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

While the pictures in our field guides depict lovely front and side views, nature isn’t always so cooperative. This little brown job simply refused to turn around. I took picture after picture of his rear end! Not exactly helpful, right?

The problem here is that we’re used to looking for specific field marks for each species, and we’re at a loss when we can’t see them.

The brown stripes and small size of this bird, as well as its location on the ground, suggest that it’s a sparrow. (We can rule out female finches, the other birds with brownish striped rear ends, by the lack of notched tail.) Hopefully you got this far. The big question is which sparrow?

We usually separate sparrows by their shape and the markings on their head and breast. Is the breast plain (as with Chipping and Field Sparrows) or does it have stripes (like a Savannah or Fox Sparrow)? Is there a central spot, such as Song and American Tree Sparrows have? Is the head rounded, or even peaked (as with Rufous-winged or Harris’s Sparrows), or is the head somewhat compressed, such as in the case of a Grasshopper or Baird’s Sparrow? And what about malar stripes (Lark Sparrow), or stripes on the head (White-crowned and Golden-crowned)? In this case, we can’t see any of that so we have to rely on other characteristics.

Let me summarize what we do know. It’s definitely a sparrow. It’s in Colorado in the winter. It is lightly toned with brown stripes. Surprisingly, just the location and time of year narrows the field to four options: Rufous-crowned, American Tree, Song, and White-crowned Sparrows.

Now it’s a simple matter to look them up and see if anything matches. Neither Rufous-crowned, American Tree, nor White-crowned Sparrows have stripes. Eliminating those leaves us with a Song Sparrow. Could it be?

Song Sparrows have stripes all over them, but they look much darker in my Western Sibley’s field guide. However, Song Sparrows are highly variable. Those along the California coast are much more contrasty than those of the southwest. Northwest birds are darker, as would be expected in a place where the sun rarely shines much of the year. To quote Sibley, “Variation is most pronounced in overall color as well as color and thickness of streaking on underparts.” In other words, our bird could easily be a Song Sparrow.

Eventually, my subject did turn a bit…

And a bit more…

The side view doesn’t help much, does it? I’m so used to identifying Song Sparrows by the pattern of stripes on the head and the spot in the middle of the breast that I never really look at the rest of the bird. Yet, even with only the nether regions of the bird visible, ID-ing this little guy wasn’t all that hard. I think my lesson here is to pay attention to even common birds that I think I know well, and get to know them better!