US Fish & Wildlife Service
Date of this Version
7-22-2004
Citation
U.S. Fish and Wildlife Service. 2004. Waterfowl population status, 2004. U.S. Department of the Interior, Washington, D.C. U.S.A.
Abstract
In the Breeding Population and Habitat Survey traditional survey area (strata 1-18, 20-50, and 75-77), the total-duck population estimate was 32.2 ± 0.6 (± 1 standard error) million birds, 11% below last year’s estimate of 36.2 ± 0.7 million birds (P<0.001), and 3% below the 1955-2003 long-term average (P=0.053). Mallards (Anas platyrhynchos) numbered 7.4 ± 0.3 million, similar to last year’s estimate of 7.9 ± 0.3 million birds (P=0.177) and to the long-term average (P=0.762). Blue-winged teal (A. discors) numbered 4.1 ± 0.2 million, 26% below last year’s estimate of 5.5 ± 0.3 million (P<0.001) and 10% below the long-term average (P=0.073). Among other duck species, only northern shovelers (A. clypeata, 2.8 ± 0.2 million) and American wigeon (A. americana, 2.0 ± 0.1 million) differed significantly from (both 22% below, P<0.003) their 2003 estimates. As in 2003, gadwall (A. strepera, 2.6 ± 0.2 million, +56%), green-winged teal (A. crecca, 2.5 ± 0.1 million, +33%), and northern shovelers (+32%) were above their long-term averages. Northern pintails (A. acuta, 2.2 ± 0.2 million, -48%), scaup (Aythya affinis and A. marila, 3.8 ± 0.2 million, -27%), and American wigeon (-25%) were well below their long-term averages in 2004 (P<0.001). Total May ponds (Prairie Canada, and the north-central U.S. combined) were estimated at 3.9 ± 0.2 million, which is 24% lower than last year (P<0.001) and 19% below the long-term average (P<0.001). Pond numbers in both Canada (2.5 ± 0.1 million) and the U. S. (1.4 ± 0.1 million) were below 2003 estimates (-29% in Canada, and -16% in the U.S.; P<0.033), and pond numbers in Canada were 25% below the long-term average for this region (P<0.001). The projected mallard fall flight index was 9.4 ± 0.1 million birds, similar to the 2003 estimate of 10.3 ± 0.1 million (P=0.467). The eastern survey area is comprised of strata 51-56 and 62-69. The 2004 total-duck population estimate for this area was 3.9 ± 0.3 million birds. This estimate was similar to last year’s estimate of 3.6 ± 0.3 million birds, and to the 1996- 2003 average (P>0.102). Individual species estimates for this area were similar to 2003 estimates and to 1996-2003 averages, with the exception of American wigeon (0.1 ± 0.1 million) and goldeneyes (Bucephala clangula and B. islandica, 0.4 ± 0.1 million) which were 61% and 42% below their 1996-2003 averages (P<0.052), respectively, and ring-necked ducks (Aythya collaris, 0.7 ± 0.2 million), which increased 67% relative to their 2003 estimate (P=0.095).