vireo (bird) philadelphicus (of the city of Philadelphia, where it was first collected by John Cassin in 1851)
Saturday, May 15, 1982 — 10:00 am
Elk Grove Village, Illinois — Busse Woods
This must have been the stage of my birding experience when I gained the expertise necessary to identify vireos. I got three lifer vireos in a week.
I tracked this one down by its song. It was foraging slowly through the woods, moving branch to branch, up and down from treetops to understory (as low as 15 feet above the ground). It was picking at leaves and occasionally fluttering out like a flycatcher. It often stopped to sing. It moved slower than the warblers that were foraging nearby.
I spotted a Red-eyed Vireo about five minutes later. The Philadelphia Vireo was smaller, and its song, although similar, was slower and not as continuous.