THE UNCHARTED SKY 125 



turning birds. In April the migratory move- 

 ment is rising fast and, during tlie latter part 

 of the month, one may report arrivals of new 

 species daily. In May, come the birds who keep 

 a calendar, apparently, for they return year after 

 year on precisely the same date. When the 

 weather is fair, this migration may almost 1 3 

 called a wave, and one single observer, on a single 

 day in the middle of May in Ohio, recorded 144 

 species as having been seen in migration. 



"May and June are nesting months, July the 

 month of the young birds, yet facts collected by the 

 Biological Survey show that the returning migra- 

 tion movement has begun by July 10th, and in 

 some years, by July 1st. The Orchard Oriole, the 

 Redstart, and the Summer Warbler are restless 

 and eager to be away by the second week in July, 

 the minute, indeed, that the nestlings are able to 

 fend for themselves. They do not wait for the 

 winter storms to sound the alarm. In August, the 

 birds which went far north to nest are coming 

 back, and towards the end of the month, the south- 

 ward migration becomes dense, reaching its crest 

 toward the end of the month. By October nearly 

 all the summer visitors are gone and the winter 

 vistors arrive to stay two, three or sometimes; 



