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believed that an understanding has been gained of the '^ mys- 

 terious disappearance" and the phenomena of the migration. 

 It has been previously stated that the young remain in the 

 vicinity of the nesting site frequently for ten days after the 

 cessation of care by the parents. They then make their way 

 to the borders of the marsh, where they are joined by other 

 young until considerable flocks are formed. With them a 

 very few adults of either sex are usually associated. They 

 spend the day gleaning food about the alder-willow and grass 

 zones, but generally spend the night in the open marsh. 

 Their food is still largely animal, consisting primarily of 

 weevils and lepidopterous larvae. By the first of July, small 

 flocks begin leaving the marsh in the morning to seek their 

 food on the uplands. They join the numerous Grackles and 

 Cowbirds which are now through breeding, and together 

 they visit grain and stubble fields, where they frequently do 

 considerable damage by reason of their large numbers. Their 

 diet now changes from the insectivorous marsh type to an 

 almost strictly herbivorous diet of grain and weed seeds. By 

 the first of August the breeding season is entirely over, and 

 they are joined by the females and the young of the second 

 brood, while the males congregate in flocks by themselves. 

 For several weeks now, no Redwings are found in the marsh 

 during the day, but may be seen coming in at sundown and 

 leaving at dawn in considerable flocks. But the molting 

 season has commenced. The inner primaries and many 

 of the body feathers have already been replaced. The 

 ''mysterious disappearance'^ now begins to take place. The 

 adult males, which begin molting about two weeks earlier than 

 the females or young, are the first to go, and shortly they are 

 followed by the females and young. To the ordinary observer 

 they have completely disappeared. No longer are they seen 

 leaving the marsh in the morning or returning at evening. 

 Along the ponds, streams, and lake shore there are none to be 

 seen. They are apparently gone from the neighborhood. If 

 at this time, however, one penetrates into the heart of the 

 marsh, where the flags wave four and five feet over his head, 

 he may hear a rush of wings ahead of him as a flock of birds 



