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THE 1909 IRRUPTION OF THE CROSSBILL AS 

 OBSERVED IN THE BRITISH ISLES. 



BY 

 H. F. WITHERBY and C. J. ALEXANDER. 



The arrival and early progress of the Crossbills * in the 

 British Isles was shoAvn in a series of maps, prepared by 

 Commander Lynes and published in Vol. III. (PI. xii., 

 p. 228) ; it will therefore only be necessary here to give 

 a brief summary of that part of the movement. 



The first record was from Pair Isle on June 23rd, 1909 ; 

 this was followed by others from the Shetlands, Orkneys, 

 and Outer Hebrides, and from Durham and Merioneth- 

 shire before the end of the month. 



During July, Crossbills were observed in all parts of 

 England except the extreme south-west, in a number of 

 places in Wales, and in a few widely-separated places in 

 Ireland. 



How long actual arrivals from oversea were taking 

 place cannot be determined for certain ; the latest record 

 of their being seen at sea was from off the Shetlands 

 about August 10th. The records from off Scarborough, 

 Yorkshire, at the end of June, from off the Fame Islands, 

 Northumberland, on July 9th, the Outer Dowsing light- 

 vessel (off the Wash), in July, and from a ship making 

 for Hamburg from Hull on August 1st, show that arrivals 

 took place on the east coast of England as well as further 

 north ; so that it is probable that the rather later appear- 

 ance of the first invaders in the south of England was due 

 primarily to the southern part of the west-moving wave 

 being behind the northern part, and not to these first 

 southern birds having landed in the north of Scotland 

 and afterwards worked their way southwards, though 

 some maj' have taken this course. 



* All the examples taken in England and examined were of the 

 typical form Loxia curvirostra curvirosfra, but Mr. W. Eagle Clarke 

 has remarked that those obtained in the Scottish Isles and examined 

 by him (eleven specimens) had finer bills than any collected in England 

 which he had examined, and he suggests that these birds may have 

 had a different origin {.cf Ann. Scot. yuf. Hist., 1910, p. 67). 



