LIFE HISTORIES OF NORTH AMERICAN GULLS AND TERNS. 187 



female insisted upon fluttering about and sitting down so long at a certain 

 place on an island where the colony of rosy gulls and terns was situated that 

 I carefully marked the spot and examined it, but only a tern's nest was there. 

 I thought at first that this was only an accidental occurrence, but immediately 

 afterwards the same female rosy gull tried to attract my attention as per- 

 sistently to another spot, lying still more out of my way, and another tern's 

 nest was there. The terns understood these treacherous tactics quite well, 

 and at the last nest the female with angry screams engaged in a short battle 

 with the gull. 



Plumages. — The newly hatched gulls in down are some 13 or 13i centimetres 

 in length, but they grow quickly and measure from 18 to 20 centimetres by the 

 time that the feathers appear on the back and flanks. Eyes dark blackish 

 brown; legs and feet intense fleshy, tinged with gray, or fleshy gray, with 

 brownish claws; bill grayish fleshy with brownish tip. The ground color of 

 the downy dress is dusty yellow, varying in tinge irrespective of growth ; in 

 some examples it is pale sulphur-yellow, in others a somewhat burnt wood- 

 yellow, occasionally, with a rusty tinge. This ground color is densely covered 

 with numerous irregular and ill-defined blackish-gray markings, taking up at 

 least as much space as the yellow ground color itself. They are pale and quite 

 ill-defined on the flanks, while the middle of the breast and belly is without 

 them and whitish. They are sharply defined and nearly black on the head, 

 where they are narrower. The markings vary in detail in different specimens, 

 but in all the pattern is somewhat longitudinal on the body, transverse on the 

 nape, and wedge shaped on the crown. This pattern is much obscured, especially 

 on the body, as the markings are so much broken up and wavy. The sides of 

 the throat, the eyebrows, and the down which covers the uppper mandible nearly 

 to the nostrils, are marked with dark color. 



The feathers begin to appear first on the wings, and nearly at the same time 

 on the scapulars and tail ; next on the upper part of back and on the flanks, 

 and then on the uropygium. So far as can be seen the new primaries are 

 blackish ; the secondaries and tail feathers white ; the tertiaries, wing coverts, 

 scapulars, and, back feathers brownish black, with wide rusty-yellow ends, as 

 are also upper tail coverts. Flank feathers and those of the uropygium white 

 rusty ends and blackish-gray subapical portions. 



The sequence of plumages to maturity can be only provisionally 

 inferred from the limited amount of material available for study. 

 Doctor Buturlin (1906) gives us a very satisfactory and detailed 

 description of the first or juvenal plumage, the principal characters 

 of which are : " White under parts, tinged on the chest and breast 

 with pale grayish cinnamon buff; upper parts dark brown, barred 

 with ochraceous on the ends of the feathers; lesser wing-coverts of 

 the foremost and inner half of the wing white, with narrow, ochra- 

 ceous tips ; all the primary coverts blackish brown ; the three inner 

 primaries practically blackish brown with the inner half of the inner 

 web (excluding the end) white; remaining primaries outwardly 

 edged with blackish brown, decreasing inwardly ; and tail white, with 

 a narrow ochraceous tip and a blackish brown apical band." 



This plumage is well illustrated in Hansen's (1899) colored plate 

 of this species, based on specimens collected by his expedition near 



