I know that no one else is contributing to this blog any more, but I can hope some people are still reading it. Is there another forum for sharing Costa Rica sightings I'm not aware of?
In any event, I'm here at Turtle Beach Lodge just scouting out lodges, and in between the squalls (continuous almost all night long, heavy downpour) today (Dec 1) I saw a brown morph Red-footed Booby sailing southward with a group of about 20 Magnificent Frigatebirds over the line of coconut trees on the inland side of the beach. There were hundreds of Laughing Gulls of all age classes also moving southward, and two Brown Noddies also going south but low over the breakers. Royal Terns were barely identifiable quite distant and mostly flying north.
There are still a few birds I would consider migrants headed to South America: Scarlet Tanager, Gray-cheeked and Swainsons's Thrush, and a group of at least 10 Chimney Swifts (the latter only yesterday afternoon).