full-year instead of three-quarter year 1961- 
62 sales, Although the 1961 adjustments are 
of a lower magnitude than the 1962 adjust- 
ments, the revision was necessary to make 
valid measurements of harvest and activity 
changes between the 2 years, | 
Both years’ estimates are based on the 
analytical method employed in 1961. The 
(1962 estimates were also derived using the 
Bureau’s recently developed electronic com- 
puter program, In the Central and Missis- 
sippi Flyways they agreed well with the 1962 
estimates derived by the ‘1961 method,’’ but 
tended to give higher results in the Pacific 
and Atlantic Flyways. Therefore, the com- 
puter estimates are not presented and need 
further scrutiny before being accepted or 
rejected. (While the computer program is 
mathematically correct, difficulties, if real, 
probably stem from occasional meager re- 
turns from post offices selling large numbers 
of Duck Stamps.) 
All 1961 and 1962 flyway estimates of the 
duck, goose, and coot bags have been ad- 
justed for response bias by reducing the re- 
ported bags by the same proportion as in the 
.1960 analysis, This method of bias adjustment 
was used because the existing procedure 
(Atwood, 1956)1/ was not designed to deal 
with axg-duck daily bag limit as prevailed 
during both years in many States, and because 
new studies of the nature of response biases 
may suggest refinements. 
The contributions of unlicensed ‘‘junior’’ 
hunters to the various harvest and activity 
totals were not measured directly in 1962, 
but instead have been included in thesetotals 
from estimates based on the proportions of 
their contributions during the 1961 season 
when direct junior estimates were made, The 
above proportions are small, ranging from 2 
to 5 percent of the various totals, so that 

even if moderately in error, they have re- 
latively little effect on the accuracy of the 
survey totals, 
The species composition of the duck kill 
is based both years on the findings of the 
Bureau's Duck Wing Survey. The species 
composition of the 1962 goose bag has been 
derived from the new Goose Tail Survey, 
while that for 1961 is from questionnaire 
reports of hunters. Since the two methods 
may not yield strictly comparable results, 
estimates of percentage change in the bags 
of species of geese are not shown. 
The 1962 estimates reported herein, which 
have been derived from the responses of 
approximately 36,700 hunters contacted 
throughout 2,300 post offices, include the 
following measurements: 
1, Total flyway bags of ducks and 
geese, by species, and coots, each 
adjusted (as described above) for 
response bias; and total ducks, 
geese, and coots knocked down but 
not retrieved. 
2. State estimates of total duck and 
goose bags unadjusted for response 
bias, and the full-season average 
bag a hunter of ducks and of geese. 
3. State and flyway estimates of the 
total number of ‘“‘potential’’ hunters 
(those purchasing Duck Stamps for 
the purpose of hunting and junior 
members of their households 
expecting to hunt); (tables A-1, A-2, 
A-3, and A-4, pp. 59-60) the total 
number of ‘‘active’’ hunters (those 
potential hunters who hunt at least 
once during the season); the total 
number of hunter-days_ afield 
amassed by all hunters; and the 
average number of days afield an 
active hunter during the season. 
WING COLLECTION SURVEY 
Data supplied by Samuel M. Carney and Alfred J. Godin 
Bureau of Sport Fisheries and Wildlife 
Each year while the hunting season is in 
progress, the Bureau of Sport Fisheries and 
Wildlife collects through the mail from 
hunters a sample. of duck wings that is rep- 
lsee Literature Cited, page 58. 
resentative of the total duck kill. These 
wings are used to: 
1, Determine the age and sex ratios in 
the kill for the mallard, the black 
duck, and for certain other. species 
of ducks, 
