96 PROCEEDINGS OF THE ACADEMY OF 



ON HABITS OF SOME AMERICAN SPECIES OF BIEDS. 

 BY THOS. G. GENTRY. 



The ])ocly of facts contained herein is the result of observations 

 carried through a period of four consecutive seasons, and is con- 

 fined to species which, though of extended range, breed within the 

 State of Pennsjdvania. This paper is designed to cover the ground 

 from the Family Icteridae to the end of the Family Picariffi, ex- 

 clusive of western species and a few whose habits have been de- 

 scribed by the writer in the forthcoming work of Dr. Coues. 



Family ICTERID^. 



Subfamily AGELiEiNJE. 

 Molothruis pecoris, Swainson. 



This well-known species, though an early visitor in Massachu- 

 setts, which, according to the authorit}' of Samuels, makes its ap- 

 pearance there as early as the middle of March, from some cause 

 or other has never been observed by the writer earlier than the 

 second week of April, long after the blue-birds, robins, and black- 

 birds have made the fields and woods resound with their music. 

 Its arrival is announced by the coming of the warblers and spar- 

 rows, betw^een w^hom and it exists such mysterious relations. 

 The anomalous habit which the female possesses of visiting the 

 nests of smaller species of birds when she wishes to deposit her 

 eggs, and thus shifting a responsibility which she should alone 

 assume, is familar to all. There is no doubt that primitively all 

 species were as equally social and gregarious in their habits as the 

 cow-bird of to-day ; and that the present system of mating, which 

 is surely an index of a high state of improvement, has been 

 gradually evolved. The art of nest-building has doubtless also 

 been slowly acquired. In some families it has attained a wonder- 

 ful degree of perfection, while in others it may be said to be in its 

 infancy. With the cowMjird either it has never been studied, so 

 to speak, or else it is a lost art which the species has never been 

 able to regain. 



The species of birds which seem to be the objects of its special 

 regard, are comprehended within the three great families of the 

 Sylmcolidse, Vireonidse, and Fringillidae; Geothlyxjis trichas, 



