1921.] Bird-Migration hy the Marking Method. 495 



Many records of: this species are available from other 

 sources, and these iuclude several curious instances of winter 

 movement in a noitherly direction, A bird marked as a 

 chick in Co. Tyrone was recovered in its first winter in 

 Inverness-shire, but others were recorded from Cornwall 

 and from Middlesex in their second winters (7). Birds 

 marked as chicks in Northumberland reached Argyllshire 

 and Forfarshire in their first winters, although another went 

 to Ireland and one was recorded from Brittany in its third 

 winter (14). Several winter records from the places of 

 marking were also obtained during each of these investiga- 

 tionso Of 33 birds marked as chicks in Co. Sligo 

 and subsequently recovered, all, except one from Spain, 

 were reported either from the same neighbourhood or 

 from within sixty miles at most, the records being almost 

 exclusively for the winter months (6). Witherby (2G) has 

 also a number of records for this species. 



IV.— HERRING-GULL (Larus argeiitatus Pontopp.) : 

 ANALYSIS OF RECORDS. 



The Herring-Gull is found all the year round in the 

 British Isles, immature birds remaining in summer in many 

 districts where no suitable breeding-places exist. By purely 

 observational means it is not possible to determine the nature 

 of the wandering movements that appear to take place in 

 winter. 



During the course of the Inquiry, 461 birds of this species 

 were marked, 375 of them in the northeast of Scotland. 

 Of the latter, 289 were marked as chicks, and 8G as full- 

 grown birds caught on the shore at night and mainly in 

 September and October 1910, and it is these two categories 

 which have provided nearly all the records. The two sets of 

 reappearances are treated separately below, as they reveal 

 certain differences which are doubtless due to one category 

 consisting entirely of native birds while the other may 

 contain at least a proportion of winter visitors. 



