Sunday, November 25, 2012

Fall Warbler Quiz - Answers

It's long overdue, but here are the answers to the fall warbler photo quiz I posted a while back. Be sure to try the quiz before reading the answers.

Photo 1:

Photo 1 shows a bird that, in my opinion, falls under the category of "confusing fall warbler." This particular bird is plain, with some streaks, and relatively few prominent field marks. However, there are some characteristics on this bird that can help narrow it down quite easily. First, there are two prominent wingbars. In addition, the underside of the bird is a pale yellowish color, rather than the bright yellow of some warbler species. Looking through a field guide, there are only a few birds that fit this image, those in the Bay-breasted/Blackpoll/Pine group. These three species can appear very similar when viewed in the field. Pine can be ruled out for our bird by the streaks on the back. This leaves the "Baypoll" warblers. A few things to note are the few, dark streaks on the sides and the yellowish feet. These two field marks help identify this bird as a Blackpoll Warbler.

Photo 2:
Ahh! A warbler in flight. Impossible, right? Actually, this warbler is quite easy to identify. The first thing to notice is the bright yellow underside. This coloration rules out a number of warbler species. What other field marks are visible? One particularly useful field mark to use when identifying fall warblers is the undertail pattern. While many species have a similar pattern, there a few warblers, namely Palm, American Redstart, and Magnolia that have easily recognizable tail patterns. On this quiz bird, note that the tip of the tail is black, while the rest is white. This pattern is unique among the warblers and identifies this as a Magnolia Warbler. The yellow underside supports this identification.

Photo 3:
Like the previous photo, we can easily see the underside of the tail and body of this warbler. Unlike the Magnolia, the tail pattern is very plain. In fact, it appears entirely dark, rather than having a distinct pattern of white and black. This tail pattern narrows the pool of possible species down significantly. Next, take note of the bright yellow underside. This still doesn't identify the bird to species, but it gives us another clue as to its identity. Finally, look at the head. Yes, it is obscured by branches, but the gray color, strong white eyering, and yellow throat are all visible. These characteristics and the field marks previously mentioned all point to Nashville Warbler.

Photo 4:
Here we have a plain warbler species with a yellowish underside and two very strong white wingbars. As with the first photo in this quiz, these field marks leave us with the Blackpoll/Bay-breasted/Pine group. We cannot see streaks on the back to rule out Pine, but noting that this bird has no streaking on the underside and has all-dark feet help to eliminate Blackpoll. Next, look at the bird's flanks. Careful inspection shows a light pinkish wash. This is a characteristic of a fall Bay-breasted Warbler.

Photo 5:

In this photo, we have a very plain warbler. It is obvious that there are no bright colors or even significant field marks. Basically it's a brown, streaky bird. While brown and streaky may make sparrows difficult to identify, once we realize that this is a warbler (bill and body shape, behavior) the identification is actually quite easy. If we compare this bird to the one in the first quiz photo, we see that both birds are dull with dark streaks. However, one noticeable difference is the lack of bright wingbars in this bird. There are two faint lines visible, but nothing close to the immediately noticeable white wingbars on the Pine and "Baypoll" warblers. A lack of bright wingbars on a brown, streaky warbler narrows the identification down significantly. In fact, it really only leaves us with two possibilities, Yellow-rumped and Cape May Warblers. From this angle, we would be able to see a yellow patch near where the wing connects to the body if this were a Yellow-rump. Also, the bill would be shorter. That leaves Cape May Warbler. This is an extremely variable species in the fall, as some adult males are brilliant yellow, orange, and black and younger birds can be entirely brownish. When not immediately identifiable using the typical Cape May Warbler field marks (thick white wing patch, orange mark on face, grayish head on females), a good field mark for this species is the lack of obvious field marks!

I hope this quiz has been somewhat educational for those readers who have been perplexed by these confusing fall warblers! Although most warblers leave for the fall, Yellow-rumped Warblers and occasionally other species remain in this region for the winter... so keep an eye out for any winter warblers!

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