Page:The Migration of Birds - Thomas A Coward - 1912.pdf/90

74 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 composed 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 circumstances, 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-