358 THE NATIONAL GEOGRAPHIC MAGAZINE 



tween the nests in Siberia and the winter 

 resorts in southern Asia. In the course 

 of time the species spread eastward in 

 the winter to Australia, to the islands 

 along the eastern coast of Asia, and 

 throughout Oceanica, while at the same 

 time the breeding range was extended 

 eastward across Bering Strait to Alaska. 



If all these extensions took place be- 

 fore there was any cutting off of corners 

 in the migration route, then at this stage 

 of development the Alaska - breeding 

 birds were journeying over 11,000 miles 

 (page 359, No. i) to reach the Low 

 Archipelago, distant only a little more 

 than 5,000 miles in an air-line. 



It is fair to suppose that early in 

 the course of the eastward extension 

 among the Pacific islands, the plover be- 

 gan to shorten the roundabout journey 

 by flights from the northern islands to 

 eastern Asia, and finally to Japan (No. 

 2). The most northern island is Pal- 

 myra, and the flight from there west- 

 ward to the nearest of the Marshall 

 Islands is about 2,000 miles ; thence a 

 3,000-mile journey, with several possible 

 rests, brings the birds to Japan. 



It is easily possible that birds accus- 

 tomed to this 5,000-mile flight might be 

 driven by storms a thousand miles out 

 of their course and discover Hawaii. 

 When from Hawaii they attempted to 

 reach Japan (No. 3) they would find a 

 chain of islands stretching for 1,700 

 miles in the desired direction, and the 

 final flight of 2,000 miles from the last 

 of these — the Midway Islands — to Japan 

 would be no longer than previous flights 

 to which they had become accustomed. 



Having once learned the route from 

 the Midway Islands to Japan, it would 

 be natural that the place of alighting on 

 the Asiatic coast should be gradually 

 carried north and east until the direct 

 flight was made from the Midway Is- 

 lands to the Aleutians (No. 4). A natu- 

 ral and easy carrying of this line east- 

 ward would result in the present route 

 (No. 5) between Hawaii and Alaska. 



NEIGHBORS AND STRANGERS 



Both the American and Pacific golden 

 plovers nest in Alaska near Bering Strait, 



the former on the north and the latter 

 on the south side of the strait. The 

 American bird reached there by a west- 

 ward extension from Canada, and the 

 Pacific by an eastward extension from 

 Siberia. The birds themselves are so 

 nearly alike that only an expert can dis- 

 tinguish them ; and, notwithstanding they 

 are such near neighbors during the sum- 

 mer — scarcely a hundred miles apart — 

 the beginning of migration makes them 

 utter strangers ; for those north of the 

 strait travel 3,000 miles east and then 

 6,000 miles south to Argentina, while the 

 others make a 3,000-mile flight directly 

 south to their winter home in Hawaii. 



the world's most extraordinary 

 traveler 



The shore-birds, such as the golden 

 plover, present the longest migration 

 routes among land-feeding birds ; but 

 even their surprising records are sur- 

 passed by some of the birds which glean 

 their living from the waters. The world's 

 migration champion is the Arctic tern 

 page 360). It deserves its title of Arc- 

 tic, for it nests as far north as land has 

 been discovered ; that is, as far north 

 as the bird can find anything stable on 

 which to construct its nest. 



Indeed, so Arctic are the conditions 

 under which it breeds that the first nest 

 found by man in this region, only 7^ 

 degrees from the pole, contained a downy 

 chick surrounded by a wall of newly 

 fallen snow that had been scooped out 

 of the nest by the parent. 



When the young are full grown the 

 entire family leaves the Arctics, and sev- 

 eral months later they are found skirting 

 the edge of the Antarctic continent. 



What their track is over that 11,000 

 miles of intervening space no one knows. 

 A few scattered individuals have been 

 noted along the United States coast south 

 to Long Island, but the great flocks of 

 thousands and thousands of these terns 

 which alternate from one pole to the 

 other have never been met by any trained 

 ornithologist competent to learn their 

 preferred path and their time schedule. 



The Arctic terns arrive in the far north 

 about June 15 and leave about August 



