46 BUUjETIN 113, UNITED STATES NATIONAL MUSEUM. 



we were obliged to pull away, and the bird, which came back, lighted on the 

 rock where her nest and young had been with evident astonishment at the 

 mysterious disappearance. After flying about a little she again settled on 

 the spot, and, suddenly making up her mind that foul play on the part of some 

 other bird had taken place, she commenced a furious assault on her nearest 

 neighbor. As we pulled away the little fellows began to be effected by the 

 motion of the boat, and with the most ludicrous expression of nausea, imitat- 

 ing as closely as a bird could do the motions and expression of a seasick person, 

 they very soon deposited their dinner on the edge of the nest. It was composed 

 of small fishes or minnows, too much disorganized to be identified. Eggs, in a 

 moderately fresh condition, were obtained about the same time, but most of 

 them were far advanced toward hatching. 



In Bering Sea we found this to be one of the commonest gulls 

 and found it breeding on all of the islands where it could find high, 

 rocky cliffs. On Walrus Island, where there are no high cliffs, we 

 had an unusually good opportunity to examine the nests. Among 

 the hosts of sea birds which made their summer home on this won- 

 derful island a few little parties, of from four to six pairs each, of 

 Pacific kittiwakes found a scanty foothold on the vertical faces 

 of the low, rocky cliffs. Here their nests were skillfully placed on 

 the narrow ledges or on little protuberances which seemed hardly 

 wide enough to hold them, and often they were within a few feet 

 of nesting California murres or red-faced cormorants, with which 

 the island was overcrowded. The nests were well made of soft 

 green grass and bits of sod securely plastered onto the rocks and 

 probabl}^ were repaired and used again year after year. They were 

 well rounded, deeply cupped on top, and lined with fine dry grass. 

 Most of the nests, on July 7, contained two eggs, some only one, but 

 none of them held young. The incubating birds and their mates 

 standing near their nests were very gentle and tame. We had no 

 difficulty in getting near enough to photograph them. 



Eggs. — The eggs of the Pacific kittiwakes are practically indis- 

 tinguishable from those of the Atlantic kittiwake, though they will 

 average a trifle larger and a trifle more pointed. The ground color 

 seems to run more to the lighter shades, from '^ tilleul buff " or " olive 

 buff " to " cartridge buff " or " pale olive buff." Many sets show 

 very pale shades of " glaucous green " or even greenish or bluish 

 white. The markings are about the same as in the Atlantic bird, 

 but average lighter with a larger proportion of the drab or gray 

 spots. The measurements of 40 eggs in the United States National 

 Museum and the writer's collections average 58.4 by 41.3 milli- 

 meters, the eggs showing the four extreme measure 63 b}' 43.5, 

 55.5 by 41.5 and 58,5 by 37.5 millimeters. 



Young. — The young remain in the nests and are fed by their 

 parents until they are able to fly. Both old and young birds spend 

 much of their time on their breeding grounds and frequent their old 



