1921 .] Bird-Migration by the Marking Method. 497 
The age analysis shows that all the records refer to the 
first year of the birds* lives with the exception of two in 
the second year (Co. Durham and Yorkshire) and one 
in the fourth year (Moray Firth). The annual analysis 
merely reflects the numbers marked in the different 
seasons. 
There is a noteworthy absence of any winter records from 
the district of marking, although the conditions there are 
favourable and the species gives a good percentage of re¬ 
appearances. A southward wandering, mainly along the 
east coast of Great Britain, is clearly indicated, and one bird 
is shown to have crossed the North Sea to Heligoland as 
early as 9th September in its first autumn. 
The records contrast markedly with those for the Lapwing 
and the Woodcock in revealing no gap between the native 
district and a comparatively distant winter area. This may 
be taken as an expression of a different type of migration, a 
gradual dispersal with a southerly trend rather than a 
definite and rapid change of area. 
TABLE XIII. 
List of Reappearances of Herring-Gulls caught on the 
SHORE AT NIGHT, MARKED AND RELEASED, NEAR ABERDEEN, IN 
September and October 1910. 
Case No. 
Date of Reappearance. 
Locality of Reappearance. 
104 
15.11.10 
Aberdeen. 
205 , 
20. 5.11 
(and released) 
Burray, Orkney. 1 
11. 1.13 
nr. Aberdeen. 
217 
26. 6.11 
Aberdeen. 
333 
7. 3.12 
Aberdeenshire. 
334 
6. 5.12 
Asaa, east coast of 
Jutland, Denmark. 
374 
27. 6.13 
Gera, Thuringia, Germany. 
375 
28. 4.14 
Caithness. 
