Ray Murdy, South Dajcota Department of Game, 

 Fish, and Parks, Pierre, South Dakota. 



Harvey K. Nelson, Shiawassee National Wildlife 

 Refuge, Saginaw, Michigan. 



Maynard M. Nelson, Minnesota Department of Con- 

 servation, Fairmont, Minnesota. 



Norman J. Ordal, Minnesota Department of Con- 

 servation, Fergus F'alls, Minnesota. 



E. V. Pierce, Upper Mississ.ippi Wildlife and Fish 

 Refuge, Muscatine, Iowa. 



Charles K. Rawls, Jr., Tennessee Game and Fish 

 Commission, Tiptonville, Tennessee. 



George B. Saunders, United States Fish and Wild- 

 life Service, Atlanta, Georgia. 



Lyle Schoonover, Mingo Swamp National Wildlife 

 Refuge, Puxico, Missouri. 



James G. Sieh, Iowa Conservation Commission, 

 Okoboji, Iowa. 



Parker Smith, Tennessee Game and Fish Commis- 

 sion, Paris, Tennessee, 



M. E. Stempel, Iowa Conservation Commission, 

 Ottumwa, Iowa. 



Milton Stenlund, Minnesota Department of Con- 

 servation, Ely, Minnesota. 



R. T. Sterling, Ducks Unlimited, Wynyard, 

 Saskatchewan, Canada. 



Marshall L. Stinnett, United States Fish and Wild- 

 life Service, Peoria, Illinois. 



Richard Vaught, Missouri Conservation Commis- 

 sion, Trimble, Missouri. 



Peter Ward, Delta Waterfowl Research Station, 

 Delta, Manitoba, Canada. 



Jerald J. Wilson, Snake Creek National Wildlife 

 Refuge, Riverdale, North Dakota. 



Richard K. Yancey, Louisiana Wild Life and Fish- 

 eries Commission, Ferriday, Louisiana. 



Douglas M. A. Jones, Meteorologist with the 

 Illinois Water Survey, Urbana, aided in the interpreta- 

 tion of weather maps. 



Several members of the staff of the Natural History 

 Survey Division were involved in making this paper 

 ready for publication. Dr. Thomas G. Scott and the 

 Editorial Committee of the Section of Wildlife Research 

 reviewed and improved the manuscript. James S. Ayars 

 edited it. William E. Clark made the photographs for the 

 frontispiece and fig. 1. Charles C. Harper and Forrest 

 D. Loomis prepared the maps and graphs. Loomis made 

 the silhouettes for the cover. 



For all assistance that furthered the preparation 

 and publication of this report, the writer is most grate- 

 ful. 



FLIGHTS PRIOR TO THE MASS MIGRATION 



Prior to the mass waterfowl migration that began 

 on October 31, 19-5.5, there had been a steady but un- 

 spectacular movement of waterfowl into the Mississippi 

 Flyway, fig. 1. Population levels for most of October, 

 1955, approximated those of October, 1954. 



In the northern section of the flyway, there were 

 two pronounced movements of waterfowl previous to 

 October .31, 1955, one in the period October 23-24 and 

 one in the period October 28-30. Jerald J. Wilson re- 

 ported a constant movement of ducks, largely divers, 

 through the Turtle Mountains of North Dakota on 

 October 23 and 24. Four conservation officers in 

 Wisconsin observed flights of ducks, principally divers, 

 on the same 2 days. Large flights of diving ducks and 

 small flights of mallards (Anas platyrhynchos)* and 

 other dabbling ducks arrived in Illinois on October 23, 

 24, and 25. 



William G. Leitch reported that large flights of 

 ducks departed on October 29 from the Libau Marshes 

 at the southern end of Lake Winnipeg, Manitoba. Also, 

 ducks were observed leaving the Delta Marsh, some 70 

 miles west of Libau, on October 30. 



J. C. Carlsen reported that heavy movements of 

 gadwalls (Anas strepera) were noted at the Mud Lake 

 National Wildlife Refuge near Holt,^ Minnesota, on 

 October 28 and 29. On October 28, Jerald J. Wilson 

 observed a large movement of coots (Fulica americana) 

 from the Garrison Reservoir area of North Dakota. In 

 Wisconsin, seven observers reported the arrival of im- 

 portant flights of ducks, especially scaups (Aythya)AnA 

 other divers, on October 28, 29, and 30. Few, if any, 

 diving ducks arrived at this time in Illinois, but small 

 flights of mallards arrived along the Mississippi River. 

 between East Dubuque and Savanna, Illinois. 



OBSERVATIONS ON MASS MIGRATION 



Periiaps there was no sharp demarcation in time 

 between the duck flights just previous to October 31 

 and the initiation of the mass movement from the Great 

 Plains of Canada on October 31. There was. however, 

 a demarcation in magnitude: The earlier trickle of 

 southbound waterfowl developed into a flood of migrants 

 on October 31 and the 2 days following. 



Canada.— For the area of Calgary, Alberta, George 

 Freeman reported to Ducks Unlimited of Canada that 

 blizzard conditions prevailed there on October 31 and 

 November 1, resulting in the exodus of most of the 

 waterfowl then present. After the storm, only a few 



*Tliis and other scientific names from Smith & Parmalee 

 (1955). 



