312 BULLETIN 17 6, UNITED STATES NATIONAL MUSEUM 



reach of predatory animals and birds, not excepting the human 

 egg collector. 



James B. Dixon has sent me the following not«s: "This bird is 

 a common breeder in the rougher, more mountainous sections of the 

 whole of southern California, as I have found them nesting in every 

 county south of Tehacipi, and from the ocean cliflfs to the highest 

 peaks up to 6,500 feet above sea level. I have seen them nesting in the 

 dug-out holes of rough-winged swallows and right in the middle of a 

 large colony of swallows, where it was extremely difficult to teil 

 which one of a myriad of holes the swifts were inhabiting. 



"Usually the nests are very flimsily built of feathers glued together 

 into one complete structure. The nest naturally takes the shape of 

 the crack in which it is located and therefore takes all kinds of shapes ; 

 but where they have room they will build a nice, round, well-cupped 

 nest that is so well stuck together that il can be dropped from the 

 cliff and not a feather will be lost. Nest building begins very early 

 in spring and continues for a long time. I have seen birds enter 

 the cracks in a cliff early in March with feathers in their bills, which 

 they must have carried for miles, as the feathers were chicken 

 feathers and there were no poultry yards nearer than 6 or 8 miles 

 in an air line. 



"In 1915 I made a special effort to collect several sets of eggs. 

 As we did not know when the eggs would be laid and had seen them 

 building their nests so early, we started operations in April. At 

 this time we found the females sitting on their nests and still build- 

 ing by adding occasional feathers. We inspected these locations 

 week by week from early in April until the last of May before any 

 eggs were laid. The females were in^ the nests the better part of 

 the time, and the minute a female left a nest every male within 

 sight would take after her. 



"The main colony of about 12 pairs was located in the center of a 

 400-foot hard granite cliff. Here we located three nests that could 

 be reached; the others were too far back to be seen, although the 

 sitting birds could be heard twittering and giving their typical 

 shrill calls." 



There is a set of four eggs, with the nest, collected by J. B. Dixon 

 and C. T. Schnack, in the Thayer collection in Cambridge, which 

 came from the same nesting site. In the elaborate data that came 

 with it they state that the nest was located on a large granite cliff 

 in a steep, narrow canyon near San Pasqual, San Diego County, 

 Calif. It was taken on May 25, 1913, from a diagonal crack on the 

 face of the cliff, 175 feet from the top and on a projecting point of 

 the cliff. The nest is a compact wad of white plant down, mixed 

 with feathers, all securely glued together, and is lined with white, 

 brown, buff, and black feathers, with a few small, bright-yellow 



