475 
1921.] Bird-Migration by the Marking Method. 
In 1909, the first efforts were made at bird-marking on a 
large scale in the British Isles, two inquiries being started inde¬ 
pendently and almost simultaneously, namely the Aberdeen 
University Inquiry, now under review, and Mr. H. F. 
Witherby’s scheme (26) in connection with the magazine 
“ British Birds.” Of these, the latter is still in progress and 
close on a hundred thousand birds have been marked : the 
eventual publication of the collected and analysed results 
will be an event of great importance to students of migration. 
It may also be noted that some of the earlier markers merged 
their work with the new schemes, as Mr. Tomlinson did his 
with the Aberdeen University Inquiry, and Dr. Ticehurst 
his with the “ British Birds ” scheme, the work being- 
profitable only if undertaken on a very large scale. 
Methods of the Aberdeen University Inquiry. 
Each ring bore the address “ Aberdeen University ” 
(contracted to “ Aberdeen Univ.” on the smallest size), and 
an identification number. A plain number, sometimes 
written in two lines, was used where possible, but on the 
smallest size the need for brevity led to the use of such 
numbers as “0798,” and letter combinations like “299 A.” 
After the first experimental stage the rings were made in the 
following seven sizes, named in fractions of an inch, the first 
four for ordinary use and the three largest for those markers 
who had special facilities for ringing sea-fowl and other 
large birds. The first three sizes were of the claspless pat¬ 
tern, while the other rings were provided with the form of 
clasp already described, and had also edges turned outwards 
as flanges. 
1/8 th—Finches, Swallows, Titmice, Redbreast, Lark, Sandpipers, 
Little Tern, etc. 
3/l(5lhs—Thrushes, Starling, Lapwing, Snipe, etc. 
l/4th—Woodcock, Jackdaw, Black-headed Gull, Kestrel, Teal, Stock- 
Dove, etc. 
'5/16ths—Rook, Crows, Owls, Wood-Pigeon, Guillemot, Wigeon, etc. 
3/8ths—Herring-Gull, Mallard, etc. 
1/2—Gannet, etc. 
5/8—Heron. 
(All these rings were made by Mr. Samuel Brahe, Halifax.) 
