Gymnogyps californianus March 15, 1976 Hopper Canyon, Calif. and the lower imm. also took off as if frightened from the perch. When imm. was perched, it gave at least 2 "yawns" which disclosed brownish yellow inside mouth. This imm. & adult circled over Cardon Knoll, the imm. above the adult. Then they returned over me. The imm. soared especially close to me several times while adult only came within 50 ft. once. Adult had small crop buldge tho it seemed not when perched. None of these 3 had bands. About 11:05 the other immature took off & circled very close over me, feet down a large part of the time & sometimes flex gliding. I took a photo of this bird in flight. These immatures showed a brownish black triangle in the under wing patches - another sign of youth? The tail of one was quite square out rather than a smooth arc: ( ) - a peculiarity which I noted in J.L. Murray's color painting. 11:10, I started to erect my blind 100' SW of falls limb. The last imm. to take off alighted atop cliff over Whitewash Ledge. At about 11:20 I was settled in blind - the imm. took off & in company with another soared over me close, again & again, for