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In western Washington heavy cover and the diversity of habitat preclude 
the use of the standard transect. The production index for this region is based 
upon habitat-type productivity studies made in 1948 and 1949, and upon approxi- 
mations of the amount of each habitat type, which were made from the best maps 
available. The production index thus arrived at has been adjusted yearly by means 
of a brood trend census on established plots. 
Weather and Water Conditions 
The growth of cover and waterfowl breeding activities were considerably 
retarded over the entire State during the spring of 1955. Following the coldest 
spring on record, periods of hot, dry weather rapidly reduced the amount of pothole 
habitat. Although the eastern Washington pothole index showed an eight percent 
increase during the May survey, this increase occurred in the yellow pine zone of 
northeastern Washington, a breeding area of lesser importance. Potholes in the 
remaining areas continued to shrink despite increased seasonal rainfall, and by 
mid-July only 50 percent of the May survey water remained. Floods and hail 
storms caused some local damage to nesting and broods. Excellent water conditions 
prevailed in central Washington irrigation areas, and in western Washington 
throughout the summer. 
Breeding Population Trends and Brood Data 
The decrease of the total breeding population east of the Cascades was 
negligible in 1955. Although the decline occurred largely among the more import- 
ant duck species, ensuing production made some significant changes. The teal 
group, the diving ducks, gadwall and shoveler, all present in increased numbers 
on the breeding grounds, showed decreases in relative production. By contrast, 
mallard and baldpate both showed a decrease in the breeding population, but in- 
creased in production in 1955. Relative production gains generally occurred 
among early nesting species, the species utilizing the northern timbered habitat 
and those using the irrigation areas. The gradual drying of the open country 
potholes is reflected in the production decreases in species favoring these areas. 
The Yakima River basin supported an average of 12.5 breeding water- 
fowl per square mile in 1955. In the Columbia Basin, where the section-sample 
method was employed for the first time, an average of 1.9 waterfowl per square 
mile was found. Increased use is expected as the habitat improves and becomes 
more established. 
East of the Cascades the nesting season was approximately three weeks 
late, with the peak of the hatch occurring during the last week of June. Although 
a late nesting season was also in evidence in 1954, 95 percent of the hatch was 
out by July 1, while this year only 77 percent of the hatch was complete prior to 
that date. The belated appearance of mallard broods characterized the 1955 
season throughout the State. 
