and nearly to Great Slave Lake, is concentrated in winter chiefly in the 

 West Indies, its metropolis at this season being the island of Hispaniola. 



Long-distance migrations 



Some of the common summer residents are not content with a trip 

 to northern South America, but push on across the Equator and finally 

 come to rest for the winter in the pampas of Argentina, or even in 

 Patagonia. Thus some species that are more or less associated with 

 each other in summer, as nighthawks, barn swallows, cliff swallows, 

 and some of the thrushes, may also occupy the same general winter 

 quarters in Brazil. Some individual nighthawks and barn swallows 

 travel still farther, and of all North American land birds these species 

 probably have the longest migration route, as they occur north in sum- 

 mer to Yukon and Alaska, and south in winter to Argentina, 7,000 

 miles away. Such seasonal flights are exceeded in length, however, 

 by the journeys of several species of water birds, chiefly members of 

 the suborder of shore birds. In this group there are 19 species that 

 breed north of the Arctic Circle and winter in South America, 6 of them 

 going as far south as Patagonia, and thus having a migration route 

 more than 8,000 miles in length. 



The arctic tern is the champion "globe trotter" and long-distance flier 

 (fig. 8). Its name "arctic" is well earned, as its breeding range is cir- 

 cumpolar and it nests as far north as it can find a suitable place. The 

 first nest to be found in this region was only 7V2 degrees from the 

 North Pole, and it contained a downy chick surrounded by a wall of 

 newly fallen snow that had been scooped out by the parent. In North 

 America the arctic tern breeds south in the interior to Great Slave Lake, 

 and on the Adantic coast to Massachusetts. After the young are grown 

 the arctic terns disappear from their North American breeding 

 grounds, and a few months later they may be found in the Antarctic 

 region, 11,000 miles away. Until very recently the route followed by 

 these hardy fliers was a complete mystery, for although a few scattered 

 individuals have been noted south as far as Long Island, the species is 

 otherwise practically unknown along the Atlantic coasts of North 

 America and South America. It is, however, known as a migrant on 

 the west coast of Europe and Africa. By means of numbered bands 

 the picture is now developing of what is apparently not only the longest 

 but also one of the most remarkable of all migratory journeys. 



38 



