286 BULLETIN 17 6, UNITED STATES NATIONAL MUSEUM 



The most spectacular event in the swift's life, from our point of 

 view, occurs during the autumnal migration when the birds, late 

 in the afternoon, congregate in a large, wheel-shaped flock and circle 

 about the chimney they have selected as their roosting place for the 

 night. . The following quotations describe in detail such gatherings. 



Townsend (1912), writing of the bird in the St. John Valley, New 

 Brunswick, says: 



At Fredericton, on July 25, I watclied a large flock of Swifts enter for the 

 night a chimney on the southwest corner of the Parliament Building. Sun 

 set at about 8 p. m. At 8.24 p. m. one bird set its wings and dropped into the 

 chimney and soon they began dropping in fast, while the flock circled first one 

 way then another or crowded together in a confused mass, twittering loudly 

 all the time. Owing to the proximity of the dome regular circling was some- 

 what interfered with, but as a i-ule the birds circled in the direction of the 

 hands of a clock, and individuals would drop out and into the chimney in 

 dozens when the circle passed over it. Occasionally they would all swoop off 

 to the other side of the building, soon to return. At 8.45 p. m. practically all 

 the birds had entered the chimney and I had counted roughly, — at first singly 

 and later by tens, — 2200 birds. 



The setting of the wings, which Dr. Townsend speaks of, takes 

 place just over the mouth of the chimney. The bird raises its wings 

 above its back and drops into the chimney or very often shies off, like 

 a horse refusing to take a fence and, after making another circuit, 

 tries again. 



Linton (1924) gives us a vivid picture of the Swifts "at bedtime," 

 showing a spirit of play among the birds. He writes from Augusta, 

 Ga.: 



October 5, 6.5 p. m. : Sky overcast ; large numbers of Swifts in the upper air ; 

 look like swarm of bees ; general direction of flight in circle, counter-clockwise. 

 6.7 : A few began to enter the chimney, when a passing auto frightened them 

 for a short time. 6.8: Entering again, average probably not far from 15 per 

 second, at times many more than this [the flue of this chimney was said to be 3 

 feet square] ; circling continuously counter-clockwise. As the circle approaches 

 the chimney, a column of Swifts, from a point 20 feet above the level of the 

 top of the chimney descends to the chimney. The Swifts in this column which 

 fail to enter continue the circle at a lower level, joining the higher level at the 

 opposite side of the circle, and in a position which makes them contributing 

 parts of the descending column, when they again come to that point. Great 

 swarms of Swifts could be seen in the upper air, their paths apparently cross- 

 ing and recrossing, but really all flying in circular paths at different levels. 

 Many appeared as minute specks in the upper air. At 6.23 all were in, stop- 

 ping abruptly ; probably no more than a dozen stragglers in the last 5 seconds. 

 It thus took the flock a little over 15 minutes to enter the chimney. 



October 8, 6.12 p. m. : Sky clear ; 3 or 4 Swifts seen from window. 6.13 : 12 or 

 more Swifts in sight. 6.15 : 100, more or less, in sight. 6.15 : 20 : 500, more or 

 less, in sight. 6.16 : Increasing in numbers rapidly ; general course in wide cir- 

 cles, counter-clockwise. 6.17 : Seem to be enjoying themselves too much to go 

 to bed ; immense numbers ; upper air full of them. 6.19 : 20 : Getting closer to 

 chimney ; some of them dipping down to within a foot or two of the top. 6.20 : 

 Changed their minds for a few seconds ; again enjoying themselves in the air. 



