1614 U.S. NATIONAL MUSEUM BULLETIN 23 7 part 3 



not at all consonant with what is known of passerine birds generally, 

 and when all longspur nests on a given area are censused, the number 

 of males in the area, whether counted in small groups or singly, 

 generally agrees with the nest count. 



Coincident w r ith incubation and the general subsidence of terri- 

 torial behavior, the males are attracted to any female who happens 

 to be away from a nest. Undoubtedly a few males and females are 

 unmated, and these together with birds that have lost nests, may 

 commence flocking by mid-June. Males collected from obvious 

 small flocks in generally uninhabited areas had testes smaller than 

 those of the breeding component of the population. 



Nesting.- — A striking f eature of arctic bird life generally is the sudden 

 onset of nesting after the arrival of the migratory birds. The Lapland 

 longspur is an example of a species that has compressed this interval to 

 a minimum. With the arrival of the females, which may be as much 

 as two weeks after that of the males, the nesting cycle is set rapidly in 

 motion. The females start nest-building as promptly as four days 

 later, and many records show nest-building spans just three days. 



Edward W. Nelson's (1887) comments on general nest structure 

 indicate that considerable size variation is commonplace: 



The walls are thick and strong, composed of an abundance of material, or 

 they may be a mere cup-shaped shell, barely sufficient to hold the eggs. The 

 majority of nests are composed of rather coarse grass, sometimes with moss 

 interwoven, forming a thick layer, which was frequently as thoroughly water- 

 soaked as a wet sponge when the nest was collected. The amount of material 

 used depends greatly upon the locality; in damp places a much greater amount 

 is made use of, while in dry places the nests are much lighter. Though the 

 outer part of the nest was frequently formed of old and often grimy or partly 

 decayed vegetable matter, the interior was invariably composed of fine, soft, dry, 

 yellow blades of last year's grasses. These in many instances are unmixed with 

 other material, and in others are combined with feathers of the Ptarmigan or 

 other wild fowl. In a few cases the lining of the nest is a warm cup of feathers 

 resting upon fine grass, and one has a thick lining of feathers and dogs' hair. 

 Some nests are so small that they may be inclosed in the hand, while others can 

 scarcely be inclosed by both, and the smallest nest collected may be inserted 

 entire into the cavity of the largest one. 



I feel that much of this size variation can be attributed to the use of 

 a nest from a previous year. Nest depressions, and undoubtedly the 

 old material they contain, are used repeatedly. This material may be 

 carried to a new site and made into a more compact nest, or it may be 

 simply left in place, slightly modified, and then lined with fresh grass. 

 Such a nest would be considerably larger both in bulk and size of the 

 opening than a new one. The virtual impossibility of finding old, 

 unoccupied nests suggests that the premium placed on particular nest 

 locations is great and their reuse routine. Nevertheless, my examina- 



