How Birds Molt 



159 



,iK 



h 



of specimens taken after the breeding season show that molt begins at defi- 

 nite parts of the body and the reclothing extends in definite directions. The 

 wonderfully systematic and gradual renewal of plumage is best seen and 

 measured in the wings, for a gap appears at 

 the middle of the quill-feathers, extending 

 outward until but three or four primaries 

 remain, then extending inward among the 

 secondaries, so that the new innermost of 

 these and the outermost primary reach 

 maturity at about the same time. It 

 should be noted that the tertiaries (three 

 in small birds, more in others) are partly 

 renewed before the secondaries begin to 

 drop out. The wing-coverts are replaced 

 in alternate rows. There is a time relation 

 between all that goes on in the wings and 

 the growth of body-plumage, which be- 

 gins to be molted at a number of points, 

 so many, in fact, that the renewal is traced 

 with some difficulty. When the wings are 

 grown, at the end of a month or two, 

 depending upon the size of the bird, 

 the body plumage has also completed its 

 growth. As for the tail, usually after the 

 fall of several primaries, the middle pair of 

 feathers drops out, followed rapidly by suc- 

 cessive pairs, so that very often a bird will 

 appear 'bob-tailed' if the new middle pair is 

 slow in growth. Woodpeckers lose the 

 middle pair last, and irregularities are found 

 in other species. 



At the end of the breeding season 

 every species of bird undergoes a complete 

 molt. Land birds and the Gulls and 

 Waders molt as just described, but water- 

 fowl, that protect themselves by swimming 

 and diving, as well as by flight, such as 

 the Ducks, Grebes, Loons, Guillemots, and 

 others, molt the quill-feathers of the wings 

 all at once, so that for a time the birds are 

 unable to fly. The males of certain bright- 

 plumaged species of Ducks are protected for a couple of months by a dull 

 body plumage that begins to appear before their young broods are out of 



WESTERN MEADOWLARK 



U. S. N. M.. No. 127+95, ?. Aug. 14, 

 1892, San Bernardino Ranch, Ariz , E. A. 

 Mearns. Showing abrasion and fading of 

 plumage. From the Bull. Amer. Mus. Nat. 

 Hist. 



