62 THE MIGRATIONS OF BIRDS 



northern South America, in a relatively short time. 

 It is highly probable that most migrations are per- 

 formed in a leisurely manner, and that after a flight 

 of a few hours, the bird pauses to feed and rest for 

 one or several days if it finds itself in congenial sur- 

 roundings. 



The Sense of Direction in Birds 



No less wonderful than the fact of migration itself 

 is the regularity and system with which birds pursue 

 journeys that in many cases cover thousands of 

 miles across the earth's surface. Let us consider for 

 a moment the instance of a white-throated sparrow 

 (no. 38160), banded by Mr. S. P. Baldwin on an 

 estate near Thomasville, Georgia, on March 5, 191 6. 

 As the white-throat nests in the northern portion of 

 eastern North America, from Massachusetts, New 

 York, Michigan, Minnesota, and northeastern 

 Wyoming, north to Great Bear Lake and Labrador, 

 this individual was in its winter range when cap- 

 tured in Georgia. Subsequently this identical bird, 

 identified by its numbered band, was trapped on 

 March 7 and 19, 1917, on several occasions from 

 February 25 to March 22, 1920, and on March 27, 

 1 92 1, in each case within one hundred yards of the 

 spot where it was first secured. Since this was its 

 winter home, we must assume that on each of the 

 years from 191 6 to 1921 this bird had migrated 



