THE BRITISH ISLES: AUTUMN 143 



them lingering" iiniil the falling temperature acts as a 

 sharp reminder that it is time to seek more genial 

 climes ; then great rushes southwards and westwards 

 set in. 



Speaking generally, the insectivorous species are the 

 earliest emigrants among the smaller birds to quit the 

 neighbourhood of their nesting areas, and the latest to 

 leave are the frugivorous and granivorous groups, such as 

 the various thrushes and finches ; for these the abundant 

 crop of wild berries which carpets the northern forests 

 and moors offer attractions which are irresistible to the 

 majority, and induce them to remain until the season is 

 far advanced. The latest of all the miijrants to leave 

 their summer quarters are to be found among the arctic 

 and sub-arctic sea-birds, such as the Glaucous and 

 Iceland Gulls, the Little Auk, etc. The date of the 

 first arrival of the Winter Visitors and Birds of Passasfe 

 depends upon the nature of the breeding season on the 

 Continent, especially in the north — whether it be an early 

 or late nesting season there. 



At this season the numbers of the migrants are 

 much greater than during the spring, as their ranks 

 are swelled by numerous young recruits, most of them 

 only a few weeks old. This circumstance, and the 

 leisurely manner in which the fall migrations are per- 

 formed, combine to make the autumn movements much 

 in evidence and comparatively easy to observe. 



To the autumn really belong those erratic appear- 

 ances of the Common Crossbill on our shores, which 

 sometimes take place ere the summer has fairly set in, 

 as in 1909. Late in June and early in July of this 

 year, both young and old of this species arrived in great 

 numbers on our shores, and remained for several weeks 



