1976 Walter D. Koenig Melanerpes formicivorus Arnold 3 Hastings Reservation (19 April) 1815. While walking up to Arnold Top, I flushed what was surely the A3 pack from the top tree; the gang consisted of 8 birds. They flew across the fence and a bit south, where they all sat for several minutes. This time, even more than before, all the birds flew off in as tight a flock as I've ever seen: 7 of the 8 all took off and remained within [illegible] 3 feet of each other (1 straggled behind). Later I watched here at dusk. The birds did not croost until very late (~1910) by which time I could barely hear them much less see them. Apparently they roosted in the tall young Valley Oak between the '75 nest tree and the 2nd storage tree. One bird flew to the hole on the hill toward A1, but after going in briefly flew back to the others. Lots of calling attended this whole business. At first several birds straggled up to the tree, but then about 1900 came the pack—still incredibly cohesive and all zooming in and landing within a second of one another. Finally there was still lots of calling, some flying back and forth, but nearly everybody seemed to end up in the above roost tree. 22 April 1320. 8"205 at UA2 again/still. 1330. The 'pack' came zipping along the fence line from near Keep Out # past the '75 storage tree, numbering 7 birds. Since I saw the same type of thing at Keep Out earlier this morning, it apparently is a behavior characteristic of the early breeding season. 1345. Watching (I'd like to watch the gang for a while).