Answer:

The overall shape, color, and habitat tell us this is a sparrow we’re dealing with. The overall drab coloring can make this bird confusing, but it helps to rule out many of the more distinctive sparrows. The bird has a dark crown and eye stripe, and a faint moustachial stripe, along with some streaking on the back.

This is similar to a Song Sparrow, but the bird doesn’t look quite right for that; it’s too dark reddish-brown overall, and lacks the heavy streaking on the breast, belly, and sides that a Song Sparrow would have. A similar sparrow, the Lincoln’s Sparrow, would be much paler overall with fine streaking on the breast and belly and some pale gray in the face.

Another similar sparrow, the Swamp Sparrow, matches this bird’s pattern and color much better, and that’s what this bird is. These sparrows are found in similar habitats as Song and Lincoln’s Sparrows and have similar habits, but Swamp Sparrows lack the streaking of the other two and are generally more reddish-brown overall. Swamp Sparrow is uncommon in California, but it’s helpful to know how to identify one in case you come across one in the fall or winter, which is the time of year they’re usually found around here.

Congratulations to Calvin, Henry, Jennifer, and Thomas, who all figured out Swamp Sparrow!