115 
els Gray Lodge Refuge - 2,500 acres.of ponded, farmed, and undisturbed 
land, intensive predator control during winters of 1946-47, 1947-48 and 
1948-49. Sa 
2. Tobin Gun Club - 300 acres of ponded and natural marsh land along 
Butte Creek, Ideal cover with some predator control. 
3, Fenn's Rice - 90 acres of rice field in production. Located near 
natural marsh. Little or no predator control. 
' In the spring and early summer of 1950 the three areas under study were 
as follows: 
1. Gray Lodge Refuge - conditions essentially the same ,as in 1949. No 
intensive predator control during winter of 1949-50, 
| 2. Tobin Gun Club - essentially the same as in 1949. Located near 
Gray Lodge Refuge so may have been affected by lack of predator control 
in 1949-50. 
3. Sartain Ranch - 15 miles northwest of Gray Lodge Refuge. Intensively 
managed small grain agricultural land. Located near natural marsh areas, 
_ A summary of the nesting data gathered during the past two nesting seasons 
is presented in the following tables. 
Nesting Data Summary - Sacramento Valley Study Areas 
STUDY AREA: Gray Lodge Tobin . Fenn Sartain 
“YEAR: 1949 1950 . 1949. 1950 1949 1950 
Approx. no. acres searched - ‘800 400 80 80 90 130 
Total nests located - be. 28 27 29 45 71 
Acres per nest = 45 14 3 : 2 2 
Percent Successful - 69 35 85 66 56 37 
nt destroyed = 14 61 4 34 33 50 
" deserted wy 17 4 11 0 1l 13 
Species Composition in Percent 
of nesting ducks - Mallard - 56 . 68 56 69 75 82 
Gadwall_ - 27 18 15 10 7 0 
Cinn. teal- 17 14 29 21 16 18 
Pintail - 0 0 0 07 “2 - 0 
Pertinent data evident from this table indicates that nest density was almost 
identical on the same area in each of the two years. Nesting success was significantly 
lower on the two comparable areas (Gray Lodge and Tobin) in the 1950 season. Much 
of this decreased success is attributed to decreased local predator control and probably 
was not true throughout the whole of the Sacramento Valley in which there is little effort 
made to control predators on private lands. It is also of interest to note the absence of 
gadwall nesting on the Sartain study area. The reason for this is at present unknown, 
Absence of gadwall nesting on agricultural lands was also noted in 1948 on a similar 
area near Woodland, 100 miles south of this general locality. 
