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Brown's Park - This is primarily a heavily grazed, sagebush-covered mountain 
park, bisected by the Green River. It is located in extreme northwest Colorado, 
and both the park and the river extend into the adjoining State of Utah. Waterfowl 
habitat in Colorado is limited to the floodplain area along a 15-mile stretch of the 
river. Since this bottomland averages about 1 mile wide, available waterfowl 
nesting ground consists of approximately 15 square miles. The entire bottomland 
portion was included in the survey. Cattail and bulrush marsh, flooded hay meadows, 
and willow-bordered stream banks characterize the waterfowl habitat found in this 
region. 
Studies in Brown's Park were begun in April 1952 and the last brood counts 
were made late in August. Results are given in Table XII. 
On this 15-square mile sample, constituting 100 percent of the waterfowl 
nesting ground in the Colorado portion of Brown's Park, the breeding-pair density 
was 19.6 per square mile. Brood density was 13.8 per square mile, giving 1.4 
pairs of birds per brood for the area. Production, expressed in number ‘of young 
produced per square mile, was 96.7. The indicated production for the entire park 
was 1,451 young. 
Table XII - Observed Waterfowl Pairs and Broods - Brown's Park, 1952 * 


Species Breeding Percent No. of Percent No. of Average No. 
Pairs of Total Broods of Total Young Per Brood 
C anada geese 21 7.1 12 4.1 60 5.0 
Mallard 113 38.4 90 45.6 662 7.4 
Pintail 14 4.8 10 4.6 66 6.6 
Gadwall 60 20.4 9 3.7 55 6.1 
Shoveler 7 2.4 1 0.1 1 1.0 
Teals 40 13.6 37 19.5 283 7.6 
Redhead 34 11.5 18 9.0 131 7.2 
Ruddy duck 5% 1.8 7 2.6 37 5.3 
Unidentified 0 - 23 10.8 156 6.8 
Total 294 100.0 207 100.0 1,451 7.0 
* Duplicate broods eliminated. 
* * Apparently all Ruddy duck breeding-pairs were not observed 
during the period of breeding-pair counts. 
High-Country Lakes and Beaver Ponds - This phase of the Colorado waterfowl 
breeding ground survey was initiated about mid-June 1952. Weekly breeding 
population and brood counts were conducted from that time until early in September. 
The study area for this type is confined to high-mountain lakes and beaver 
ponds in the spruce-fir zone above 9,000 feet elevation. Approximately 20 small 
lakes and several miles of stream were included in the 18-square mile sample, 
