Sunday, in Ferrisburg, at one of my CLO (Cornell Lab. Ornith.) sites, I heard a familiar call that I wasn't able to name. I tried to check it out, without luck, though there were sounds from two immatures added in to the adult call. Some minutes later I turned to see an adult accipiter fly into the area the sounds had come from. Size of a female sharpie or male Cooper"s, but the call had not been a sharpie. At home I checked the vocalizations and yes, they were Cooper"s.