This video from the USA says about itself:
White-eyed Vireo singing
22 July 2015
The White-eyed Vireo is small and brightly-colored, but often secretive as it forages in low shrubby vegetation. Its loud, chattering song is a familar sound in spring and summer in the southeastern U.S.
The white-eyed vireo is a small bird often confused for a warbler, and because of its secretive habits it can be difficult to see and properly identify. As birders get more familiar with these birds, however, the more they will notice vireos appropriately and recognize what makes them unique: here.