234 



SEA-BIRDS 



the late spring snow and the 

 latter the grey summer tundra. 

 Clarke (1898) states that mor- 

 tality may be heavy among 

 the young ivory-gulls, many 

 having been found dead in the 

 nest, "their crania indented" 

 from some avian attack (not 

 improbably the ivory adults 

 themselves? But see note on 

 terns attacking gulls, p. 232). 



The ivory-gull is about the 

 size of the common gull, but 

 much more bold and aggressive. 

 It must be one of the hardiest 

 gulls in the world, since its 

 southern boundaries of breed- 

 ing distribution are more north- 

 erly than those of any other 

 bird (extreme north Greenland, 

 east and north Spitsbergen, 

 Franz Josef Land, probably 

 Lonely and Bennett Islands, 

 and in the Canadian arctic 

 archipelago on Prince Patrick, 

 Melville, north Baffin, and 

 Ellesmere Islands; see Fig. 40). 

 Under the circumstances it is not 

 surprising that its habits have 

 not been more than spasmodically studied. Even in winter the ivory-gull 

 only reaches regions where other arctic birds summer — round the 

 mainland shores of the Polar Basin. 



The beautiful Ross's or rosy gull, Rhodostethia rosea, with pale 

 grey mantle and rose-flushed white head and breast, and neat neck- 

 lace of black is one of the most mysterious birds of the world. For 

 long the breeding-quarters of this species were unknown; as the 

 Handbook says, "very few ornithologists have seen this gull alive." It is 

 therefore worth giving the details of its strange distribution. 



The rosy gull was first discovered for science in June 1823 at Alagnak 

 on the east side of Melville Peninsula in the central Canadian Arctic 



Fig. 41 

 Distribution of the rosy, or Ross's 

 gull, Rhodostethia rosea. Black line 

 embraces breeding distribution; 

 known breeding-places marked by 

 stars. (Greenland once only.) Dots 

 represent some sight and specimen 



records. 



