US Fish & Wildlife Service

 

Date of this Version

7-30-2000

Citation

U.S. Fish and Wildlife Service. 2000. Waterfowl population status, 2000. U.S. Department of the Interior, Washington, D.C. 33 pp. + appendices.

Abstract

In the traditional survey area (strata 1-18, 20-50, and 75-77), total duck abundance was 41.8 ± 0.7 million birds. This was similar (P=0.12) to last year’s record high estimate of 43.4 ± 0.7 million birds, and 27% above the long-term (i.e., 1955-99) average (P<0.01). Mallard (Anas platyrhynchos) abundance was 9.5 ± 0.3 million, which is 12% below (P<0.01) the 1999 estimate of 10.8 ± 0.3 million and 27% above the long-term average (P<0.01). Blue-winged (Anas discors) and green-winged teal (Anas crecca) abundances were both at record high levels this spring. Blue-winged teal abundance was 7.4 ± 0.4 million, which was similar to last year’s estimate of 7.1 ± 0.4 million (P=0.61) and 69% above the long-term average (P<0.01). Green-winged teal abundance was 3.2 ± 0.2 million, 80% above the long-term average (P<0.04) and 21% higher than last year (P=0.03). Gadwall (Anas strepera; 3.2 ± 0.2 million, +100%), northern shovelers (Anas clypeata; 3.5 ± 0.2 million, +73%), and redheads (Aythya americana; 0.9 ± 0.1 million, +50%) were all above their long-term averages (P<0.01), while northern pintails (Anas acuta; 2.9± 0.2 million, -33%) and scaup (Aythya marila and A. affinis combined; 4.0 ± 0.2 million, -25%) remained below their long-term averages (P<0.01). American wigeon (Anas americana) and canvasback (Aythya valisineria) estimates were similar to those of last year (P≥0.42) and to long-term averages (P>0.07). May conditions in the traditional survey area were generally drier than last year. The estimate of May ponds in Prairie Canada and the U.S. combined was 3.9 ± 0.1 million, down 41% from 1999 and 20% below the long-term average (P<0.01). The eastern survey area comprises strata 51-56 and 62-69. The 2000 total duck population estimate for the eastern survey area was 3.2 ± 0.3 million birds. This was essentially identical to last year’s total duck estimate of 3.2 ± 0.2 million birds. Abundances of individual species were similar to last year, with the exception of scoters (Melanitta spp.; 182 ± 59 thousand, +288%, P=0.03) and green-winged teal (202 ± 29 thousand, -52%, P<0.01)). The total duck fall flight index for 2000 is 90 million birds. This is 13 percent lower than last year’s record fall flight. Because of additions to the survey area for which we do not have production information, we propose to stop calculating the traditional fall-flight index for total ducks in the future. The Service may consider other alternatives to provide a reflection of duck abundance in the fall. The midcontinent mallard fall flight is predicted to be 11.3 million mallards, 16.2% lower than that of last year (P<0.01).

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