74 THE MIGRATION OF BIRDS 



migration, southern British birds leaving the country, 

 northern British retiring to winter in the south of 

 England, and northern European birds replacing 

 these as autumn immigrants. The study of local 

 races quickly altered this opinion ; it was guessed 

 that in Britain there was a sedentary insular race 

 and a migratory passage race ; others, however, saw 

 that some of our home-bred birds left in autumn. 

 What do we find ? A song thrush, marked as a 

 nestling in July in Northumberland, is found in 

 November in Durham ; another one, marked in 

 Berkshire travels to Norwich and is recorded in 

 November, but a third, born in Aberdeen takes an 

 autumnal flight of at least 1500 miles and is found 

 in Portugal. Evidently we cannot yet frame any 

 rule for our British-bred birds. 



It is said that home-bred lapwings are somewhat 

 sedentary, and that the large winter flocks are com- 

 posed of Continental immigrants. The frequent 

 westward migration of lapwings during exceptionally 

 severe winter weather has led to the supposition 

 that these birds fly for refuge, under these circum- 

 stances, to Ireland. This is true, so far as it goes, 

 but a lapwing marked as a nestling near Stirling has 

 been found in the south of France, and two others in 

 Portugal, whilst five have been recovered in Ireland. 



The results of marking seabirds are interesting, 

 showing that the young birds often wander north- 



