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WATERFOWL BREEDING GROUND SURVEY IN SOUTH DAKOTA 
Ray Murdy and Maurice Anderson 
Introduction 
This report presents the findings of waterfowl breeding ground surveys in 
South Dakota during 1953, It covers the annual May inventory of the breeding 
population and a brood survey which was initiated this year to estimate brood 
production by mid-July. The information presented is a summary of that which 
was submitted to the U. S. Fish and Wildlife Service for use by the Director's 
Waterfowl Advisory Committee. 
Breeding Population Survey 
Methods of Survey 
The breeding population survey consisted of two phases, a State-wide aerial 
survey and a ground survey in the better-than-average habitat in most the counties. 
The aerial survey provided estimates of the State-wide duck and water area densities 
and distribution, The ground survey contributed: 1) a correction factor, based on 
observed sex ratios, which was used to correct the aerially-observed duck densities 
to compensate for unobserved females on nests; 2) species composition data which 
were also used to estimate species densities; and 3) an estimate of the relative coot 
density. These aerial and ground surveys were made concurrently during the period 
from May 12 through May 18. Descriptions of these methods of survey appear below: 
Aerial Survey 
The aerial survey consisted of 16 east-west-1/4-mile wide transects spaced 
12 miles apart, north to south. These transects totaled 5,720 linear miles, or 
1, 430 Square miles, and were flown by 3 pilot-observer teams. 
Ground Survey 
The ground survey consisted of transects in 50 counties, run by 37 State game 
wardens. These transects totaled 2,232 linear miles of 1/4-mile ground transects, 
or 558 square miles of coverage. 
Waterfowl Densities 
A total of 17,435 ducks were observed on the 1,430 square miles of aerial 
transects, indicating an average State-wide observed density of 12.19 ducks per 
Square mile. The correction factor for hens on nests, based on 8,419 males and 
6,193 females observed on ground transects was 1.12. Correction of the observed 
density of 12.19 ducks per square mile by the correction factor of 1,12 indicates 
an average State-wide duck density of 13.65 birds per square mile, This is a 
minimum density because a considerable but undetermined portion of the ducks on 
aerial transects are not observed. From the density of 13.65 ducks per square 
mile and the 74,778 square miles in the State (excluding the Black Hills) the 1953 
minimum breeding population was estimated to be 1,021,000 ducks. 
