Michigan Ornithological Club 89 



and then dropping exhausted to the bottom of the nest. We then retired to a 

 distance and watched proceedings through the glasses. For three-quarters of 

 an hour the Bunting did not get a particle of food, both parents being busy 

 trying to fill up the bottomless pit inside of the intruder. A visit to the nest 

 two weeks later discovered that the Cowbird had gone, but also that the Bunt- 

 ing was dead. Here, then, is a case where the life of one Cowbird destroyed 

 the lives of four Indigo Buntings, for the remaining three eggs which go to 

 make up a normal set of this species, must have been pushed out by the adult 

 Cowbird. 



A Vireo's nest, found on June 12th, 1904, and shown in the accom- 

 panying photograph, was placed about six feet from the ground amidst 

 a thick growth of underbrush and mosquitos, practically impregnable to man. 

 But again the birds had a worse enemy than man, as ' the nest contained 

 three eggs of the Cowbird and three of the Vireo. The nest being full, one 



Vireo Nest Showing Three Cowbird Eggs. 



of the latter was piled on top of he rest and consequently one side was 

 smashed in. This fact alone would prevent it from hatching, while the 

 remaining two Vireos would soon have been crowded out of existence by the 

 three Cowbirds. 



But this intrusion is not only during the period in the nest, but lasts until 

 the young Cowbirds can fly and are apparently able to take care of themselves. 

 Tn this connection I have watched a male Black and White Warbler (Mniotilta 

 varia) continually feed a young Cowbird for an hour without intermission, 

 during which time the Cowbird flew around immediately after the warbler 

 with its mouth open, ready to receive the food as fast as its foster-parent 

 could find it. 



I have watched this same performance with the Black and White Warbler. 

 Redstart, Red-eyed Vireo, Yellow Warbler, and Wood Pewee. In the latter 

 case both parent Pewees did nothing brt feed the Cowbird. I was unable 

 to find their nest, in order to discover what condition the young birds were in. 



