REPORT 



ON THE IMMIGRATIONS OF SUMMER-RESIDENTS IN 

 THE SPRING OF 1911. 



INTRODUCTORY, 



This Report has been drawn up on the same lines as those 

 previously issued and deals with the autumn migration of 

 1910 and the spring migration o£ 1911. 



To the ever-increasing number of records supplied by 

 our observers- have been added various notes on migration 

 from many current publications, and in order to keep the 

 Report within reasonable limits it has been found necessary 

 to condense the material as much as possible. This year, 

 therefore, in order to save space we have added two sections 

 at the end of the spring and autumn records respectively, 

 and have placed in them isolated notes. 



The spring migration commenced on the 10th of March 

 and continued until the 29th of May. During March the 

 influx, though daily increasing, M^as very slight. The main 

 movement seems to have begun about a month later, and 

 during the latter half of April there were three distinct 

 waves of migration — on the 17th and 18th, on the 23rd, and 

 on the 27th and 28th, — each of increasing intensity. There 

 was another large influx on the 5th of May, after which, with 

 the exception of two much smaller movements on the 13th 

 and 16th, the migration gradually subsided. 



The immigrations of the Willow-Warbler (probably in- 

 cluding two races), which lasted from the 11th of March to 

 the 6th of May, and of the Wheatear (including both races), 

 from the 19th of March to the 10th of May, covered the 



B 



