The Northwest hosts a number of native sparrows during the fall and winter months. Golden-crowned, White-crowned, White-throated and Fox Sparrow join the resident Song Sparrows in many of our backyards. The first three sparrows mentioned sport striking crown patterns which helps set them apart from the other little brown birds. The two that often give people pause are the Fox and Song Sparrows. They are both mostly brown with streaking on the belly but are easily told apart by several field marks. I should add that both species vary from west to east coast and that I am only representing the races that occur here in the Portland area. In the east, the Fox more closely resembles the Song than in the west (at least from what I see in the field guides!).
All good Song Sparrow photos used with permission by Greg Gillson.
All bad Fox Sparrow photos used with permission by me.
Three photos of the typical Song Sparrow: gray and brown striped crown and face, dark streaks on the chest, central darker breast spot.
Now three photos (in bad light, sorry) of a typical Sooty race Fox Sparrow: Uniform brown head, chest streaks are heavier....like chevrons or arrowheads, central darker spot on chest is larger, lower mandible of bill is yellow. Overall shape is chunkier. It scratches on the ground, as does the Song, but has a distinctive behavior of raking its feet back hard and fast. I watched one dig a hole right though a thick layer of mulch in no time at all.
OK students, there's your ID Lesson for today - - Go forth and find thee a Fox Sparrow!