THE BIKDS OF HELIGOLAND 169 



under side, which, however, was undoubtedly also white. There can 

 further be no doubt of this bird having been a Falcon, and not the 

 more commonly occurring white variety of Buzzard, seeing that the 

 observer was one of the brothers Aeuckens. As their names will be 

 mentioned very frequently in the course of my notes, I will here state 

 at once, that their knowledge of the birds occurring here, their powers 

 of observation, exactness, and reliability are almost without a parallel. 

 Unfortunately the eldest of the brothers is no longer living. 



This Falcon has his home in the high Polar regions of the 

 Northern Hemisphere. It appears to have visited England [Britain] 

 with greatest frequency. Harting (Handbook of British Birds, 

 p. 85) gives about twenty instances of its occurrence up to 1872. 



2. Jer Falcon [NORWEGISCHER FALKE]. 

 FALCO GYRFALCO, Linn. 



Heligolandish : Blii-futted falk = Blue-footed Falcon. 



Falco gyrfalco. Naumann, xiii. ; Blasius, Nachtrage, 22. 



Jer Falcon. Dresser, vi. 1 5. 



Gerfaut. Schlegel, Krit. d. Europ. Vogel, ii. and 5. 



Although the Jer Falcon occurs here either once or several times 

 in the course of every autumn, it is only very rarely shot ; in fact, 

 this has not happened on more than six or eight occasions during 

 all the time I have been collecting. The birds appear in October 

 and November, all the examples hitherto met with having been birds 

 of the year, with the backs of uniform dark amber-brown colour. 

 I possess, however, one beautiful example of this species, in which 

 all the scapulars, as well as the greater and greatest outer wing- 

 coverts, are marked by bands of a dull buff colour ; in the smallest 

 of these feathers the markings merely consist of oval spots, which 

 extend from the margins of the feathers half-way across them to the 

 shafts ; but on the longest scapulars, and more especially on the 

 largest outer wing-coverts, as well as on the upper tail-coverts, 

 they pass into regular bands or bars, which extend close up to 

 the shafts, and in some cases touch them. The longest feathers 

 of the flanks are marked by very broad bands of this kind, which 

 on the outer webs of the feathers extend to the shafts, but do not 

 quite reach them on the inner webs. 



The colour of the cere and talons was in this example of a pale 

 yellow, with only a slight tinge of the earlier bluish grey colour. 



The total length of the freshly killed bird was 19'68 ins. 

 (50cm.); length of wings, 13'85 ins. (352 mm.); length of tail, 

 815 ins. (207 mm.); length of tail left uncovered by the wings, 



