66 THE MIGRATION OP BIRDS 



Brazil, but the Mexican birds are more or less 

 stationary at all seasons. 



Our swallow and its congeners have an almost 

 cosmopolitan range, summering in the Northern 

 and wintering in the Southern Hemisphere or 

 comparatively near to the Equator in the Northern. 

 Towards the centre of its range its migrations are 

 either short or the bird is non-migratory. 



Mr W. L. Sclater, addressing the South African 

 Ornithologists' Union (42), stated that the swallow 

 arrives at Cape Town at the end of October, and is 

 common from November to March ; practically all 

 have left by the middle of April. Swallows begin to 

 arrive from the south in Africa north of the Sahara 

 in the latter half of February ; early in March they 

 reach southern Europe, later in the same month they 

 are in Central Europe and by the middle of April 

 large numbers arrive in England. Thus swallows 

 leave South Africa actually after they have arrived 

 in England ; the South African birds cannot be the 

 same which are in North Africa a month earlier ! 

 The swallow supports Seebohm's thesis that the 

 individuals which go farthest to the south in winter, 

 breed farthest north. A day-migrant and by no 

 means a rapid one, the swallow may be timed from 

 place to place, and it is not presumption to suggest 

 that the birds which reach Britain to nest came from 

 lands little south of the Sahara and well north of 



