I saw some kind of white hawk today stalking our bird feeder.

I don't think it was a kestrel, it was bulkier, all white (tail included) except for the upper leading edges of its wings, and the tips of its wings as viewed from beneath. I didn't get a good picture, just this one when he stopped in a tree. The crows were making a terrible fuss, which is why I went outside to look, but they were not getting anywhere near him, which made it hard for me to judge his size.



Later he caught an updraft and soared in circles, up, and up, and up without flapping his wings until he was out of sight. Experienced at traveling long distances without using much energy, I'd say.

I live in Central California, near the coast.