numbers of shovelers, baldpates, and coots swelled 

 populations already present. 



Yancey made the following statement: "Although 

 the waterfowl flight |_of November 2 and 3_] descended 

 to a degree like a blanket over Louisiana, it appeared 

 to develop its greatest magnitude along the Mississippi 

 and Red rivers. For the most part, the flocks were 

 traveling in a southerly direction, and the flocks ob- 

 served were flying principally at altitudes of 300-400 

 feet. . . . During the course of this early November 

 waterfowl inventory l_aerial_|, migrant flocks could be 

 seen at almost any point over the rice fields of south- 

 western Louisiana, or in the vicinity of any major body 

 of water in north and central Louisiana." 



Dr. George B. Saunders reported that the flight ar- 

 rived on the Louisiana coast at the Lacassine National 

 Wildlife Refuge on November 3. 



POPULATION CHANGES AS A RESULT OF FLIGHT 



The effect of the mass migration of 1955 on water- 

 fowl populations in the Mississippi Flyway was pro- 

 nounced. Waterfowl censuses made in five states, im- 

 mediately prior to and after this spectacular flight, 

 show more than a three-fold increase in the duck popu- 

 lations of the flyway, table L Among the 12 areas for 



which there are data, the relative increases were simi- 

 lar in all but two areas: Martin County, Minnesota, and 

 Swan Lake National Wildlife Refuge, Missouri, both of 

 which registered a 12-fold increase. 



Information on the change in species composition 

 resulting from the mass migration is available for a 

 Minnesota area, the lower Illinois River valley, and the 

 state of Louisiana, tables 2, 3, and 4. In the Minnesota 

 area, table 2, a large ingress of mallards and lesser 

 scaups occurred along with an egress of gadwalls and 

 pintails. In the Illinois River valley, table 3, a sizable 

 ingress occurred in mallards, black ducks, lesser 

 scaups, and canvasbacks concomitant with a sizable 

 egress in widgeons, green-winged teals, shovelers, 

 ring-necked ducks, and coots. 



All species of waterfowl but the blue-winged teal 

 (Anas discors) increased in numbers in Louisiana, 

 table 4. The influx of migrants was especially pro- 

 nounced for the mallard, gadwall, green-winged teal, 

 redhead, canvasback, ring-necked duck, and lesser 

 scaup. 



The chronology of waterfowl migration in the 

 Illinois River valley in 1954 and 1955 is shown in fig. 

 2. The population trend for October, 1955, was similar 

 to that for October of the year before. By November 1, 

 1955, the number present in the Illinois River valley 



Table 1.— The increase in waterfowl populations in areas of the Mississippi Flyway which were 

 mediately before and after the spectacular waterfowl flight of late October and early November, 1955. 



;d in 



State 



Obs 



Area 



Preflight 

 Population* 



Postflight 

 Population* 



South Dakota 



Minnesota 



Illinois 



Indiana 



Missouri 



Louisiana 

 Total 



Ray Murdy 

 Maynard M. Nelson 

 Edward A. Davis 



Frank C. Bellrose 

 Dale N. Martin 



L^wis G. Helm 



Richard K. Yancey 



Missouri River 



Martin County 



Calhoun Refuge 



Batchtown Refuge 



Lower Illinois River valley 



Jasper-Pulaski Refuge 



Kankakee Refuge 



Willow Slough Game Preserve 



Squaw Creek Refuge 

 Swan Lake Refuge 

 Other northern areas 



State-wide 



* Figures are based on waterfowl censuses made on the following dates: South Dakota, October 26-27 and November I; 

 Minnesota, November 1 and 2; Illinois, November 1 and 3; Indiana, October 31 and November 3; Missouri, October 31 and 

 November 5; Louisiana, October 31 and November 4. 



11 



