| DwicutT, Moult of North American Shore Birds. 379 
and a few of the lesser coverts, but apparently not the remiges 
nor the rectrices. I have already discussed the evidence which 
proves a moult in adults as well as young birds, the late winter 
specimens with worn wings and tails indicating either adults or 
possibly young females. One specimen may be cited in full 
winter dress at a late date (U.S. Nat. Mus. No. 133016, March 
1g, [Arizona ?)). 
The following species has a distinct postjuvenal moult. 
SANDERLING (Calidris arenaria) . 
1. Vatal Down. Not seen by me. 
2. Juvenal Plumage acquired by a complete postnatal moult. 
This plumage is much washed with buff, the edgings of many of 
the feathers distinctly buff, including those of the sides of the 
breast, the tint fading quite rapidly. A bird (Am. Mus. Nat. 
Hist. No. 60751, 2, August 20, Labrador) of fresh plumage illus- 
trates this stage. 
3. First Winter Plumage acquired by a partial moult which 
includes the body plumage, tertiaries, and wing-coverts but not 
the remiges nor rectrices. A wholly gray plumage, white below, 
is assumed and, save for left-over tell-tale feathers, especially 
tertiaries, young birds become practically indistinguishable from 
adults that have completed their postnuptial moult, although 
the feathers of young birds are paler centrally and therefore with 
less obvious shaft-streaks. September and October specimens 
in every collection show the gradual growth of the gray body 
feathers and one from Bolivia (Amer. Mus. Nat. Hist. No. 
30860, August) shows that this far southern locality may be 
reached before the moult is far advanced. Another specimen 
(U. S. Nat. Mus. No. 161921, October 1, Virginia) is largely in 
first winter dress; also one (G. B. Sennett, No. 404, ¢, Novem- 
ber 1, Pennsylvania) and one (Am. Mus. Nat. Hist. No. 64551, 
2, November 9, Lower California), possibly an adult, is wholly 
gray. Among winter specimens of young birds, determined by 
retained juvenal feathers, especially dusky-tipped tertiaries, the 
buff edgings of which fade to white, are the following, viz.; U.S. 
Nat. Mus. No. 163525, January g, California; No. 102063, Jan- 
