Date May 25, 2022
Location Market Lake Wildlife Management Area, Roberts, ID
For this bird's picture I'm taking the unusual step of showing the page from the field guide instead of an actual photograph because this page (and the Audubon app) were integral to the identification. I made the ID on this Empidonax flycatcher without using voice, so a thorough explanation is warranted.
First, a description of what I saw. There were two white wing bars and a complete white eye ring. I also viewed it from behind -- the head was essentially gray and the back a greenish-gray, both of intermediate shade (neither dark nor light).
This particular habitat was a small forested area near an extensive wetlands. I was not in the mountains. The trees were mostly deciduous.
Even though this was obviously an Empidonax, and it wasn't making any noise (call or song), I decided to give a shot at identifying it, even though I usually don't bother trying under such circumstances.
I first narrowed it down by range. Only one eastern bird made the cut (Least), and four western birds were possible: Hammond's, Gray, Dusky, and Cordilleran. Least seemed unlikely since it was the extreme western edge of its range; Gray was out of range, but only by a little bit, so I included them for completeness.
Least is described as having a "rather bold white eye ring," and I did not observe this. The white eye ring was there, but it was thin. Along with the unlikelihood due to range, I eliminated Least.
Gray was eliminated rather easily since it is mostly gray and white -- no greenish or olive-colored areas. Plus, as noted above, it would be out of range according to the field guide. The season-specific drawings in my field guide were particularly useful here, as the Gray does have some olive coloration in the winter, but not in the spring.
Hammond's was eliminated by both habitat and eye ring. Hammond's are generally in coniferous woods in the mountains, which was not the habitat I was in as noted above. Also, the eye ring flares out creating an "almond" shape. As noted above, I saw a simple eye ring.
Cordilleran can also be eliminated by habitat, as in breeds in coniferous forests in the mountains, not the lowlands where I was. The wing bar on the Cordilleran is also less white.
This leaves only Dusky, and perhaps the flip side of the question: does Dusky match what I saw? In other words, rather than eliminating all the possibilities and being left with one, can I start with Dusky and match it to what I saw? The answer is yes. Coloration, habitat, range, eye ring, and wing bars all match the Dusky.
I never thought I would be able to identify an Empid without sound, or perhaps even dared, but there were enough clues in this case to be confident about the ID.
No comments:
Post a Comment