16 Wd/4 1964 Aimophila ruficeps August 24 16'2mi SW. Mutat Can, Oaxaca, Mexico Km 616 on Pen A- Hwy. + gave chatter duet. Little wing flicking by at least one bird, but soon stopped - before end of duet. Both birds then dropped back forward ground. One flew up to 1'foot above ground in shrubs after 15 minutes + bird wiped. Other flew in + also bill-wiped, then flew off along slope. Other (1st) bird hopped over some dead branches of the shrubs - bill wiped again + then also flew off along slope. During this time pair across gully to S chattered 3 times + this pair showed no reaction. 0700- have not seen this pair for 1/2 hr. have heard soft + tweet notes from downline, so left + walked over to find the pair to view. 0710 - ? singing from top of 7 foot dead shrub nearly at crest of tree. ? comes up from on a near ground as I approach + ? stops singing. Both 1-2 feet aboveground in shrubs then work up into nearby tree about 6 feet up. ? giving chu, chu, chu, chut etc. calls while ? giving single loud tut notes. ? drops in one nearly vertical flight to ground then into low shrub. works back up + drops down again. ? disappears (probably down into gully) + ? works up into nearby tree (6-7 feet up) when gives series loud two-parted notes that are the loud introduction to trill in regular song. occasionally pauses + begins again with the tweet introductory note. Never launched into trill, altho birds across gully to S were singing complete song. 0730- heard bird tweet note + bird appeared on low shrub (2+ft) about midway up hillside. worked across hillside in shrubs 2-3 feet above ground. no trees + shrubs form nearly closed canopy