209 

Blue-winged teal 115 Baldpate 5 
Mallard 82 Canvasback 4 
Ringneck 38 Wood duck 4 
Ruddy duck 37 Gadwall i 
Redhead 32 Lesser scaup 1 
Goldeneye 14 Unidentified 11 
Pintail 10 Total 354 
The percent composition which could be calculated from this species distri- 
bution of broods does not necessarily reflect the composition of the breeding 
waterfowl population of the State. The beat-out method was not used and it is likely 
that the less wary species were recorded more often than those that lead their 
broods into heavy cover. However, blue-winged teal, mallard, and ringneck, in 
this order, were the most prominent species in the breeding pair census as well 
as in th: brood count. These three species made up 80 percent of the breeding 
pairs and 66 percent of the broods. 
The principal objective in conducting the three brood counts was to secure 
data which would enable the plotting of curves to show (1) dates of nest establishment, 
(2) dates of hatching and (3) the dates when young ducks are first able to fly. The 
brood information is plotted in this manner in Graph l. 
Each brood was dated back to the probable day of hatching. Then the beginning 
of incubation was determined by subtracting from the hatching date the number of 
days in the normal incubation period of the species. The flight ape was determined 
by adding to the hatching date the number of days it takes young of the species to 
mature sufficiently for flight. 
An examination of Graph 1 shows that some incubation had begun during the 
week of April 12 - 18. This was mostly mallard and pintail. The greatest number 
of ducks had started incubating during the period from May 31 to June 6. A dropis 
shown for the week of June 14 - 20. This is the period when heavy downpours occurred 
in some of the better waterfowl breeding areas of the State. A second peak in incubation 
occurred during the week of June 21 - 27. 
Corresponding peaks are noted for the periods of hatching. The greatest hatch, 
as indicated by the data, occurred during the week of June 21 - 27. The second peak 
is shown for the week of July 12 - 18. 
The period when the greatest number of the broods would start flying was July 26 
to August l. Considerable numbers were getting on the wing through the period of 
August 30 to September 5. Of the 354 broods, 44 or 12.6 percent, would not be able 
to fly until after September 6. One late brood of blue-winged teal was noted which 
would not be able to fly until the period of September 20 - 26. Most of the other very 
late broods were redheads and ringnecks. A note of interest is that two very late 
nesting records for these species were recorded in 1950 and 1951. On September 15, 
1950, Gerald Bue found a redhead nest at Heron Lake, Jackson County. Robert Farmes 
saw a flightless Class III b ringneck at Twin Lakes, Kittson County, on October 10, 
1951. 
