Phyl, I've been watching the same activity! I'm guessing that it's HM because it's a really large bird with a big head and beak and long wings that almost reach to the end of the tail. Could be totally wrong. Anyhow, it started out perched way high above N1 before 4:00, then flew to the stream (creek) to putter in the water like in your pic, sharing the space with the squirrel. Then it perched for a short while above the water, then obtained a stick and flew with it to the Y, where it has been perching for some delicious closeups to be posted next.