The other day I found some odd-looking Swamp Sparrows. For comparison, I thought I'd first show a couple normal-looking Swamp Sparrows. These top two photos have either no streaking or very diffuse streaking on the breast.
This one below has streaking a little more well-defined, and I'm no good at aging sparrows, but I think this suggests that this is a first year sparrow, since juveniles have clear streaking on the breast.
But yesterday I found this Swamp Sparrow. It was in deep cover, so my photos are really pretty bad. But the streaking on this sparrow below puzzled me. It was so dark and well-defined that I actually sent these photos to our Florida listserve to confirm that in fact this is a Swamp Sparrow and not a Lincoln's. Anyway, it looks like this is just a strange looking Swamp Sparrow, I'm guessing a first year sparrow with streaking left over from its juvenile plumage.