146 THE SCOTTISH NATURALIST 



records have already been published, 1 but all are repeated 

 here. We make no attempt, at this early stage of the work, 

 at drawing conclusions from the facts collected. We have 

 also thought it would be premature to give statistics of the 

 numbers of birds marked, or of the percentages of " re- 

 appearances," as no such figures could be final. 



II. Methods. 



Rings. — In its essentials the method consists in marking 

 a large number of birds in some way or other for the sake 

 of the data afforded by the subsequent reappearance of 

 a small proportion of these. The mark employed in our 

 Inquiry is a small aluminium ring which fastens round the 

 bird's foot, but is too light and neat to inconvenience it 

 in any way. Each ring bears the address " Aberdeen 

 University" (contracted to "Aberdeen Univ." on the 

 smallest size), which ensures that anyone finding the bird 

 will communicate with us. Each ring also bears an identifi- 

 cation number, different, of course, in each case. A plain 

 number (sometimes written in two lines) is used where 

 possible, but on the smallest size the small space has 

 necessitated the use of such numbers as "0798," and letter 

 combinations like " 299A." After a good deal of experiment- 

 ing we have settled on the following seven sizes (named 

 according to their approximate internal diameter measured 

 in fractions of an inch), the first four for ordinary use, and 

 the three largest for those markers who have special 

 facilities for ringing sea-fowl, etc. The first three sizes are 



1 In a general paper on "The Possibilities of Bird-Marking," in the 

 Proceedings of the Royal Physical Society of Edinburgh, vol. xviii., pp. 

 204-218, 191 1 (reprinted in the Aberdeen University Studies), I included 

 a brief account of our Inquiry and its methods, and a selection of our 

 earlier results. A similar selection of results has also appeared in the 

 magazine British Birds, vol. hi., p. 220 ; vol. v., pp. 98-102, 129. Some 

 records have also been included in notes which I have contributed to 

 The British Bird Book, edited by F. B. Kirkman, 1910-1912. Two 

 records were mentioned by Mr Francis Gunnis, one of our co-operators, 

 in the Annals of Scottish Natural History, 191 1, p. 118. In addition to 

 this, many records have reached us through the daily press or have 

 received notice therein. 



