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WATERFOWL BREEDING GROUND SURVEY IN WISCONSIN - 1950 
R. C. Hopkins, F. A. Hartmeister, R. W. Mihalek, 
L. R. Jahn, and W. M. Kitz 
Waterfowl Breeding Population, Spring - 1950 
Introduction 
During the period from May 8 to June Z, 1950, personnel of the Wisconsin 
waterfowl research project again conducted the annual waterfowl breeding ground 
survey. The same five methods of census were employed over nearly identical routes 
covered in 1949. With the exception of ground cruises conducted on Horicon Marsh, 
which are not covered in this report, the other four methods employed were as per 
standard operating procedure outlined by the Fish and Wildlife Service with all methods 
employing 1/4-mile census strips. 
Methods 
To simplify and standardize computation of the total number of breeding pairs, 
the following procedure was used. In all instances and for all species, the estimated 
number of breeding pairs was computed on the basis of the total pairs seen plus total lone 
drakes, plus total lone females. (The last comprise less than 1 percent of the total). 
No attempt was made to differentiate between species which are known to breed locally 
and late breeding transient species such as scaups and ruddys: An examination of the 
tables on species composition (not included in this report) indicates quite clearly that 
these late breeding transient species were largely flocked. Consequently, their 
representation as breeding pairs in a few instances should not alter final results 
appreciably. However, there is no question but that this method will tend to favor 
the data for 1950 slightly. 
The following cited digressions constitute the only known human factors 
which differ from last year's coverage of census routes. 
1. Coverage of transects was begun one week later in 1950 than in 1949 to allow for 
an apparent phenological lag induced by a later spring in 1950. Itis the opinion of the 
waterfowl research project that, phenologically speaking, our census work was begun 
at approximately the same time during the breeding season or slightly earlier than 
during 1949. (First reported mallard hatching dates -- May 21 and May 24 -- tend to 
substantiate this). 
2. Small portions of two automobile transects involving only a few miles were altered 
to enhance travel. These changes were of such insignificance as to be hardly note- 
worthy. 
3. Project personnel were present on all transect coverages made; the employment 
of cooperators was largely discontinued in the interests of standardizing observations 
and because our staff had been increased. However, itis highly questionable if any 
difference whatsoever would be encountered here in view of the fact that cooperators 
employed previously were all top caliber observers, 
4, One aerial transect of about 40 miles in south-central Wisconsin was discontinued 
because of a fur farm,on the transect course. Here again it is questionable if any 
discrepancy should arise in view of the fact that roughly 250 lineal miles were censused 
elsewhere in this soil region. | 
