302 BIOLOGY FOR BEGINNERS 



Ducks, hawks, swallows, and swifts migrate by night, while 

 warblers, thrushes, orioles, sparrows and shore birds travel by day, 

 thus gaining opportunity for day time feeding, and nights for rest 

 and protection. The distances covered are enormous and could 

 hardly be believed, were they not abundantly verified. Here are 

 some examples of the start and finish of their journeys: 



The bobolink travels from New York to Brazil 

 * ' black poll warbler from Alaska to South America 5 ,000 mi . 

 " night hawk " Yukon to Argentina 7,000 " 



" shore birds " Arctic regions to Patagonia 8,000 " 



" arctic tern " Arctic to Antarctic circles 11,000 " 



This last is the champion long-distance traveller. They make 

 the round trip in twenty weeks. 



While many birds migrate slowly, feeding by the way, and 

 averaging only twenty to thirty miles per day, there are others 

 which are marvels of speed and endurance. Bear in mind that it 

 is considered a record performance to drive a car from San Francisco 

 to New York, 2500 miles, in a week and that the trains require 

 about four days. Then look at some of these records. 



Gray-cheeked thrush travels from Louisiana to Alaska in thirty 

 days, a distance of 4000 miles. 



Golden plover travel from Nova Scotia to South America in 

 forty-eight hours, a distance of 2400 miles. Over the open ocean 

 without chance for rest, this bird uses two ounces of its fat as fuel 

 for the whole 2400 miles. Compare this with the fuel used in the 

 best aeroplanes, which even then have seldom travelled half this 

 distance without stopping. The tiny humming bird has a record 

 of 500 miles per night, across the Gulf of Mexico, and then is not 

 tired enough to rest, but often flies on inland to make a good 

 trip of it. 



Routes. Wonderful as are birds' speed and endurance, a real 

 mystery surrounds their knowledge of the times and routes for 

 migration. Similar species follow the same routes year after year, 

 some going direct over the ocean (like many water birds) some 

 follow the West Indies across to South America; many cross the 



