
132 
WATERFOWL BREEDING GROUND SURVEY IN WASHINGTON, 1955 
Robert G. Jeffrey and Wendell H. Oliver 
Introduction 
Personnel contributing field data to this report are as follows: Homer 
I. Brent, Donald S. Galbreath, Stanley E. Guenther, Russell W. Hupe, Robert G. 
Jeffrey, Wendell H. Oliver, Carl V. Swanson and Fred C. Zwickel, all biologists 
of the Washington State Game Department, and Wayne Hanson, Wildlife Technician, 
Hanford AEC Project, Richland, Washington. 
The 1955 waterfowl breeding ground survey is the ninth such inventory 
carried out in Washington. Field data was collected under the supervision of the 
two waterfowl biologists by resident biologists in each of the various game districts 
of the State. 
The waterfowl breeding habitat of eastern Washington is composed mostly 
of potholes, and produces about 70 percent of the ducks raised in the State. Here, 
the productivity is highly dependent upon adequate winter and spring precipitation. 
Central Washington, including the Columbia Basin, contains most of the 
irrigated lands of the State, and the bulk of its duck production is from such habitat. 
This region produced about 23 percent of the duck crop in 1955. 
Most of the duck production in western Washington originates in the lower 
valleys and flats of the many river systems. The breeding habitat is extensive, but 
much lower in productivity than the areas east of the Cascade Mountains. The 
region accounted for about seven percent of this year's duck production. 
Method of Sampling 
It has been determined from extensive aerial counts in eastern Washington 
that under optimum water conditions approximately 10,000 potholes exist. This 
number provides a base for compiling the waterfowl production index. Standard 
one-fourth mile ground transects have been set up to include about five percent of 
the annual breeding population of this region. 
A slightly different method is applied to the irrigated areas of central | 
Washington. With the variety of habitat encountered here, it was found necessary 
to make a complete survey of randomly chosen square-mile blocks of this land. 
These sample sections amounted to about a three percent sample in the Columbia 
and Yakima basin irrigation projects in 1955. . 
