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temporary areas, to marshy ones of several square miles in extent. There are some 
lakes that are highly alkaline and with relatively sparse cover. Nearly every transect 
mile includes or borders on a water area until the usual summer dry-up of July and 
August. 
In recording data, the figures for pairs include lone males assumed to be 
territorial and representing pairs. In total numbers, however, lone males count as 
Singles. 
A 10-square-mile sample of Route B was used during the three seasons 
covered by this report as a basis for the July brood counts that were sent to the U. 5S, 
Fish and Wildlife Service Regional Office. 
Weather and Water Conditions 
Generally, the Nebraska Sandhills are in a region of fluctuating water 
conditions during each breeding season and from year to year, The frequency of 
local thunder storms and the areas covered by them influences the water supply and 
the movements of the ducks. During the three seasons under discussion water levels 
remained up until mid-June. During the summer of 1949 the exception for the three 
seasons, levels remained up all summer. This is readily explained by the great 
amount of 1948-1949 winter snow and the spring rains of 1949. In the eastern Sand- 
hills excessive amounts of water prevented travel in June over many areas. Conditions 
in 1950 in the western Sandhills were similar to those wf 1948, near drought in some 
spots and good water levels in others, with the usual mid-summer drying. Conditions 
in the eastern part were much better but without the extremely high levels as in 1949. 
The tables to be discussed indicate a trend in the observed duck production that is 
correlated with the changes in weather and water conditions. 
Data Collected 
June Counts 
Preliminary counts in 1948 indicated (1) that prior to mid-June a high percent 
of the ducks observed were migrants and (2) that numbers leveled off to what could be 
considered as the breeding population by that time. Data from the June counts (Table 1) 
indicate for the western Sandhills an increase in 1949 of breeding pairs and a decrease 
in 1950. The data for the eastern Sandhills is incomplete since no comparable figures 
are available for June 1949. Itis to be noted that the number of ducks observed per 
square mile does not follow the same trend as does the number of:pairs. It seems that 
there may be a considerable number of non-breeders in the summer population. 
The aerial counts made by Vance and Edmunds along the Lazy S Route of 
29 1/3 square miles showed the following results: June 10, 1949 - 644 ducks; June 13, 
1950, - 641 ducks; amounting to an observed 21 birds per square mile of sample, or, 
no change indicated in observed numbers. 
July Brood Counts 
It appears from brood counts (Table 2) that the fluctuations of the trend in 
brood occurrence, upward in 1949 and downward in 1950, were less pronounced in the 
eastern Sandhills where water conditions|were more stable than they were in the 
western areas where noticeable fluctuations occurred during the three-season period. 
The average size of broods observed (Table 2, Young Per Brood) appears 
not to have varied much over the three-season period, but to have been slightly higher 
