2877 Gymnogyps californianus February 12, 1946 Whiteacre Pk., Calif. ed to outermost point. First followed, & with an easy spring with wings half raised, landed on top of second. Both birds stood calmly thus for about 30 seconds after top one gained its balance. Then it seemed that top one had head & bill close to head of bottom one, & top one flopped gently as if balancing. Top bird jumped off onto rock about 1:16 1/4, & a few seconds later took off & landed in a dead tree 150+ yds. W. of & 100' below the other. The ♀ (?) remained on its perch, unperturbed apparently after this mounting, & was still the same at 1:25. The ♂(?) was facing ♀'s direction perched on a top branch of a dead topped Ps. on a SW & WSW leading ridge running from the first perch point. I believe this is the first mounting I have seen which was at all successful - copulation probably did not take place unless very briefly. A raven alighted 30+ 'from & 10' above the ♂ - no reaction. Raven later alighted on top of ♂'s branch - ♂ seemed unconcerned, tho head down, for 10+ sec- onds, then suddenly raised wings (possibly balancing movement) & raven flew. 1:42, another raven on center stub of ♂'s tree - 6+' from ♂ & at same level, but no reaction apparent from adult. 1:45, ♂ ruffled up wings, then gave a half stretch with left