24 
(1950-60) average. It is the lowest index 
recorded since surveys were started in 
1950. The previous low was 2.24 in 1959. 
The Statewide, mid-July pond density 
index decreased from 4.16 in 1960 to 2.29 
ponds per square mile in 1961, or a 45- 
percent decrease. The 1961 mid-July pond 
index is 27 percent below the 1953-60 index 
of 3.11 ponds per square mile for the 8-year 
average. Data concerning number of water 
areas are presented in table D-7 (p. 79). 
BREEDING POPULATION INDEXES 
The 1961 population index of 310,573 was 
2 percent below that of 1960 and 44 percent 
below the ll-year (1950-60) average of 
550,100 ducks. The duck density index in 
1961 was 4.22 ducks per square mile com- 
pared with 4.30 in 1960. Breeding popula- 
tion data are presented in table E-23 
(p. 96). 
PRODUCTION INDEXES 
The Statewide, mid-July brood density 
index decreased slightly from .49 broods 
per square mile in 1960 to .45 in 1961 
(-8 percent). The 1961 index was 2 percent 
below the ll-year (1953-60) average of 
.46 broods per square mile. Production 
Survey data are presented in table F-24 
(p. 118). 
CONCLUSIONS 
Based primarily on a deterioration of 
habitat conditions, it is estimated that the 
fall flight of ducks from South Dakota will 
be smaller than in 1960. 
NEBRASKA 
Data supplied by George 
Schildman, Nebraska Game, 
Forestation and Parks 
Commission 
WEAFHER AND HABITAT CONDITIONS 
Water conditions in the Nebraska Sand- 
hills were generally good at the time breed- 
ing ground flights were made during May 19 
through May 22, 1961. 
The eastern and central areas had less 
water than at the same time in 1960, but 
conditions were very good. The western 
area was in good shape at the time of 
inspection; however, much of the water at 
that time was in the form of temporary- 
runoff ponds. The northern extremities of 
all of the areas were in fair to poor condi- 
tion in mid-May. 
A period of very light, scattered rainfall 
accompanied by a week of near 100° and 
above temperatures in late June and the 
first 15 days of July dried many potholes 
and sloughs in the eastern and central 
Sandhills. The small water areas of the 
western area suffered somewhat but did not 
deteriorate so badly because of occasional 
rainfall. 
Water conditions were excellent in the 
rainwater-basin area of south-central 
Nebraska, at the time of the breeding 
ground flights, but less than the near- 
record amounts of 1960. However, water 
levels were quite low during the spring 
migration, and the ducks had moved on 
before the rains occurred. As a result, 
there was considerable unoccupied habitat. 
At the time of the aerial brood-count 
flights, which were made July 7 through 
July 10, 1961, water conditions throughout 
the Sandhills were fair to good. Most small 
potholes and sloughs had dried. Larger 
water bodies were in good to excellent 
condition. Most larger lakes had as much 
or more water than at the same time in 
1960. Northern areas were still dry. 
BREEDING POPULATION INDEXES 
The data indicate a breeding population 
index in the Sandhills of 141,800 ducks; 
about the same as a year ago, but 12 per- 
cent above the average of the previous 6 
years. The south-central part was verydry 
during the spring migration, but had excel- 
lent water conditions by late May. However, 
much of this habitat was unoccupied and 
the calculated population of 16,300 was 
57 percent below the 1960 population. 
Comparison of aerial and ground determi- 
nation of the species compositionare shown 
in table E-24 (p. 96). Blue-winged teal 
showed the greatest loss in numbers--about 
13,000 in the Sandhills and 15,000 in the 
south-central part of the State. Pintails 
and green-winged teal showed appreciable 
decreases, while mallards, redheads, and 
scaup showed significant increases. 
