it's the most monochrome of the three species once combined as Solitary Vireo. Plumbeous sings a pleasing, burry song as it forages through dry pine forests in the beautiful canyons and mountains of the interior West, Great Basin, and Mexico. During migration and the nonbreeding season, this species often joins mixed-species flocks of woodland birds, especially on its wintering grounds.