A. L. THOMSON: MARKING BIRDS. 363 



grants of widely different needs and habits congregate. So 

 great is the number of migrants passing along the Nehrung, 

 and so large the proportion that break their journey 

 at Rossitten, that, as a station from which to observe 

 migration, it is now regarded as rivalling, if not sur- 

 passing, the more famous Heligoland, being inferior only 

 in that it is less easily searched. 



For five years now Dr. Thienemann, director of the 

 Vogelwarte, has been actively engaged in marking 

 birds at Rossitten. The mark employed 

 consists of a strip of aluminium bent into 

 the form of a ring, with the two ends pro- 

 jecting outwards together where they 

 meet, and fastened by folding one of 

 these ends over the other. The inscription 

 engraved on these rings varies with the 

 size of the ring. On the Crow and Gull sizes it reads : 

 " Vogelwarte, Rossitten," followed by a number. On 

 the larger sizes, for Storks, etc., " Germania," or even 

 " Ost-Preussen Germania," is added. On the smaller 

 sizes, for Terns, small Waders, small Passerine birds, 

 etc., there is no room for anything except the number, 

 and consequently very little success has been obtained 

 with these birds. The difficulty lies entirely with the 

 finder of the bird — once sent in to the Vogelwarte it is 

 easy to tell whether the ring is a Rossitten one or not. 

 This indicates the need for a new pattern of ring for small 

 birds. Dr. Thienemann has rejected the idea of a metal 

 label attached to the ring ; such a label would interfere 

 with the bird too much, and would create a doubt as 

 to whether results thus obtained could be regarded as 

 normal. 



Birds are procured for marking at Rossitten in two 

 ways. A large number of birds are marked as nestlings, 

 not only at Rossitten, but also in other parts of East 

 Prussia. The other method is to capture resting 

 migrants, mark them, and then let them continue 

 their journey. Large numbers of Hooded Crows are 



