July 29, 2005


Migrating ducks returning to important nesting areas in the north-central United States and southern Canadian prairies early this spring were greeted by dry conditions, according to the U.S. Fish and Wildlife Service's annual waterfowl survey.

However, the U.S. and Canadian prairies received substantial rain in late May and during the entire month of June that recharged wetlands and encouraged growth of vegetation. While this improved habitat quality on the prairies, it probably came too late to benefit early-nesting species or waterfowl from breeding farther north.

"We are certainly excited about the amount of rain that fell on the prairies and parklands since late May," said Acting Service Director Matt Hogan. "We don't know what impact it will have on production but likely the rains benefited late nesting and re-nesting efforts. It does bode well for maintaining nesting water this year and perhaps better habitat conditions next spring."

The Waterfowl Breeding Population and Habitat Survey, which is 50 years old this year, is the largest and most comprehensive survey of its kind in the world. The survey samples 2.2 million square miles across the northcentral and northeastern United States, Canada and Alaska. Pilot-biologists who fly the survey estimate the number of ducks in the continent's most important nesting grounds, commonly referred to as the traditional survey area. Many State and Canadian partners help collect the data.

In the traditional survey area of western Canada, Alaska and the northcentral United States, the total duck population estimate (excluding scoters, eiders, long-tailed ducks, mergansers and wood ducks) is 31.7 million birds. This estimate is not statistically different from last year's estimate of nearly 32.2 million birds. It is 5 percent below the 1955-2004 average.

- Mallard abundance was 6.8 million birds, which is 9 percent below last year's estimate of 7.4 million birds and 10 percent below the long-term average.

- Blue-winged teal were estimated at 4.6 million birds. This value was similar to last year's estimate of 4.1 million birds and the long-term average.

- Among other duck species, northern pintail, at 2.6 million, and northern shovelers, at 3.6 million, were significantly above 2004 estimates, while the estimate for the gadwall, 2.2 million, was below the 2004 survey results. Scaup abundance, at 3.4 million, was the lowest ever recorded on the survey. Biologists are studying the reasons for the decline.

- In comparison with long-term averages, the 2005 estimates were higher for gadwall -- up 30 percent, northern shoveler -- up 67 percent, and green-winged teal at 2.2 million -- up 16 percent. The 2005 estimates as compared to the long-term average were lower for northern pintail -- down 38 percent, American wigeon at 2.2 million -- down 15 percent, and scaup down 35 percent. Estimates for the redhead, at 592,000, and canvasback, at 521,000, were similar to their long-term averages.

Across traditional duck nesting areas of western Canada and the north-central United States, total pond numbers were 37 percent higher than last year. This increase is primarily the result of changes in Canada, where pond numbers increased 56 percent to 3.9 million ponds. In the northcentral United States, nearly 1.5 million ponds were observed, similar to last year's estimate.

Nesting habitat was particularly poor in South Dakota because below average precipitation allowed tilling and grazing of wetland margins. Birds may have flown over the State for wetter conditions to the north.

Water levels and upland nesting cover were better in North Dakota and eastern Montana, and wetland conditions in these regions improved markedly during June with the onset of well-above average precipitation. The prairies of southern Alberta and southwestern Saskatchewan were quite dry in early May.

The Canadian Parklands fared much better this year, due to a combination of several years of improving nesting cover and above-normal precipitation last fall and winter. These areas were in good-to-excellent condition at the time of the survey. and conditions have remained good through early summer. Record high levels of rain flooded portions of lower elevation prairie areas of central Manitoba during April, producing fair or poor nesting conditions for breeding waterfowl in some areas. Portions of northern Manitoba and northern Saskatchewan also experienced flooding, resulting in only fair conditions for breeding waterfowl.

Most of the Northwest Territories were in good condition due to adequate water and a timely spring thaw that made habitat available to early-nesting species. However, dry conditions in eastern parts of the Northwest Territories and northeastern Alberta resulted in low water levels in lakes and ponds and the complete drying of some wetlands. Habitat was classified as fair in these areas.

Annual survey results help guide the Service in managing its waterfowl conservation programs under the 1918 Migratory Bird Treaty Act. The Service works in partnership with State representatives from the four flyways - the Atlantic, Mississippi, Central and Pacific - to establish regulatory frameworks for waterfowl hunting season lengths, dates and bag limits.

Alaska was in mostly excellent condition, with an early spring and good water, except for a few flooded river areas and the North Slope, where spring was late.

In the eastern United States and Canada, habitat conditions were good due to adequate water and relatively mild spring temperatures. The exceptions were the coast of Maine and the Maritimes, where May temperatures were cool and some flooding occurred along the coast and major rivers. Also, below-normal precipitation left some habitats in fair to poor condition in southern Ontario at the time of the survey. However, precipitation in this region following survey completion improved habitat conditions.

In eastern North America, the Service and Canadian Wildlife Service are developing new methods of integrating data from multiple surveys. As a result, estimates for the eastern survey area are not directly comparable to those reported in previous years. In the eastern survey area, the American black duck population estimate was 827 thousand birds, a decrease of 24 percent from last year's estimate of 1.1 million but similar to the 1999-2004 average. The estimate for the mallard, at 412 thousand birds, declined 36 percent from 2004, but was similar to the 1999-2004 average.

To see the full results of the survey, which includes graphs and maps, please see http://migratorybirds.fws.gov/reports/reports.html. To see how the survey is conducted and learn about the Survey's 50th anniversary, please see http://www.fws.gov/waterfowlsurveys/.