Trends in Duck Breeding Populations 1955-2012

Abstract

This report summarizes information about the status of duck populations and wetland habitats during spring 2012, focusing on areas encompassed by the U.S. Fish & Wildlife (USFWS) and Canadian Wildlife Services\u27 (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 48.6 ± 0.8 [SE] million birds (Figure 3, Appendix A). This represents a 7% increase over last year\u27s estimate of 45.6 ± 0.8 million, and is 43% higher than the long-term averagea (1955-2011; Table 1). Estimated mallard (Anas platyrhynchos) abundance was 10.6 ± 0.3 million, which was 15% above the 2011 estimate of 9.2 ± 0.3 million, and 40% above the long-term average of 7.6 ± 0.04 million (Table 2). Estimated abundance of gadwall (A. strepera; 3.6 ± 0.2 million) was similar to the 2011 estimate and 96% 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 similar to the 2011 estimate and 17% below the long-term average of 2.6 ± 0.02 million (Table 4). The estimated abundance of green-winged teal (A. crecca) was 3.5 ± 0.2 million, which was 20% above the 2011 estimate and 74% above the long-term average (2.0 ± 0.02 million; Table 5). The estimates of blue-winged teal (A. discors; 9.2 ± 0.4 million) and northern shoveler (A. clypeata; 5.0 ± 0.3 million) were similar to their 2011 estimates and 94% and 111% above the long-term averages of 4.8 ± 0.04 million (Table 6) and 2.4 ± 0.02 million (Table 7), respectively. The estimate for northern pintails (A. acuta; 3.5 ± 0.2 million) was 22% below the 2011 estimate of 4.4 ± 0.3 million and 14% below the long-term average of 4.0 ± 0.04 million (Table 8). The estimated abundance for redheads (Aythya americana; 1.3 ± 0.1 million) and canvasbacks (Aythya valisineria; 0.8 ± 0.07 million) were similar to their 2011 estimates and were 89% and 33% above their long- term averages of 0.7 ± 0.01 million (Table 9) and 0.6 ± 0.01 million (Table 10), respectively. Estimated abundance of scaup (A. affinis and A. marila combined; 5.2 ± 0.3 million) was 21% above the 2011 estimate and similar to the long-term average of 5.0 ± 0.05 million (Table 11)