THE BIRDS OF HELIGOLAND 311 



native to those countries takes place to Heligoland. This is proved 

 by the fact that species which count among the commonest in 

 Sleswick - Holstein, such as Lanius collurio, S. arundinacea, 

 Alauda cristata, Ember iza miliaria, and others, are in Heligoland 

 only of very rare occurrence : the last but one, in fact, has only 

 occurred singly at intervals of many years. 



Russow does not include the Aquatic Warbler in his Birds of 

 Esthonia and Courland, nor does Biichner mention it among his 

 Birds of the St. Petersburg Circuit. It would appear therefore that 

 the birds of this species which reach Heligoland, do so by a route 

 direct from east to west, like S. certhiola and Anthus richardi, 

 whose breeding homes are in the Amoor countries. 



My two earliest examples from Heligoland I obtained on the 

 9th and 18th of August respectively of 1847 ; two others were 

 obtained on the 6th of October 1853 ; a bird entered in my ornitho- 

 logical diary as cariceti ? on the 22nd of April 1854. In the course 

 of 1855 I obtained examples on the 13th, 14th, 17th, and 30th of 

 August, and also on the 8th of October. In the following year, 1856, 

 I obtained several on the 12th of August, but the day after that the 

 birds were so abundant that I shot eighteen of them in some narrow 

 plots of land Avhich were lying fallow and thickly overgrown with 

 wild mustard. I might easily have doubled or quadrupled this 

 number, but was unwilling to sacrifice any more of these pretty 

 little creatures, and had enough material to convince myself that 

 the grey cariceti plumage is not to be found among freshly moulted 

 autumn birds, but only, as in the case of the April examples men- 

 tioned above, in individuals in faded spring plumage. 



Among the examples obtained here we find every gradation, 

 from the most beautiful rich orange-buff (rostorange) to a pale 

 yellowish-buff (rostgelb), and from individuals in which every 

 feather on the sides of the breast and flanks has a strong black 

 streak running along the line of the shaft, to those in which 

 there is not the least trace of such a marking. A most interesting 

 example was brought to me a few years ago. This individual was 

 almost of a uniform, very light, yellowish-buff, all that was left 

 of the black markings of the crown of the head and back being in 

 the form of very narrow streaks. Unfortunately the shooter in his 

 eagerness to secure the bird, had fired at such close quarters that 

 it was completely useless for preserving. 



