Tuesday, December 1, 2009

Sparrows (again, and corrected)

I received a nice note from a fellow birder, which I'll copy here mostly unedited.

I noticed the "Maine Sparrows" entry, and since I'm a sparrow fan, I read that entry. I thought I would point out that your "White-throated Sparrow" (nice photo!) actually features what I am fairly certain is an adult Swamp Sparrow. Notice that the white throat is pale, but not really bright white. Also, the white throat on WTSP usually looks like it is bordered completely in black, although the lower margin is often not as solid black as the lateral edges. On your bird, note how the pale throat has a black border only laterally, where this margin is formed by the heavy, dark malar streak. The black lateral margin to the white throat on WTSP is actually formed by the moustachial stripe (the dark line above the malar streak). Look also at the supercilium (pale line above the eye), which is greyish, rather than the tan or bright white of WTSP. White-throated Sparrow would have a bright yellow area at the front of the supercilium (the supraloral spot) but your bird is the same color there as in the rest of the supercilium. Several other features point to Swamp Sparrow, but the above are sufficient, in my opinion, to make the ID. Just as you say in your blog, sparrows are tricky. If you get more interested in sparrows, you may decide to come down sometime for SparrowFest. We had 20 species in a single day last year.

Sincerely, Byron, Austin, Tx

Here is the photo I had posted and called a White-throated Sparrow. After getting that note I went back to my field guides (I have one that shows only sparrows, with many pictures of each sparrow) and saw just how very much this does look like a Swamp Sparrow. I had seen the white throat and yellow by the eye and *assumed* I knew what I was seeing. But, the yellow is at the *base of the bill* not *at the front of the eyebrow*. (By the way, if you click on the photo in the blog, you can see it slightly larger.)

I'll tell a little more about the circumstances under which the photo was taken. I was having tea with friends, binoculars at the ready, and a bird was eating the seeds in this late summer / early autumn flower garden. I couldn't make it out and eventually walked over with camera in hand. I pished (made a noise that causes some birds to become curious) and a bird appeared and I shot the photo and lowered the camera, but the bird had already disappeared back into the leaves. Then it peeked out at the bottom, and was clearly a Common Yellowthroat with the black mask. Only later, when I downloaded the photos, did I see that I had not photographed the Yellowthroat, but instead some sparrow had appeared. I had been seeking the White-throated Sparrow in Maine, and would look for the yellow spot to eliminate other sparrows when I saw a sparrow. So, when I saw this photo with a yellow spot and white throat ... well, the rest is history. And, now that I see the difference made by the placement of the yellow spot (as well as all the other factors mentioned above) I think I'll be able to identify these sparrows a little better in the future. Learning about birds never ends.

Normally I wouldn't burden you with looking at a photo of this low quality. I was at Orono Bog in Maine in the evening and a flock of sparrows was moving through the underbrush. Hand-holding a telephoto lens in low light is a recipe for disaster ... but this now becomes the best photo I've taken of a White-throated Sparrow, with a yellow spot at the front of the eyebrow. Ironic that it was in a swamp, huh?


Robert Mortensen said...

Good stuff about that sparrow ID! I'm glad there are experts out there to help us. One thing about birding is that you have to let go of your pride and be teachable at all times, especially on the tricky ID's.

Anonymous said...

Live and learn, eh? I'm just amazed at your patience with the multitudes of sparrows.

Anonymous said...

BTY....the white breasted nuthatches have taken over my backyard -- they're EVERYWHERE!