MORTALITY AMONG WATERFOWL. 3 



records of V. T. Davis) were gathered and buried between August 22 

 and September 21, and about 30,000 birds are said to have been 

 picked up on the Weber River. From the nature of the country this 

 can not represent more than 20 per cent of the total number of birds 

 that died, and probably not more than 10 per cent. Conditions in 

 1913 were somewhat improved, but still great numbers died. Dur- 

 ing the past year fewer birds perished, though the mortality was 

 great enough to cause alarm. 



In the southern San Joaquin Valley, Cal., many birds have died 

 on Soleta, Goose, Buena Vista, and Tulare Lakes since 1909. At 

 present the two lakes first named are dry and the third contains an 

 abundance of fresh water. On Tulare Lake, however, conditions 

 are unchanged. In November, 1914, it was estimated by Tipton 

 Matthews, deputy game warden of Kern County, and the writer that 

 at least 15,000 birds had perished there during the preceding summer. 

 Mr. Matthews stated that he has known of sick birds around Goose 

 Lake and at Browns Knolls (Widgeon Gun Club grounds) for at 

 least 20 years when the water was low hi summer. Goose Lake is 

 now dry, and as the water at Browns Knolls is kept fresh by artesian 

 wells there is little trouble. 



In June, 1891, Dr. A. K. Fisher, of the Biological Survey, noted 

 large numbers of eared grebes and spoonbills dead around the shore 

 of Owens Lake, Cal., and estimated the number of dead grebes at 

 35,000.! From the 12th to the 14th of November, 1914, the writer 

 found many dead birds of these same species in this locality, and 

 he was informed that this was an annual occurrence. 



TERRITORY COVERED IN INVESTIGATIONS. 



On July 12, 1914, work was begun in the Salt Lake Basin and con- 

 tinued until October 30. Investigations were made at the mouths 

 of the Jordan, Weber, and Bear Rivers, the main areas affected (see 

 Pis. I and III). Because of the large area involved, diversified condi- 

 tions, and convenience of access to the marshes, most of the experi- 

 mental work was carried on at the mouth of Bear River. In addi- 

 tion to the localities mentioned, conditions were studied at Willard 

 Spur, Promontory Point on Great Salt Lake, and Locomotive Springs 

 near Kelton. 



From November 3 to 1 1 Tulare Lake, in California, was visited, in 

 order to investigate the mortality in that region, and conditions at 

 Owens Lake in the same State were studied from November 12 to 14. 



At the mouth of Bear River, in Utah, quarters were furnished at 

 the Duckville Gun Club, and thanks are due the officers and members 

 of the club for assistance and facilities extended. Much assistance 

 was rendered by A. P. Bigelow, of Ogden, and L. B. McCornick, of 



1 North American Fauna No. 7, 1893, p. 12-13. 



