352 THE STRUCTURE AND LIFE OF BIRDS chap. 



for some species, of the southern region for others. 

 There is also an east and west migration of which I 

 shall speak soon. 



It is vain to search the animal kingdom for other 

 migrations on so great a scale as those of birds. The 

 movements of fish afford the nearest parallel, for they 

 occur annually at regular seasons and are connected 

 with reproduction. At a certain season every year 

 the salmon betakes him to his river, and the herring 

 and the mackerel move towards the coast. These, 

 though far less wonderful than the regularly recurring 

 movements of birds, are true migrations. But when 

 the monkeys in the Himalayas ascend to a height of 

 10,000 feet or more in summer, or when the lemmings 

 in Norway, at long and irregular intervals, sweep like 

 a great flood towards the sea, they do not, in the 

 strict sense, migrate. 



The Distances Covered. 



The Sanderling nests in Iceland or on the shores of 

 the Arctic Ocean, and in winter it has been seen as 

 far south as Cape Colony. The nestlings of the Knot 

 have been found in Grinnell Land in lat. 82 33' N, 

 and the bird is known to winter as far south as 

 Australia and New Zealand. The Turnstone is a 

 great traveller, nesting in Greenland or the coasts of 

 Scandinavia, and wintering in Australia, New Zealand, 

 South America, or Africa. The distances travelled 

 amount sometimes to over 7,000 miles. 1 The dim- 

 inutive size of a bird is no evidence at all that he is 



1 Mr, Seebohm puts the longest at 10,000 miles. 



