Gymnogyps californianus February 18, 1948 Hopper Canyon, Calif. Rock Ridge. 10:30, one (min.? same?) now on top top of Flat Ps. Water visible at Carder Falls. Moderate white- weak at Big Cave - not evidence of concentrated roosting there. Sky V/ocino-stratus - faint to light SE breeze. Estimated 60°F. 10:38, 2 circling over E. slope top of Hopper Mtn. Five cards minimum present. Two adults atop Flat Ps, Carder To sun. 10:40, 2 circling high over Spring Canyon Mdw; a red-tailed hawk circling above them; both adults. One soared S. about ¼ mile E. of lookout, crops bulging (how come if indicative feeding?). Tilted right side of tail down, pointed bill 45° to left, then turned left. Descended E. over Rock Ridge - gave a dip; feet down; wings up though descending. 10:45, turned back W., gave 2 dips, 4 swooped up to land on branch of dead Ps. near Rock Ridge, 100±' from perched min. and 20±' above. 10:47, min. there extended wings ½ way as if begging. 10:48, the min. hopped to a 6±' higher branch facing adult. 10:59, min. off to S. and turned a large circle, taking 21 flaps in first half, then swooped to top of dead Ps. 30±' from 4 15±' above adult. 10:51, min. off to ¼± mile S., then circled & rose. Another min. + adult circling & rising over Spring Canyon Mdw., and 2 others joined there at 10:57. 1 adult (other) landed atop Flat Ps. Imm. from Rock Ridge above Horgan; adult perched as light.