On the Great Invasion of Crossbills in 1909. 331 



is metallic grass-green ; the lower back and rump are dull 

 azure-blue instead of pale bluish grey; the sides of the head 

 and throat dingy bluish green instead of pure white ; the 

 remainder of the lower parts is bluish; white, more whitish in 

 the middle, decidedly tinged with bluish green on the flanks; 

 the feathers of the chest are black with the slightly attenu- 

 ated tips bluish white, but there is no trace of the golden 

 yellow tinge, so conspicuous a feature in C. palmeri ; the 

 lesser wing-coverts, bluish grey in the latter, are metallic 

 azure blue, more greenish blue at the tips, and shading into 

 violet towards the edge of the wing; the edges of the median 

 and greater wing-coverts, as well as those of the remiges 

 and rectrices, are dull azure blue in C. cabanisi, bluish grey 

 in C. palmeri. In the former the base of the lower 

 mandible is pale brown, while the latter has the bill entirely 

 black. 



The type of C. palmeri (from which the figure (PI. V.) is 

 taken) is in the Zoological Museum of Munich. 



XIV. — On the Great Invasion of Crossbills in 1909. 

 By Joseph I. S. Whitaker, F.Z.S ., M.B.O.U. 



The following notes are the results of an inquiry which I 

 have attempted to make regarding the exceptional, and, so 

 far as regards recent years, I may say unprecedented, invasion 

 of the Common Crossbill (Loxia curvirostra) , which has 

 occurred during the past summer and autumn throughout 

 a considerable portion of Europe.. This inquiry, I may at 

 once observe, has no pretension to being a searching or 

 exhaustive one. It was, indeed, my original intention to 

 write of the Crossbill invasion so far as regards Italy alone, 

 but the consideration that it was a matter which concerned 

 the whole of Europe has induced me to extend, my remarks 

 to the wider sphere. 



As in the case of Pallas's Sand-Grouse (Syrrhaptes para- 

 doxus), partial, although occasionally very considerable, 

 migrations of the Crossbill occur, from time to time, at 



