258 BULLETIN 17 6, UNITED STATES NATIONAL MUSEUM 



edge of the nest, and jflapping its long wings, which projected well 

 beyond the end of its tail, could hardly be anything but a black swift. 

 The next account comes from Charles W. Michael (1927), who, on 

 July 6, 1926, discovered a colony of northern black swifts, containing 

 at least six pairs, nesting in a canyon in the Yosemite Valley, Calif. 

 He writes: 



In the inner chasm of the Tenaya Gorge a hundred paces beyond the 

 "wedged boulder", where vertical walls rise two hundred feet or more, the 

 swifts had chosen a nesting site. The nest was placed on a bit of projecting 

 rock which presented a level space of perhaps four by six inches. The projec- 

 tion was located within the shelter of an overhung wall, thirty feet directly 

 above a deep pool in the creek. Towering above the nest the cliff rose sheer for 

 a distance close to two hundred feet. The inner chasm is here very narrow; 

 the vertical walls stand not fifty feet apart. The channel is dark and cool; 

 in the long summer days the sun lights its depth for but a brief hour. And 

 at no time or season does the sun ever play on the nest of the swift — cramped 

 quarters, I should say, for birds of the wide skies. 



It was the wild, erratic wingings of a lone Black Swift, as he whizzed 

 back and forth through this narrow flight lane, that first attracted my atten- 

 tion. * * * While I watched, tlic bird suddenly swooped and fairly seemed 

 to plaster himself to the wall not fifty feet from where I stood. Then, with 

 fluttering wings the bird moved upward — not straight upward, however, but in 

 an angling course across the face of the cliff. As I followed the movements 

 of the swift the nest was suddenly descried. The swift paused, clinging to the 

 projection that held the nest, and I thought at first that he was feeding young. 

 After a moment he scurried on upward a few feet, fell backv.ard, and then 

 twinkling wings carried him away down the channel. * * * 



As for the nest itself, as best I cotild see it, it resembled in form and con- 

 struction that of the Western Wood Pewee; but in size it appeared larger. 

 Also it reminded me of certain cormorant nests I have seen plastered to the 

 ledges above the sea. The general appearance of the structure, its apparent 

 adhesion to the shelf, and the droppings plastered to the granite immediately 

 below, led me to suspect that the nest may have been occupied through several 

 nesting seasons. The rock wall roimdabout was absolutely bare and di'y- There 

 was not a growing plant within ten feet of it. 



Of a later visit, July 11, he says : 



Beyond the "wedged boulder" I moved cautiously, but before I had come within 

 sight of the nest a swift was seen to leave the wall and dash down the canyon. 

 I was afraid that I was not to find the swift at home, but as I came opposite the 

 site, there was the bird in plain sight. She sat on the nest with her tail ap- 

 pressed against the wall and with one long wing drooping over the side. Her 

 body rested in a horizontal position and she appeared much too large for the 

 nest. 



While I was watching the bird a second nest was discovered. The second one 

 was tucked away in a niche and, but for the droppings below, it would hardly 

 have been noticed. The nest was a little round cup, shallow, and composed, 

 apparently, of some soft, brown material like dry leaves ; the rim was tinted 

 slightly green. On a later visit, with assistance and encouragement from "Big" 

 Con Burns, I managed to climb to a point within eight feet of the nest. And 

 then it was learned that the nest was composed of the delicate pinnae of the 

 five-fingered fern. Great banks of these ferns hung from neighboring walls, 



