Philadelphia Vireo
Fairhaven, Humboldt County
Arcata, California
3 October 1998

During the annual Western Field Ornithologists' Annual Meeting in Arcata, Robbie Fischer and I decided to spend the morning checking various willow thickets near the tip of the north jetty of Humboldt Bay in search of vagrants. The weather was clear and few migrants were in evidence. A Philadelphia Vireo had previously been reported from the Fairhaven "Airport Patch" but we were unable to locate it on our first try. In fact the patch seemed totally devoid of birds and other birders had checked the patch earlier without results. As we were leaving the "Horse Pasture Patch" a couple alerted us and others that they had just seen the Philadelphia Vireo back at the Airport patch.

We returned and spent close to an hour searching carefully through the patch along with several other interested observers. During this time, we were told of a roosting Saw-whet Owl which had been found in the willows and we were able to study this bird at close range.

Finally I located the Philadelphia Vireo at the northwest corner of the patch near a small birdhouse and was able to show it to several other people including Mike Rogers. It was working slowly in the willows trying to kill a very large green caterpillar. Eventually it flew off to the east and was not relocated at that time, but was reportedly seen by numerous other observers in the afternoon.

It was a small vireo about the size and shape of a Warbling Vireo but easily distinguished by the entirely yellow underparts, brightest on the throat, mid-breast and undertail coverts and less yellow on the sides and belly. Also the face pattern was different in that it had a better defined eyebrow than on Warbling Vireo and a dark gray line extended from the eye to the bill, this line being widest at the eye and narrowing to a point at the bill. The upperparts were greenish on the back and grayish on the crown. The bill was short, thick and pale and the feet and legs were blue-gray.

Joseph Morlan
380 Talbot Avenue #206
Pacifica, CA 94044