TRAVELS OF WATERFOWL 



of Delta; there is another over Dr. Cadham's garden, and still another not 

 far to the east. It has been so for countless springs — the trails to the north- 

 west cross the lake ridge at the same places year after year. Are these 

 passes cues to orientation, each a step in the long journey from the winter- 

 ing grounds to the breeding marshes far beyond? 



The annual return of the Whistling Swan ° to their April rendezvous, the 

 turning of the wavies at Slack's Bluff, the lakeshore crossings of the Mallard 

 and Pintail are examples of the avian reaction to the pattern of landscape. 

 These movements are not indiscriminate, nor are they directed primarily 

 toward the final destination somewhere beyond. Here is an awareness of 

 special plots of terrain along the way, responses to mere pinpoints on the 

 map of total migratory movements. Here are the resting places and local 

 crossings that are just as incidental, yet just as important, to the over-all jour- 

 ney as a Chicago transfer is to a transcontinental railway passenger. Clearly 

 the Delta Marsh is a key point in the northward travels of a great number of 

 waterfowl. Yet in Manitoba this is but one of many such stopping places. 

 The Libau and Netley marshes at the south end of Lake Winnipeg are hosts 

 to wildfowl each spring. Whitewater Lake, the marshes of Lake Dauphin 

 and Lake Winnipegosis, and the delta of the Saskatchewan are all focal 

 points where ducks, geese, and swans cross or stop for a while on their 

 travels to the breeding grounds. These lakes and marshes are steps along 

 the highway of migration. 



There is a temptation to think of the journeys of waterfowl in terms 

 of such steps. For instance, the Canvasback from Chesapeake Bay has a 

 route marked by important stopping places at Lake Erie, Lake Winnebago 

 in Wisconsin, Lake Christina in Minnesota, and Delta in Manitoba, to name 

 but a few. The pattern is so broad, however, that any discussion would soon 

 become lost in complexities should it begin with this wide aspect of migra- 

 tion. The following chapters of Part I, therefore, consider only the local 

 movements of waterfowl on their home range on the Delta Marsh. 



The Delta Marsh lies at the south end of Lake Manitoba, separated from 

 the lake by a low, narrow, heavily-wooded sand ridge that skirts the shore- 

 line. Behind the ridge, and protected by it from the lake, the marsh spreads 

 south to reach the rich agricultural land of the Portage Plains. East and west 

 the marshland stretches more than twenty miles, and at its deepest point 

 there are five miles between the agricultural prairie and the lake ridge. From 



° See Appendix I for scientific names. 



