XII. 

 Cow-bird THE INSTINCT OF THE COWBIRD 



THE books on ornithology tell us that the 

 cowbird (Molothrus ater) is a common summer 

 resident of New England, without regard to 

 locality. However true this may be as to other 

 parts, it is a fact that the bird was unknown 

 to me in Penobscot County, Maine. 



Cowbirds are summer residents of Cape 

 Ann, and I have studied their habits for years. 

 I commenced by requiring answers to the fol- 

 lowing questions: 



Why do birds, when victimized, rear the 

 young cowbird? 



Why does the young cowbird desert its fos- 

 ter parents to associate with its own kind? 



Why do young cowbirds lay eggs in other 

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