Posted by Brennan Mulrooney on October 11, 2003 at 15:32:05:
In Reply to: Quiz photos by Brennan Mulrooney. posted by Larry Manfredi on October 07, 2003 at 12:04:17:
Well I hope everybody enjoyed those, I assume from the lack of recent posts that you're all done guessing. So here are the "official" answers. These birds were all banded this fall at our (Audubon) study site in the lower keys.
1. Tennesee Warbler; adult female. This plumage is not safely distinguished in the field from first fall birds of either sex, but because we had the bird in hand, we could say it was adult by the shape of the outer tail feathers and primary coverts as well as the fully ossified skull. A male of this age would show a grayer crown and nape and whiter supercilium. Plumage marks eliminating other species have already been mentioned.
2. Cape May Warbler; first fall female. This bird proved to be rather tricky. These birds are certainly in the group of "confusing fall warblers". Some field marks in the photo do allow us to ID it however. First of all, the downward curving bill shape of this species is rather distinctive and consistent at all times of the year. The fairly bold white edges of the median coverts (upper wingbar) eliminate Orange-crowned Warbler and supports CMWA which has a very bold upper wingbar/wing patch in all other plumages. Also elminating OCWA are the white undertail coverts (protruding from the left side of the tail). Further support for CMWA (visible in this photo) are the flecks of yellow behind the auriculars and the yellow/green edges to the primaries.
3. Yellow Warbler; first fall female "Golden Warbler", the subspecies that's resident in mangrove habitat of the FL Keys. I thought this was the trickiest one. When I first pulled it out of the net I thought it was might be a vireo (bell's perhaps). I wasn't really sure what it was until I saw the tail pattern and remembered that I was banding in the FL Keys. This bird had pale yellow tail spots that extended to the tips of the feathers eliminating any vireo and all other warblers. But that didn't help you guys at all. First off, the lack of bold wingbars eliminates any of our small flycatchers (e.g. empids and pewees) though that bill (heavy for a warbler) is deceiving. Vireos would have a fairly strongly hooked bill compared to this birds straight bill. So as far as other warblers go, Tennesse can be eliminated by this bird's lack of a supercilium, heavy, slightly blunt bill, and bold eyering. Orange-crowned can be eliminated by white tertial edges and (mostly) complete eyering among other things. Lucy's can be eliminated by bill shape and olive tones to the upperparts. Fall Chestnut-sideds show a lime green crown, nape and back and have bold wingbars. The subspecies is most convincingly clinched by the reletive length of the outer primaries (not visible in this photo, but trust me). Sibley shows a "northern" bird with similar plumage, but to my knowledge, the only "northern" taxon with such a gray plumage is sonorana of the desert southwest, which would be quite unlikely to show up here.
Hope you had fun, feel free to email me if you have any questions, or protests.
Brennan Mulrooney
Cudjoe Key, FL