
IOWA 
Weather and Water Conditions - 
/ 
The dry fall of 1956 followed by very little spring run-off eliminated 
most of the temporary ponds in the State during 1956.. Consequently, many 
migrants were concentrated along the major rivers, their tributaries, and in 
the deeper lakes and marshes. Large temporary concentrations were the 
rule, with a minimum of overland distribution. 
Breeding Population Data - 
Table I - Wood Duck Stream Survey Data 
Stream Miles Wood Ducks Counted Dates 
Year. Gensused Males Females Pairs Unid. Total of Census 
TC | 
1953 66 11 8 10 IZ’ 51 May 5-14 
1954 78 9 5 3 8 28 May 5-13 
1955 90 8 1 0" 6 15 Apr.22-May16 
1956 26% 0 1 1 La = 15 #$=May 3-June 9 

* Many streams too dry to float in 1956. 
‘Table II - Wood Duck Nesting Box Occupancy at Lake Odessa, Louisa County, Ia. 
No. of Nesting Boxes Checked No.of Nesting Boxes Occupied 
Year Wooden Metal Wood Duck Merganser 
1950 26 18 
1951 36 13 and 9* 
1952 24 . 18 
1953 30 15 
1954 A 50 7 
1955 12 44 5 ] 
1956 6 «42 5 
—— 
* There were 13 nesting boxes occupied prior to flooding and 
9 afterwards. 
Production Data - 
Practically all temporary ponds were dry during the spring of 1956. 
Water levels of the deeper permanent marshes likewise declined. Under these 
dry conditions many nesting areas formerly used by nesting ducks were un- 
attractive to gravid females this spring. Blue-winged teal constituted the 
88 
