ARTICLE: Extremely Dry Conditions Greet Ducks Returning To Prairie Breeding Grounds From the U.S. Fish & Wildlife Service
Migrating ducks returning to important nesting areas in the north-central U.S. and southern Canadian prairies this spring were greeted by extremely dry conditions, according to the U.S. Fish and Wildlife Service's annual survey. Although water levels on the prairies declined dramatically this spring, the effects on duck populations have not yet been felt and the total population of breeding ducks remained near their long-term average. The total population of breeding ducks in parts of Canada and the northern United States fell to approximately 31.2 million birds in areas that have traditionally been surveyed. That number represents a decline of 14 percent from last year's population of 36.1 million birds, and is 6 percent below the long-term average since surveys began in 1955.
"While water levels have declined and duck breeding populations are down from the exceptional situation we saw between 1995 and 2000, it's encouraging that total duck populations are only slightly below their long-term average," said Tom Melius, assistant director for Migratory Birds and State Programs. "Most species in the midcontinent region also are near their long-term averages, but we continue to have concerns over the status of pintails and scaup, whose populations did not respond to the run of good habitat conditions."
The Waterfowl Breeding Ground Population and Habitat Survey, the largest and most comprehensive survey of its kind in the world, samples 1.3 million square miles across the north-central United States, south-central and northern Canada, and Alaska. The survey estimates the number of ducks in the continent's most important nesting grounds, commonly referred to as the traditional survey area.
Annual survey results help guide the Service in managing its waterfowl conservation programs under authority of the 1918 Migratory Bird Treaty Act. The Service works in partnership with state representatives from the four flyways - the Atlantic, Mississippi, Central and Pacific - that waterfowl and other birds use during their migrations, to establish regulatory frameworks on waterfowl hunting season lengths, dates and bag limits.
The breeding population estimate for mallards in the traditional survey area, at 7.5 million birds, was largely unchanged from last year and remained near the long-term average. Surveys of mallards conducted in the Great Lakes states (Michigan, Minnesota, and Wisconsin) indicated the population had increased from 780,000 in 2001 to 1 million this year. The combined estimates of mallards from the traditional survey area and from the Great Lakes states (8.5 million) are used for setting duck hunting regulations through the Adaptive Harvest Management (AHM) process.
Blue-winged teal numbers, at 4.2 million, fell 27 percent from last year's estimate, but are near their long-term average. The breeding population estimate for green-winged teal of 2.3 million birds is comparable to last year, but is 28 percent above its long-term average.
Most other species experienced declines from last year's estimates, including gadwall (down 17 percent from last year but 37 percent above its long-term average) and northern shovelers (down 30 percent to 2.3 million, 10 percent above the long-term average). The pintail breeding population continues to decline, falling 46 percent from last year's survey to 1.8 million, a number 58 percent below the long-term average. Populations of scaup, American wigeon and canvasbacks were largely unchanged from last year, yet remain below their long-term averages.
The presence of water is critical to breeding success for waterfowl. Conditions in the traditional survey area were dry this year, due to below average winter and spring precipitation. Drought conditions hit much of western Montana and southern Saskatchewan, Manitoba and Alberta. Aerial surveys found birds crowded on the remaining ponds. Survey results show that many prairie-nesting species, such as mallards, flew over the prairies and parklands to boreal forests farther north, where wetland conditions are more stable.
Dry conditions were reflected in a 41 percent decline in the number of ponds found during May surveys in southern Canada and the north-central United States. May pond numbers fell to 2.7 million, from 4.6 million ponds last year, 45 percent below the long-term average. The 1.439 million May ponds found in southern Canada this year was the lowest number since that survey began in 1961. The previous low was 1.443 million in 1981. May ponds in the U.S. portion of the survey were down 32 percent this year compared to 2001.
"Periodic drought, though it may lead to short-term declines in duck numbers, is a characteristic feature of the Prairie Pothole Region and is necessary for the long-term productivity of prairie wetlands. Conservation efforts to restore wetland basins and improve nesting cover are continuing to make significant progress, and will enhance the value of water once it returns to the prairies," added Melius.
The cold spring temperatures found in much of the traditional survey area had another negative effect on nesting waterfowl this year. Winter-like conditions in May halted migration for two weeks, while lingering snow and ice may have caused some nest loss in the prairies and parklands.
Since the breeding ground surveys were flown, several inches to a foot or more of rain and/or snow have fallen over portions of Montana, the western Dakotas and the southern prairie provinces of Canada. However, most biologists believe that the precipitation was too late to help nesting waterfowl this year.
Habitat conditions in the eastern areas of Canada and the United States, which are not part of the traditional survey area, were good to excellent in southern regions, but poor in the north due to delayed spring ice break-up. At 4.4 million birds, the total breeding duck population in the eastern survey area is 32 percent higher than last year's level and 41 percent higher than the 1996-2001 average. This survey includes the eastern provinces and northeastern states and is a part of the Service's effort to expand the surveys outside the traditional midcontinent area. Most species estimates were similar to last year.
The entire 2002 Trends in Waterfowl Breeding Populations report can be downloaded from the Service's Web site at: http://migratorybirds.fws.gov/reports/reports.html.
The U.S. Fish and Wildlife Service is the principal Federal agency responsible for conserving, protecting and enhancing fish, wildlife and plants and their habitats for the continuing benefit of the American people. The Service manages the 94-million-acre National Wildlife Refuge System which encompasses more than 535 national wildlife refuges, thousands of small wetlands and other special management areas. It also operates 70 national fish hatcheries, 64 fishery resource offices and 78 ecological services field stations. The agency enforces Federal wildlife laws, administers the Endangered Species Act, manages migratory bird populations, restores nationally significant fisheries, conserves and restores wildlife habitat such as wetlands, and helps foreign governments with their conservation efforts. It also oversees the Federal Aid program that distributes hundreds of millions of dollars in excise taxes on fishing and hunting equipment to state fish and wildlife agencies.
For more information about the U.S. Fish and Wildlife Service, visit them at http://www.fws.gov
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