2 BULLETIN 217, U. S. DEPARTMENT OF AGRICULTURE. 
Great Salt Lake was made in the latter part of August, 1913, by S. E. 
Piper, of the Biological Survey. Following this, the writer began 
investigations in July, 1914, continuing the work throughout the 
summer and fall. The present paper discusses the results obtained 
and may be considered a report of progress. It is planned to con- 
tue the investigations during the present year (1915). 
HISTORY. : 
The fact that many ducks were dying around Great Salt Lake was 
noted in the newspapers in Salt Lake City and Ogden in 1908 or 1909, 
but the prevalence of a malady among waterfowl was known many 
years earlier. Fred Hansen, who lives near the mouth of Bear River, | 
says that in October, 1896, two guides brought 400 mallards from ~ 
Klondike (at the mouth of Bear River), part of which were found dead | 
and the rest alive but helpless. Dr. M. R. Stewart, of Salt Lake City, | 
says that in 1902 or 1903 a few birds died on the New State Gun Club | 
grounds at the mouth of the Jordan River. At the mouth of the | 
Weber River birds were occasionally found helpless in the growths of 
“bayonet grass’ during the fall of 1904, and were the subject of much 
speculation among the hunters. Early in the season of 1909 a few 
sick birds were noticed at the mouth of the Jordan River, and in the 
fall others, thought by some to be crippled birds from the fall shoot- 
ing, were reported. 
About July 15, 1910, sick birds appeared at the mouth of the Jordan 
River, and shortly after others were found on the Weber. Later, 
birds were found dying on the great expanse of mud flats and marshes 
built up in the delta of Bear River. Attention was now fully aroused, 
and as the mortality among ducks and other waterfowl increased, 
many theories as to its cause were advanced. The season was ex- 
ceedingly dry, the water in the marshes was low, and the birds died 
in enormous numbers, the trouble continuing on Bear River until 
November. How many wild ducks and other waterfowi perished 
during that year will never be known. Thousands died both on the 
Jordan and the Weber, while on the Bear River marshes the mortality 
was almost incredible. V.T. Davis, in charge of the Bear River Club 
grounds, estimated that 85 per cent of all ducks on the lake died, and 
this statement was fully corroborated by others. Thestench inSeuth 
Bay arising from the dead bodies is said to have been unbearable. 
Mortality among the birds began again in 1911, but was not so dis- 
astrous as during the preceding year. In 1912 few birds died on the 
New State Gun Club grounds, on the Jordan River, as the marshes 
were dramed and water was not admitted until September 20. 
Elsewhere, however, conditions were more serious. At this time the 
trouble was considered contagious, and it was decided to clear the 
marshes of dead birds. On Bear River 44,462 wild ducks (from the 
