CORDEAUX: HELIGOLAND. II 



spot, perhaps with the idea they are over land, strike directly down- 

 wards — as it has been described at the light-vessels — as if descending 

 perpendicularlv through a funnel, and as they come within the plane 

 of the reflectors will, we are told, dash to and fro erratically for 

 hours round the lantern, ^h. Gatke thinks that this phenomenon of 

 the circling flock, as his observations at Heligoland have shown, is 

 more likely due to a continuous stream of birds constantly recruited 

 from above, rather than the same flock flying for hours round the 

 light, and that as soon as birds find out their mistake, after circling 

 once or twice round" the light, they pass forward again or rise to 

 their former altitude. 



Birds, indeed, do not appear to be attracted to bright lights in 

 the same manner as moths, for these latter come on bright nights 

 just as on dull : the former, as a rule, only in fogs, snowstorms, 

 thick and obscure weather. 



There is no doubt that the phenomena attending a migration of 

 Gold-crests at Heligoland maybe repeated at one and the same time 

 at Borkum, Ter Schelling, and other stations on the European coast- 

 line. Observations, as recorded in the migration reports, show that 

 the Gold-crests, as well as other birds, do sometimes arrive on the 

 British coasts in one broad front, which on the one side may touch 

 the Shedands, and on the other the Channel islands. The migratory 

 movement is, however, not invariably a broad stream ; as an illus- 

 tration out of many, take that remarkable migration of the Honey 

 Buzzard past Heligoland on Sept. 19th, some years since. Their 

 course, Mr. Gatke told me, was nearly due E. and W.. crossing the 

 sandspit which stretches out north-east of Sand-insel. About noon, 

 five to ten together : then gradually somewhat larger numbers at 

 short intervals: then from three to six p.m. an almost interrupted 

 stream, the rear of one lot almost mingling with the van of the 

 next. It was a very fine September day, and so calm and still that 

 spectators on the main island, distant three-quarters of a mile or 

 more, thought they could distinguish the winnowing sound of the 

 wings. This migration of the Honey Buzzard is the more remarkable 

 from the fact that these birds are very solitary in their habits, nesting 

 considerable distances apart, and that they are not often visible in 

 the great woods and forests they mostly frequent. It is difticult to 

 understand how so rapid a mobilisation of the species was effected 

 over the vast area of their breeding range, as well as to understand 

 the impelling cause which drove them westward in numbers suflicient 

 to keep up a continuous stream of many hours past Heligoland. 



I left this bright little island in the North Sea with regret — a 

 regret apparently shared by many of my fellow-passengers, for long 



Jan. 1888. 



