310 THE BIRDS OF HELIGOLAND 



125. — Aquatic Warbler [Binsen-Eohksaxgek]. 



SYLVIA A(^UAT1CA, Latham. i 



Heligolaudish : Straked Siillen-Kroper = 6'h-y)(!f( Meed Warbler. 



Sylvia aquatica. Naumann, iii. p. 686. 



Aquatic Warbler. Dresser, ii. p. 591. 



Bee-fin aquatic. Temminck, Manuel, i. 188, iii. p. 1 14. 



I first found tliis handsome bhd in 1847, since which time it has 

 been met with and shot in Hehgoland almost every year, though, 

 for the most part, in solitary cases. In 1S5.5, however, the bird 

 occurred pretty frequently, and in the following year in extraordi- 

 narily large numbers. 



The distribution of this species as a breeding bird is scarcely 

 as j-et ascertained to its full extent ; at any rate, the conditions 

 under which it makes its appearance here are not in harmony with 

 the statements made in regard to its breeding area. The nesting 

 stations cited for this species are Algiers, Italy, France, Germany — 

 especially the west — Holland, and in solitary instances in Sleswick- 

 Holstein and Denmark. 



From the frequent, and in one case at least, very mnnerous 

 appearances of young birds during the autunm migration, and their 

 complete absence in the spring — I have only once obtained a bird 

 in April — we may with safety conclude that, so far as Heligoland is 

 concerned, the species is a far Eastern one. This conclusion received 

 considerable support from the fact that, on the 13th of August 1856, 

 when these birds appeared here in unprecedented numbers, another 

 species from Eastern Asia was taken — viz. Sylvia certhiola. Again, 

 during September 1876, when several individuals of S. aquatica 

 were seen and shot here, a very strong migration of eastern species 

 took place. Thus, on the 4th, 6th, and 15th, and daily from the 

 last date to the end of the month, Anfhus richanli occurred in 

 numbers from live to twenty ; on the 22nd, two examples oi AntJms 

 cervinus and one of Motacilla citreola ; on the 25th, two examples 

 of S. aquatica were shot, and one example each day oi S. siiperci- 

 liosa on the 26th, 29th, and oOth. Similar occurrences were 

 repeated m the course of October. 



The hundreds and more of these birds that arrived here on the 

 13th of August, above referred to, could not have come from Sles- 

 wick-Holstein or Denmark ; for, in the first place, they are far too rare 

 in the latter countries for such a possibility, and secondly because, 

 from reasons hitherto unexplained, no migration at all of species 



' Acroctphahiis aqualicus (Gmel. ). 



