A. humilei 94 Rio Guanol, 14 mi. E Nativitas; Oaxaca May 3 "pajaro novo" tree (similar to guanuchle in leaf shape & form) - the drier-the better and in some spots only the acacia was present. No nests in other than BHA. They were only sparse along the river in the more luxuriant vegetation there - madre de agua x guanocaste trees, larger guanuchles; and an indetator of the common evergreen & fairly large (25-30 feet) acacia mimosa trees with good sized trunks x losambes. Probably common over most of Isthmus - but I think not in pure thorny, woolly brushforest. In some places the vegetation along the road is similar to north of Laguna Caguya in Guerrero. Ecological situation near camp and at Rio Ocotla (where again there were few wrens actually along the river in riparian situation and much more in drier areas) is very similar to that from Arriaga to Tonala - perhaps more pure stands of acacia but very similar - some places along the Rio Agua Dulce are similar also. Thus humilei is a bird of dry, deciduous acacia-guanuchle forest and not riparian as I had thought. Foraging is in mid & high levels. Thryothorus pleurostictus is abundant - about equal to humilei - in same area and in places where there is a dense low thicket. I saw both species in exactly the same spots - but never does pleurostictus get