FAP 1957 Selasphorus rufus March 28 Owens Rd., Berkeley, Calif. (at least never noted clearly) The tail was not spread and it is difficult to say anyone now than that the strong rhythmic sound as produced by more than the wings. Once this display was seen from the rear, when it was clear that the bird did not roam in a single plane, but moved then swung alternately in planes at about 20° to each other; thus -> such shifting seems reasonable in view of the likely enhancement of the flash effect of the gorget which this transition (in angle) would promote. The angle is evidently too small to be apparent when a bird making this type display rapidly is watched at 30-40 feet distance from the side: confirmed This display was seen clearly at least six times and heard many more - perhaps 10-15 in the 13-day period the male has been here. It was addressed to hummingbirds and also to other birds moving into favored areas and particularly near or onto the