200 STUDIES IN BIRD-MIGRATION 



There are, however, many records of the appearance in 

 Great Britain of odd birds, and, more rarely, small 

 parties in September, but such occurrences must be 

 reofarded as somewhat unusual.^ 



There are annual arrivals of comparatively small 

 numbers in the first half of October ; but at Fair Isle 

 in 1907, a number arrived on 2nd October, and very 

 many on the loth. It is not, in most years, however, 

 until after the middle of the month that the first of the 

 great autumnal immigrations is to be expected ; for the 

 date of the northern exodus is dependent upon the 

 nature of the season, and especially on the luxuriance of 

 the crop of berries, in Scandinavia, and, as a rule, the 

 birds do not move southwards until the third or fourth 

 week of October. They continue to arrive on our 

 coasts in considerable numbers until mid-November, the 

 19th being the latest date for the years covered by the 

 inquiry instituted by the British Association, and the 

 24th for Fair Isle. 



The following are the dates of the chief immigrations 

 recorded during the years 1880-87, ^^d at Fair Isle 

 for 1906, 1907, 1908, 1 9 10, and 191 1 : — 



1880. October 21-28. November 18. 



1 88 1. October 19. 



1882. October 15-16, 18-19. 



1883. October 19, 28-30, November 1-2, 8. 



1884. October 24, 29. November 2, 4, 12. 



1885. October 14, 31. November 8, 10-12. 



1886. October 28, 29. 



1887. October 26. 



* The most remarkable of these early immigrations was the occurrence of 

 a large flock near Norwich on 9th September 1880 (T. Southwell). 



