A BI-MONTHLY MAGAZINE 



DEVOTED TO THE STUDY AND PROTECTION OF BIRDS 



Official Organ of the Audubon Societies 



Vol. XI 



July— August, 1909 



No. 4 



A Cowbird's Nursery 



By CLINTON G. ABBOTT 



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HERE ignorance is bliss, 'tis 

 folly to be wise" — and, to 

 judge by the serenity of her 

 expression, the little Chestnut-sided War- 

 bler in our picture has not the least suspi- 

 cion that the three eggs which she is brood- 

 ing so happily are not all of her own lay- 

 ing. Who knows but that it may even be 

 to her a source of pride that two of them 

 are considerably larger than the third, giv- 

 ing promise as they do of babies twice as 

 lusty as those of her neighbors! As a matter 

 of fact, it is the work of the lazy Cowbird. 

 When the rightful owner of the nest has 

 been absent, no less than two eggs of this 

 shiftless vagrant have been imposed upon 

 her for incubation and care. Whether both 

 were laid by the same bird I could not of 

 course determine; but the fact that the eggs 

 were quite differently marked would indicate 

 perhaps that two Cowbirds had visited the 

 nest. 



As a general thing, I ha\e no qualms of conscience whatsoever in destroying 

 every Cowbird's egg that I tind. For although the Cowbird in itself is a harmless 

 bird, its advent into the world seems necessarily to be attended by the sacrifice 

 of other birds at least as harmless and usually more attractive. But in the case 

 of the Chestnut-sided Warbler's nest an unusual problem presented itself. Here 

 were two Cowbird's eggs and only one Warbler's. Had I removed both Cow- 

 bird's, the bird would almost certainly have deserted her home. So, as the nest 

 was in a convenient situation for observation— in a bush alongside a path, and 



CHESTNUT-SIDE ON NEST 



