never to be satiated and, unlike most nestlings, which relapse after a meal and 

 give their brethren the next chance, he seemd ready for every fresh opportunity ; 

 and, by reason of his superior display, he usually succeeded in obtaining the 

 coveted morsel. However, the young Warbler did manage to get an occasional 

 portion, and I had strong hopes that he might reach maturity. For I realized that 

 a Chestnut-sided Warbler's usual laying is about five eggs, and that, therefore, 

 some four eggs must have been made to give place to the two Cowbird's. Hence 

 the young Cowbird in the nest might reasonably be granted the room and food 

 of four young Warblers. More than this I hoped he was not getting. 



''On July 18, at 3:30 p. m., when the birds were about four days old, I took 

 them from the nest to compare their sizes. I replaced them in the nest, but that 

 was the last I saw of the poor little Warbler. When I returned at 5 p. m., the 

 Cowbird was in sole and triumphant possession of the nest. Just what became 

 of the Chestnut-sided Warbler will never be known, but my theory is that, weak- 

 ened by lack of sufficient food, the little fellow at last became too feeble to raise 

 himself at all, and was crushed to death by the Cowbird's gross body. The parent 

 birds, returning and finding the little corpse in the bottom of the nest, were no 

 doubt impelled by their instinctive sense of cleanliness to carry it to a distance ; 

 for the most careful search over a large area beneath the nest failed to reveal any 

 sign of the missing bird, thus proving that it had not fallen from the nest nor been 

 forced out by the Cowbird. 



"The Cowbird now had things all his own way and, there being no one to dis- 

 pute his right to all the food, he grew with amazing rapidity. The dainty little 

 cup of a nest, never built to accommodate such a monster, was soon completely 

 forced out of shape. His body then protruded beyond the lower rim of the nest, 

 and the ground underneath became littered with droppings, quite baffling the 

 cleanly, sanitary instincts of the Warblers. 



"The Cowbird, now almost twice as large as his devoted foster-parents, rises 

 with hideous chitterings of delight to receive an ever-acceptable meal. I visited 

 the nest at 7 :30 a. m. on July 26. As I walked home to breakfast, I resolved that 

 in the interests of justice I ought to put an end to that Cowbird as a murderer 

 and a menace to the welfare of birddom. But when I returned to the spot, about 

 9 a. m., he had escaped me ; the nest was empty, my bird flown. No doubt, if I 

 had searched and listened, I should have heard him shouting for food not far 

 away ; but my spirit of vengeance was only half-hearted at best, and so I left him, 

 a criminal abroad, to be the parent, I -suppose, of others as bad." 



589 



