202 Bird -Lore 



singing from a distant tree, and then he disappeared entirely from the premises 

 until the young were ready to leave their box, some two weeks later. Two days 

 before the departure of the young from the box, the father returned, and was 

 seen to carry a horse-hair into the box, though the latter was filled to overflowing 

 with five fully fledged young. The day after the young left the nest, the male, 

 singing constantly, remained about the box all day, and spent some time tearing 

 down the old nest and flinging horse-hair, fine stripped bark and small twigs 

 to the ground. These actions indicated that the male, who took no more part 

 in caring for the young after they left the nest than he had done before, possessed 

 the nest-building instinct at an ineffectual time, and when it was absent in the 

 female. Now, if these facts can be taken as a criterion for the actions of other 

 individual House Wrens, they may readily explain the presence in former years,, 

 of nest-building single males, which had been similarly banished by females 

 with broods elsewhere in the neighborhood. On the other hand, the single males 

 mentioned may have been simply bachelors disappointed in love. May there 

 not also be a possible connection between this curiously persistent nest-building 

 instinct of the male House Wren and the instinct which impels his first cousin, the 

 Long-billed Marsh Wren, to construct several complete nests, though occupy- 

 ing but one? 



The return of the nest-building impulse to the female Wren, preparatory 

 to her raising a second brood, also interested me. At first the expression of this 

 instinct was confined to late evening twilight, after the female had finished her 

 day's toil in feeding the young. I first observed this love-making the second 

 evening after the young left the box. I again observed it on the fifth evening. The 

 corresponding early morning hours may also have been employed in love-making, 

 but I was not then on watch. During much of the time throughout the eighth 

 day, the parents were together, and on the ninth day the female had entirely 

 abandoned the young, and thereafter devoted all her time to the raising of her 

 second brood. 



In the feeding of the young, I was puzzled for some time to name a shin\", 

 blue, berry-like object, which was occasionally administered. These objects 

 proved to be blue-bottle flies, stripped of their legs and wings. However, these 

 flies were more often given intact. 



Another incident in the feeding of the young apparently deniDnstrated that 

 a Wren, like many human mothers, may make a mistake in the selection oi food. 

 I one day noticed a young Wren disgorge food from the box hole. An examina- 

 tion of the substance disclosed an old dried-up snail shell, about one-half inch 

 in diameter and too large to serve for even grinding j^urposes. 



In the disposition of the young's excrement, which my records show to have 

 been about one-third of the number of feedings, the excrement was always carried 

 up into a neighboring tree, and, whenever I could see its final disposition, was 

 laid on a limb, and not dropped to the ground. 



I was greatly interested in comparing the length of lime between the liatching 



