58 
Populations 
The number of waterfowl on Whitewater Lake was obtained by aerial 
transects on an average of once every nine days from May 12 to August 1. All 
waterfowl seen along quarter-mile wide transects located‘along section lines were 
counted, giving 25 percent coverage. Weekly air-thrust boat trips around the shore 
of the lake were made from May 7 to September 1 in conjunction with the aerial flights 
to obtain the species composition of the population, areas of utilization, and progress 
of the moult, (See accompanying map for location of air and water routes. ) 
The migrant population reached a peak (15,000) the first week in May. By 
the end of the month the population (3, 000) consisted of the breeding population and 
Summering drakes began arriving the first week in June and 
residual migrants. 
their peak number (70,000) was attained about the end of July. 
The first flightless mallard was observed on June 22. The peak of the 
flightless period for the summering population as a whole was towards the end of 
July. Relatively few birds were still flightless on September 1, but several thousand 
gadwall and many hens of all species had not yet completed the primary feather moult 
on that date. 
Due to space limitations some subjects were only briefly discussed in this 
report, and others that are more involved were necessarily omitted. The findings 
of the entire study will be presented more fully in a forthcoming report. 
