96 BIRD STUDIES WITH A CAMERA 



Five species are represented. Named in the or- 

 der of their abundance they are the Tree, Bank, 

 Barn, Eave, and Rongh-winged Swallows. The last 

 are comparatively rare, while the Tree Swallows are 

 so in excess of all the species named that the follow- 

 ing remarks relate largely to them alone. 



Although Tree or White-breasted Swallows nest 

 locally throughout North America, from the table- 

 land of Mexico to Labrador and Alaska, there are 

 but few instances of their breeding in the lower 

 Hudson River valley, where they appear only as 

 migrants or transient visitants. They arrive from 

 the south early in April, and their northward migra- 

 tion is not concluded until about June 1st. During 

 June they are rarely seen, but between the 1st and 

 the 5th of July they begin their journey to their 

 winter homes — a movement which inaugurates the 

 fall migration. 



This stage of their journey takes them only to 

 certain marshes, which become stations on their line 

 of travel where countless numbers of their kind, 

 impelled by the flocking impulse, gather to roost 

 in the reeds. Their numbers increase steadily 

 through July and August, the maximum of abun- 

 dance being reached about September 1st ; then they 

 gradually become less numerous, and by October 10th 

 comparatively few remain, though if the weather be 

 favorable, they may be observed daily until late in 

 the month. 



Throughout this period — from July to October — 

 the marsh is used only as a dormitory, the reeds evi- 

 dently offering suitable perches to these weak-footed 

 birds, who in the morning radiate throughout the sur- 



