I saw a Cassin's Kingbird at Lake Murray today, 10-05-02. It differs from the Western Kingbird in that the Western has some white feathers on the outer portion of the tail and the Cassin's does not. I'm going to try to attache a photo of each Kingbird in this thread. Don't know if that's possible but I'll find out. Photo of the Western Kingbird was taken on 09-25-02, also at Lake Murray, San Diego, CA, USA.