Garrett, I was searching on the internet for a bird that I have never seen before. It looks like a seagull but has the call of a hawk. When I saw your picture, it looks identical to the bird I've been trying to identify. He sits at the top of the tree near an open field and is a great mouser. He looks like a young bird, I live in Livermore so it must be the White Tailed Kite.
