484 Dr. A. L. Thomson : Results of a Study of [Ibis, 



II.— THE LAPWING ( Vanellus vanellus Liiin.) : 

 ANALYSIS OF EECORDS, 



Although found all the year round in the British Isles, 

 except in some inland districts, this species is well-known 

 as a mitrrant. The mio;rations which may be observed are 

 indeed extremely complex, and they have already been very 

 fully worked out from the point of view of mass movements 

 {cf Eagle Clarke, Report Brit. Assoc, for 1902, p. 277). In 

 addition to autumn movements within the country, there are 

 at that season both immigiations from the north and east 

 and emigration to the south. If very severe weather occurs 

 during the winter there may be a resumption of these 

 movements, even if so late that the normal date for the 

 spring migrations in the opposite direction is close at 

 hand. 



The case is typical of a great part of the general 

 phenomena of migration in the British area, and the obstacle 

 which stands in the way of a full understanding of what 

 takes place is the difficulty of ascertaining the respective 

 parts played by the native birds and by the winter visitors 

 and birds of passage from the Continent : to what extent, 

 one asks, do the former remain sedentary while the latter 

 journey on to form the southward stream? And it has 

 already been argued that it is questions of this kind which 

 probe the very nature of the migratory habit. 



Fortunately the species has proved a very suitable one 

 for study by the marking" method, and the results already 

 obtained show how the data from other sources may be 

 supplemented in important respects. The writer would 

 indeed urge the value of a concentrated investigation of this 

 species, on a larger scale than has yet been tried, as being 

 likely to yield results of very great theoretical interest. 



Table II. gives the numbers of Lapwings marked during 

 the course of the inquiry, and the numbers recovered 

 in the respective categories. For the ])urpose of grouping, 

 the following arbitrary geographical regions have been 

 defined : — 



