240 BULLETIN 196, UNITED STATES NATIONAL MUSEUM 



but the material of the two nests." And Mr. Todd (1940) quotes 

 an anecdote by J. Warren Jacobs concerning a bluebird appropriating 

 the finished nest of a Carolina chickadee: "The nest was in two parts; 

 one constructed by the Chickadee, and the other, which was the top 

 story, was made by the Bluebird. The first story contained two 

 [eggs] of the Chickadee, and in the next were five eggs of each species." 

 I once found a flicker's egg in a bluebird's nest, together with five 

 eggs of the bluebird; and in the same orchard there was a flicker's 

 egg in a tree swallow's nest, with five deserted eggs of the swallow. 



The nests of the bluebird are poorly and loosely built structures; 

 this is probably all that is necessary in the snug cavities in which 

 the nests are usually made, where a firmly built nest is not required. 

 The nests are often made entirely of dried grass and weed stems, 

 carelessly arranged; sometimes a few fine twigs are added; the lining 

 may consist merely of finer grasses, or sometimes a little hair or a 

 few feathers are added. The possible nesting sites are often pointed 

 out by the male after he has attracted the female to his breeding 

 territory, but she evidently makes the final choice. Both sexes help 

 in building the nest, though most of the actual work on it is done by 

 the female. 



Wendell P. Smith (1937) made the following observations at his 

 banding station at Wells River, Vt.: 



Nest-building did not proceed with uniform speed, especially in the case of 

 an early beginning. There seemed to be some correlation with temperature, as 

 cessation of activity coincided with lower temperature and resumption of con- 

 struction began with the coming of warmer weather. The time required for a 

 nest's completion differed in consequence. The shortest period recorded was 

 four days, and the longest twelve days. 



Material was secured within a radius of seventy-five feet of the nest, and much 

 of it within less than half that distance. In one case dried grass was used, while 

 in the other, dead pine needles were obtained from the ground near by. Observa- 

 tions showed that the female performed nearly all the work of collecting. Be- 

 tween the completion of the nest and the laying of the first egg some time inter- 

 vened, usually two or three days. 



Dr. W. T. Harper (1926) has published some detailed observations 

 on the building of a second nest by a pair of bluebirds. He concludes 

 with the following summary: 



The most interesting points disclosed by these observations seem to be the 

 following: First, the site for a second nest seems to have been selected while 

 the first brood was still in the nest, and the male took the initiative in the selection. 

 Second, the male laid the first foundation of the second nest, but the female did 

 practically all the work while the male acted as watchman or boss. Third, work 

 was faster at the beginning of the building operations and, as finishing touches 

 had to be added, the work became constantly slower. Fourth, parts of four 

 days were required to build the nest, most of the work being done between 6.30 

 and 10 A. M. Fifth, at least two hundred and eighty-nine trips with nesting 



