ON BIRD MIGRATION. 365 



of the most representative species of migrants. The Song-Thrush, 

 White Wagtail, Skylark, and Swallow being now done, it is proposed to 

 invite Mr. Clarke's attention to a like treatment of the Starling, Eook, 

 Lapwing, and some others, which will presumably present no little 

 divergence in the character of their migrations. 



Thus your Committee respectfully repeats its request for reappoint- 

 ment, and, if possible, with an increased grant of money. 



Statement made to the Committee. 

 By Wm. Eagle Clarke. 



During the past year I have devoted much time to the study of the 

 seasonal movements of a number of our birds, and I present herewith, for 

 the consideration of the Committee, histories of the various migrations 

 performed annually within the British area by the Skylark and the 

 Swallow. 



The preparation of these complete and particular accounts has proved 

 to be a laborious and difficult undertaking, since a number of the 

 movements to be treated of are so intricately interwoven with or so 

 insensibly merge into each other, or are performed under such obscure 

 conditions, as to render their discrimination and intci'pretation matters 

 demanding most careful consideration. 



The following accounts of the migrations of the Skylai'k and the 

 Swallow are in the main based upon the data obtained at the Light- 

 stations and elsewhere during the years 1880-87 ; but other sources of 

 information have been consulted, including the Scottish Migration 

 Reports for 1892-1900 of Messrs. Hinxman and Laidlaw, and the 

 Irish Reports for 1888-97 of Mr. Barrington. 



It is my pleasing duty to acknowledge the assistance I have received 

 from Professor Collett, of Christiania, who has most obligingly furnished 

 me with useful notes relating to the movements of birds in Southern 

 Norway ; and from Herr Knud Andersen, of Copenhagen, who has given 

 me much valuable information on the migratory birds observed in the 

 Fseroe Islands. 



The Migrations of the Skylark {Alauda arvensis). 



In the British Islands the Skylark is not only one of the best- known 

 species, but also one which can be almost always met with, so that com- 

 paratively few people suspect the extent to which it is migratory, and 

 fewer still are awai-e of the complexity of its migrations, which present 

 problems more difficult to solve than those of any other British bird • 

 yet this is undoubtedly the case. 



As a migrant, no species makes so great a show in the returns of the 

 several Light-stations, and the account which follows is based upon 

 upwards of four thousand individual records. Yet within the British 

 area the Skylark is for the most part Resident as a species, though 

 shifting its quarters when affected by frost or snow, as is obvious to 

 almost any observer. The degree to which our native Skylarks are migra- 

 tory depends on the varying conditions of climate and food. In the 

 lowlands of Great Britain, especially in the south-west of England and 

 throughout Ireland generally, the migratory habit is less exercised, pre- 

 sumably because it is less necessary there than elsewhere. On the other 

 hand there are considerable tracts which, from their elevated, exposed, or 



