Feathers 45 



part of the young birds to take care of themselves as 

 soon as hatched. They pass the entire first moult within 

 the egg itself, and are covered with perfect feathers and 

 fully developed flight-quills when they emerge from the 

 shell. A wild duckling, although provided with a thick 

 waterproof coat of down, has, like the robin, to wait a 

 long time for his flight-feathers; but his aquatic habits 

 and powers of diving make the dangers to which he is 

 exposed far less than is the case with the young Bob- 

 white. 



The causes of wear and disablement to feathers would 

 make a long list if we but knew them all. As one instance 

 take the wings of a Chimney Swift after she has reared 

 her brood in the depths of some blackened chimney, or 

 even a lightning-struck hollow tree. Her primaries are 

 so matted and clogged with balls of soot that she would 

 often find the migratory flight difficult indeed, were the 

 feathers not replaced by new ones. 



When birds return from the South, and when a hint 

 of spring warns winter residents to cease their roving, 

 they prepare to develop all the advantages which may 

 in any way aid them in securing a mate. Some indus- 

 triously practise dance-steps, others flight-evolutions, a 

 larger number rehearse their songs under their breath, 

 while still others passively await the development of 

 plumes, gorgets, spots and splashes of colour which, if 

 the feathers come out large and brilliant, may stand them 

 in as good stead in their wooing as any song or antic. 

 Thus we find a class of birds which have a partial or com- 

 plete moult in the spring. These feathers may last all 



