F 165 
Methods 
The geological subdivisions of Montana as described in'Waterfowl 
Breeding Conditions in Montana for 1949" (Crissey and others’) were used as the 
basis for the surveys. The survey was begun as soon as it was determined that 
the spring migration was nearing completion. 
The comparative results for 1953, 1954, and 1955 are shown in Tables 
[and II. The effect of early spring precipitation on water conditions at the start 
of the breeding season is illustrated in Table I. The increase in water areas of 
all types over the 1954 conditions was uniform throughout, 
Generally speaking, the spring migration was less than last year in 
the important hi-line production areas east of the divide. Mr. Adams, Refuge 
Manager at Medicine Lake Refuge, says (communication dated June 21, 1955), 
"Spring migration was about 25 to 30 percent less than last year. However, there 
were lots of birds that went right on north without stopping so the number that 
stopped is no indication of the total flight.'' The same trend was noticeable just 
east of the Continental Divide at Freezout Lake, an important stop-over point 
during migration. 
The 1955 breeding population trend census indicate a 17 percent 
decrease from the 1954 level and 15 percent increase over the six-year average 
(Table II). The areas sampled were identical with those flown in previous years 
with the exception of the Great Falls Piedmont, where data were not available for 
the sector from Shelby to the Divide. In the southern unglatiated prairie, a com- 
plete count on one strategically located trend area constitutes the determination. 
of waterfowl conditions. Although the area is large, the waterfowl density is low. 
Stock water reservoirs contain the bulk of the available water. This area hada 
42 percent decrease in waterfowl numbers from the 1955 level and a 29 percent 
decrease from the past three-year average. 
Crissey and others, ''Waterfowl Populations and Breeding Conditions - 
Summer 1949/'Special Scientific Report: Wildlife No. 2, PP. 125-135. 
