
195 
5. In the interests of standardizing our methods of coverage by automobile transects, 
all observers were instructed to cruise on foot the edge of all water areas lying within 
the transect to eliminate, in so far as possible, any possibility of omission of birds 
through "superficial" coverage. (Note: Previously cruising was occasionally limited 
to approach of an area and examination with binoculars when cover conditions were 
sparse; for our purposes such coverage is herewith termed "superficial" in contrast 
to a complete cruise of the periphery of the water area being censused). Thus, in 
view of slightly more intensive coverage during 1950, it is probable that the 1950 
ground transect data would be favorable as compared with the 1949 data. 
6. A small amount of additional data from new transects covered in 1950 was elimi- 
nated from this report to obviate any possible statistical error through such inclusion. 
Weather Conditions 
Climatological data for Wisconsin for the month of May as prepared by the - 
U. S. Weather Bureau are not available for this report, but there appears to be little 
doubt that there was a definite increase in rainfall in Wisconsin for the spring of 1950 
as compared to 1949. Secondly, the month of April was reported to be the second 
coldest in some 50 years, Cold weather persisted throughout most of May. Weather 
conditions appeared comparable to those of the spring of 1947 in southeastern Wisconsin 
if not more severe, and in the northern half of the State the spring breakup was perhaps 
the latest on record. 
There is no doubt that the severe spring weather delayed spring migratory 
movements of waterfowl in Wisconsin, particularly in the northern half of the State; 
and there were opinions expressed by many observers to the effect that breeding birds 
apparently stayed in Wisconsin whereas in a normal year they would have moved on 
north into Canada. This assumption, although seemingly logical, would be exceedingly 
difficult to prove. A subsequent chronological analysis of territorial observations 
showed much later breeding dates for mallards and blue-winged teal than is normal; 
and the conclusion that weather is responsible for retarding the breeding season two 
or more weeks seems inescapable. 
An analogous retardation of territorial behaviour and egg production was 
observed generally for captive Canada goose breeding flocks in southeastern Wisconsin 
and at Horicon, and for the breeding flock of captive mallards at Horicon. Since such 
flocks are provided with all essentials to be needed in the way of food, grit, and habitat, 
it again seerms very evident that weather must be the causative factor in retarding the 
breeding phenology during 1950. 
Water Conditions 
An analysis of ground transect data indicates a 51 percent increase in the 
number of water areas for the State; the total estimated acreage of water area censused 
involved increased to roughly 6,000 acres from about 3, 700 acres in 1949. There was 
an average of some 2.55 areas per square mile in May of 1950 as compared with an 
average of 1.65 areas per square mile last year, and 2. 28 areas per square mile in 
1948, 
Flood conditions on the Mississippi River evidently persisted until well into 
May and might have had a serious effect on local breeding conditions for waterfowl. 
