NOTES. 193 



February (1909)."* Five Crossbills were obtained near 

 Madrid, where it is a great rarity, during the summer, 

 according to Herr Kracht. 



Food. — They have been reported to us as feeding upon seeds 

 of grass, "weeds," pine, spruce, larch, alder, and on 

 spruce-aphis-f and green fly. Mr. W. Eagle Clarke (loc. cit.. 

 p. 217) states that in the islands of Scotland they have 

 resorted to the following makeshifts for their more usual 

 food : — The yellow centres of daisies at Lerwick ; flowers 

 and berries at Fair Isle ; and sea-pinks at the Flannans. 



Origin and Cause of the Irruption. — The records we have 

 published show that the irruption has been of enormous 

 extent and that countless numbers of Crossbills have been 

 involved in it. There is no doubt that a great number 

 if not all of these birds have come from northern Europe. 

 Mr. Clarke (loc. cit.) has received a number of specimens 

 : 'taken in various localities in Scotland and all these he 

 affirms belong to the typical continental form Loxia 

 curvirostra curvirostra, which can be readily distinguished 

 from the much larger-billed Scottish race (L. c. scotica). 

 Moreover, we have the evidence of birds coming on board 

 ship in various parts of the North Sea. In Fair Isle 

 and in the Flannan Islands several specimens of the Two- 

 barred Crossbill (Loxia bifasciata), a native of northern 

 Russia and Siberia, were detected amongst the flocks of 

 the commoner species (cf. W. E. Clarke, loc. cit., p. 217). 

 Furthermore, a large movement has been observed upon 

 the Continent ; they were seen in Heligoland in June and 

 July, and near Berlin, early in July passing westward, and 

 on September 19th; they have also been observed in the 

 Rhine provinces, near Aix-la-Chapelle, in the Northern 

 Eifel (August 9th), near Baden, in the Black Forest, near 

 Leipzig (June 27th — July 24th), in Pomerania and in 

 Mark Brandenburg (end July). With regard to those 

 which have been reported from so many parts of England, 

 there can be no doubt that most of these birds form part 

 of the irruption from the Continent, though some are 

 likely to have been bred in England. Unfortunately, the 

 differences between the English Crossbills and the con- 

 tinental form, as pointed out by Dr. E. Hartert in 



* Mr. Abel Chapman has very kindly sent me two specimens of these 

 Crossbills, which I have submitted to Dr. E. Hartert, who pronounced 

 them to be undoubtedly of the distinct Spanish form Loxia curvirostra 

 hispana. This incursion of Crossbills into Andalusia has therefore no 

 direct connection with the irruption from northern Europe. — H. F. W. 



f Some specimens shot in the act of feeding upon the galls had many 

 immature aphides {Chermes abietis) in their gizzards. 



