408 THE BIRDS OF HELIGOLAND 



Crossbill — Loxia. — In the case of the Crossbills, Heligoland 

 affords a practical proof, if only on a humble scale, of the influence 

 which changes in the physical appearance of a district can exert on 

 the occurrences of bird species. The last generation of oin- islanders 

 was very fond of planting poplars, so that fifty years ago there was 

 hardly a house, with its small garden attached to it, which was 

 without one of these trees. The present generation seems to enter- 

 tain a veritable hatred for trees of any kind, and has destroyed to 

 such an extent what their fathers planted, that at present there is 

 scarcely a single one of these trees left on the island. These poplars, 

 however, which in this island never attain to any great height, were 

 the favourite resort of the Crossbills visiting here ; and the birds, 

 owing to their simple confiding nature, used to be shot down from 

 them in dozens by boys with blowpipes. AVith the disappearance 

 of these trees, the occurrence of the birds has diminished to 

 such an extent that hardly twenty individuals have been killed 

 during the last decades. Now and again smaller or greater flocks 

 of them may be seen Hying across the island, amid loud utterance 

 of their call-notes ; inasmuch, however, as no reply is given to the 

 latter, and the birds at the same time miss their favourite resorts — 

 the poplars — they continue their journey without alighting. 



Another instance of the same kind is furnished by the Longicorn 

 beetle (Saperda cardiarias), which formerly was very abundant on 

 the poplars, but likewise vanished with the latter. 



The genus of the Crossbills comprises only four species ; they 

 are principally iiahabitants of the northern regions of the Old and 

 New World : three of them are resident in Europe, and also visit 

 Heligoland. 



To the above, which was written several years ago, I have to add 

 by way of supplement, that in 18S7, Heligoland was visited by L. 

 curvirostra in multitudes such as I .had never seen here before, 

 and that the species again occurred very numerously in 1889, being 

 in this instance accompanied by L. hifasciata. 



210. — -Parrot Crossbill [Kiefern-Kreuzschnabel]. 

 LOXIA PYTHIOPSITTACUS, Bechstein. 

 Heligolandish : Groot Borrfink = Great Burr-Bird. 

 Loxia pythiopsittacus. Naumann, iv. 339. 

 Parrot Crossbill. Dresser, iv. 121. 



Bee crois6 perroq^ud. Temminck, Manuel, i. 325, iii. 242. 



Judging from the Heligolandish name, one would imagine that 

 the Crossbills had a predilection for burrs, perhaps on account of 



