
91 
These data indicate that by late August almost as many waterfowl 
occupied the newly flooded 10 square miles of farm land and pasture as did 
the remaining 49 square miles of marsh. Thus this segment of marsh played 
an important part in providing loafing sites for the greatly increased numbers 
of waterfowl using the Delta Marsh during the molting period of 1955, when 
compared with similar populations of a year ago. 
Production 
By mid-July it was obvious that the nesting season on the Delta 
Marsh would be extended, resulting in a late hatch, particularly among the 
diving ducks. The results of three brood surveys conducted by motorboat 
(Table Il.) bear this out. 
Table I], - Results of Three Delta Marsh Brood Surveys - 1955. 
7/13-14/55% 7/31 /55%* 8/20/55 *** 
Age Class # Broods Total Yng. # Broods Total Yng. # Broods Total Yng. 
la 8 9 5 12 2 13 
Ib l 7 2 12 6 22 
Ic 2 14 i ll 3 16 
Ila l 7 - - 1 2 
TIb l 7 - - 1 9 
IIc 2 26. - - 3 10 
Ill 2 19 5 35 2 12 
is 1 5 1 2 2 12 
Seen off Trans. l 2 
Total 10 85 14 Be 21. 98 
* §8 dabbling and 2 diving duck broods. 
x* 6 dabbling and 6 diving duck broods (2 broods unidentified). 
* ** 3 dabbling and 18 diving duck broods. 
These data are not directly comparable one with another since the 
first survey involved 15 transects; the second, 10; and the third, 14. They do 
indicate, howéver, the extended nesting season with a late hatch of diving ducks. 
A total production estimate for the marsh must await the calculation 
of appropriate conversion factors but Iam reasonably certain that it exceeded 
that of 1954. Aerial surveys provided an estimate of 104 broods on the marsh 
as of August 17. This is somewhat higher than my best aerial estimate of 1954 
(80 broods on August 16). 
