374 Dwicut, Moult of North American Shore Birds. aoe 
California), with the three proximal primaries growing, and no 
new body feathers as yet; Zringa fuscicollis (U.S. Nat. Mus. No. 
116227, 9, January 16, Gregory Bay, Patagonia) the primaries 
new except the first, the middle pair of rectrices new, but no new 
body feathers; Actétis macularia (U. S. Nat. Mus. No. 169037, 
9, February 9, Culebra Id., W. I.), retaining one old primary, the 
old tail and old body plumage; Charadrius sguatarola (Amer. 
Mus. Nat. Hist. No. 39072, 9, February 27, Florida), with two 
old primaries remaining, together with old tail and body plumage ; 
and other specimens, with incomplete data, which confirm the 
evidence of those cited. It is possible, although not probable, 
that some of these are adults, but the plumage seems to indicate 
young birds, and the rarity of adults at any season is an argu- 
ment against their being adults. At all events, a moult begins 
in January or February, and there are many specimens of many 
species which show growth of new body feathers later in the 
winter. April specimens are often in the midst of moult or at 
the end of it, some of them with fresh remiges and rectrices, and 
others with them evidently much worn. My impression is that 
the more worn birds are adults, the fresher ones young birds 
which complete their moult earlier. The probability also is that 
species with a postjuvenal moult are later in consummating the 
prenuptial, but the material available does not furnish conclusive 
evidence upon these points. The numerous specimens in worn 
winter plumage showing no evidence of moult during February 
need not be cited. As adult females are indistinguishable from 
young males at this season, and adult males are not conspicuously 
different, the difficulty of drawing conclusions from them, even 
after the beginning of the prenuptial moult, becomes apparent. 
In addition to the young birds just cited there are some 
others which illustrate the onset of this moult presumably in 
adults, viz., Zrimga alpina pacifica (U.S. Nat. Mus. No. 102142, 
d@, March 29, Japan), with worn wings and tail, but new ‘ blood- 
feathers’ scattered on the body; another (No. 154206, May to, 
California) still showing new feathers in the new plumage; 
Calidris arenarta (Amer. Mus. Nat. Hist. No. 45580, ¢, April 13, 
California), with new ‘blood-feathers’ on the body at various 
points; another (No. 60007, 2, April 30, Florida) more advanced, 
