LLWolf 1964 28 Aimophila humeralis July 26 Leon de Lobos, 7 mi E. Cuauacaca, Moulos, Mexico 4800+ft. apart then come close together so facing at 90 deg left angle < both wing flicking (right) then chase so facing to N + 2-3" apart. Pair #3 then flew off to N after following chatter by pair #1 from area of tree #1. 0815 pair #3 chattered at N edge of gulch, then several pitz-a notes from pair #1 well downhill (50-60 yds). Then quiet. 0822 - hear pitz-a notes from wooded gulch. see bird fly S to tree #2 while other stays in vine tangle giving pitz-a calls. then 2nd flew to tree #2 giving pitz-a + chatter duet. began to land then work close together (6 ft inches). one ex (yt flicking right wing [outside wing]). other bird is wet on ventrum (grass still wet). followed by chatter by pair #1 near tree #1. one of pair #3 flew down to them + another chatter - followed by yet another chatter. Bird still in tree #2 flew uphill 10+ yds where gave chip notes (as doing in tree) then gave two pitz-a notes + bird from our pair #1 flew in just at level of bush tops. Chatter + then chatter (20 sec later) from slightly further uphill then quiet. 0843 - 70+ yds uphill from tree #2 flushed single bird from orn or near ground, had just been chirping softly. flew up into lower (6-7 up) bunches of partly defoliated tree when turned about in flight as if freezing - then flew to E (down hill) 15+ yds. Flight normal at start, but fluttery 5+ yds landing. Also began trill portion of duet chatter. No bird joined it + began pitz-a calls. Birds from uphill flew down to tree in gulch where sat near end of time. First gave short (1x) chirp then began pitz-a calls. 30 sec later one of pair #2 began pitz-a calls from uphill + then chattered. Bird in gulch flew out to N when heard pitz-a calls + then trill portion of chatter + finally chattered.