LLWO/F 1964 Aimophila semidistracti August 18 Fwi: E. Tehuantepec, 100+ft, Oaxaca, Mexico nest chatter (separated by > 12") 0825 - ♂ sang from shrub behind me + ♀ flew off along fence + ♂ flew out to join her. Two sat on fence - on different strands of wire + chatter sounded like both contributing but ♂ louder. One then to top of fence post + both disappeared at 08:25 while I wrote notes. 0828 - ♀ up to fence + drops to oxcart trail on N side - works along edge in grasses + flies back up to fence (08:30) carrying short pieces of dead grass stems in her bill. Flies off to AE between fence + road. - same direction as last time with nesting material. As I walk over (after watching 5 minutes for her to disappear) a bird begins soft tee, tee series from fence. Then free notes + moves to W along fence. 0925 - after not seeing or hearing from either member of pair for nearly one hour, 2 birds fly rapidly from W to E - one chasing other. Chaser stops at tree #1, but chased continues on 30+yds to E. + lands in 6 foot tree. moves to far side (in shade) & sits quietly. 0930 - flies off to NNE to fence + drops down in to pile of Acacia branches. flight song (muted) 0937 - as truck passes ♂ sings loud chatter + another on flight from near road to large Acacia along fence at west end. Sings several more loud songs. ♀ to J sings once. 0940 - several chatter songs from W of Acacia. 0945 - one chatter song as truck passes on road.