Monday, February 22, 2010

Quiz #337 (2010-1-08) Answer

Click the picture for a larger view.

Answer by Bryan Guarente and Tony Leukering

Thank-you, Bryan Guarente!! As I've been incredibly busy working on a massive report on the field project on which I've been working, I've had no time to deal with recent quizzes. Now that we've got the report mostly put to bed, I'm trying to play catch-up. Again! So, I greatly appreciate Bryan's amusing and fairly thorough answer, which I happily co-opt below. Take it away, Bryan!

"Much like a lot of ABA area bird watchers, I don't think a lot about subspecies until they have to be identified because of potential splits (e.g., Winter Wren vs. Pacific Wren) or when I will be experiencing them in the field due to, say, an upcoming trip. Without having seen Bill Schmoker's email [via the Cobirds listserver] in my inbox this morning that mentioned towhee subspecies in passing, I wouldn't have thought about the subspecies of towhees. Then you add this bird as the quiz subject and make me learn about towhee subspecies. How dare you ask me to learn something! ;)

"So, to the quiz bird. By shape alone, this bird could be grouped into the Emberizidae. Let's cut to the chase now, this bird has a red eye. From a large group (Emberizidae), we are immediately down to two species: Eastern and Spotted towhees. You can even say that this bird has to be an adult because of the eye color (juveniles have darker eyes [though, see age comment, below]). This should mean we are left with only two species and two sexes with adults being the only birds we need to consider, so four plumages. However, we actually have 12 plumages to worry about (see below).

"Although we don't need to identify this bird to subspecies to get the answer correct, this is actually a very educational topic for this complex. We can exclude the alleni subspecies of Eastern as it has yellow to white eyes. So we are left with two species which include 5 subspecies -- ten plumages left. The subspecies we are left with are:

"Eastern Towhee: erythrophthalmus (translating to "red eye") and
Spotted Towhee: arcticus ("from or of the arctic"), montanus ("from or of the mountains"), oregonus ("from or of Oregon"), and megalonyx ("great claw" even though I thought it would loosely translate to "big black"). [Editor's comment: LOL!]

"The next step was to attempt identify to species first. The beigey-grey spots on the wing exclude Eastern Towhee from candidacy because Eastern Towhees (all subspecies) have a solid white stripe on the wing at the base of the primaries instead of spots. Usually, a towhee with a spotless back is an Eastern Towhee,
but there is one subspecies of Spotted Towhee that has a spotless back: oregonus. That is what we are left in this case. Spotted wings and a spotless back.

"So, with just a few simple tests - eye color, wing spotting, and back spotting - we have identified this bird to species as well as subspecies. By knowing the subspecies, one would expect this photo to have been taken in the Pacific Northwest, but that is the guessing part of this game and knowing that birds have wings, I could be way out in Northwest field. Bad joke, I'm sorry."

Thanks, Bryan. Aaron Brees provided a bit more input, though it doesn't much help us in the ID.

"This female towhee could be a hybrid, I guess, given the extreme lack of spotting and the somewhat brownish tint. But, with the bird having no visible white at the base of the primaries, I'm going to guess that this bird is at the extreme end of what a Spotted can look like. I dug out my Rising/Beadle sparrow book, which I haven't looked at in a couple years, and was stunned at how inadequately the towhees are illustrated and described. No help at all!"

Finally, Peter Wilkinson, suspected that, with the inclusion of the hybrid gull two quizzes back, I was trying to sucker folks into going for a hybrid towhee. All I can say is that if I'd have had a reasonable pic of such, I'd certainly use it! But, no, I was actually trying to expand understanding of Spotted Towhee, as many are unaware of oregonus. Additionally, the "Rufous-sided Towhees" comprise a group that I believe needs a bunch more work focused on it. There are some cryptic things going on. In central Georgia, red-eyed and white-eyed Easterns both breed at Piedmont NWR and my experience there suggests the possibility that these two forms may be acting as good species, as I never noted intermediate eye colors. Of course, eye color might be controlled by a dominance/recessive system, but the situation did give me pause. This is just one example.

Steve Mlodinow took the picture of this adult female oregonus Spotted Towhee on 29 December 2009 at Mount Vernon, Skagit Co., WA. Even fairly advanced youngsters wouldn't show such deep-red eyes at this date, so the bird has to be an adult -- that is, at least 1.5 years old.

One respondent's answer was indeterminable, as it included two options. Another's was precluded as it omitted all capitalization. Please read the rules!

Incorrect species provided as answers:
Eastern x Spotted Towhee - 2
Eastern Towhee - 6
Rufous-backed Robin - 1
Rufous-sided Towhee - 1

Congratulations to the 20 of 30 getting the quiz correct:
Louie Toth
Kirk Huffstater
Tyler Bell
Bryan Guarente
William Velmala
Chuck Carlson
Chris Warren
Al Guarente
Su Snyder
Margie Joy
Aaron Brees
Bruce Gill
Peter Wilkinson
Joe Bens
Joel Such
Marcel Such
Andrea Smith-Guarente
Chishun Kwong
Thomas Hall

Answer: Spotted Towhee