146 GRAY LADY AND THE BIRDS 
Warbler in about a fourth and the Grosbeak in less than 
an eighth of the summer area. 
“The next variation is illustrated by the Robin, which 
occurs as a species in the middle districts of the United 
States throughout the year, in Canada only in summer, 
and along the Gulf of Mexico only in winter. Probably 
no individual Robin is a continuous resident in any section; 
but the Robin that nests, let us say, in southern Missouri 
will spend the winter near the Gulf, while his hardy 
Canada-bred cousin will be the winter tenant of the 
abandoned summer home of the southern bird. 
‘“Most migrants entirely change their abode twice 
a year, and some of them travel immense distances. 
Of the land-birds, the common eastern Night Hawk seems 
to deserve the first place among those whose winter 
homes are widely distant from their breeding-grounds. 
Alaska and Patagonia, separated by 115 degrees of 
latitude, are the extremes of the summer and winter 
homes of the bird, and each spring many a Night Hawk 
travels the 5000 miles that lie between. But some of 
the shore-birds are still more inveterate voyagers. These 
cover from 6000 to 8000 miles each way, and appear to 
make travelling their chief occupation. 
Routes of Migration 
‘* Birds often seem eccentric in choice of route, and many 
land-birds do not take the shortest line. The fifty 
species from New England that winter in South America, 
instead of making the direct trip over the Atlantic, in- 
volving a flight of 2000 miles, take a slightly longer route 
