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Pius TIN ‘OF THE 
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¥, Contribution from the Bureau of Biological Survey, Henry W. Henshaw, Chief. 
May 26, 1915. 
MORTALITY AMONG WATERFOWL AROUND 
GREAT SALT LAKE, UTAH. 
. (PRELIMINARY REPORT.) 
By ALEX Wermorse, Assistant Biologist. 
INTRODUCTION. 
It is widely known that in recent years vast numbers of waterfowl 
frequenting the marshes along the eastern shore of Great Sait Lake, 
Utah, have died, apparently from disease. Untold thousands of wild 
ducks, snipe, sandpipers, and other birds of less economic value have 
perished. Nor is the effect of this mortality confined to the region 
in question. While countless numbers of waterfowl have perished in 
comparatively small areas, the effect upon the abundance of these 
birds in other regions is widespread. In the marshes around Great 
Salt Lake are bred annually great numbers of waterfowl, and hordes 
from more northern regions migrate through in spring and fall. 
These breeding and migrant birds form an important percentage of 
those migrating or wintering farther south, and serious diminution 
of their numbers in the affected localities will be felt heavily in other 
regions. The question of the causes of this mortality and possible 
measures for its prevention are therefore of widespread interest and 
importance. 
it is to be noted that a similar mortality occurs in other localities, 
as Tulare and Owens Lakes, Cal., where for several years thousands of 
birds have perished annually. Reports not yet fully investigated 
have been received from other districts, and apparently the trouble 
may occur anywhere in the West under similar conditions. 
Early in the investigations a number of dead ducks sent to the 
Biological Survey were turned over to the Bureau of Animal Industry 
for examination, the results of which are discussed on another page. 
Later, agents of that bureau made brief field inquiries into the mor- 
tality in Utah. A preliminary examination of the conditions around 
Note.—This bulletin is a report of progress in investigating the causes of mortality among ducks and 
other waterfowl in marshes about Great Salt Lake, Utah. Itis for the information of sportsmen and others 
Se 5s ee 
interested in game birds. 
87711°—Bull. 217—15 
