Gymnogyps californianus February 12, 1946 Whiteacre Pk, Calif. wing. 30+ sec. later turned about, facing seen. A raven perched 3+ toward trunk from adult - no reaction (adult preened) until raven flew off; then adult's wings flew up (balancing). Adult turned around again (facing ?) & both adults were in air about 1:48. They circled over head of a steep canyon near their perch until at Rim level. One had feet down. One showed "croft ledge". One with feet down held close to them together. This one also excreted in air - a watery substance. Earlier the ? excreted over edge of cliff; the excrement going straight straight down in a stream. The two circled rose over me to 1,500+ above me, then flew glided to NW toward San Rafael Pk. area. (gone at 1:55). Breeze very light still. In calm air dihedral seems greater than in wind; & more primaries bent up (only 3+ when flying gliding in wind). A duck hawk soared within 50 ft. of the condors several times without attacking - condors showed no reaction. Both adults seemed to have all flight feathers. About 2:30 left for Hopper Basin. Saw 2 over W. Rim heading SE about 2:45. At 3:30 reached road. Too air dead calm but cool. 3:45, one adult circled & rose to about 4000' level above Arundell Cliffs, then glided NW until over me, then circled & rose over W. Rim, then glided SE just W. of