Migration Info This species, famous for the huge flocks that migrate southward each fall, moves back into the United States in spring along a broad front. The only significant concentrations of these birds during the spring are found along the southern shores of the Great Lakes in late April. The yearly migratory path of this species is a classical elliptical pattern. Spring migrants move northward up the Mississippi River valley, remaining west of the Appalachians. In fall, northern populations follow a southerly course down along the eastern side of the Appalachian crest.