■ !920 J Dwight, Plumages of Gulls. 267 



on several of the proximal (Plate XII, fig. 1)). Rectrices, square-tipped 

 and dull black, more finely peppered or sprinkled with white than in the 

 first winter. (Plate XII, fig. 2). Body plumage, much like the first win- 

 ter, but usually whiter below and about the head and with a few gray 

 feathers on the back. Bill, black from tip to nostrils, the base pale and 

 yellowish in dried skins. 



6. Second Nuptial Plumage. A partial second prenuptial moult renews 

 some of the body plumage, birds becoming much whiter below and grayer 

 on the back. Many of the new feathers, however, are still brown or parti- 

 ally so. 



7. Third Winter Plumage. A complete second postnuptial moult wid- 

 ens the field for variation because pattern is now pronounced in the pri- 

 maries (Plate XIII, fig. 1). They are black with more or less white 

 tipping, a "mirror," often with blurred margin, of variable extent is 

 found on the "first" or distal, and gray "wedges" of greater or lss extent 

 appear. The tail also shows new pattern (Plate XIII, fig. 2), smudges of 

 black on the white rectrices varying greatly in extent. In some birds the 

 red spot on the bill appears indistinctly but as a rule a dusky band or 

 clouding is found. The body plumage is either adult or there may be a 

 few obscurely dusky areas on the outer surface of the wings. 



8. Third Nuptial Plumage. A partial third prenuptial moult is hardly 

 noticeable among the body feathers that are already mostly adult. 



9. Fourth Winter Plumage. After the third postnuptial moult, which 

 is of course complete, it is unusual for evidences of immaturity to remain. 

 The primaries (Plate XIV, fig. 1) are all white tipped and the "mirror" 

 on the first is large and clearly defined, sometimes merging with the white 

 tip, although it is possible that such specimens are still older. A white 

 spot may or may not be found on the next primary, and the "wedges" 

 are more extended but vary with each primary. The tail is now wholly 

 white (Plate XIV, fig. 2). The body plumage is fully adult. The bill is 

 bright yellow with a red spot at angle of mandible. 



So it is possible to trace the development of plumages in the 

 Gulls with considerable accuracy and it is a pity to see writers of 

 recent date still clinging to the inadequate term "immature," 

 and to the old-fashioned idea that many years are required to 

 attain adult plumage. With moulting specimens to bridge the 

 gaps between plumages and knowing the characters that develop 

 in sequence much can be learned about age and it is with such ma- 

 terial at hand that I have endeavored to show as briefly as the 

 conditions permit, the correlation that exists in the Gulls between 

 plumage and age. 



Taking the Gulls of the North American Check List, they may 

 be grouped as follows: 



