LIFE HISTORIES OF NORTH AMERICAN WILD FOWL. 43 



dead ducks were well lilled with the })ellets which had })rohably been 

 picked up by mistake for graA'el. 



One stomach cojilaini-d 19 shot, one 22, and the other 27. The Uirj^'e intestiuo 

 was heavily leaded and seemed contracted, while the lining of the stomach could be 

 easily scaled off in quite large crisp pieces. The gastric juices had evidently worked 

 ou the allot to some extent, as most of them were considerably worn and had taken 

 various shapes. 



Dr. Alexander Wetmore (1919) has published an interesting paper 

 on this subject, based on investigations made near the mouth of 

 Bear River, Utah, in 1915 and 1916, in which he shows that lead 

 poisoning is a real cause of mortality among this and other sp(!cies 

 of ducks, where these birds have been feeding on grounds which have 

 been shot over for many years. No practicable remedy has been 

 suggested. 



Doctor Wetmore (1915 and 1918) has published two other papers, 

 based on liis extensive investigations in Utah, from which it ap])ears 

 that the great mortality among waterfowl around Great Salt Lake 

 is due largely, if not wholly to alkaline poisoning. Countless thou- 

 sands of ducks and other waterfowl have perished v.ithin recent years 

 in this and other similar localities, apparently from disease. lie 

 explains the cause very well as follows: 



After June 15, as the sprbig waters in Bear River recede, great expanses ol mud 

 flat are laid bare in the sun. Surface evaporation and capillary attraction rapidly 

 draw the salts held in solution in the mud to the surface and tliere concentrate them. 

 As the mud becomes drier these concentrates are visible as a white deposit or scale 

 (efflorescence). This in many cases is exposed only an iiich or so above the surround- 

 ing water level. In the large bays strong winds bank up tlie water and blow it 

 across these drying flats. As it advances it takes rapidly into solution the soluble 

 salts, largely sodium chloride, but containing calcium and magnesiiun cliloride also. 

 This inflow oi water carries with it quantities of seeds and myriads of bei.'iles, bugs, 

 and spiders, waslied out of crevices and holes in the dried and cracking soil. The 

 ducks (;onie in eagerly to feed on this ciisily secured food and work rapidly along at 

 the front of the advancing water, each bird hurrying to get his fill. Many individ- 

 uals in this way secure a sufficient quantity of these poisons to render them helpless. 

 As the water recedes again small pools are left in shallow depressions, and other ducks 

 and shore birds feeding in these are affected. 



The only remedy suggested is to suj)ply the birds with a sufficient 

 quantity of fresh water, under which treatment tiiey recover. 



BrJiamor. — The wild mallard is an active, wary bird, well worthy 

 of the prominent place it hohls among the game birds of the world, 

 ft springs from the Avater, at a single bound, straight up into the air 

 for several yards and, when clear of all siuTounding reeds, bushes or 

 trees, flies directly away in a swift, strong and well-sustained (light. 

 Several loud quacks are usually uttered as the bird springs into the 

 air. The mallard, especially the femah^, is a noisy bird on its feeding 

 grounds, the loud fiuacking notes, suggesting familiar barnyard sounds. 



