752 U.S. NATIONAL MUSEUM BULLETIN 237 part 2 



in dry years but after a rainy cycle such places become too damp for 

 Baird's spaiTow and the species may disappear from a locality which 

 it has occupied for several years." 



My observations in Manitoba suggest that Baird's sparrow likes to 

 keep its feet dry and thus prefers well-drained terrain. A field of 

 tangled grass, both old and new growth, mixed with various species 

 of native plants, and with patches of western snowberry, wolfwillow, 

 rose, or low willow perhaps present in the area, is a favorite habitat. 

 This terrain may be close to wetlands, or it may be quite a long way 

 from them. The main concentration near my own city of Brandon, 

 Manitoba, is more than 2 miles from the river, the nearest water. 



In selecting her nest site, the female Baird's sparrow prefers longer 

 grass than do some of her neighbors, such as the prairie horned lark, 

 the chestnut-collared longspur, and sometimes the Sprague's pipit. 

 For her home she chooses a tangle of grass interspersed with prairie 

 plants within the ample territory her mate has estabhshed. The pair 

 may have the whole field to themselves, but more often a few pairs 

 nest fairly close to one another, forming a small community. 



Occasionally, one or more singing males wUl appear in an area late 

 in July, and it appears that they and their mates are the overflow from 

 a community where there was not enough room for all. Such a 

 situation is described by Cartwright et al. (1937), who also furnish 

 the following on nest types: 



The situation of Baird's sparrows' nests varies somewhat but is limited in the 

 one respect of being always placed upon the ground amongst the grass. For 

 convenience of description they can be divided into three general types, although it 

 must be borne in mind that this is an arbitrary classification and that the dis- 

 tinguishing characters may not be strictly adhered to from nest to nest. 



First comes the tj'pe where the nest is placed in a tuft of grass which is usually 

 held up by a wolfberry or other kind of shrub. The tuft is hollowed out, a floor 

 of grass is added, and the sides are then built up with grass woven in and out 

 sometimes to a height of five inches. In another type, the location is chosen 

 beneath an overhanging often horizontal tuft of dead grass, leaving only a small 

 entrance hole at the side. Frequently there is a slight depression underneath the 

 tuft, but if none exists, a shallow one is made by the bird. In the third type, 

 which seems to be the most common, the nest has no overhead concealment. 

 Nests of this type are quite often situated in cavities — generally hoof marks — 

 that in some cases are so deep as to place the nest two or three inches below 

 ground level. If such a cavity is not utilized, however, a shallow excavation is 

 made so that the nest is sunken to the level of the surrounding recumbent dead 

 grass. 



Differences in structure are only slight and depend largely upon the type of 

 situation. In the first and second types the floor is composed of short lengths of 

 dead grass laid down to form a sort of thick mat. This is surmounted by a rim 

 of interwoven grass which varies in height, being high in the flrst case and low 

 in the second. The entrance in the first type is fairly high up in the tuft, where 

 the side is gradually pressed down by the birds in alighting and departing. In 

 the second type the entrance is at ground level, is small, and is usually the only 



