The manner in which birds find their way over thousands of miles of migration routes to their wintering grounds and back to the very spot where they nested or were hatched the previous year, continues to be a mystery. Since 1885 the U. S. Fish and Wildlife Service has been accumulating information on the migrations of waterfowl. Much of it is based on the records of a great number of banding stations and other cooperators such as the Illinois Natural History Survey, and the Delta Waterfowl Research Station in Manitoba, Canada. This information established the fact that waterfowl, with few exceptions, move south and north between their traditional breeding places and wintering grounds through regular migration routes. The Mississippi flyway is used by a great variety of ducks and geese with breeding territories that extend from the Dakotas and Wisconsin to the Arctic and from Hudson Bay to Alaska.
Cook County is located near the eastern edge of that flyway.
During six years of trapping and banding ducks at McGinnis Slough, we demonstrated that black ducks from Ontario, as well as mallards and several other species from the north and northwest, stop here on their way to the Mississippi Valley. Also that blue-winged teal, from Saskatchewan and Manitoba, habitually stop here on their southeasterly migrations. Perhaps that is because we lie at the head of the DesPlaines and Illinois river valleys angling toward the Father of Waters. Perhaps this is a traditional stop-over learned long ago when so much of the Chicago region was swamp land. Argonne National Laboratory, Division of Educational Programs, Harold Myron, Ph.D., Division Director.