Has anyone checked on whether animals can recognize their own smell? It would be hard to tell whether an animal recognizes its own smell or is just discounting it as not interesting-- I can't figure out an experiment to make the distinction-- but it's at least as likely a sensory mode as vision.
Now that I think about it, surely the interesting thing about self-awareness is tracking one's own mental states, and I'm not sure that recognizing oneself in a mirror is a good surrogate for that.
Addendum: I reread the article more carefully, and it's mostly about self-recognition rather than self-awareness. I'm not sure how important self-recognition is.