LL Wolf 1963 Aimophila mystacalis August 12 Km. 616 on Pan Am. Hwy., S. of Orizaba, Oaxaca, Mexico Shaking high up on strawb tank that goes down hillside near where pair foraging. She emerged without straws + bill wiped. o flew back to song perch + began singing. Flew 10-15 yards uphill + sang several times when o uphill began singing. Then back to song perch (l) to sing. F flew along slope just below where o singing + disappeared. o there left also - not sure where or to where. 0851 - o back to song perch #1. - singing but without trill. Chick -> ) 2 ). 0853- began adding trill to occasional song. Another o is singing on hillside several hundreds yards to north. Dropped to ground + uphill at 0858. Heard _ _ _ _ (chwat, chwat -- ) from uphill; also occasional tzeet. This is apparently a pair reunion call so shortly the pair appear foraging. I think they forage mostly on the ground + possibly in low vegetation. Except for moving bushes the only time I see the birds is when one or other flies up to horizontal limb to bill wipe. Then by steps it walks back to ground + continues foraging. While birds observed can hear occasional tzeet which probably is some sort of location call. Sounds very similar to note given by A. carpali when flock feeding on ground. Birds seem to forage most frequently in dense herb layer vegetation around bases of shrubs. (011)