There is no doubt the birds are beginning to move. There are very few Western Kingbirds left--I saw my last one over the past weekend. There may well be a few left in the area, but not many.
The purple martins are not gone, but the ones that nested around Wild Bird Rescue have dispersed. Usually someone finds the roost where the birds are staging before departure, but not so this year. It was a very poor nesting year for many of the colonies in the area, judging from the number of emaciated birds brought in to WBR this season.
One of my favorite birds is the chimney swift. It is time again for the "Swift Night Out," sponsored by the Driftwood Association, taking a census of chimney swifts congregating for migration. Instructions are on their web site.