from two to three times greater in the late spring and early fall than 

 it is at present. The results of this study show that this increase 

 in channel water salinities will result in substantial increases in 

 soil salinities when the water is applied to the duck hunting clubs 

 in the locale. Such widespread increases in soil salinities could be 

 expected to reduce the amount of important waterfowl food plants and 

 ultimately decrease the value of the Suisun Marsh as a waterfowl win- 

 tering area. (L.H. ) 



Keywords: marsh salinity, soil salinity, waterfowl food plants, 

 California 



V-B-17 



Wheeler, R.J., and S.W. Harris. 1970. Duck nesting and production in 



the Humboldt Bay area of California. California Fish and Game 56:180-187. 



The nesting season for mallards ( Anas platyrhynchos ) lasted about 

 145 days in 1964 and 130 days in 1965. The nesting season for cinnamon 

 teal ( Anas cyanoptera ) lasted about 135 days in 1964 and 115 days in 

 1965. From 1964 to 1966, 49 mallard and 15 cinnamon teal nests were 

 observed. Approximately 53 percent of the mallard nests and 46 per- 

 cent of the cinnamon teal nests were on banks of sloughs or ponds. 

 Nearly 70 percent of all mallard nests and 80 percent of cinnamon teal 

 nests were in grasses or grasslike plants. Nests of most mallards and 

 cinnamon teal were either completely concealed or had only one side or 

 the top exposed. The average size of mallard broods ranged from 9.2 

 at hatching to 4.6 near the time of flying; for cinnamon teal the 

 range was from 10.7 to 5.8. Estimated duck production was one per 

 8.1 acres in 1964 and one per 10.2 acres in 1965 in the Humboldt Bay 

 area. 



Nests were found in four ecological situations: on banks of sloughs 

 or ponds, on dikes, in fields, and over water. Sloughs and intermittent 

 marshes in the pastures supported stands of one or more of the follow- 

 ing: mares tail ( Hippuris vulgaris ), sago pondweed ( Potamogeton 

 pectinatus ), alkali bulrush ( Scirpus robustus ), three-square bulrush 

 ( S. amerTcanus ), spike rush ( Eleocharis macrostachya ) , saltgrass 

 ( Distichlis spicata ) , marsh pennywort ( Hydrocotyle ranunculoides ) , 

 cattail ( Typha latifolia ), arrow grass ( TriglochTn maritima ) , rush 

 (Juncus spp.), water cress ( Rorippa nasturtium-aquatica ) and horse- 

 tail ( Equisetum spp.) . 



Portions of some lowland pastures held approximately six inches of 

 temporary water early in the nesting season, and four mallard nests 

 and two cinnamon teal nests were over water in clumps of rushes in 

 such areas. (H.D. ) 



Keywords: mallards, cinnamon teals, duck nesting, productivity, 

 Cal ifornia 



220 



