To refresh your memory, here is the photo from August’s Bird Quiz. The bird was seen in Colorado during the month of August. Don’t read any further if you want one last chance to identify this bird.

If you’ve been reading these quiz answers, you should know the routine:

1. Figure out what we know about the bird.
2. Narrow the options.
3. Look for unique field marks.
4. Double-check—does the answer make sense?

So—what do we know about this bird? By the shape and habitat, we can tell it’s a “perching songbird,” a member of the Passerines. That eliminates waterfowl, raptors, woodpeckers, and a whole host of other avian families, and sends us to the rear half of the field guide.

What else do we look for?

• Color—the bird is yellow, black, gray, and white. There’s a black line from the beak, running through the eye, to the back of the head (and the eye is dark). The head and rump are yellow, as is the tail. Underside is white. Wings are black, gray, white, with a zigzagging white line at the shoulder. And the upper back is a yellowish gray. Keep this in mind.
• Beak—pointed, slightly curved downward (the bird almost looks like it’s frowning), and on the sturdy side. It’s not dainty enough for a warbler, and it’s not triangular, so our bird is probably not a seed-eater, or at least not primarily so. Beak color is silver gray.
• Size—medium, based on the branch it’s standing on. Perhaps bigger than a warbler and smaller than a dove or robin. Size is always tricky, especially in a photo where there are few reference points for comparison.
• Legs are a bluish gray.
• And finally, we know it was seen in Colorado in August.

With all this in mind, what are our options?

The yellow color and black eye stripe might suggest a flycatcher, specifically a kingbird, but there are no feathers at the base of the bill and the head is rounded. Plus, none of the flycatchers have a yellow head—the bright color is usually on their undersides.

Let’s continue through the families in our guide, looking for yellow birds. Our bird is too big to be a vireo or a warbler, and besides, we’ve already eliminated the latter by the shape of the beak.

The next group of candidates are the tanagers. Hmmm. Keep a bookmark there and keep going.

Yellow Grosbeaks are the same colors, and they have black and white wings. Is that an option? Aside from the fact that they aren’t found in Colorado, not the namesake “gross beak”—our bird’s bill is too thin for it to be a grosbeak.

Yellow-headed blackbirds can have yellow heads, but their backs are black. Nope, not that. And it’s clearly not a meadowlark, either. How about an oriole? They’re often yellow, with black, gray, and white wings! Time for another bookmark.

Female Pine and Evening Grosbeaks are sort of yellow, but we’re already discussed the beak issue with grosbeaks. Crossbills can start out yellow, but the crossed bill would be obvious. And that leaves us with the bright yellow goldfinches. They’re much smaller, and have wedge-shaped seed-eating beaks. Nope.

Now back to the tanagers and orioles. It’s clearly one of these. But which one? A quick look at the female tanagers eliminates that option. None of them have both the white/gray wings and the eyeliner. (Probably the closest is the Western Tanager pale adult female, but she lacks the eye line her bill is orange.) How about an oriole?

Again, what are our options? Female Hooded Orioles are darn close. The beak is the right shape, but a tad on the long side. The legs are that pretty blue-gray. They aren’t found in Colorado, but there’s always an exception.I say it is rather unlikely. Is there anything closer?

According to Sibley, Orchard Orioles have “well-defined white wingbars” and our bird has more of a wiggly wing line. Streak-backed Orioles are too dark, with hints of orange in their yellow, and again, finding on in Colorado would be a rare event.

How about a Bullock’s Oriole? Look closely. It’s not too light, not too dark, not too orange. Yellow and white in all the right places. And look, there’s a black line coming out of the back of the eye. It has the requisite grayish back, too. I’d bet my money on this species. And based on the extensive light gray, especially on the upper back, it’s probably an adult female rather than an immature male. Pretty, isn’t she?