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by March 23 waterfowl were again present. The migratory flight appeared to move 
rapidly into Iowa, and the concentration of both ducks and geese caused by a late spring 
and ice conditions farther north may have given a false impression as to the actual size 
of the migratory flight in Iowa. In the northwestern part of the State, concentrations of 
ducks and geese were more impressive than last spring, but there was no evidence to 
support an actual increase in total migratory numbers over last year. Certainly the 
concentrations were larger and more impressive, with more birds present in local 
areas for a short period of time. 
This year the duration of the migratory flight was shorter than last year. The 
main flight began about March 25 and began to diminish appreciably by April 20 in north- 
western Iowa. Mallards and pintails were the most abundant species; and diving ducks, 
with the exception of lesser scaup and ruddy ducks, were present only for a very few 
days during the second and third week in April, The green-winged teal flight overlapped 
somewhat beyond the limits of the aforementioned species, while the blue-winged teal 
and ruddy duck flight continued beyond May 15, 
The blue-winged teal flight was estimated to be larger (total number of 
migrants) than last spring with approximately the same number of resident (breeding) 
birds remaining in Iowa. More Richardson's or Hutchin's geese (B. canadensis 
hutchinsi) were observed in northwestern Iowa this year. Wilson's snipe (Capella 
gallinago) and Wilson's phalarope (Steganopus tricolor) also appeared more numerous 
this spring than during the spring of 1949. Coot populations were again low and 
approximately the same number of migrants were observed as in 1949. . 
Waterfowl Production 
The late spring of 1950 caused the blue-winged teal in Iowa to nest within a 
more restricted period this year than in 1949. More teal began to nest about the same 
calendar date and broods appeared closer to the same calendar date. The effect this 
had on survival or renesting was not determinable. There was no apparent change in 
blue -winged teal production between 1949 and 1950. Nesting coot appeared fewer in 
number and in density per area checked during 1950 than during 1949. From all 
indications mallard and redhead production was slightly better than last year. Data 
indicate fewer ruddy ducks nesting in the check areas this year, but the data are not 
conclusive. Authentic reports of wood duck broods were received the second week in 
June from the eastern part of the State to compare with excellent production and 
survival witnessed on several areas. No broods or nests of lesser scaup were seen 
in Iowa during 1949 or 1950, but some adults were observed throughout both nesting 
seasons, Comparatively large groups (5-25) of both paired and unpaired lesser 
Scaup remained in Iowa until the second week in June and then disappeared. There 
was no evidence that they attempted to nest before disappearing. <A few scattered 
groups of male shovelers remained in Jowa until the second week in June and also 
disappeared. All other waterfowl observed were considered as breeding adults, 
Waterfowl counts on the same marshes have been made in 1949 and again in 
1950. These waterfowl counts (see Table 1} represent breeding adults and are only 
partial indicators of comparative waterfowl abundance (trend) in Iowa. This was 
indicated by the complete absence of coot from one former nesting area (Hottes Lake) 
where nesting habitat was eliminated by water level change during 1950. The reduction 
in ruddy duck numbers on Round Lake may have been caused by the incompatibility of 
ruddies and black-crowned night herons occupying the same area for nesting purposes. 
All other counts are apparently unbiased. 
