Figure 19. The eclipse molt in the 

 Pintail drake. The male arrives on 

 the breeding grounds wearing the 

 conspicuous white, brown, and 

 gray nuptial plumage (right). When 

 he leaves his incubating female in 

 late April or May, however, he en- 

 ters the postnuptial molt, donning 

 a drab, inconspicuous, female-like 

 plumage (left). When the molt of the 

 body feathers is nearly complete, 

 the wing feathers are molted all at 

 one time, and the bird is flightless 

 for a period of nearly four weeks. 



from their original breeding territories. Then these join to form small flocks 

 of a dozen or so, the progress of the molt now being apparent to the ob- 

 server's unaided eye. These flocks may go directly to the place where flight 

 is lost; or they may move to yet another intermediate rendezvous, where 

 they join others to make up aggregations of hundreds, and sometimes 

 thousands. 



The major molting marshes and lakes are used year after year by flight- 

 less adults, and banding returns show that some drakes return to the same 

 place each summer. Yearling males, ending their first breeding season and 

 approaching their first flightless period,* may find their way to molting areas 

 with older drakes, or they may be drawn there by a postbreeding require- 

 ment for companionship. Some, no doubt, visited these same places in their 

 juvenile wanderings of the previous summer, for many molting lakes and 

 marshes are also autumn gathering places for all sex and age classes. 



There is strong suggestion of appetitive behavior, the birds moving to 

 special ecological situations. During the weeks of foregathering, for instance, 

 many Mallards and other river ducks loaf in large companies on the south 

 shoreline of Lake Manitoba; but there is no evidence that members of these 

 species are flightless on the lake as are Canvasback and other diving ducks. 

 The lakeshore Mallards and their companions always manage to arrive on 

 the marsh when the flight feathers are lost. Since the pinions may be shed all 



* Although the juvenile passes through a change of body plumage its first autumn, in which 

 it loses the female-like juvenal plumage and takes on the breeding plumage, the flight feathers 

 of the wing are not lost in the autumn molt. The bird wears its first wing feathers through the 

 year. 



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