244 STUDIES IN BIRD-MIGRATION 



Only a few birds with late young were seen by 

 us at Hirta, but It was very numerous on the sea 

 around Boreray on 8th October 1910, and on the 12th 

 in 1911. 



CoLYMBUS GLACiALis, Great Northern Diver. — 

 There is, as yet, only a little information regarding 

 this species in St Kildan seas. Dixon (p. 89) was 

 told that a pair were blown in by a terrible gale in the 

 autumn of 1882. He also informs us (p. 361) that 

 Mr Mackenzie shot an immature specimen, during 

 the first half of June 1885, from several that were 

 swimming in the bay, but failed to secure it ere it had 

 been mutilated by the Great Black-backed Gulls. Steele 

 Elliot (p. 285) observed one in the East Bay on 6th 

 June 1894. Dr Wiglesworth received a specimen 

 which had been picked up dead on the water on 4th 

 December 1903. 



We saw an adult bird in the bay on 2nd October 

 1910. 



^ PoDiciPES AURiTUS, Slavoutmi Grebe. — An adult 

 appeared in the bay on loth October 191 1, and was 

 observed busily engaged in diving for small sand- 

 eels, which it captured in the shallow water close in 

 shore. 



Procellaria pelagica. Storm Petrel. — The island 

 of Soay seems to be the main breeding-station of this 

 species, which has been known as a native of St Kilda 

 since 1697, when Martin (p. 63) found it there and 

 described it under the name of " Assilag." Milner (p. 

 2062) mentions Boreray as a haunt in which he found 

 it in June 1847. 



OcEAXODROMA LEUCORRPiOA, Fork-taikd Petrel. — The 

 first British and third known specimen of this bird was 



