FLIGHT TRAILS SOUTH 



Lower Souris Refuge, in North Dakota, northward into Manitoba, this 

 amounting to a "reverse migration" involving thousands of birds. During a 

 mild spell after heavy frost in November 1949, the Delta Marsh, empty of 

 Mallards and other waterfowl, was repopulated by great flocks of Mallards 

 which we saw arriving high from the south and southwest. A similar return 

 of Mallards from the south brought an abundance of "green-heads" to a 

 nearly empty Delta Marsh in November 1954. 



Probably all ducks at least once each autumn partake in a mass migra- 

 tion sweeping southward over traditional routes, young and old together. 

 At other times, adults as well as juveniles, wander in all directions from 

 stopping places along the way of migration. 



113 



