I'd BULLETIN 672, U. S. DEPARTMENT OP AGRICULTURE. 



supply attracting the ducks apparently is found in the seed heads of 

 the tules or rushes and other similar growth found with them that 

 cover great areas. Draining the marshes at this season should not 

 affect these growths, as the water table will not be lowered far 

 enough to deprive them entirely of water. It is true that it will 

 destroy the leaves and plants of the potato moss (Potamogeton 

 pedinatus), as this is entirely an aquatic growth. Tubers of this plant 

 will often remain, however, and it is largely upon these that the ducks 

 feed. In normal circumstances, where water stands in the marshes 

 all summer, hunters usually attract the ducks to certain parts of the 

 marsh by baiting with grain. 



At the mouth of the Weber River it may be possible to remedy 

 some of the existing conditions by improved drainage. The North 

 Channel in summer is marked by shallow pools with very slight 

 current, while at either side are smaller bodies of water entirely shut 

 off. It is in these that the ducks die. The South Channel has 

 higher banks and runs directly through the flats ; in summer it carries 

 drainage from the irrigation canals. As has been stated, no sick 

 ducks are found along its course. Ditching the course of the North 

 Channel and drawing the water from the shallow pools might aid 

 conditions here, as it would leave less of the dangerous area for 

 birds to use. 



On Bear River it is not practicable to use these methods of drain- 

 age, because the areas involved are too great and because the land 

 is too near the level of the lake to permit concentrating the water 

 in canals. 



CURE OF SICK BIRDS. 



Birds with the duck sickness recover in a short time (unless too 

 far gone) when placed on water that is moderately fresh. A large 

 number of ducks were cured by this means at the field laboratory 

 on Bear River, and it has been proved that recovery is permanent. 

 In past years men have been employed to gather and bury the dead 

 birds on the marshes. If they were set to work gathering the sick 

 birds and bringing them in, a large number of ducks could be saved at 

 comparatively small expense. This method is one that is strongly 

 recommended for bettering conditions among the waterfowl in severe 

 outbreaks in Utah and elsewhere. 



In the course of the present investigation 1,211 individuals belong- 

 ing to the seven species of ducks most severely affected were treated 

 in this manner. Of these 284 died and 927 recovered. Among the 

 ducks treated were a large number of very weak birds that were 

 so far along that ordinarily they would have been disregarded. 

 Eliminating these, the ratio of recovery was about 90 per cent of 

 those brought in. Table I shows the number and percentage of 

 recoveries and deaths among individuals treated in the seven impor- 

 tant species affected. 



