30 



" The migration of this Warbler commences in Heligoland 

 during the last ten days of September, and continues until the 

 end of October. On several occasions the bird has been met 

 with as late as the beginning of November." And, again, on 

 p. 43, he further states that this bird may be met with almost 

 daily in favourable weather during the autumn migration. From 

 these assertions it might be inferred that the bird appeared during 

 this period, more or less every day. But when the records of 

 the examples shot and seen, or reputed to have been seen, are 

 examined, it will be found that the average occurrences have not 

 exceeded two examples per year. It is true that in certain 

 years as many as half-a-dozen have been reported ; but, on the 

 other hand, at certain times none have appeared at all. It may 

 also be the case that, when the species has been most numer- 

 ously noted, that the same individuals have been reported more 

 than once, as in one or two instances the records refer to con- 

 secutive dates. In any case, the average occurrence of two 

 individuals per year, of an Asiatic species whose distribution is 

 very imperfectly known, furnishes but little proof of a general 

 east to west autumnal migration. As an instance of how our 

 knowledge of the geographical distribution of these smaller spe- 

 cies may be at fault the case of the Sedge Warbler may be 

 pointed out. Until Mr. Seebohm visited the Yenesay valley this 

 noisy and conspicuous species was supposed not to breed east of 

 the Urals, except in Western Turkestan. Commenting on this 

 fact, Mr. Seebohm pertinently asks, " Where do the Yeuesay 

 Sedge Warblers find a winter home?" No rigidly adhered to 

 north-to-south or east-to-west line of flight would convey them 

 to Africa, the only locality known at present. Again, even so 

 experienced an observer as this gentleman overlooked Pallas' 

 House Martin on his Yenesay journey. It was not until he 

 returned home that he discovered he had been amongst thou- 

 sands of this species. 



The contemporary records of the appearance of the Yellow- 

 browed Warbler relating to other parts of Europe, throw some 

 light on the theory of migration being conducted in a broad front. 

 According to Herr Gatke's views, the species should pass through 

 central Europe in numbers proportionate to the vastly greater 



