MIGRATION. 



35 



compelled the survivors to extend their migrations far and wide, until the shores of nearly- 

 all the rest of the world were visited on passage or included in the winter range of some 

 species of the family. 



The British ornithologist naturally classifies migratory birds into three groups — birds 

 which, like the Swallow and the Cuckoo, come to our shores in spring to breed, and, having 

 bred, leave them again in autumn to winter elsewhere ; birds which, like the Fieldfare and 

 the Widgeon, come to our islands in autumn and spend the winter with us, but leave again 

 in spring in search of better breeding-grounds ; and birds which, like the Little Stint and 

 the Dusky Redshank, are migratory birds par excellence, being only seen on our shores for a 

 month in spring, and again for a month in autumn, in the act of migrating to and from 

 breeding-grounds far away to our north, and winter-quarters far away to our south. An 

 examination of the geographical ranges of these various birds will, however, show that they 

 only differ in their relation to our islands. They all represent birds which breed in the 

 north and winter in the south. Every migratory bird wintering in England goes north to 

 breed, and every migratory bird breeding in England goes south to winter. It is a rule 

 without exception in the northern hemisphere that each bird breeds in the extreme north 

 point of its migrations. To make the rule apply to the southern hemisphere as well it 

 must be modified as follows : — Each bird breeds in the coldest climate which it visits on 

 its migrations. 



Any ornithologist who visits the Sussex Downs on a fine clay in autumn — no 

 better place could be selected than those between Brighton and Shoreham — may see small 

 parties of birds passing up and down the coast, many of them unfortunately falling victims 

 to the bird-catchers, who lure them down to their destruction by miserable call-birds 

 pinioned within the flap-nets. If he be a novice he will scarcely be likely to regard their 

 apparent flitting to and fro as in any way connected with migration. But by-and-by he 

 will probably discover that the birds which are moving in the direction of Dover are soft- 

 billed insect-eating species, who are migrating east to cross the Straits on their way to 

 warmer winter- quarters down south ; whilst those who are migrating towards the Land's 

 End are hard-billed seed-eating species, who are migrating west, having crossed over the 

 German Ocean from Scandinavia, possibly by w r ay of Heligoland, and are now following 

 the English coast-line, continually sending small parties inland to winter in our mild 

 climate. 



The former birds are migrating out of England, the latter are migrating into it in 

 autumn; and these two parties represent two more or less distinct classes of migrants. 

 The hard-billed seed-eating birds may be called Gipsy migrants. Their home is wherever 

 they can find food. In winter they are perpetually hovering on the outskirts of the frost, 

 perpetually being driven southwards by snowstorms, but continually trying to force a 

 passage to their breeding-grounds. The consequence is that their movements depend 

 largely upon the weather ; in some seasons they are very abundant, in others very rare. 



f2 



Classifica- 

 tion of 

 migrants. 



Relation of 

 climate to 

 Migration. 



Migration 

 on the south 

 coast of 

 England. 



Gipsy 

 migrants. 



