WSP03031

• File Number: 8543
• Description: Closed Basin Division
• State: CO
• Basin: Rio Grande
• Water Division: 3
• Date: 6/1/1981
• Title: Fish and Wildlife Plan - Closed Basin Division - San Luis Valley Project
• Water Supply Pro - Doc Type: Report/Study

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Table 1
Duck Production in San Luis Valley. Colorado
1964-1978 ~
Average number Es timated Percent total Percent total
Area size Acres of .of breeding average annual wetland in production in Ducks producedl
Area 11 acres l! wetland lJ pairs production San Luts Valley 4/ San Luis Valley acre of wetland
(acres)
San Luis/Head Lakes 4,470 2,235 315 945 1.0 1.1 0.42
(180-2,439)
Mishak I;akes 2,570 1,285 253 759 0.6 0.9 0.59
(540-1,596)
Russell Lakes 3.829 1,9,15 1,131 3,393 0.8 4.1 1.77
(489-1,845)
Adams Lakes 640 320 38 114 0.1 0.1 0.35
(18-309)
Monte Vista NIlS 14,227 6,9<10 3,861 11,583 3.0 13.8 1.68
~ (9,000-13,260)
Total for high-
density breeding
areas 26,345 12,655 5,598 16,794 5.5 20.0 1.33
(11,808-19,575) ~
Low-density breeding
area ~ 805,655 218,345 24,402 67,206 94.5 80.0 0.31
Total for
San Luis Valley 832,000 231,000 28,000 84,000 100.0 10.0 0.36
Total for Closed
Basin project
a rea 2J 130,000 43,122 4.540 13,620 18.6 16.2 0.31

1/ Breeding pair and area size data taken from Hopper et al. (1975). Updated by personal communication Howard Funk 1981.
2/ Identification and delineation of low- and high-density breeding areas from Hopper et al. (1975).
1/ Acreage estimate for high-density areas was" based upon FWS estimate of wetland densities with Hopper et al. (1975) study areas.
Acreage for Monte Vista NWR was taken from the refuge annual reports which indicated an average of 6,900 acres annually
available for duck production. .
~ Annual production estimates assumed 50-percent nest success and 6 fledglings (class llc-lll) per brood.
Data supporting these figures came from"studies on Monte Vista NWR (Anderson 1967, Pospabala 1969, Schroeder 1972, and Robinson 1971).
~I Range of production does not include 1964 when San Luis/Head, Misbak, and Adams Lakes were not surveyed by Hopper et a1. (1975).
In 1965 Adams Lake was not surveyed.
!/ Includes San Luis/Head Lakes from high-denSity breeding areas; data from Mishak Lakes was not included but an unknown portion
of Mishak Lakes may be included in wetland acreage for Closed Basin project area.