THE IVORY GULL. I0 9 



later . . . . Z. ebnrneus was breeding on the N.E. side of the island, close to or 

 only a short way above, high- water mark, on low-lying ground like L. canus, 

 L. fuscus, &c., and not in the cliffs. Captain Johannesen estimated the number 

 of nests at from 100 to 150 ; they were somewhat apart, at distances varying 

 from two to four yards .... there were one or two eggs or young, but never 

 more in a nest .... several black-spotted young, capable of flight were seen, 

 likewise several young birds of the previous year's brood remained on the 

 breeding ground. 



" The nest is composed chiefly of green moss, which forms about nine-tenths 

 of its mass ; the rest consists of small splinters of soft wood, a few feathers, 

 single stalks and leaves of algae, with one or two particles of lichen .... under 

 the microscope they [the splinters of soft wood] are proved to be of conifers, 

 probably Larch, drifted from the Siberian rivers .... The average of nine eggs 

 was 59.9 millim. in length by 33.7 niillim. in breadth [at inches long by it in 

 breadth]. The ground-colour of five specimens is almost entirely alike, viz., a 

 light greyish-brown tint with faint admixture of yellowish green, such as often 

 appears on the eggs of L. canus, which, however, have often a deeper brown or 

 green hue. In structure and gloss all nine eggs greatly resemble those of 

 L. canus .... The eggs are easily distinguished from those of Rissa tridadyla 

 by their greater gloss, and the small excrescences do not lie so crowded, and are a 

 little more flattened than they usually are in the last mentioned species. 



" Newly hatched young in down . . . [are] white all over ; the down white to 

 the root. Even in this first stage, the young in down may be distinguished from 

 the young of other species by the strong and hooked claws, especially on the 

 hind toe, the somewhat marginated web on the toes, and the forward nostrils 

 .... In a somewhat older bird .... the tips of the feathers appear on the 

 shoulders, which exhibit a broad dark-brown transverse band within the white 

 and still down-bearing tips." 



Fully fledged birds are more or less lavender-grey all over ; birds still older 

 but immature, have the throat and face grey, with black spots on the back and 

 scapulars and on the secondaries. As they advance in age, the young Ivory 

 Gulls have greyish black spots on the wing coverts ; and a black spot at the tips 

 of the primaries ; while the tail has a black sub-terminal bar. The spots get fewer 

 with the bird's age. 



In winter the plumage is the same as in summer. 



The Ivory Gull is a very fearless species as compared with other Gulls. Its 

 note is spoken of by Captain Fielden as " shrill " and similar to the Arctic 

 Tern's. Nanseu calls it " an angry cry." " They are very bold," he says, " and last 



VOL. VI S 



