134 THE GULLS 



Co. Dublin coast, but enormous colonies are to be found in Antrim, Donegal, and 

 thence southward to the islands off the Kerry coast. Outside the British Isles 

 this species breeds in great numbers on the Faeroes, Iceland, Jan Mayen Island, 

 Franz-Josef Land, Spitzbergen, and Novaya Zemlya, while on the Continent it is 

 said to nest in Brittany, and many colonies exist along the Norwegian coast, 

 especially in the extreme north, and eastward to the Murman coast, and at one or 

 two localities off North Siberia. On the American side it breeds in Greenland and 

 on the coasts of N. America south to the St. Lawrence, but is replaced on the 

 Pacific coast by an allied race. In winter it ranges south to the Canaries, Azores, 

 and Madeira, and has even been recorded from the Cape Verde group and Senegal, 

 as well as from the Mediterranean : while on the American side it migrates to the 

 Great Lakes and the middle Atlantic States, and has occurred in the Bermudas. 

 [F. c. E. J.] 



3. Migration. Resident within our area as a whole, but seasonally absent 

 from various parts. To the south of England it is a winter visitor, but at that 

 season it is scarcely known on many parts of the Irish coasts (cf. Ussher and 

 Warren, B. of Ireland, 1900, p. 346). There appears to be a regular southward 

 movement in autumn with a return journey in March (cf. Ussher and Warren, 

 loc. cit.; etc.), but to what extent these movements may extend beyond our area, 

 both to north and to south, it is impossible to say. In winter the species often 

 congregates in huge flocks (cf. Nelson, B. of Yorks., 1907, p. 691). [A. L. T.] 



4. Nest and Eggs. Generally this species breeds in colonies, sometimes 

 of enormous extent, and always on precipitous cliffs or in the roofs of sea-caves. 

 Almost any little ledge is sufficient to support the nest, which is sometimes only 

 a few feet above the sea, and at other times some hundreds of feet higher. In the 

 great mixed colonies of rock-birds on the British coasts, the Kittiwakes generally 

 occupy the lowest sites, but some of the bird-rocks within the Arctic Circle are 

 occupied almost exclusively by this species from top to bottom. The nest is built 

 chiefly of seaweed and mud, but grasses, moss, and other plants are also used, 

 chiefly for the lining, and both sexes take part in building (see p. 188). (PI. XLIV.) 

 The eggs vary from two to three in number : in some colonies clutches of two are 

 general, while in others three are quite common. The ground-colour is rather 

 light as a rule, and varies from greyish white to olive-buff, while the markings 

 consist of blotches of brown and ashy shell-marks, sometimes forming a zone. 

 (PL J.) Average measurements of 100 eggs, 2-21 x 1-6 in. [56-3 x 40-8 mm.]. 

 Both sexes brood in turn, and, in Iceland, Hantzsch noted that the female incu- 



