Thanks to all who responded. Since they are usually so very high (except the day a couple were chasing up, down, and around) I don't think it has to do with feeding, in this case; since it is so late, the roosting idea has merit. As Bill pointed out, I've heard them even well after dark, quite late. Strange...there's a lot we still don't know, isn't there?! I'm about a mile north of Edmonds dock, a block inland...have seen them going in many directions, and often, as someone else stated, heard as often as seen.

Dee Warnock
beachdee at hotmail.com
Edmonds, WA