2^irb=1tore 



A BI-MONTHLY MAGAZINE 



DEVOTED TO THE STUDY AND PROTECTION OF BIRDS 



Official Organ of The Audubon Societies 



Vol. XXIII July- August, 1921 No. 4 



The Yellow-breasted Chat and the Cowbird 



By WILBUR F. SMITH, South Norv,alk, Conn. 



I HAVE been re-reading Dr. A. A. Allen's article on Warblers in Bird-Lore 

 for March- April, 19 19, and especially his experiences with the Yellow- 

 breasted Chat. Dr. Allen tells us that he has never known a Chat to 

 hatch out a Cowbird's egg, and I find in the 'Warblers of North America' the 

 following quotation from F. L. Burns (M.S.): "The nest is watched very 

 closely, although the owner is seldom flushed from it, while a disturbed nest 

 will almost invariably be deserted after the owner has pierced or broken its 

 eggs. While the Cowbird frequently deposits its egg in the Chat's nest, it is 

 never incubated, but destroyed by the bird with her own." 



In the face of such a positive statement as the last, some experiences I have 

 had with the Chat take on an added interest, though perhaps I am overbold in 

 upsetting what seems to be an accepted belief in the Chat's super-keenness in 

 detecting the Cow-bird's egg, which is so like her own. 



Let me first fortify my position by quoting a fellow bird student, Mr. Jesse 

 Meeker, who writes me that "on June 2, 1902, at Milford, Conn., I found a 

 Chat's nest with three Chat's eggs and one Cowbird's egg, and the Chat flushed 

 from the nest. All the eggs were slightly incubated." 



The only Cowbird I ever caught in the act was seen slipping from a Chat's 

 nest, and I removed the newly laid Cowbird's egg and photographed the nest, 

 with the three Chat's eggs, and know that they all hatched and the young 

 were raised. 



In typical Chat country, an abandoned field overgrown with bushes and 

 vines, I found a Chat's nest with one egg and one Cowbird's egg. It was built 

 in a tangle of escaped honeysuckle vines and was not as cleverly concealed as 

 is generally the case. I had only recently been reading of the Chat's ability to 

 detect the alien egg which is so like its own, and a desire possessed me to leave 

 the Cowbird's egg in the nest and see what would happen. If the Chat was as 

 keen as I had been led to believe, she would desert the nest anyway, while if she 

 finished laying her set of eggs and hatched and raised the Cowbird's, something 



