Warbling Vireo in Finca Hartmann

Julie Craves and Darrin O'Brien sent in the third record of Warbling Vireo for Panama:
Date and time: 12 January 2008, approximately 12:40 PM

Location: Santa Clara, Chiriqui Panama: just below Ojo de Agua section of Finca Hartmann. Lat/long approximately 8.858, -82.7468.

Circumstances of sighting: We were returning to the Hartmann residence after birding the finca’s upper Ojo de Agua section. We were just downhill from forested patches and there were bananas/plantains growing on the left side of the road. O’Brien stopped to point out a vireo foraging in a Musa by the side of the road, about 15 to 20 feet away from us. The Musa was only about 10 feet tall, so the bird was foraging at or near eye level, in good light. We immediately identified it as a Warbling Vireo, a common species where we live in southern Michigan, USA.

We stopped to examine the bird as it was the first Warbling Vireo we’d had on the trip, and because we did not recall this species being shown in our plates from “A Guide to the Birds of Panama” by Ridgely and Gwynne. We had only these plates with us, and we confirmed that Warbling Vireo was not pictured and double-checked that this bird was not another vireo species, taking care especially to eliminate Philadelphia Vireo, a bird which we also see at home. Since Warbling Vireo was not pictured we felt it must have been unusual, and therefore noted the bird’s features at that time as it is our habit to submit all our notable sightings to North American Birds when we travel. As we did not have the text or any other references with us, we did not fully know the rarity of Warbling Vireo in Panama, and did not fully appreciate the significance of our sighting – or that, coincidentally, the other recent record was also at Finca Hartmann – until we purchased “An Annotated Checklist of the Birds of Panama” several days later.

Identification: We saw the bird well under excellent conditions, and observed it for about two minutes.

The bird was a medium-sized vireo, somewhat slender with a medium-length tail. It had a dull dusky eye line (faint on the lores) and paler supercilliary, giving it an indistinct facial pattern. It had a grayish brown cap, and unbarred wings. It was dull grayish-olive above, and pale below except for a yellowish wash visible on the upper flanks. The bird had a dark eye and bluish-gray legs and feet. The bill was medium-length with a tiny hook at the tip.

Warbling Vireos are abundant spring and fall migrants where we live, and also nest commonly in our area. Both of us have handled many dozens in the many years we have been banding birds.