US Fish & Wildlife Service
Date of this Version
7-1-2009
Citation
Zimpfer N.L., W.E. Rhodes, E.D. Silverman, G.S. Zimmerman, and M.D. Kone , U.S. Fish and Wildlife Service, Trends in Duck Breeding Populations, 1955-2009, (July 1, 2009).
Abstract
This report summarizes information about the status of duck populations and wetland habitats during spring 2009, focusing on areas encompassed by the U.S. Fish and Wildlife (USFWS) and Canadian Wildlife Services' (CWS) Waterfowl Breeding Population and Habitat Survey. We do not include information from surveys conducted by state or provincial agencies. In the traditional survey area, which includes strata 1-18, 20-50, and 75-77 (Figure 1), the total duck population estimate (excluding scoters [Melanitta spp.], eiders [Somateria spp. and Polysticta stelleri], long-tailed ducks [Clangula hyemalis], mergansers [Mergus spp. and Lophodytes cucullatus], and wood ducks [Aix sponsa]) was 42.0 ± 0.7 [SE] million birds. This estimate represents a 13% increase over last year's estimate of 37.3 ± 0.6 million birds and was 25% above the long-term averagea (1955{2008; Table 1). Estimated mal- lard (Anas platyrhynchos) abundance was 8.5 ± 0.2 million birds, which was a 10% increase over last year's estimate of 7.7 ± 0.3 million birds and 13% above the long-term average (Table 2). Estimated abundance of gadwall (A. strepera; 3.1 ± 0.2 million) was similar to the 2008 estimate and 73% above the long-term average (Table 3). Estimated American wigeon abundance (A. americana) was similar to 2008 and the long-term average (‒1% and ‒5%, respectively; Table 4). Estimated abundances of green-winged teal (A. crecca; 3.4 ± 0.2 million; Table 5) and blue-winged teal (A. discors; 7.4 ± 0.4 million; Table 6) were similar to last year's estimates and well above their long-term averages (+79% and +60%, respectively). Northern shovelers (A. clypeata; 4.4 ± 0.2 million) were 25% above the 2008 estimate and remain well above their long-term average (+92%; Table 7). The estimate for northern pintails (A. acuta) was 3.2 ± 0.2 million, which was 23% above the 2008 estimate of 2.6 ± 0.1 million, and 20% below the long-term average (Table 8). Estimated abundance of redheads (Aythya americana; 1.0 ± 0.1 million) was similar to last year and 62% above the long-term average (Table 9). The canvasback estimate (A. valisineria; 0.7 ± 0.06 million) was 35% above the 2008 estimate (0.5 ± 0.05 million) and similar to the long-term average (Table 10). The scaup estimate (A. affinis and A. marila combined; 4.2 ± 0.2 million) was similar to that of 2008 and 18% below the long-term average of 5.1 ± 0.05 million (Table 11).