314 BULLETIISr 17 6, UNITED STATES NATIONAL. MUSEUM 



horizontal crevice about two and one-half inches in width, sloping slightly 

 downward and partly filled, in places, with lava, sand and vegetable matter 

 evidently deposited by the wind. Upon reaching the crevice a Swift darted 

 forth nearly in his face, and he caught sight of its mate retreating back into 

 the crevice, from which it was not seen to emerge. Less than an hour's work 

 resulted in collecting, from a point about eighteen inches back, our first 

 nest, containing four fresh eggs. 



Florence Merriam Bailey (1907) made the interesting discovery 

 that white-throated swifts were nesting in cracks in the walls of the 

 old mission building at San Juan Capistrano, Calif. She located 

 four nests by seeing the birds enter the cracks ; bnt only one nest was 

 actually seen, of which she says: "The nest behind the end of the 

 stone arch was the only one seen and this — as it was ten feet from 

 the ground — only by climbing and peering up the crack. The crack, 

 as seen in the photograph, was behind the capitol of the pilaster on 

 which one end of the arch rested, the capitol having been jarred 

 away from the wall by an earthquake — doubtless that of 1812. 

 About ten inches up this crack the nest could be seen tightly wedged 

 in between walls less than two inches apart. As well as could be 

 seen without destroying the nest, it was made of bark, feathers, grass, 

 and, wool." 



Eggs. — The white-throated swift lays three to six eggs, oftenest 

 four and frequently five. The eggs vary from elongate-ovate to 

 cylindrical-ovate, or almost narrowly elliptical. They are dead white 

 to pale creamy wliite and without gloss. As mentioned above, the 

 eggs are often more or less spotted with the excrement of the insects 

 with which the nests are often badly infested. The measurements of 

 50 eggs average 21.24 by 13.74 millimeters ; the eggs showing the four 

 extremes measure 25 by 15, 19.1 by 12.9, and 21.9 by 12.7 millimeters. 



Young. — Enid Michael (1926) had a young swift in captivity that 

 she kept alive for ten days. 



This captive swift slept much of the time, but during his wakeful hours he 

 was a very active bird ; shoving and flopping along on his breast he could move 

 rapidly. He was kept in a wooden box with a screened cover, where there 

 were folded flannels into which he could snuggle away and sleep. When awak- 

 ened he would set out at once to explore his box. He could crawl up the ver- 

 tical wall of the box without the least difficulty, and one of his favorite stunts 

 was to race about, back down, on the under side of the cover screen. This 

 screen was ordinary mosquito-proof netting. When the screen cover was re- 

 moved he would scurry up the waU of the box and topple headlong onto the 

 floor. No sooner had he hit the floor than he would begin to skid about on his 

 breast, using his feet as propellers. He had a fancy for dark cracks, and if 

 he should find such a place he would surely disappear. Best of all, he loved 

 to crawl up one's sleeve to snuggle warmly under one's arm. He had very 

 strong feet and claws like a mammal. When attached to one's garments he 

 clung tenaciously, and each hooked toe nail had to be pried loose before he 

 could be removed. 



