16 LLWOLF (1984) Aimophila humeralis July 23 Cañon de Lobos Prieto, Cuernavaca, Morelos, Mexico breast + throat wet + matted (grass wet). Flew over to top of bush in which 1st bird sitting. As pitzza + chatter stands 1st works rapidly to top+ both chatter one rapidly flicking left wing - other alternates wings, but mostly left. then both fly downhill & slightly to N where chatter several times from slightly different locations. 0900- back to wooded gully when chatters from low down line 8 feet up - one flicking right wing - other ?, then ? one to S edge of gully vegetation into partly defoliated tree. where sat for 1st see + then picked by insect. Worked it in bill for 10 sec. before finally swallowing. joined by 2nd bird & both flew to tree #2. moved to top E side when chattered followed by chatter from area #1, then both began foraging in canopy. one then dropped almost straight down to ground + other foraged to W side then sat quietly. Gave several pitzza notes + flew off to W when gave sharp series of pitz+ pitz. 0910- heard chatter from W (uphill) of area #5 - not sure of participants. then series of pitzza notes by at least two birds this 80 ± yards to W of tree #2. 0912- pitzza moves to S + chatter from area #2 - pitzza still occurring during chatter. 0913- two birds from area #2 move downhill & pitzza loudly. bird from uphiller in area #5 flies down + loud pitzas by at least two birds then chatter, which is joined from area of tree #1 by pair #1. apparently this dispute involving pair #2 + ? of pair #3. then quiet.