and 18 percent above the 9-year average, In 
North Park, the Cache la Poudre Valley, and 
the South Platte Valley, breeding-pair popu- 
lations were increased both over last year 
and over the 9-year average, being 67 and 40; 
23 and 37; 129 and 282 percent, respectively. 
In Brown’s Park, the continuing deterioration 
of waterfowl breeding habitat, made more 
acute this year by low-river volume flowasa 
result of the filling of Flaming Gorge Reser- 
voir, resulted in adecrease induck breeding- 
pair numbers of 27 percent from last year 
and 48 percent from the 9-year average. 
In an attempt to refine the sampling techni- 
que inthe San Luis Valley, the aerial counts 
were recorded by the number of ducks 
observed a 5-mile transect segment. It was 
hoped that separate estimates of breeding- 
pair populations according to habitat quality 
would provide a more realistic picture ofthe 
duck populations in the Valley, and that 
sampling accuracy would be improved, How- 
ever, this did not prove to be the case. At 
the present level of sampling, a population 
change of 26 percent is the smallest which 
can be detected, based on 1963 sampling con- 
ditions, 
Species composition percentages of the 
breeding duck population differed from those 
of past years. Mallards and blue-winged 
teals were up considerably; shovelers and 
mergansers were up slightly; pintails, gad- 
walls, “redheads, and cinnamon teals were 
down slightly; and other species held at about 
the same level (table E-25, p. 123), 
In 1963, the western slope Canada goose 
breeding area continued to exhibit the steadily 
increasing breeding flock which has been 
noted during the past several years. The 
largest number of adult geese observed since 
the beginning of the study in 1956 occurred 
this year, and the number of goslings ob- 
served was down only slightly. However, 
this year’s survey was not comparable to that 
of last year, because of phenological dif- 
ferences. The peak of hatching this year 
occurred about 2 weeks earlier, and it was 
known that several broods and hatched nests 
were present which were not observed. The 
volume of spring runoff water was less this 
year, and the peak of high water occurred 
earlier than normal. This means that few, if 
any, nests were flooded, and nesting success 
should have been as good or better than last 
year. 
Production Indexes 
Tables F-28, F-29, and F-30 )pp. 151 and 
152) list the numbers, age composition, loca- 
tions, and past year’s comparisons of this 
breeding goose flock, Brown’s Park continued 
to show a decrease in goose numbers, and it 
appeared that it can no longer be considered 
Significant goose breeding area. The goose 
population on the Yampa River increased 26 
percent over 1962, and 164 percent over the 
1958-1962 average. The Little Snake River 
was surveyed for the second year, and showed 
a total population increase of 114 percent. 
This goose flock is continuing to show a 
steady and healthy increase, indicating that 
the restrictive harvest-type management em- 
ployed by the Bureau of Sport Fisheries and 
Wildlife, and individual States up and downthe 
Flyway, are now and will be inthe future a 
necessary part of flock management. 
Conclusion 
It is anticipated that fall duck flights from 
Colorado will be normal to or above average, 
in spite of expected short water supplies 
through the summer, Water areas should 
remain adequate to see hatching and early 
brood rearing completed successfully. 
MISSISSIPPI FLYWAY 
WATERFOWL 
An estimated 1,024,900 ducks were bagged 
in the Mississippi Flyway during the 1962-63 
waterfowl season, a decrease of 41 percent 
from the previous season (table A-11). An 
additional 318,100 ducks were knocked down 
KILL SURVEY 
but not retrieved, for a total kill (bag plus 
cripples) of approximately 1,343,000 ducks. 
Analysis of the total Flyway duck bag, by 
species, as derived from data provided by the 
Duck Wing Survey, shows that the bags of eight 
37 
