1 88 Wild Birds 



the nest. When captured at the age of fifteen days, it had 

 grown one half inch in length, but had lost one twelfth of an 

 ounce in weight. 



The next in point of vigor increased twelve times in weight, 

 or on the fifteenth day attained the stage reached by the first 

 bird when from eight to nine days old. Nestling number three 

 increased eleven times in weight in the same period. The 

 horizontal slits of the eyes opened on the fifth day in the first 

 bird; at a week old the feather-tubes had burst all over the 

 body excepting the quills of the wings and tail which began 

 to emerge from their horny sheaths on the eighth day, and 

 on the twelfth day the first unmistakable signs of fear were 

 exhibited. 



At a corresponding rate of growth a ten-pound baby, when 

 one day old, would weigh twenty -one pounds, and at the age of 

 twelve days one hundred and thirty -four pounds. 



From the first to the fifteenth day the strongest of the three 

 birds had increased in length nearly three times (measurements, 

 if and 5i inches). 



IV 



CLEANING THE NEST 



The sanitary condition of the young is a matter of great con- 

 cern to most birds, who as a class are extremely neat and clean. 

 This is especially true of the many species breeding in holes or 

 cavities of any kind like the Woodpeckers and Chickadees, the 

 young of which are crowded in close quarters or even piled 

 up in more than one layer. The Woodpecker's hole and the 

 Bluebird's nest are always sweet and clean, and the nestlings 

 immaculate. 



The duty of inspection and, if necessary, nest-cleaning 

 follows each feeding with clock-like regularity, and is one of the 

 most characteristic and important activities to be observed in 

 the nesting habits of a large number of the smaller land birds, 

 yet apparently it is not mentioned in the standard treatises of 

 ornithology, and I have found but few references to it in works 



