I took the first four pictures of (what I assumed to be) the same immature accipiter at Arastradero Preserve, Wednesday morning, 11/223/05. 1 and 2 were taken at the same time; 3 and 4 separately some time later, not far from where the first ones were taken. I thought at the time it was a Cooper's Hawk, presuming it to be the same Cooper's I saw and photographed in the same area a few days ago, shown as the fifth picture here. When I looked at the pictures, the head and bill size, and the tail tip, made me think this might have been a female Sharp-shinned rather than a male Cooper's. The bird from four days ago still looks like a Cooper's to me, given the narrow striping on the breast and what seems to be fairly robust tarsus. Most likely all four pictures are of the same bird (Later: I've since been convinced this isn't so) -- but I'd love any input anyone has.