Gymnogyps californicus March 15, 1976 Hopper Canyon, Calif. landed next to an old immature (very sooty head) and 2+ times put a foot on top of its head be- fore it flew. 5 p.m. Frequent perch shifting. Looked for banded birds - no luck. One slighted next to another on ledge - feathers flew + there was a sound like a snarling dog - inhaling + exhaling as a few feathers flew + one bird flew off. Per- haps feathers scratching on rock? A few seconds later there was a light cough sound as another off perch. My field apparently good - some slighted within 100 ft. At 5:06, 1 imm. & 2 adults near falls limb. 13 condors in view. One adult summed back 2+ minutes about 4:45, 5:08, adult & imm. stop to cliff near falls - both standing calmly. Adult off about 5:09 & imm. 5:10 - both to other perches on cliff. Stepping flaps in landing seem to be about 3/sec (less) - same for shifting perch - this is result of 3 timings. Now heard up to 11 flaps given before landing. 5:15- 6 condors in about 5' plain. Circle atop cliff over Big Cove. Dark head nubbled head often adult there. Adult nubbled head of sooty headed one. Later adult put head underneath of this one & seemed to throw it over backward - there was a grunt or of expelled air as this occurred. The sooty headed was love unfathered area be-