English: Mimus polyglottos - Northern mockingbird,

Location:
Emery Ranch Trail, Fullerton, California, USA
Identification:
1. The Laws Field Guide to the Sierra Nevada, 2007, page 292
2. Review by an individual skilled in bird identification
Some of the other internet images of northern mockingbirds seem to be somewhat stockier than this one. This individual had a black line through the eye that was much more ragged and indistinct than the lines through the eyes that are shown in the field guides I looked at.

Comment: This image was taken in Southern California near the southern limit for northern mockingbirds. It is possible that mockingbirds may be thinner near the southern limit of their range and stockier near the Northern limit of their range. Allen's rule might be an explanation for this if it is so. In flight, this bird had wing patterns that were consistent with the patterns that I associate with northern mockingbirds. I think it is likely the ID is correct.