278 STUDIES IN BIRD-MIGRATION 



Brent Goose, Branta bernicla. — The single bird 

 seen by us on nth September 1904, is the only known 

 instance of the occurrence of this species. 



BernacLtE Goose, Branta leucopsis. — About two 

 thousand are said to have their winter quarters on the 

 various islands of the group. The date of their first 

 appearance in autumn varies from 6th to 15 th October, 

 and they continue to arrive down to loth November. 



They are observed gathering for departure from 

 1 6th March, and the latest date for them in spring is 

 that of a flock seen on 1 5th May. 



Teal, Nettion crecca. — There are a few records for 

 the occurrence of single birds for January, April, July, 

 and October. 



Merganser, Mergus serrator. — The only recorded 

 visit refers to a female which appeared on 20th April 

 1903. 



Eider Duck, Somateria mollissima. — Breeds com- 

 monly, but is not present in winter, though a single 

 bird was seen on 23rd January 1906. 



The earliest record of its appearance in spring is 

 6th February, and it continues to arrive down to 6th 

 April. The latest date on which it has been observed 

 in autumn is 12th November. 



Ring- Dove, Columba palumbus. — There are two 

 records for the visits of single birds ; one was found 

 dead on Eilean Mor on 14th May 1906, and another 

 was observed resting on ist July 1904. 



Turtle Dove, Turtur turtuv. — There are six records 

 of the visits of single birds during the autumn, the dates 

 ranging from nth September to 3rd October. On the 

 first-named date the bird was obtained, and sent for 

 determination. 



