Cogswell 1948 Cremophila alpestris Dec. 21 - Carrizo Plain in Southeastern San Luis Obispo Co., Calif. By far the commonest bird in this wide expanse of bare earth. 3 large flocks were estimated at 1500, 500, & 500, respectively -- but there was such a lot of circling about when they were all in the air that it was very difficult to judge numbers. Dec. 27 - ½ mi. W. of intersection of Lincoln Blvd. & Sepulveda bluds, near Los Angeles airport, L.A. Co., Calif. - Flock estimated at 600, doing a lot of chasing about over field with low stubble and slight new growth of annuals (less than 1 inch high). Some were in 2's & 3's performing very rapid & close chases low over the ground with erratic twists & occasional sudden upward swoops. A few songs were heard from birds on the ground. The courting season is apparently beginning here.