Ford 3015 Gymnogyps californianus April 13, 1946 Hopper Canyon, Calif. and all quite calm. 3:20, we adult walked toward the immatures in the group & the 3 immatures & one adult took off (leaving 2 adults). One adult slighted near pool & 2 mins. in a single small pothole. The one near pool walked across the wet sand and about 4 ft. into the shallow (3±") water. It took 2± sips, then stood for 30± sec., then walked back toward cliff brink, out of the water, & stood looking about. The movie camera buzz seemed to make the adult attentive. at 3:30 the adult & imm. at pool (8±' sport) took off. There was a general shifting about and at 3:31 only 1(adult) remained atop the ciff while two potholes below Whitewash Ledge & the ledge over Big Cave were occupied. A frog had croaked loudly near the two at pool - no reaction noted in the birds. 3:49 the adult from atop cliff & one other slighted 40±' apart on Whitewash Ledge; an imm. perched atop cliff above them. 3:42, one adult left ledge & slighted atop cliff - the imm. left as adult approached. 3:45 - one adult atop cliff, one on ledge, 1 in pothole - an imm. slighted atop cliffover Big Cave (4 total visible). Suns mainly obscured by clouds; fair but intermittent breeze. 3:50 - the imm. off - we saw circling female N.g Big Cave. The imm. approached; adult atop cliff took off & followed; the imm. slighted atop cliff (where adult had been);