Foreword 
An extensive drought throughout the glaciated prairie pothole region during the late 1950's 
and early 1960's focused attention on the status of the canvasback (Aythya valisineria). The 
impact of drought, in combination with habitat destruction, changing land use practices, 
and other factors resulted in reduced annual production. Special restrictive hunting regulations 
during that period provided additional protection to canvasbacks and redheads (A, 
americana). 
Initiation of wetland preservation programs in the United States and Canada in 1960 created 
impetus for research on waterfowl breeding habitat. The U.S. Fish and Wildlife Service began 
a canvasback research project in 1961 to determine the impact of habitat loss and provide 
guidelines for habitat programs. 
Jerome H. Stoudt participated in the cooperative United States and Canada waterfowl 
breeding ground survey from its inception in 1947. He served as one of the early flyway biol- 
ogists and later as a research biologist. Because of his previous work on the Redvers study 
area in Saskatchewan and his long-standing personal interest in canvasbacks, he was chosen 
to serve as project leader to initiate this research effort, Throughout the course of this study, 
his concern for canvasbacks and his commitment to improving their status resulted in a wider 
appreciation of the multitude of problems confronting this species. 
The Minnedosa study area was established in 1961 in the aspen parklands near Minnedosa 
in southwestern Manitoba. Historical information indicated that the densities of breeding 
canvasbacks were highest within the Minnedosa District. The study area contains above- 
average waterfowl habitat in terms of density and permanence of wetlands and includes 
some of the most productive natural waterfowl habitat in North America. For this reason, 
the Minnedosa area has been the setting for a series of intensive and extensive waterfowl 
investigations since the late 1940's. 
As a wildlife biologist, Jerry pursued his studies vigorously by making detailed observa- 
tions of canvasbacks, their life history, habitat requirements, and population status. He began 
this important work in the early 1950’s, when wildlife as a science was in its infancy. The 
contents of this publication and its conclusions reflect the careful discrimination of an 
experienced field biologist. Jerry's observations over a 12-year period (1961-72) have provided 
valuable insight into the species biology and management potential of the canvasback. Current 
research on canvasbacks has elaborated on Jerry's earlier work and is designed to investigate 
key factors influencing annual productivity. 
This publication is a testimonial to Jerry Stoudt for his personal and professional dedication 
to waterfowl and their future management in North America. Few among us have logged 
as many hours afield as Jerry did, or accumulated as much knowledge and experience, in 
a career that spanned 35 years with the U.S. Fish and Wildlife Service. In my view, this 
contribution is a tribute to Jerry's many achievements as a biologist and to his personal con- 
cern for the well-being of the canvasback. 
Harvey K. Nelson, Regional Director 
U.S. Fish and Wildlife Service 
Minneapolis, Minnesota 
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