HISTORICAL AND EXPERIMENTAL STUDY OF HOMING. 29 



The above agrees closely with Ziegler's* account of the flights of German 

 birds. According to this author the direction and velocity of the wind greatly 

 influence the flight of the birds. In flights from great distances (100 to 600 

 km.) the average speed of the best birds with no wind is 1,100 to 1,150 meters 

 per minute. In a favorable wind the speed rises to 1,300 to 1,600 meters, and 

 occasionally to 1,600 to 1,950 meters. In unfavorable winds the speed of the 

 best birds varies from 500 to 800 meters, according to the strength of the wind. 

 The pigeons never fly to great heights never over 1,000 to 2,000 meters and 

 usually much lower. 



THE PROBLEM OF HOMING IN BIRD MIGRATION. 



In this paper, as has been stated, we shall not discuss the general features 

 of bird migration. Nevertheless, two or three migrations deserve mention in 

 this connection because it is clear that the problems involved in them are the 

 same as those involved in the general study of homing. Cooke,f after showing 

 that many of the birds fly by night as well as by day, takes up some of the 

 longer routes of the birds. The longest continuous flight in the world is 

 possibly 2,400 miles. The golden plover nests along the Arctic coast of North 

 America and when the young have become independent the fall migration 

 begins. The birds fly to the Labrador coast and remain there for several 

 weeks, where food is abundant. After leaving Nova Scotia the birds fly due 

 south to the coast of South America. The golden plover takes a straight 

 course across the ocean and, if the weather is propitious, makes the whole 

 2,400 miles without pause or rest. But if tempests arise, it may be blown out 

 of its course to the New England coast and start anew on the advent of fair 

 weather; or it may rest for a few days at the Bermudas, one-third of the way 

 along its course, or at the nearest of the Lesser Antilles, stili 600 miles from the 

 mainland of South America. These, however, are emergency stop-overs, to be 

 resorted to only in case of storms. Having accomplished its ocean voyage, it 

 passes across eastern South America to its winter home in Argentina. After 

 dwelling 6 months in Argentina it finds its way back to the Arctic regions by 

 an entirely different route. It travels across northwestern South America 

 and the Gulf of Mexico, reaching the United States along the coast of Louisiana 

 and Texas; thence it travels slowly up the Mississippi Valley and by early 

 June is again at the nesting site on the Arctic coast. 



This same bird dwells also in the Hawaiian Islands and travels from that 

 point to Alaska, spending the winter in Hawaii and nesting in the spring in 

 Alaska. The Hawaiian Islands are 2,000 miles from the California coast on 

 the east, 2,400 from Alaska on the north, and 3,700 miles from Japan to the 

 west. This is a very wonderful route, since between Hawaii and Alaska 

 there are no landmarks. 



Surprising as are these results from the golden plover, they are surpassed 

 by the exploits of the Arctic tern.! This bird dwells alternately in the Arctic 



*Zoologische Jahrbiicher, 1897, x, p. 238. 



tA summary of his work appears in the National Geographic Magazine, 1911, p. 346. 



^According to Cooke, the Arctic tern arrives in the Arctic regions about June 15, and leaves 

 August 25, spending thus 14 weeks at the nesting site. "They probably spend a few weeks 

 longer in the winter than in the summer home ; and if so, this leaves them scarcely over 20 weeks 

 for the round trip of 22,000 miles. Not less than 150 miles in a straight line must be their daily 

 task, and this is undoubtedly multiplied several times by their zigzag twistings and turnings in 

 pursuit of food." 



