BAIRD'S SPARROW 753 



position from which the interior can be viewed. In the third case, if the nest is 

 sunken in the ground, it is then a more substantial affair, being a bulky, well- 

 woven, cup-like structure. 



The average inside dimensions of a nest are: diameter, 2.5 inches; depth, 1.5 

 inches. 



The variety of materials found in the nests is very limited. Dead grass is 

 used almost exclusively, the lining often being of finer strands than the rest. 

 P. B. Peabody in North Dakota and Minnesota, and A. Dawes DuBois in Mon- 

 tana have found that weed stems were sometimes used. No similar observation 

 has been made in our studies. In one nest we have seen bits of a moss that grew 

 sparsely in the vicinity. In the lining of two nests a few strands of horse hair 

 were noticed. Another material often favored where it could be obtained was 

 the red setae of moss, greatly resembling hair and possibly used for the same 

 reason. 



The life of the nest is very short, lasting only about three or four weeks. During 

 the course of nesting it suffers greatly from the trampling of both parents and 

 young. Moreover, when the young birds leave, it has been observed by us that 

 the sides are broken down and the material of the nest strewn about so that 

 traces of its existence are obliterated. This must necessarily be done by the 

 parent birds. 



The birds are exceedingly close sitters, even on fresh eggs, and will not flush 

 until one is on top of them. One female (on fresh eggs) would even allow a light 

 rope to be dragged over her without flushing. In consequence, the nest is ex- 

 tremely difficult to find. The fact that of the thirty-five nests which are re- 

 corded * * *, fifteen of them are ours, the balance being practically all the nests 

 of this species which have been discovered in fifty-eight 3'cars, will tell the stor}' 

 of countless hours of searching much more graphically than any words. 



There seems to be little variation in nesting habit or situation in any part of 

 the breeding range. 



I believe this species delays its nesting activities till late in June 

 because the tough prairie sod is slower to grow the necessary cover. 

 This late start also reduces the probability of a second brood. 

 Normally both parents are caring for their offspring until the end 

 of July, after which a second nesting would not be feasible. 



Cartwright et al. (1937) give no nesting records for Saskatchewan, 

 but at least three nests have been found there. The first is recorded 

 by W. E. Clyde Todd (1947) from the Last Mountain Lake area: 

 "Dr. Sutton found a nest here on June 23, [1932]; it held four eggs 

 which closely resemble those of the grasshopper sparrow." Fred G. 

 Bard, of the Saskatchewan Museum of Natiu-al History, collected 

 the second nest with five eggs near Hatfield, Saskatchewan, June 28, 

 1933. The third, also with five eggs, was found by Manley Callin 

 just east of Percival, Saskatchewan, June 24, 1934. Bearing in mind 

 the vast areas of this province where Baird's sparrow occurs, it 

 probably nests more plentifully here than in all the rest of the breed- 

 ing range. Once the field naturalists of Saskatchewan become more 

 familiar with it and its habits, they should find many more nests to 

 study. 



