LIFE HISTORIES OF NORTH AMERICAN GULLS AND TERNS. 81 



he not been able, by the use of both his wings and feet, to make the beach and 

 scramble into the brush. A violent encounter lasting many seconds also 

 took place between two adult birds, the striking of their beaks and the 

 thrashing of their giant wings against the alders creating a commotion such as 

 might do credit to a bull moose. It could not be determined whether the 

 origin of these differences was a matter of food or trespass. 



Plumages. — ^The downy young is mainly "' pale olive gray," paler 

 on the head and flanks and white on the central breast portion. The 

 head is distinctly marked with well-defined spots, of various sizes 

 and shapes, of " fuscous black " ; the back is indistinctly spotted or 

 variegated with " fuscous " and the wings are more heavily marked 

 with an intermediate shade of " fuscous." The lower parts are un- 

 marked. By the time that the young bird is half grown it is nearly 

 fledged in its juvenal plumage, which appears first on the scapulars, 

 wings, breast, and back, in about the order named. The dorsal 

 feathers of this plumage are dusky, broadly tipped or margined with 

 " avellaneous " or " vinaceous buff." This color pattern, which 

 varies considerably in different feathers, is more pronounced in the 

 scapulars and wing coverts than elsewhere. The color patterns in the 

 different feathers vary from a solid dusky center, with broad buffy 

 edges, to a herring-bone pattern, showing a dusky central streak with 

 lateral processes, or to heavy transverse barring. The underparts are 

 also variegated with dusky and " vinaceous buff " or " tilleul buff." 

 The change from the juvenal to the first winter plumage is not well 

 marked, as it is very gradual and is accomplished with a limited 

 amount of molt. The buffy edgings on the dorsal surface fade and 

 wear away during the winter until they become practically white be- 

 fore spring, Avhen the back appears to be transversely barred with 

 dusky and white. The head, which was heavily streaked with dusky 

 in the fall, and the underparts also become much whiter before 

 spring. In this first-year plumage the primaries are wholly black, 

 with only the narrowest suggestion of white tips on the innermost; 

 the secondaries and tertials are dusky and more or less broadly edged 

 with buffy white ; the greater coverts are somewhat variegated ; and 

 the lesser coverts are like the back. The tail is basally white, much 

 mottled or variegated with " fuscous " or " fuscous black," with a 

 broad subterminal band of " fuscous black." This band is broadest 

 and the mottling is thickest on the central rectices, decreasing out- 

 wardly, so that the outer feather has only a large subterminal spot 

 and a few dusky markings. The bill is wholly dark. 



The second-year plumage shows only a slight advance toward 

 maturity, and is mainly characterized by the mixture of several 

 different types of feathers in the back, scapulars, and wing coverts. 

 Some of these are wholly " slate color " or " blackish slate," as 

 in the adult; others are basally so colored and terminally barred, 



