83 



of the birds seem to have travelled through the western 

 counties of England as far north as Cheshire, while a few 

 stragglers reached Wales, Cumberland and the Clyde area. 



The fourth immigration, by far the largest and most 

 protracted of the movements of the Willow-Warbler, com- 

 menced on the 20th of April, and thereafter birds continued 

 to arrive daily in greater or lesser numbers along the 

 whole of the south coast up to the 29th. They were 

 recorded in large numbers at the Channel Islands or other 

 south coast lights on the nights of the 20th, 25th, 27th and. 

 2<sth, and from the first day of this extensive movement the 

 whole country seems to have been invaded by Willow- 

 Warblers. Their passage northwards and westwards, 

 which had hitherto been somewhat slow, at once became 

 accelerated; Wales began to fill up at once, and by the 

 22nd and 23rd considerable numbers had spread to the 

 northernmost counties of England and to the south-west 

 of Scotland. About the same time the breeding-birds of 

 East Anglia began to settle down, and by the 24th and 25th 

 a good proportion of the summer-residents in Lincolnshire, 

 Yorkshire and Northumberland had arrived, though these 

 were considerably augmented towards the end of the move- 

 ment. It is probable that a considerable proportion of the 

 birds comprised in the later parts of this movement were 

 passage-migrants for Scotland and still more northern 

 breeding-haunts beyond our shores. Their progress was 

 indicated by the succeeding records from light-stations on 

 both our east and west coasts. By the beginning of May, 

 the greater proportion of our breeding-birds had probably 

 arrived, and the movements of further immigrants became 

 hard to trace. Considerable numbers, however, were certainly 

 arriving almost continuously between the 5th and 11th, and 

 were recorded nearly every night at the Channel Islands, 

 while large numbers occurred as passage-migrants at lights 

 off our east and west coasts on the nights of the 5th and 6th. 

 Several were taken on fishing-boats in the North Sea and 

 brought into Lowestoft on the 15th and l'Jth, and three late 



