390 GENERAL ZOOLOGY 



has managed to pick up a living where another bird would 

 starve to death. Most of the sparrows belong to the fields 

 and hedges, where their brownish coloration serves to make 

 them inconspicuous. 



Our American robin belongs to the family of thrashes 

 (Tur'didcu). Though not a gifted songster, like some of its 

 near relatives, the robin is dear to all dwellers in the country. 

 With the bluebird and the song-sparrow it shares the honor 

 of being spring's harbinger among the birds in eastern North 

 America. Its habits, song, and call-notes offer an interesting 

 subject for study. 



Migration of Birds. The phenomena of migration are espe- 

 cially noteworthy among birds, and the birds of a region may 

 be roughly classified in connection with this habit. Those 

 species which remain in a region all the year are spoken of 

 as permanent residents of that region. They may be more 

 or less migratory as individuals ; that is, the birds seen in 

 the summer may not be the same individuals that appear 

 in the autumn or winter. The great majority of the birds 

 of the northern hemisphere leave in the autumn to pass the 

 winter in the south, returning in great bird waves in the 

 spring. These birds are the summer residents of the region. 

 The summer residents of the eastern United States may 

 pass the winter in the southern states, or they may (like the 

 bobolink) go as far as Brazil. When the great hordes of the 

 summer residents have passed to the south, other birds come 

 down from the north; these are ivinter visitants. Often a 

 bird loses its way, or is blown out of its regular line of travel 

 to other regions ; such birds are accidental visitants to those 

 regions. 



The great migratory movements of birds are fairly regular 

 year after year, and they are participated in by thousands 

 upon thousands of individuals. When the appropriate time 

 comes each species gathers in large flocks, or the individuals 



