I saw a few more red-tailed hawks and another northern harrier near the Pines Trail, where I pulled off to take some more pictures. I scanned the field for about 20 minutes and as I was about to leave I saw a bird rise up from the edge of the field closest to the Bill Forward Pool and got excited. It was a largish shorebird-type bird with a yellowish brown butt and dark wings. I could see some white on the belly and the way it flew looked kind of large-shorebird-like, but I really couldn't get a good enough look to identify it. It flew north toward Hellcat. I jumped back in the car and drove to the Bill Forward blind for the best look at where I thought it was headed. No luck. Nothing.
Not ready to give up, having been teased by this mystery bird, I headed for Hellcat. The birders at Hellcat hadn't seen any sign of it. I ran into Steve again and told him what I'd seen, which was not enough to even call it a "maybe". I hung around Hellcat after everybody left and kept looking and hoping. Sigh.
Jim Hully, who found the bird originally this morning, posted his photos on SmugMug.
I'm sure Doug Chickering will post one of his wonderful not-finding-the-bird stories on massbird.org.