159 



In Longyear City I saw on July 18 namerous Glaucus Gulls on the 

 dust-heap of this large settlement (O.E.). 



Young birds of the year are totally covered with pale-brown spots. 

 There is a great individual difference in size in this bird. My young 

 male is much larger than the old female. 



Rissa tridactyla tridactyla (L.), the Kittiwake. 



Rissa tridactyla (L.), Trevor Battye (1897), p. 593. 



Rissa tridactyla (L.), Kolthoff (1903), p. 62. 



Rissa rissa rissa (Linn.), Schalow (1904), p. 138. 



Rissa tridactyla (L.), le Roi (1911), p. 186. 



Rissa tridactyla tridactyla L., Zedlitz (1911), p. 311. 



cf (?), Icefjord near Cape Boheman, Aug. 21, 1921. 



The Kittiwake is of frequent occurrence in the Arctic Ocean, 

 where it breeds in vast numbers on Bearisle. In Spitsbergen it is 

 one of the commonest birds. I visited only one of their breeding 

 colonies, viz. the one situated at the western side of Dickson Land 

 (Mount Congress, July 13, O.E.), where they breed in great numbers 

 together with Brünnich's Guillemots. The breeding season lasts long, 

 for when on Aug. 27 I passed the same colony, there were still 

 old specimens present (cf le Roi, p. 187). 



It is remarkable — le Roi also points to this fact — that during 

 breeding time young immature Kittiwakes, are never found in Spits- 

 bergen. So these must spend summer somewhere else, as well as 

 young Glaucus Gulls, Phalaropes and Eiders. I saw the first flying 

 young in Icefjord about the middle of August. After breeding time 

 the birds unite in pretty large flocks. Zedlitz states (1911, p. 311) 

 that old and young then are found together, but of this I saw little. 

 In the latter half of August there always was a flock of Kittiwakes, 

 consisting out of about fifty adult birds on Cape Boheman. 



The members of Koenig's expeditions observed that some Kittiwakes 

 fed together with Fulmars On whale-carrions (le Roi, p. 189). I can 

 add that Rissa can also apply the tactics of the Skua. On Sept. 2 

 I saw near Green Harbour that a young Kittiwake chased a tern, 

 till the latter was obliged to drop its food, which was immediately 

 caught by the Kittiwake. 



Adult Kittiwakes strongly resemble our Common Gulls, which never 

 occur in the Arctic Ocean, however. The Kittiwake can be distinguished 

 from it by the black of its primaries, extending down to the end of the 



