Vol. XVIII 



1901 



"I DwiGHT, Moults and Plumages of Gulls attd Terns. ^^ 



advilts) taken in Florida between May 28 and June 3, which vary 

 from birds with the first primary barely grown to those still retain- 

 ing two or three of the old primaries and a number of old rec- 

 trices and body feathers. The black cap is now assumed, the 

 dusky cubital bands disappear, and the bill and feet become 

 chiefly coral red. The significance of certain birds which reas- 

 sume the winter plumage has already been discussed. 



5. Second Winter Plumage acquired by a complete first post- 

 nuptial moult, as a rule not earlier than September. This dress is 

 hardly distinguishable from that of the first winter, and the bill 

 and feet turn black before the moult is completed. 



6. Second Nuptial Plumage acquired by a complete second pre- 

 nuptial moult. The older birds are probably represented by the 

 specimens with longer, more attenuated lateral rectrices which are 

 paler than those of young birds, but it is difficult to say how much 

 the slight differences are due to age, and how much to individual 

 variations. Young and old are not distinguishable after the first 

 prenuptial moult, and later plumages and moults are but repeti- 

 tions of winter and nuptial changes. 



What is true of sequence in Stenia hirundo is evidently true of 

 all the North American Terns and probably of other species, of 

 which I have seen but few specimens. Most species are black- 

 capped in nuptial dress. S. hiruudo, S. paradisiea and iT. dougalli 

 assume in winter white foreheads gradually blending into dull 

 black occiputs ; 6". maxima, S. elegans and 6". sandwichensis acujla- 

 vida have a distinctly black and white streaked crown between the 

 white forehead and black occiput ; S. caspia has the whole cap 

 streaked with black and white, black predominating; S.forsferi, 

 S. antillanun, S. fuliginosa^ S. amestheta. Geoc/ielidon nilotica and 

 Hydrochelidon nigra surinamensis have caps largely white anteriorly 

 and gray posteriorly. The winter mantle appears to be regularly 

 somewhat paler than the nuptial, strikingly so in the Black Tern. 

 In this species the sootiness is foreshadowed even in the natal 

 down, while the black and white mottling during the progress of 

 moults is a very conspicuous feature. In Atwus stolidus the winter 

 dress differs from the nuptial chiefly on the crown, which is nearly 

 as brown as the rest of the plumage, only a narrow white supralo- 

 al line remaining. 



