NORTHERN BLACK SWIFT 259 



and it would be quite possible for the swifts to procure material while on the 

 wing. Perhaps, though, the swifts may gather nesting material while clinging 

 to a wall, as I have often seen swifts alight on a ferny ledge above Vernal Fall. 

 In any event, this nest was rimmed with fresh green leaves. 



Another nest was later discovered near these two, all three within a 

 radius of three feet. Three other nests were discovered later in the 

 same canyon. Sunnning up his experiences, he says : 



I now feel that I have the system for locating Black Swifts' nests. Knowing 

 the precise requirements demanded by a nesting swift, the thing to do is to find 

 the locality that approximates these requirements. * * * What really sim- 

 plifies the problem is the scarcity of suitable nesting localities for Black Swifts. 

 There must be cozy niches in which to place the nests, and these niches must be 

 so situated as to afford complete protection against rain, wind, and sunshine. 

 Perhaps, too, there should be many of these niches, that nesting swifts may have 

 nesting neighbors. 



Then comes Emily Smith (1928) with her report of finding three 

 nests of black swifts close to and behind Berry Creek Falls in a not 

 very remote canyon in Kedwood Park, Santa Cruz Mountains, Calif. 

 The first nest seen "was not behind the falls, but a little to one side 

 in a niche twenty feet above the pool which lies at the base of the sheer 

 seventy-foot cliff. * * * j could not get closer than the edge of 

 the pool, but from there the nest thirty feet away was in plain view, 

 a thick, round mat of moss and possibly some mud, set in an almost 

 square little niche in the rock wall. The wall roundabout, covered 

 with mosses, five-finger ferns, and other moisture-loving plants, was 

 dripping wet." 



The other two nests were behind the falls, one only 8 feet above 

 the pool, and the other much higher up and "hardly more than ten 

 inches back from the main stream of the falling water. Some of the 

 moss of which the nest was constructed appeared green and living, 

 giving the nest a cushiony look." 



Joseph S. Dixon (1935) records the first nests found in the southern 

 Sierra Nevada : 



We found three nests, but there probably were others in the vicinity, since 

 over a dozen Black Swifts were seen. The three nests were located within a 

 linear distance of twenty feet, so that the species might reasonably be said to 

 have colonial nesting habits, at least in this instance. The nest site was located 

 in the deep granite gorge of the Marble Fork of the Kaweah River. All three 

 nests were located in a shallow cave that had been formed by the falling of a 

 section of the cliff, leaving a broad auch about thirty feet in height. The bare, 

 wet, dark granite wall rose precipitously above a deep pool beside a waterfall, 

 spray from which kept the entire surroundings drenched with mist. 



In all three instances the swift nests were made of green resurrection moss, 

 pressed down but not stuck together with saliva, and were placed on and 

 supported by a clump of fragile five-fingered ferns. The first nest was a firm, 

 mossy cup placed about eigliteen feet above the water. This nest measured out- 

 side 3 by 4 inches in diameter and was 3 inches high. The trampled-down shallow 

 cup was empty, the young bird evidently had just left the nest [August 7]. 



