THE MIGRATION OF INLAND BIRDS. HI 



loving species, still abundant in the thickets beneath me ; 

 a golden-crowned thrush; several black-throated bunt- 

 ings; and two humming-birds, male and female, still 

 keeping company. The movements of all these birds 

 impressed me with the belief that they were migrating 

 birds, and not mere chance visitors. In most instances, 

 they seemed to drop from above ; they remained but a 

 little while, never longer than ten minutes, and then 

 took a distinctly upward flight until nearly out of sight, 

 when they started down the river that is, in a southerly 

 direction. This movement, which was well marked in 

 every case, I construed into a migratory one, and occur- 

 ring as it did so early in the season as August 20th, it 

 leads to the conclusion that the return or autumnal flight 

 of our migratory birds commences very soon after incu- 

 bation is over, and is not a sudden impulse that controls 

 the movements of the entire number of any given spe- 

 cies. Certain it is that the degree of irregularity in the 

 return of the birds that pass northward in May is very 

 great much more so than is the onward movement in 

 spring to their northern summer haunts. This does not 

 apply to all species, of course, but to many ; and it is 

 precisely such exceptions such semi-migrating or "ir- 

 regular " species that give evidence that the movement 

 is slowly being relinquished, as being no longer absolutely 

 necessary for their comfort and well-being. 



There are two very common birds, belonging to widely 

 different families, the habits of which, I think, bear di- 

 rectly upon this subject. One of these is the well-known 

 yellow-breasted chat, the other the indigo-bird. 



The chat is one of our latest spring arrivals, being 

 very sensitive to changes of weather. If undisturbed, 

 these birds occupy the same nesting-place year after year, 

 building a new nest every season, more from necessity 



