US Fish & Wildlife Service
Date of this Version
7-24-2002
Citation
U.S. Fish and Wildlife Service. 2002. Waterfowl population status, 2002. U.S. Department of the Interior, Washington, D.C. 51pp.
Abstract
In the traditional survey area (strata 1-18, 20-50, and 75-77), total duck abundance was 31.2 + 0.5 [SE] million birds. This was 14% below (P< 0.001) last year’s estimate of 36.1 ± 0.6 million birds, and 6% below the long-term (1955-2001) average (P<0.001). Mallard (Anas platyrhynchos) abundance was 7.5 ± 0.2 million, similar to (P=0.23) the 2001 estimate of 7.9 ± 0.2 million, and essentially identical to the long-term average (P=1.00). Blue-winged teal (A. discors) abundance was 4.2 ± 0.2 million, which was 27% below last year’s estimate of 5.8 ± 0.3 million (P<0.001), but similar to the long-term average (P=0.22). Gadwall (A. strepera; 2.2 ± 0.1 million, -17%), shovelers (A. clypeata; 2.3 ± 0.1 million, -30%), and pintails (A. acuta; 1.8 ± 0.1 million, -46%) were below 2001 estimates (P<0.02). Wigeon (A. americana; 2.3 ± 0.1 million), green-winged teal (A. crecca; 2.3 ± 0.1 million), redheads (Aythya americana; 0.6 ± 0.1 million), canvasbacks (Aythya valisineria; 0.5 ± 0.1 million), and scaup (Aythya marila and A. affinis combined; 3.5 ± 0.2 million) were unchanged from 2001 estimates. Gadwall (+37%), green-winged teal (+28%), and shovelers (+10%) all remained above their long-term averages, whereas wigeon (-12%), pintail (-58%), canvasback (-14%), and scaup numbers (-34%) were below long-term averages. Northern pintails and scaup were the lowest and second lowest counts on record, respectively. The redhead estimate was similar to the long-term average. Below-average winter and spring precipitation in the prairies and parklands were reflected in pond counts much lower than in 2001. Total May ponds (U.S. prairies and prairie and parkland Canada combined) of 2.7 ± 0.1 million were the second lowest since 1974, when this estimate was first recorded, 41% below last year’s estimate of 4.6 ± 0.1 million (P<0.001), and 45% below (P<0.001) the long-term average. The projected mid-continent mallard fall flight index is 8.9 million, statistically similar to last year's. The eastern survey area is comprised of strata 51-56 and 62-69. The 2002 total duck population estimate for this area was 4.4 ± 0.3 million birds, 32% higher than last year's (3.3 ± 0.3 million, P=0.01), and 41% higher than the 1996-2001 average (P<0.001). Numbers of most individual species were similar to those of last year, with the exception of mergansers (Lophodytes cucullatus and Mergus spp.; 0.8 ± 0.1 million, +90%, P<0.001) and green-winged teal (0.7 ± 0.1 million, +174%, P=0.01), which increased compared to last year. Mergansers (+68%) and green-winged teal (+102%) were also above their 1996-2001 averages, as were scoters (Melanitta spp.; 0.3 ± 0.1 million, +178%, P=0.01). Estimates for all other species were similar to last year's estimates and to long-term averages.