192 LIFE- HISTORIES OF BIRDS 



it is vastly destructive to insects. Building close 

 to the barn-yard, it meets a ready supply of its 

 favorite articles of diet, which consists of the larvae 

 and im-agos of Musca domcstica, mature forms of 

 Tabamts lincola, T. cine his, and the blood -sucking 

 Stoinoxys, which delight in such places. In the 

 adjoining fields it destroys vast numbers of Pen- 

 thiiui poinonclla, Anisoptcryx vcmata, Eufitchia 

 nbcaria, and many of the Noctnidce and Tortricidcr 

 among lepidoptera; besides the young of CEdipoda 

 sulphurea and CE. ncbulosa, for which it affects a 

 peculiar fondness. 



Nidification commences during the last week 

 of May or the beginning of June. Both birds 

 assist each other in constructing a nest; the prin- 

 cipal part of the labor depends upon the male 

 under the supervision of his partner. It has been 

 affirmed that in large colonies it is a common 

 occurrence to find several females engaged in 

 incubation upon the same nest. We have never 

 observed a similar circumstance, but do not doubt 

 its authenticity. The mutual good--\vill which 

 prevails in a colony would lead us to suspect the 

 occasional existence of such a state of affairs. 



The nest is hemispherical in shape, with a small 

 opening at the side just large enough to admit 

 the passage of the female. The retort-like figure, 

 characteristic of the primitive form of structure, 

 has never been observed by us. The exterior of 

 the nest is composed of clivers kinds of earth, pro- 

 cured from puddles and low shallow streams. 



