LITTLE ROCK (AGFC) - The U.S. Fish and Wildlife Service has released its preliminary report on mid-continent breeding ducks and habitats, based on surveys conducted in May. The total duck population is nearly 41 million, which is similar to last year's estimate and 21 percent above the long-term average.
Habitat conditions across the Canadian prairies and parklands were generally good. During the survey and into early summer, many regions important to breeding ducks received significant precipitation, which could increase later breeding efforts and ensure brood survival. If these wet conditions continue, prospects going into the winter and possibly into spring 2011 could be favorable as well.
Highlights from the survey in the north-central United States, south-central and northern Canada, and Alaska (the traditional survey area) include:
- Estimated mallard abundance was 8.4 million birds, which was similar to the 2009 estimate of 8.5 million birds and 12 percent above the long-term (1955-2009) average.
- Estimated abundance of American wigeon (2.4 million) was similar to 2009 and to the long-term average.
- Gadwall estimated abundance (3 million) was similar to 2009 and 67 percent greater than the long-term average.
- The estimated abundance of green-winged teal was 3.5 million, which was similar to the 2009 estimate and 78 percent above their long-term average of 1.9 million.
- Blue-winged teal estimated abundance was 6.3 million, which was 14 percent below the 2009 estimate, but 36 percent above the long-term average of 4.7 million.
- Estimates of northern shovelers (4.1 million) and redheads (1.1 million) were similar to 2009 and were 76 percent and 63 percent above long-term averages.
- The northern pintail estimate of 3.5 million was similar to the 2009 estimate and 13 percent below the long-term average of 4 million.
- The canvasback estimate of 0.6 million was similar to the 2009 estimate and to the long-term average.
- The combined (lesser and greater) scaup estimate of 4.2 million was similar to that of 2009 and 16 percent below the long-term average of 5.1 million.
Arkansas Game and Fish Commission waterfowl biologist Luke Naylor said this year's survey results are encouraging and bode well for waterfowl hunting opportunity with the anticipation of another 60-day duck season. "Although Arkansas receives migrating ducks, including mallards, from a vast area of the Prairie Pothole regions of particular importance as sources of mallards saw good to excellent habitat conditions this spring," Naylor said. "However, as many experienced duck hunters know high spring counts are not necessarily predictors of high hunting success for individual hunters. Local habitat quality and precipitation patterns leading up to and during the fall and winter will play an important role in the number of ducks hunters see and have an opportunity to harvest," he cautioned.
From mid- to late May, the USFWS teams with the Canadian Wildlife Service and state, provincial and tribal agencies to conduct the survey, which is designed to estimate the breeding waterfowl population's size and to evaluate habitat conditions. Each year, pilot biologists and observers fly fixed-wing airplanes at low altitude (150 feet) on established transect lines throughout the continent's major waterfowl habitat areas. The survey covers more than 55,000 linear miles representing more than 2.1 million square miles of the northern United States and Canada.
The aerial waterfowl count is complemented by surveys ground crews conduct to make up for the fact that some birds aren't visible from the air. It's easy to imagine, for example, that large, bright canvasbacks are much easier to see than small, cryptically colored green-winged teal. The disparity between the aerial and ground counts of individual species helps biologists develop visibility correction factors to apply to aerial counts.
First, they use their aerial counts and adjust them based on these visibility correction factors, then extrapolate the sampled transect results to the entire survey area. Over the last 55 years, the result has been an estimate of breeding duck numbers using key nesting areas.
In some of the far northern regions of the traditional survey area, like the Boreal Forest, ground counts simply aren't feasible, as access to the land is extremely limited. In these situations, the USFWS changes its aerial game plan by conducting the visibility surveys along a limited number of transects in helicopters rather than fixed-wing planes. Since the helicopters move slower and offer greater visibility, corrections can be developed from fixed-wing versus helicopter observations.
The entire "Trends in Duck Breeding Populations, 1955-2010" report can be downloaded from the Service's Web site at http://www.fws.gov/migratorybirds/NewReportsPublications/PopulationStatus/Trends/TrendReport2010.pdf.
2010 Estimates of May Ponds and Breeding Ducks (in millions)