
94 
WATERFOWL BREEDING GROUND SURVEY IN WASHINGTON =~ 1950 
Henry A. Hansen, Wendell H. Oliver 
and 
Robert G. Jeffrey 
Introduction 
The 1950 waterfowl breeding ground survey represents the third annual study 
carried on in the State of Washington and is part of an integral study in the Pacific 
Flyway by seven western states, plus British Columbia and Alaska. This study is a 
coordinated project aimed at bringing together all information and research on water- 
fowl of the Pacific Flyway so that management and wise utilization of this great natural 
resource can be most adequately adjusted to serve the sporting desires of the public to 
whom it belongs. 
Method of Sampling 
For purposes of study, the State of Washingtonis divided into three waterfowl 
study areas. These areas are; Western, Central, and Eastern Washington. All 
primaxy breeding grounds in each area are included in the study. In Eastern Wash- 
ington there are six major waterfowl breeding areas consisting of potholes and lakes 
which produce approximately 85 percent of the waterfowl in the State. In Central 
Washington there are two major waterfowl breeding areas which are divided into 
habitat units and which produce approximately 8 percent of the waterfowl in the State. 
The remaining waterfowl are produced in the thinly distributed breeding ground 
habitat in Western Washington, 
The 1950 breeding ground survey of Eastern Washington was conducted for 
the fourth consecutive year under similar conditions and largely by the same personnel, 
Some refinements in censusing techniques have been made each year so that the data 
for 1950 are more complete and accurate than heretofore. Aerial habitat mapping and 
surveys facilitated the ground work enough that more expansive coverage of the total 
nesting habitat was possible. The production inventory started on the first of June and 
extended uninterrupted through the middle of August. H. A. Hansen and C. F. Yocom, 
of the Washington State Game Department, conducted the major part of the ground 
inventory. Homer Ford, summer student employed at the Turnbull National Wildlife 
Refuge, assisted in gathering data used from the Refuge. Kenneth Gehrman and 
Stanley Harris, graduate students in game management at Washington State College, 
gathered data used from the Medical Lake area of Spokane county and the Moses Lake 
area of Grant county during their research studies in the respective areas. Hansen 
and L..A Wadkins, of the Washington State Game Department, made the aerial surveys 
at regular intervals during the summer. 
Random ground transects were run in all areas except one. In the potholes 
region south of Moses Lake in the Columbia Basin, an attempt was made to geta 
complete coverage of the 889 individual potholes. Although many of the ponds were 
dry before the summer inventory was completed, itis estimated that a 90 percent 
coverage of the potholes area was made. The random samples of the remaining five 
areas are representative of the entire waterfowl habitat of those areas. 
In Central Washington a variety of ground sampling methods were used by 
Wendell %. Oliver. In South Central breeding units, measured linear samples of one 
mile, or equal portions of a mile, totaled 143 miles in sampling 1, 163 miles of linear 
habitat (creeks, vivers, irrigation ditches, and drain ditches). All counts of swamps, 
lakes, and ponds in the units were assumed complete. Average waterfowl population 
