TYPES OF NESTS OP BIFIDS. 



239 



pattern. An outer wall of finer weed-stems, grasses, or lichens, and an 

 inner layer of horsehair, are the essential features in the chippy's idea 

 of building at all times and places. The outer layer is variable or may 

 be lacking, but the horsehair is indispensable, and frequently the nest 



s. 



contains only this material. The chipping sparrow's habit of using horse- 

 hair has suggested its nikname of hairbird in many localities. Gener- 

 ally dark or black hair is used, but this season I found a nest in which 

 white or gray hair was used, the only nest of the chipping sparrow thus 

 finished that I remember to have seen. 



Another sparrow of this region, the western vesper, follows a plan 

 of building similar to that of the chippy. The site is a depression in the 

 ground, at the base of a tuft or small bush. There is generally an outer 



