2 BULLETIN 793^ U. S. DfiMliT^lMtElsrT OF AGEICULTURE. 



the following pages. During the course of the work the Bureau of 

 Chemistry has cooperated in making analyses to determine the 

 presence of lead in jDortions of the viscera of ajffected birds. 



HISTORY. 



At various times during past years there has been discussion in 

 sporting magazines regarding the presence of shot in the stomachs of 

 wild ducks. More recently attention was called to lead poisoning 

 in ducks by J. H. Bowles^ in 1908. On the Nisqually Flats, a large 

 marsh area in the Puget Sound district, Washington, a number of 

 mallards had been found sick or dead. Examination of three of these 

 revealed a quantity of shot still held in the gizzard. The Nisqually 

 Flats have been famous ducking grounds since early settlement in the 

 State, so that it may be supposed that shot are present in the mud in 

 abundance. 



Lead poisoning was reported in 1908, also, among canvas-back 

 ducks on Lake Surprise, Tex., and an account of it was published by 

 W. L. McAtee, of the Biological Survey.^ Lead poisoning in this 

 locality apparently had been known for several years. It was stated 

 that canvas-backs resorted to Lake Surprise in November each year, 

 and affected birds appeared in the rushes along shore about the first 

 of January, while as the season advanced these sick birds died and 

 disappeared. From all accounts, no other species of ducks were 

 affected here. 



Examination of several whistling swans from Back Bay, Va., 

 sent to the Biological Survey during January, 1915, showed that 

 these birds were suffering from lead poisoning, as from 22 to 45 shot 

 pellets were found in the gizzard of each. On inquiry it was learned 

 that sick swans were found in January every year, and that the 

 trouble among them continued until March. The malady, known 

 locally as the " keuk," was said to affect canvas-backs and other ducks 

 and geese as well as swans. 



During the summers" of 1915 and 1916, while working in the 

 marshes formed in the Bear River Delta at the northern end of Great 

 Salt Lake, Utah, the writer handled many ducks suffering from lead 

 poisoning. Here the species affected were mallards and pintails, the 

 majority being males. Birds sick from poisoning were found from 

 June to September, and the total number that died was considerable, 

 though insignificant when compared with the numbers destroyed 

 here by other diseases. 



Eeports of sick ducks in other localities in the United States seem 

 to indicate lead poisoning as the causative agent, but material has 

 not as yet been available to substantiate this. It is believed that the 

 trouble is more or less prevalent throughout the country. 



lAuk, XXV, pp. 312-313, 1908. ^ Idem, p. 472, 1908. 



