Gymnogyps californianus April 3, 1946 San Diego (200), Calif. but only with the spring). This grunt was audible 60+ feet away. I saw the imm. peck at heads of both adults on several occasions & wrestle heads with them violently violently (more violent than gymnogyps ). The imm. forced a adult backward from the high ledge upon one occasion. Imm. climb ed rocks well but had a generally soft look to plumage. Adults frequently held bills open for several seconds as if to pant or yawn (a but breathing apart from exertion cool day so probably not panting). Imm. too opened bill wide several times before taking off on a short flight. Pairs of pairs of adult birds, & adult imm. flown, a second time I saw imm. force the from perch-no later retaliation. At 11:58 the took off after long pausing with wings outspread. & imm. also grunted when spring- ing up the rocks. These birds seem to flap much more stiffly than Gymnogyps-nearly 5 flaps per second I timed. About 3 or 4 landing flaps are taken by these birds. Saw a drive adult from highest ledge once. On perching the curve of the neck seemed quite distinct from the "crop" Jedge - J I did not see these birds puff their cheeks as a Gymnogyps often does. Neck appears to be less elongated than gymnogyps and broader, & neck somewhat