BULLETIN 



No. 217 



Contribution from the Bureau or Biological Survey, Henry W. Henshaw, Chief 



May 26, 1915. 



MORTALITY AMONG WATERFOWL AROUND 

 GREAT SALT LAKE, UTAH. 



(PRELIMINARY REPORT.) 



By Alex Wetmore, Assistant Biologist. 

 INTRODUCTION. 



It is widely known that in recent years vast numbers of waterfowl 

 frequenting the marshes along the eastern shore of Great Salt 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. It is for the information of sportsmen and others 

 interested in game birds. 



87711°— Bull. 217—15 



