Scope and methods 
Each year, immediately after the hunt¬ 
ing season, the Bureau of Sport Fisheries 
and Wildlife conducts a national mail 
questionnaire survey of waterfowl hunters 
designed to meet the following objectives: 
1. Estimate, at both flyway and State 
levels, the magnitude of the waterfowl 
harvest, the total number of hunters 
active during the season, the total num¬ 
ber of hunter-days afield amassed by 
these hunters, and the average season¬ 
al performance per hunter in terms of 
days hunted and waterfowl bagged. 
2. Measure the relative changes in 
these estimates from year to year. 
3. Assess the effects of changes in 
season length and size of daily bag lim¬ 
it on total bag and on hunter perform¬ 
ance. 
The 1963-64 hunting season marks the 
12th consecutive year of the survey since 
its start in 1952. 
Since there is no complete listing of 
waterfowl hunters, this survey, by neces¬ 
sity, uses as its sampling universe those 
post offices throughout the nation which 
sell Migratory Bird Hunting Stamps 
("duck stamps"). This year, 2, 736 post 
offices were designated to cooperate in 
the survey as "sample outlets." These 
sample outlets were randomly selected, 
within States, from four strata (small, 
medium, large, and very large) of post 
offices, based on actual dollar sales of 
duck stamps instead of from two strata 
(single, multiple) as in previous years. 
A further refinement in stratification was 
used—that of subdividing each State into 
several "geographic zones", while re¬ 
taining the post office class strata within 
each zone. This year the geographic 
zoning of a number of States was revised 
from that of last year in an effort to make 
each zone a more uniform unit in regard 
to waterfowl hunter activity and success, 
thus increasing survey precision. Zoning 
also insures a more even distribution of 
sample outlets throughout a State. 
Names and addresses of hunters are 
obtained by means of a business-reply 
"contact card" distributed to all persons 
buying duck stamps at sample outlets. 
The card requests the individual’s name 
and address, the number of stamps he 
purchases, the reason for his purchase, 
and the number of persons in his house¬ 
hold under the stamp requirement age of 
16 years who might hunt waterfowl during 
the season. 
All contact-card respondents who 
purchase stamps for the purpose of hunt¬ 
ing are mailed a hunter questionnaire at 
the close of the season. The 1963-64 
questionnaire asks each hunter the total 
number of days he hunted waterfowl, his 
total bags of ducks, geese, and coots, 
and the number of each he knocked down 
but failed to retrieve. These data, in 
combination with the total reported sale 
of duck stamps by State, have been used 
to derive the various survey estimates. 
All estimates are subject to several 
sources of error (as is true for most 
types of surveys). In addition to chance 
error due to random sampling variation, 
the estimates may be affected by mis- 
reporting (respondents may tend, for 
example, to exaggerate their bag). The 
estimates are further subject to non¬ 
response bias in that hunters who fail 
to respond may have differed from re - 
spondents in their hunting performance. 
A further potential source of error, 
that of faulty reports of duck stamp 
sales, this year has again presented a 
problem, although not as serious as 
that of last year. Since it is necessary 
to present kill estimates no later than 
early July to be available for regula¬ 
tions meetings, the reported sales for 
the first three quarters of the fiscal 
year (July 1 to March 31) must be used 
in deriving total kill and activity esti¬ 
mates instead of the full year’s sales 
(the sales for the last quarter of the 
fiscal year are not available until Mid- 
August). Before 1959, the three- 
quarter-year reports were generally 
identical to those for the full year, but 
since that time, a small but increasing 
percentage of sales have been reported 
during the fourth fiscal quarter (April 
1 to June 30). Last year it became 
apparent, because of the magnitude of 
the fourth-quarter sales reports of 
many States, that the three-quarter 
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