US Fish & Wildlife Service

 

Date of this Version

2011

Citation

Published in Administrative Report (2011) 26 pages.

Abstract

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 45.6 ± 0.8 [SE] million birds. This represents an 11% increase over last year's estimate of 40.9 ± 0.7 million, and is 35% higher than the long-term averagea (1955-2010; Table 1). The estimated mallard (Anas platyrhynchos) abundance was 9.2 ± 0.3 million, which was 9% above the 2010 estimate of 8.4 ± 0.3 million, and 22% above the long-term average of 7.5 ± 0.04 million (Table 2). Estimated abundance of gadwall (A. strepera; 3.3 ± 0.2 million) was similar to the 2010 estimate and 80% above the long-term average (1.8 ± 0.02 million; Table 3). The estimate for American wigeon (A. americana; 2.1 ± 0.1 million) was 14% below the 2010 estimate and 20% below the long-term average (Table 4). The estimated abundance of green-winged teal (A. crecca) was 2.9 ± 0.2 million, which was 17% below the 2010 estimate and 47% above the long- term average (Table 5). The estimate of blue-winged teal abundance (A. discors) was 8.9 ± 0.4 million, which was 41% and 91% above the 2010 estimate and the long-term average, respectively (Table 6). The estimate for northern pintails (A. acuta; 4.4 ± 0.3 million) was 26% above the 2010 estimate of 3.5 ± 0.2 million and similar to the long-term average (Table 7). The northern shoveler (A. clypeata) estimate was 4.6 ± 0.2 million which was 14% above the 2010 estimate and 98% above the long-term average (Table 8). Redhead abundance (Aythya americana; 1.4 ± 0.1 million) was 27% above the 2010 estimate and 106% above the long-term average (Table 9). The canvasback estimate (A. valisineria; 0.7 ± 0.05 million) was similar to the 2010 estimate and 21% above the long-term average (Table 10). Estimated abundance of scaup (A. anis and A. marila combined; 4.3 ± 0.3 million) was similar to that of 2010 and 15% below the long-term average of 5.1 ± 0.05 million (Table 11).



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