Prairie Duck Populations Respond to Wet Habitat Conditions
MEMPHIS, Tenn., July 12, 2005 – Wetland conditions and duck populations on the prairies have shifted dramatically over what
|Duck breeding nubmers are mixed, according to this year's USFWS breeding birds survey.|
they were just a couple of years ago. The 2005 Waterfowl Breeding Population and Habitat survey was released Friday by the U.S. Fish and Wildlife Service, Division of Migratory Bird Management.
Prairie Canada is extraordinarily wet with 56 percent more ponds than were counted in 2004 and 17 percent more than the long-term average count. The U.S. prairies didn’t change significantly in overall number of ponds. However, large tracts of the best waterfowl habitat in the eastern U.S. prairie pothole region were extremely dry when early breeding ducks, such as pintails and mallards, arrived.
Total breeding duck numbers were relatively unchanged from last year at 31.7 million birds, slightly down from the 32.2 million estimated in 2004. Breeding ducks responded extensively to the improved habitat conditions on the Canadian prairies. Ducks settling in prairie Canada increased by 31 percent from the previous year but decreased in the U.S. prairies by 15 percent.
“The counts for early-nesting pintails and mallards in the Dakotas were lower in early May because of the parched landscapes that the ducks encountered when they arrived,” said Dr. Jim Ringelman, director of conservation programs at DU's Great Plains regional office in Bismarck, N.D. “However, heavy and continuing rains from the end of April until the present have completely changed things. We expect the late-nesting species and re-nesting birds to do well.”
Since the survey’s completion in May, rainfall has been abundant and extensive across all prairie-breeding areas in both countries. Indeed, many of Canada’s farmers, who are DU’s partners in a multitude of waterfowl habitat conservation projects, are suffering greatly from too much water.
The abundant water should assure high brood survival for hens that successfully hatch nests. It’s also encouraging a strong re-nesting effort, as hens that lost early nests will persist in re-nesting well into the summer. The extremely wet conditions also are recharging groundwater supplies, which should help sustain many wetlands into next spring.
Each of the 10 most common duck species has responded differently to the present conditions. Some with increases in numbers while the count for others is somewhat disappointing. Mallards and pintails illustrate this contrast best. The breeding mallard count was 6.8 million birds, the lowest estimated number since 1993. The pintail count was 2.6 million birds, up from 2.2 million in 2004.
Mallards declined in far northern areas, indicating that a high proportion of the population did stop on the prairies to breed. Southern Alberta had 12 percent more mallards than last year, southern Saskatchewan was up 7 percent and southern Manitoba was up 16 percent. As anticipated, numbers declined by 22 percent in Montana and the western Dakotas and 8 percent in the eastern Dakotas.
Dr. Bruce Batt, DU’s chief biologist, points out that despite the 56 percent increases in wetlands across prairie Canada, mallards are 17 percent below the population goals of the North American Waterfowl Management Plan (NAWMP).
“This is not unusual,” Batt said. “We expect a lag between increased pond numbers and duck populations, because it takes more than one breeding season for the population to catch up to the increased habitat Nevertheless, the mallard numbers are not as strong as we hoped they would be.”
“The positive response in pintail numbers is welcome,” Batt said. “It appears that a large proportion of the population did settle to breed in prairie Canada. Research being conducted by Ducks Unlimited Canada in Saskatchewan is yielding good pintail nest success. We think this will result in a modest recovery of pintail numbers, which have been languishing near record low numbers for several years. This will be quite helpful as we continue to conserve and restore critical breeding habitat under our pintail conservation initiative that is designed to sustain a more prolonged recovery of the species.” Pintails are still 54 percent below the NAWMP goal.
Three other species showed increases in 2005. These are: northern shoveler at 3.6 million, up 28 percent and 80 percent above the NAWMP goal; American wigeon at 2.2 million, up 12 percent but still 26 percent below NAWMP goal levels: and blue-winged teal at 4.6 million, up 13 percent and just 2 percent below the population goal.
Five other species declined in numbers. The gadwall estimate was 2.2 million birds, down 16 percent to their lowest level since 1993 even though they are still 45 percent above the NAWMP goal. Green-winged teal are down 12 percent at 2.2 million birds, their lowest number since 1998 but still 14 percent above the NAWMP goal. Redheads are relatively unchanged at 592,000, down 2 percent since last year and 8 percent below goal level; canvasbacks are at 521,000 birds, down 16 percent from last year and 4 percent below the NAWMP goal, and; scaup are at their lowest estimate ever at 3.39 million, down 11 percent from 2004, and 46 percent below the goal level.
Waterfowl managers are concerned about scaup. They will benefit from several DU habitat programs including the North American Grasslands Conservation, Living Lakes and Western Boreal Forest initiatives. They are also the subject of several research projects supported by DU and other partners to discover the underlying causes of the scaup decline. The majority of them nest in the Western Boreal Forest where habitat changes may be affecting scaup.
“This is a very unusual year with both positive and disappointing results emerging from the surveys,” said Dr. Alan Wentz, DU’s group manager for conservation programs.
“Never has the urgency for habitat conservation been clearer,” Wentz continued. “It is critically important to keep the breeding grounds across the U.S. and Canada intact so ducks can take advantage of good moisture conditions wherever they occur, just as they did this year in shifting to the very wet Canadian prairie region. We expect a reasonable recovery of duck numbers as a result of this breeding season.”
The Waterfowl Breeding Population and Habitat surveys are conducted by the U.S. Fish and Wildlife Service and the Canadian Wildlife Service throughout May and June on the main waterfowl breeding habitats in the mid-continent area across to Alaska. The data for the Eastern Survey Zone are not yet available. These surveys serve as the scientific basis for many management programs across the continent including the setting of hunting regulations. This is the 50th consecutive year that the survey has been conducted.
Contact Dr. Bruce Batt, Ducks Unlimited Chief Biologist, 901-758-3786
With more than a million supporters, Ducks Unlimited is the world’s largest and most effective wetland and waterfowl conservation organization. The United States alone has lost more than half of its original wetlands − nature’s most productive ecosystem − and continues to lose more than 100,000 wetland acres each year.