HOMEWARD MIGRATION 



intervals of from fifteen to twenty minutes. There was a small movement of 

 hawks, mostly Red-tailed Hawk, and a massive westward drift of Juncos and 

 Tree Sparrows. About 9:00 o'clock the wind shifted to come from the west, 

 and all westward travel ended an hour later. At noon the wind was blowing 

 about 10 m.p.h. from the northwest, there was a heavy, low overcast, and 

 the temperature dropped below freezing. Shortly after noon I noticed 

 Juncos and Tree Sparrows drifting eastward; all afternoon they moved 

 through the thickets and across the clearings in that direction, the volume of 

 their eastward passage being equal to the morning travel the other way. 

 Flocks of blackbirds and small numbers of Crows also flew eastward. Next 

 morning the wind continued from the northwest, but it was bright and 

 clear. A few Juncos, one flock of blackbirds, and several hawks going west 

 made up the total of the migration for the day, while the Juncos and Tree 

 Sparrows remained about the hatchery in their many hundreds. April 23 

 was cold and cloudy, with a west wind, and there was no migration. The 

 twenty-fourth broke bright and clear, with a south wind, and there was a 

 short but heavy westward migration of blackbirds and Crows in the morn- 

 ing; but the Juncos and their companions did not travel. The twenty-fifth 

 brought rising temperatures, strong southeast winds, and the heaviest migra- 

 tion of all species for the year. 



When these reverses occur at Delta, I have seen evidence of the turn- 

 about on the prairie country to the south, where on such days there is a 

 steady drift of birds to the southeast. Whatever the influence, many birds 

 over a broad region are induced to turn back on their migratory highway, 

 retracing their steps several, sometimes many miles. 



Though such reverses occur most frequently in the small species, I 

 have seen similar changes in the flow of waterfowl. On the evening of April 

 23, 1950, for example, a migration of ducks, mostly Mallards and Pintails, 

 began soon after 7:00 p.m., the birds all going in their usual direction toward 

 the northwest. Shortly after the flight started, ducks began arriving on the 

 marsh from the northwest, and it was apparent that they had turned back 

 soon after they were out over the open lake. The same evening there was a 

 reverse movement of blackbirds and Crows; Juncos and hawks had been 

 going eastward all afternoon. Next morning the prairies were blanketed with 

 three inches of snow. Sowls ( 1955 : 19 ) describes a reverse in which the ducks 

 departed completely from the Delta region. 



The homeward passage of birds somehow touches the fives of us all; and 

 yet we have been mainly concerned with these wayfarers when they stop 



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