WATERFORL BREEDS GROUND SURVEY IN SOUTH TLAROTA, 1949 
J. Wa Kimball, Bernard A. Nelson and Ray Murdy 
Totraduction 
In 1948 a waterfowl tresling ground survsy was initiated in the north- 
sagtern portion of South Dakota. Most of the field werk was done by Steta 
Bama wardens, The msthod of survay was the standardized fround transect 
developed by the U. &. Fish and Wildlife Sarvice for uss on the prairis brasd- 
ing grounds, Thirty-one transscts ware run in 17 counties between May 24 and 
30, sampling an area of 226 square miles. The transects wera re-run in Juna, 
but advanced yegetativs growth reduced the accuracy of the counts made on this 
follow-up survey. 
In 1949 these transects wears run approximately ths same datea as in 1944, 
New transects were astablished in & additional counties. The June follow-up 
survey was onitted. Additional data were kindly submitted by J. H, Stoudt, 
U. 5. Fish and Wildlife Servics flyway biolorist, for four transects he ran 
in Day, Marshall, Merherson, and Brown Gountias, The counties in which tran- 
sects wars run ares shown in Firure l. 
Tha data obtained by this survey pertain solvly ta population and habitet 
conditions as thay existed in late Vay. No information was obtained regarding 
Tenroductive success, 
This report contains the results of the 1949 breeding ground surysy. 
hoere the data permit, comparisons ars made between 1948 conditions and thoss 
that existed during the current breasding season. 
Density of Areedins Population 
The data parteining to the density of the breeding waterfowl population 
afte tabulctsd in Tables 1 and 2. Table 1 contains only the figures for thoge 
transects that were run in toth 948 and 1949, and a comparison is made between 
the two years, Table 2 is conecemed only with these transects wiich were run 
for the first time in 1949 and se cannot be used in = comparison with 1948 
figures, 
The area of this year's sample was 462 square miles of which 284.4 squares 
miles represent transects that were run in 1948 and 177.3 square miles of new 
transects run for the first time thie year. Ths: total number of pairs of 
breeding birds obsaryed on all the transects was 7,231, indicating an averages 
density for ths total sampls of 15.7 pairs per square mils. {Lone draksa wer 
considered to represent pairs.} The ranges in density by counties was great, 
transects in Beadls, Hanson, Spink, Walworth, Laks and Miner countiss ayeraz- 
ing less than five pairs per square mile while those in Marshall, Pay, MePherson, 
Roberts, and Grant counties all averaged more then 25 pairs per square mils, 
Thess values may not be rapressntativs enouch to estimate the everag?: densi ty 
of breeding dueks in #ath county, or for the arga as a thole with preat sccuracy, 
because it is not known to what extent the transects ars Trepresentativa of tha 
conditions in the counties they represent. When taken as a whole, the figuras 
are of talus in determining trends in weterfowl density. 
170 
