C56 DwiGHT, Moults and Plumages of Gulls a?id Ter?is. ff ""^ 



The period of the prenuptial moult on the Atlantic coast covers 

 the months of February, March, April and May, large species like 

 S. maxima and those with a southern breeding range moulting 

 chiefly in the first two of these months and other species later. 

 The postnuptial moult begins in July in some species and not till 

 September in others. The postjuvenal moult seldom begins before 

 the postnuptial and often not till October. The species are all so 

 harassed on their breeding grounds that the natural season of 

 moult is doubtless much extended when eggs or young are swept 

 away by the elements or the equally ruthless hand of man. 



I have examined the type specimen of " 6'/6V-«(7 ///'<?/" which 

 has correctly been identified as 6". paradiscea. The bird is appar- 

 ently assuming winter dress with dusky cubital coverts, retaining 

 only one primary of the old plumage. The broken bill seems to 

 be in traiwition from the carmine nuptial to the black winter color. 

 '■'■Sterna havelli" is of course the winter plumage of S. forsteri, 

 and such birds as are found in summer in this dress will probably 

 prove to be non-breeding, like " S. portlandica^^ 



To illustrate the plumages and moults of the smaller Gulls I 

 might chose any one of several species of which I have seen full 

 series. I have selected the following as a typical species. 



Larus Philadelphia (Ord). Bonaparte's Gull. 



1. Natal Down. — Much like that of Sterna /linindo, yellowish 

 with dusky mottling above. 



2. Juvenal Plumage acquired by a complete postnatal moult. 

 The upper surface is decidedly brown with paler edgings, a black- 

 ish brown band extends along the cubital border of the wing into 

 the tertiaries, the secondaries have dusky markings, the primaries 

 show little white, their coverts being partly black, and the tail is 

 white with a broad subterminal black band, the rectrices being 

 tipped with buff. The sides of the head are white with a dull 

 black auricular patch and an anteorbital spot, and the rest of the 

 lower parts are white with a brownish wash on the sides of the 

 neck and breast. The bill and feet are black. 



3. First Winter Plumage, acquired by a partial postjuvenal 

 moult late in September and October which involves only the body 



