1. Sacramento Valley 
ae 
Area - 2,400 Square Miles. 
141 
b. Type - Agricultural land including 290,000 acres of rice, plus 
managed refuges and private gun clubs. 
c. Coverage -2& 1/2. percent aerial 1950 and 1951, 4 & 1/2 percent 
aerial in 1952, 2 & 1/2 percent aerial in 1953. 
d. Production summary: 
Estimated Total Nesting Pairs Total Fall Population 
Species 1950 1951 1952 1953 1950 1951 1952 1953 
Mallard 28,920 29,240 34,300 25,930 145,000 150,000 171,500 90, 750 
Gadwall 120 200 600 600 750 1,000 3,000 Zz, 100 
Pintail 40 0 300 200 250 0 1,500 700 
Cinn, Teal 440 400 1, 700 1, 160 2,500 2,400 &,500 4,060 
Redhead 0 0 60 70 0 0 300 240 
Shoveler 0 80 40 240 0 400 200 840 
Total 29,480 29,920 37,000 28,200 148,500 153,800 185,000 98,690 
Coot 1, 140 1,720 4,500 8, 080 5,000 8, 000 22,500 28,280 
e. Remarks: There was an indicated decrease of 24 percent in nesting 
pairs of ducks, and a 47 percent decrease in the total fall population. 
This decrease is thought to be due to the wide spread spraying of the 
rice crop with dieldrin during May and June. This spray seemed to 
be lethal to many birds - especially egrets. An aerial reconnaissance 
the first of July revealed only a few broods. Pairs of coots increased 
80 percent but the total fall population increased only 25 percent, 
probably due to the dieldrin spraying. 
2. Suisun Marsh 
a. Area - 140 Square Miles. 
b. Type - Natural tidal marsh, private gun clubs and agricultural land. 
c. Coverage - Aerial: 5 & 1/2 percent 1950, 5 percent 1951, 5 percent 
1952, 5 percent 1953. 
d. Production summary: 
Estimated Total Nesting Pairs Total Fall Population 
Species 1950 1951 1952 1953 1950 1951 1952 1953 
Mallard 1,913 980 3,640 1, 400 10, 000 5,000 18,100 7,000 
Gadwall 180 340 480 200 900 2,000 2,500 1,000 
Cinn. Teal 54 100 580 100 350 550 2,900 460 
Others 180 20 180 140 1,000 100 900 700 
Total 2,327 1, 440 4, 880 1, 840 12, 250 7,650 24,400 9, 160 
Coot - - 180 120 - - 900 600 
e. Remarks: Figures indicate a 62 percent decrease in both nesting ducks 
and in the fall population. 
