PACIFIC FLYWAY 
The trend in wintering population of ducks in the 
Pacific Flyway has been generally upward during the past 8 years, 
reaching a peak population in January 1959. In some respects 
this is in disagreement with information collected on the 
breeding grounds. For example, the total breeding population 
index for pintail reached a peak in 1956, and the 1959 breeding 
population is at leagt 40 percent below the 1956 level. In view 
of the fact that the Pacific Flyway winters from half to two- 
thirds of the total pintail population, there appears to be a 
discrepancy between the two sets of data. 
There have been increases in population on some of the 
breeding areas supplying the flyway, and decreases in others, i 
There were small increases this year in Alaska, southern Alberta, 
Montana, and Wyoming, and there was a major increase in northern | 
Alberta and the Northwest Territories. ‘There was a corresponding 
major decrease in breeding population in southern Saskatchewan 
and in the Dakotas, overall, the increases were somewhat greater 
than the decreases. As mentioned above, the total breeding 
population of pintail has decreased more than 40 percent from a 
peak population reached three years ago, and mallards have 
decreased more than 20 percent from a peak reached last year. 
Since approximately two-thirds of the total ducks killed in the 
Pacific Flyway is made up of these two species, they are of 
major importance in predicting fall flight in the Flyway. 
For the most part, weather and habitat conditions in 
the breeding range supplying the Pacific Flyway were unfavorable. 
Severe drought sharply reduced production in the important 
breeding areas in southern Alberta and southern Saskatchewan. 
Many of the prairie nesters were obviously displaced northward 
into northern Alberta and the Northwest Territories by this 
drought, but in the north they ran into the latest spring that 
we have recorded since surveys were first initiated in this 
region in 1947. A species which ordinarily nests in pothole 
habitat in the prairies and parklands is not likely to reproduce 
at a normal rate in northern habitat even under the best of con- 
ditions, but when faced with a late spring, which drastically 
reduces the length of an already short breeding season, the 
chances of normal production from prairie nestess in northern 
habitat is very small. A report from a survey crew operating 
in the Northwest Territories indicated that broods were just 
beginning to appear on July 28. During three other years when . 
July surveys were conducted in this area (1951, 1952, and 1954). 
the bulk of the broods from early nesting prairie species were 
158 
