ML612903735

Age

Not specified

Sex

Not specified

Observation details

***probably very rare, but the pattern of occurrence for this western subspecies (ridgwayi) in our area appears to be poorly known; a combination of a challenging identification (see below) plus a probable lack of general consideration. Thus, winter records of Nashville warblers in the northeast may be partially comprised of these birds (i.e., western vagrants) rather than entirely lingering eastern birds. While birding the shrub-thickets east of the Gatsby building, this bird popped up in response to some pishing, etc., and was instantly identifiable as a Nashville warbler with conspicuous white eye-ring, gray head, sharp bill, and yellow underparts. However, we were quick to notice that the bird's head and back lacked any discernable contrast and, upon getting better views, it was clear that the two were entirely concolorous! Indeed, the head and back of this bird were both entirely a cold-gray color with the back almost lacking any olive tones until it met the rump, which was itself a glowing lemony-yellow. Furthermore, the bird's underparts were very bright yellow; possibly brighter than an eastern NAWA would be, with a very well-contrasted white vent area. Perhaps most importantly (at least per some references), the bird wagged/bobbed its tail a lot while we watched it, another large mark towards ridgwayi. We were initially unable to photograph it and progressed on our CBC-route while all agreeing that it was as good of a candidate for western Nashville warbler (ridgwayi) as one could expect. After a while, Pete suggested we go back to better document the bird (wise). To coerce it back out of the same shrubby area, we decided to play some western Nashville warbler song, which is noticeably different than eastern counterpart. The bird quickly reacted to the song of ridgwayi, by coming out and calling a bunch. Then Tim was able to get some very nice documentation shots, which clearly show the aforementioned field marks. I am not aware if the call-note is diagnostic, but we failed to record it in any event. There appears to be some overlap between the two subspecies, but every metric that we viewed this bird against (e.g., head/back contrast, back color, tail-wagging, underparts color, rump color, vent color, etc.) pointed strongly towards ridgwayi and against the eastern, nominate subspecies. Photos to be added.

Technical information

Model

NIKON D500

ISO

1600

Focal length

500 mm

Flash

Flash did not fire

f-stop

f/5.6

Shutter speed

55924/44739201 sec

Dimensions

1793 pixels x 1195 pixels

Original file size

761.27 KB