TRAVELS OF WATERFOWL 



large bays. About 3 p.m. there began a flight of Canvasback that moved 

 over us in an apparently endless stream until we departed at dusk. The wind 

 was just south of west, and the birds came out of the northeast, alighting in 

 the bay west of us to feed on the abundant beds of sago pondweed. It hap- 

 pened that we had but half a dozen shells apiece ; hence it was with keen 

 anticipation that Ward returned to the spot the following afternoon, well 

 equipped for a fine shoot. But the wind had changed and, although he re- 

 mained until dusk, no birds crossed the narrows. As he paddled home, Pete 

 found the west bay again littered with Canvasback which apparently had 

 arrived by some other route. 



Some passes are very narrow. The crossing of ducks just mentioned was 

 confined to a span hardly more than 30 yards wide. At one narrow gap the 

 lane of flight is not more than 25 yards across, the width of the waterway. 

 I know of several other passes that are similarly restricted. On the other 

 hand, where a long thin strip of land separates two large lakes, the passes 

 may be very wide. 



Many of the passes are used by all species of ducks. Some, however, are 

 followed frequently by one species and seldom used by others. I believe this 

 is simply because different kinds move to different places to loaf and feed. 

 Canvasbacks that rest daily on the open water of Cadham Bay fly east to 

 their feeding waters over a route that is seldom followed by Mallards. Mal- 

 lards crossing the marsh to stubble fields take flight lines rarely used by 

 Canvasbacks. Several passes at Delta are used heavily only in late autumn, 

 when Lesser Scaup crowd the marsh. 



Since the marsh is a maze of scattered potholes, channels, bays, and 

 sloughs, a flight of any distance must take a duck over a number of passes. 

 The pass itself is merely a step in the flight trail. In general, traffic from one 

 pass to another follows well-defined routes. Where ducks cross large bodies 



