R.K.Selander, 1954 C. zonatus Compsathydae zonates April 18 6 mi. SE San Cristobal, 7300ft., Chi, Mex. At 6:00 A.M. I found three pairs in a ridge stand of giant oaks above camp. They were calling almost constantly as they moved from tree to tree. Each pair seemed localized in a particular area but movements were made in either direction from the center of the foraging area up to 100-150 yds. Each time a pair moved one bird flew just behind the other or slightly above and behind and both birds made a sort of "chaing" noise as they flew. On landing both birds called loudly together, "cha-cha-cha-cha cha-cha" - usually several 1, 1; 1, 1; 4 times before they began foraging. Movements from tree to tree or even from limb to limb, if any distance at all, were made together. When dueting the body was held horizontal but the head seemed thrust forward a list. Calling usually induced neighboring pairs to calling in a similar fashion. These calls, which seem to serve to keep a pair in contact & coordinate movements, are extremely loud and harsh and can be heard at a considerable distance. There is little var- iation in the pattern and the two birds keep together almost perfectly. One two occasions & head a single bird give another call - perhaps the "song"- cha-cha-cha - this