A HERMIT'S WILD FRIENDS 



made it a male in my note-book. While the 

 bird was in the nest I fastened a bit of copper 

 wire to its leg, and the next spring, when it 

 returned, I found that the bird was a female. 

 I saw her with another female, I think it was 

 the mother, visiting birds' nests. So the young 

 cowbird was educated to lay its eggs in other 

 birds' nests. Nest-building is educational and 

 not instinctive. 



My fourth question could not be answered 

 by observation. 



How did the cowbird acquire this unnatural 

 habit? 



The answer to this question is not within 

 the province of proof. It is fair to assume 

 that the cowbird, in the distant past, reared 

 its young in a nest of its own. It may have 

 happened that some tragedy had deprived 

 a family of young cowbirds of their parents. 

 Other birds may have reared the young ones 

 until they were capable of providing for them- 

 selves. In migration all would remain to- 

 gether, but when nesting begun the young 

 cowbirds would not be tolerated near a nest. 

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