MIGRATIONS OF WATERFOWL 



6,000 to 8,000 feet. These were considered necessary because an RCAF 

 Mitchell Bomber flew into a flock, damaging the aircraft." 



This is a part of a migration which Cooch (1955) traced in nonstop 

 flight from James Bay, Ontario, to Louisiana, a 1,700 mile trip which con- 

 sumed about 60 hours. Those electing to go above the overcast would be 

 aware of the direction and velocity of their travel by reference to the cloud 

 below. In short trips over cloud, the course of travel would not be greatly 

 altered; but if they went many miles with cloud as reference, the birds must 

 become geographically displaced because the clouds themselves are mov- 

 ing. In this instance the weather records show that the sky was clear over 

 Ohio and Lake Erie, so that the geese had not more than 200 miles of cloud 

 ahead. 



Captain Earl D. Sherman, T.C.A. pilot, tells me that several times he has 

 observed geese flying above cloud and that late in 1952 a companion pilot, 

 Captain Don Patry, saw thirteen or fourteen Canada Geese flying south at 

 an elevation of 7,000 feet between cloud layers near North Bay, Ontario. 

 In this case clear sky was in sight to the north, but not to the south. 

 R. C. Hanson, of the U.S. Fish and Wildlife Service, wrote me that at about 

 10 a.m. on March 12, 1953, he saw Mallards and Pintails migrating over a 

 layer of cloud that was 300 feet above the ground at the bottom and 1,000 

 feet above at the top. The ducks were flying northwest up the Mississippi 

 Valley between Burlington and Muscatine, Iowa. Alvin P. Noltemaier, also 

 of the Fish and Wildlife Service, has told me that in the process of herding 

 Canada Geese away from concentration areas with an aircraft, he has seen 

 them rise to disappear into the overcast above. 



Such abundant evidence of above-cloud travel makes it clear that water- 

 fowl do at times migrate without visual reference to the earth and that, as 

 in the observation of Captain Patry, they may move between cloud layers 

 without reference to either earthly or celestial guides. We must not con- 

 clude from this, however, that such individuals are possessed of the ability 

 to navigate precisely overland without reference to it. If the birds moved 

 with the weather, as is usual in migration, their displacement by movement 

 relative to cloud might not be great. But migration, we know, does not 

 always carry the travelers unerringly to their destinations, and above-cloud 

 passage may be one cause of displaced migrants. 



Though both spring and fall migrations of waterfowl generally occur 

 with a favoring wind, they do not always do so. The Lesser Snow and Blue 

 Geese, going to the northeast, are often seen migrating with a cross wind 



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