A Study of the Cuckoo 



By Clara Kern Bayliss 



Scores of writers on the Cuckoo assert that only the European species 

 imposes its eggs upon other birds. Only two writers that I know of state the 

 contrary. Ridgway, in Illinois Ornithology, says that the Yellow and the Black- 

 billed impose upon each other and, rarely, upon other species. And in Ahsts and 

 Eggs of North American Birds, David Davie states that they occasionally deposit 

 their eggs in nests of the Robin, Cardinal Grosbeak, Mourning Dove, Catbird, and 

 Waxwing. 



On July 24, 1916, I found a Yellow-billed Cuckoo's nest, with the bird in- 

 cubating, ten feet from the ground on the horizontal branch of a small elm. Not 

 having my "periscope" (an adjustable mirror at the end of a bamboo pole) with 

 me, I assisted a little girl who had accompanied me, to climb the tree, and she 

 reported that the nest contained three green eggs, one of them smaller and darker 

 than the other two. As seen through the mirror next day I should describe the 

 smaller as bluish-green, almost as dark as a Catbird's egg, and the others as 

 greenish-blue. 



July 29th, at 6 :30 P. M. the eggs Avere there as usual and the bird remained 

 on the nest until I was almost under her, giving me an opportunity to see her 

 yellow bill and her graceful, horizontal flight as she slipped noiselessly into 

 another tree. The following day was Sunday and was exceedingly hot, as was 

 Monday forenoon. In the afternoon of Monday, July 31, there was a severe 

 storm, and the nest was not visited until the forenoon of August 1st, when there 

 were three young birds in the nest, all black as ink, the two larger with black 

 hairs and the smaller with white hairs on the body. They were certainly one day 

 old and may have hatched on July 30th. When jarred, they made a faint hissing 

 or buzzing like that of a bee. 



On this morning I had invited Professor C. W. Hudelson to accompany me, 

 and we had taken a camera and a step-ladder, expecting to photograph the nest 

 and eggs. Finding the young birds, he strapped the camera to the trunk of the 

 tree and took the accompanying picture. 



Thinking the little white-haired birdling might be crowded of¥ the frail plat- 

 form, I took one of the larger birds home with me ; and of that I will speak later. 



At sunset August 2nd, on my approach, a male Nighthawk, uttering his 

 peent, peeiit, flew down from the tree to a dead limb on the ground where he 

 tarried a moment, shuffling his long wings and complaining ; then he spread them 

 and sailed away. I feared that he might have been bent on mischief ; but both 

 the birds were in the nest. Toward evening August 4th, they were still there, 

 though the white-haired one was crowded to the edge of the nest with the big 

 one lying partly over it. At sundown August 6th, only the black-haired one was 

 there, no trace of the other being discernible. 



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