29/6 Gymnogyps californianos March 3, 1946 Hopper Canyon, Glitter Knoll - 500+ above creek bed. The same app. seared to face W. and had a large (6'tall) mouth, 5' high was apparently quite shallow. The adult was still in this cave - a small part of bird visible - at 2:32. Sky 4/10 cumulus, fair breeze, at 2:30. Retrogressing - at about 1:40 I saw 4, all adults apparently circling flapping often next over SE corner of North Slope. One seemed to be chasing another while rising & flapping. Flaps were about 6/2½ seconds - 7 maximum number of consecutive flaps seen. Once the chased bird flapped faster than the normal tempo for 6+ flaps - as if to elude pursuer. I went higher on North Slope to view White- wash Ledge & #11 nest. Counted 16 condors total - 7 in air - at Big Cave area at 2:50. The 7 next circled over foot of East Canyon and grew to 10, then over Brundell Ridge & grew to 13. 11 were on cliff - so at least 24 condors, & at least 5 of these immature. One imm. had orange head but sooty or if still covered with black small feathers. The cave where lone adult was perched proved to be well whitened at mouth and apparently a pathole roost. I have seen condors roosting here on previous occasions. The lunch episode