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AVERAGE TEMPERATURE 

 MINIMUM TEMPERATURE 



0-1 1 1 1 1 1 1 1 1 1 1 1 r 



15 17 19 21 23 25 27 29 31 2 4 6 8 10 

 OCTOBER NOVEMBER 



Fig. 7.— The minimum and average daily temperatures from October 15 through November 10, 1955, at Winnipeg, Manitoba, 

 Canada. 



flight, observations indicated that the increase was 

 small compared with that in the western and central 

 regions of the flyway. 



Speed of Flight. —The mass waterfowl migration of 

 1955 moved with unusual rapidity from the Great F'lains 

 of Canada to the marshes of Louisiana. The exodus 

 started from southern Alberta and Saskatchewan on 

 October 31 and from Manitoba on November 1. The 

 flight in the western sector of the Great Plains moved 

 ahead of the flight in the eastern sector. 



By early morning of November 1, the flight was in 

 full force tiirough North Dakota and along the northern 

 part of the Missouri River in South Dakota. As interpo- 

 lated from field reports, part of the flight was moving in 

 front of and part was moving bciiind the cold front 

 progressing southeastward through South Dakota and 

 North Dakota, fig. 4. Farther east, in west-central 

 Minnesota, the flight appeared near Detroit Lakes at 

 11:00 A.M. and, at other points, from 1:00 P.M. through 

 the afternoon. In east-central South Dakota it was first 



19 



