140 
Weather and Water Conditions 
This year water conditions were again nearly ideal. Winter precipitation was 
sufficient to fill all the lakes and impoundments, some reservoirs were even higher 
than in 1952, In late January and throughout February and March the State experi- 
enced unseasonably mild weather. These indications of an early spring caused 
waterfowl to move north earlier than usual, In northeastern California, Canada 
geese showed signs of nesting by late February. However, in April the weather 
turned cold, and in May and June the temperatures were below averaze. These 
adverse weather conditions retarded duck nesting about two weeks later than normal, 
Scope and Methods 
Fundamentally the survey consists of an aerial census of the pairs of ducks 
present on the breeding grounds during the last half of May and the first half of June, 
assuming an even sex ratio, Production is based on the number of pairs found, the 
relative nesting success, and the average brood size on each area. The latter two 
factors require considerable ground work and it is not always possible to conduct 
such surveys on each unit every year. An attermpt is made to keep the data current 
on major areas. 
Goose production in California is confined to the northeastern section and 
involves only Canada geese. By June 1 when the survey is made in this region, the 
nesting season is over for this species and most of the birds are more than half 
grown. The total number of old and young is counted and this figure is used for the 
total fall population. 
Insofar as possible the areas covered, census routes travelled, and methods 
employed have been duplicated from the pattern established in previous years. 
Census flights were made with a pilot and two observers, On some flights a 
different observer was used than in previous years, but in all cases at least one of 
the observers had flown the census route before. 
All of the aerial transects were flown at elevations of 150 feet at speeds of 85 
to 90 miles per hour with the two observers covering a ground strip 1/8-mile wide 
on either side of the airplane. Under these conditions experienced observers can 
accurately record species and sex of those ducks exhibiting divergent sex charac- 
teristics as well as note whether the birds occurred as pairs, singles, or groups 
of males. 
Results 
For the following areas comparable data have been gathered in all four years. 
A standard pattern of reporting has been used to include pertinent facts with reference 
to individual areas. On a sampling basis, coverage of the entire State production can 
be considered as essentially complete; thus figures are shown as actual numerical 
estimates of the total number, rather than as ducks per square mile. Data on 
individual areas studied are summarized with such remarks as are pertinent. 
"Total fall population" includes resident adults plus locally reared young. 
