1 92 1.] Bird-Mir/ration In/ the Marking Metlwd. -^11 



method, and even in the cnse of purely resident species the 

 extent oi: local movements was considered worthy of study. 

 Earlier schemes, perhaps more by chance than by intention, 

 had been confined for the most part to a limited number of 

 especially interesting species which had well repaid the 

 labour and cost of marking : no guide, therefore, existed 

 as to the possibilities of a more comprehensive plan of 

 campaign. 



It soon became evident, nevertheless, that in many direc- 

 tions the results were very meagre as compared with the 

 number of birds being marked. The scope of the Inquiry 

 was according!}^ limited to a few species, selected for a 

 variety of reasons. Three qualities were thought necessary 

 for a species to be classed as a good subject : the birds had 

 to be procurable for marking in large numbers, they had to 

 afford a good percentage of reappearance records, and their 

 migratory movements had to be of interest. Some of the best 

 subjects under the first and second of these headings, such as 

 certain gulls and game-birds, were unfortunately lacking in 

 the third quality, while most of the small passerine birds 

 showed an extraordinarily low percentage of reappearance 

 records apart from cases where they were re-caught by the 

 marker. The species finally selected were the Lapwing, the 

 Starling, the Song-Thrush, the Blackbird, the Woodcock, 

 the Mallard, and the Herring-Gull. To these were added 

 the liedbreiist and the Swallow, chiefly because a large stock 

 of the appropriate size of ring remained, and also the Lesser 

 Black-backed Gull in the expectation, never realised, that a 

 large number could be marked. Had the work continued, 

 the tendency would have been to concentrate more and 

 more on the Lapwing and the Starling. 



The Interpretation of Results. 



In the following sections a few species which have 

 afforded interesting and comparatively numerous records 

 are discussed separately and at length. The method adopted 

 in each case has been based on a system of grouping in 



