In Ontario the Warbling Vireo is a bird of village shade trees or by rural roadsides, not a dweller in forest tree tops like the Red-eyed Vireo. In winter they go south to Central America.
Their long warbling song which usually ends in a question (rising pitch) makes them easy to locate.
This is the source of the handouts I got when I took a precovid warbler class at Tommy Thompson.
light of the moon
moves west, flowers’ shadows
creep eastward – Yosa Buson (1716–84)