WILD DUCKS OF THE BEAR RIVER MARSHES, UTAH. 11 



weed (Potamogeton pectinatus), known familiarly to hunters as 

 " potato moss " or " duck moss," is the dominant plant of the open 

 bays and sloughs, where it grows submerged in the water. This 

 plant springs from a tuber buried from a few inches to a foot or 

 more in the mud. It appears in the bays in abundance during 

 the last part of May and by the end of June has filled the greater 

 part of the open water with dense growth. During July it produces 

 a mass of hard seeds, and then a great deal of it dies down in the 

 bays at the mouth of the river and breaks off at the roots, to drift 

 out into the lake and leave the bays bare open expanses with a 

 smooth mud bottom. In other places, as the Chesapeake Bay, the 

 summer growth sinks to the bottom and remains throughout the 

 fall. The sago pondweed is one of the best of known duck foods, 

 as all parts of the plant, the tubers, stems, leaves, and seeds are 

 palatable and are eagerly sought as food by wild ducks. The ducks 

 dig great " duck holes " in the mud of the open bay from 1 to 20 

 or 30 feet wide and from a few inches to a foot deep, in search of 

 the succulent tubers. These roots furnish a great part of the food 

 of the. pintails and mallards on the marsh in fall and are eaten 

 eagerly by most if not all of the other ducks. In summer and early 

 fall the stems and leaves also are sought. 



Sago pondweed seems to. be strongly resistant to the action of al- 

 kalis, as it will grow in areas where the soil is impregnated with 

 salts, though in such places the growth of the plant may be some- 

 what stunted. This plant also thrives in the fresher water of channels 

 and sloughs, and here makes a very heavy growth. Its tubers are 

 frequently as large as a kernel of "corn, and, if the sprout is discarded, 

 they have a pleasant, nutlike flavor. They persist even during years 

 when the bays are dry during summer, and so insure a supply of this 

 food the following year. After the plants have died down in the 

 lower bay the seeds still remain, and often are- washed up in long 

 windrows on the mud bars. Green-winged teals as well as other 

 ducks are fond of these, and in fact hardly a duck stomach was 

 examined in late summer and fall that did not contain a few of them. 

 Bits of gravel or other hard particles are essential to digestion of 

 food in ducks, but in alluvial deposits like those at the mouth of 

 Bear River, situated far from the foothills, small pebbles and grit 

 are difficult to secure. The hard seeds of the " potato moss " are 

 firm enough to aid in grinding up other softer foods, while at the 

 same time they are themselves digested, so that they serve a double 

 purpose in the economy of the birds concerned. 



The second plant, equal in importance as a duck food to the one 

 just described, is the bayonet grass, rush, or tule {Scirjyus pahidosus) . 

 (PI. Ill, fig. 1.) This is the dominant plant of the marsh growth and, 

 except where saline conditions in the soil are too strong, covers the 



