2008 Waterfowl Forecast
Drought on the prairies reduced duck production this year, but most waterfowl populations remain healthy
by Matt Young
Like the stock market, North America's waterfowl populations are dynamic, soaring to lofty heights in some years only to plummet back to earth in others. While economic forces have a powerful influence on stock values, waterfowl production is largely determined by habitat conditions on the breeding grounds. In 2008, widespread drought in the prairie "duck factory" led to a sharp decline in the quality and quantity of waterfowl habitat. According to the U.S. Fish and Wildlife Service (USFWS), the May pond estimate—the "market index" for wetland abundance on the prairies—fell by 37 percent from 7 million ponds in 2007 to 4.4 million ponds this year.
This year's total breeding duck estimate in the traditional survey area was 37.3 million birds—down 9 percent from the previous year, but still 11 percent above the long-term (1955-2007) average. The status of the 10 most common ducks varied by species (see chart on page 56). Top performers included redheads, which had a record breeding population this year, and green-winged teal, which had the second largest breeding population on record. Of particular importance to waterfowl hunters, this year's mallard breeding population of 7.7 million birds was down slightly from last year and was near the 10-year and long-term averages. Populations of canvasbacks, pintails, shovelers, and gadwalls showed significant declines in 2008, while blue-winged teal, wigeon, and scaup numbers were statistically similar to last year.
Ducks Unlimited's Chief Biologist Dale Humburg provides some perspective on this year's wetland conditions and waterfowl numbers. "Most waterfowl populations remain in good shape, with eight of the 10 most common duck species near or above their long-term averages," he says. "Pintails and scaup, however, remain a significant concern. Habitat conditions continue to drive waterfowl populations. With widespread drought on the prairies in 2008, we can expect a smaller fall flight this year, although the difference may not be noticeable to waterfowl hunters in many areas.
"Dry cycles are a natural part of the prairie ecology and are vital to maintaining wetland productivity," Humburg adds. "Equally important to note is that more stable wetland areas such as the boreal forest also provide critical breeding habitat and help sustain waterfowl populations when the prairies are dry. The real threat to waterfowl populations isn't drought; it's habitat loss. Unfortunately, we're losing small wetlands and grasslands on a massive scale on the prairies right now. If these habitat losses continue, we are likely to see lasting declines in prairie duck populations."
May pond counts and waterfowl breeding population estimates are compiled during extensive air and ground surveys conducted by the USFWS, Canadian Wildlife Service, and state and provincial wildlife agencies. These spring surveys provide the scientific basis for many waterfowl management decisions across the continent, including the setting of hunting regulations. The following report provides an overview of the status of habitat conditions and waterfowl populations across key breeding areas in the United States and Canada.
Pacific Flyway
Most Pacific Flyway waterfowl are raised in Alberta, Alaska, British Columbia, the Northwest Territories, and the western United States. On the prairies of southern Alberta, May pond numbers were down 31 percent in 2008. Breeding duck numbers, however, were similar to last year's estimate and the long-term average.
DU Canada biologist Ian McFarlane reports that shortly after waterfowl surveys were conducted, heavy precipitation improved wetland conditions across much of southern Alberta, benefiting breeding waterfowl. "Periodic showers and locally heavy rains maintained and locally improved wetland habitat on the prairies and much of the southern aspen parklands," he says. "DU staff saw an abundance of broods, particularly of late-nesting ducks, in these areas. Overall, average production was anticipated in Alberta this year."
Large numbers of Pacific Flyway waterfowl breed in the western boreal forest of northern Alberta, northeastern British Columbia, and the Northwest Territories. In 2008, breeding duck numbers were up 13 percent in this region, with many individual species posting increases as well. In Alaska and the Yukon, breeding ducks declined 10 percent but remained 42 percent above the long-term average. This year's pintail count of 1.25 million birds in the Alaska-Yukon-Old Crow Flats survey area accounted for almost half the continental pintail estimate in 2008.
"Spring was late in arriving to many areas of the western boreal forest, but the weather moderated in time for most waterfowl to breed," says DU biologist Dr. Fritz Reid. "Widespread rainfall in June also improved wetland conditions. DU staff saw good numbers of broods in many areas, suggesting that waterfowl production was typical across much of the region this summer."
Dry spring weather plagued breeding waterfowl in many areas of the western United States. In California, breeding mallards were down by 23 percent. "Following the driest spring on record, severe drought conditions continue across much of California," Reid says. "A lack of rainfall in the Central Valley greatly reduced wetland habitat for breeding waterfowl this spring, which limited production of mallards and other ducks."
This was a generally good year for most Pacific Flyway goose populations. Favorable weather and habitat conditions on northern breeding areas should result in fall populations of geese and brant that are similar to or larger than last year, with the possible exception of Wrangle Island snow geese, which suffered poor production on their breeding grounds.
Central Flyway
The majority of Central Flyway waterfowl are raised on the prairies, as well as in the western boreal forest and the Arctic. Saskatchewan is perhaps the most important breeding area for midcontinent waterfowl populations. In 2007, an abundance of water, especially in the parklands, helped duck numbers in this vast prairie province soar to the highest level in more than two decades. Unfortunately, in 2008, below-average winter snowfall and dry spring weather led to a 46 percent decline in May pond numbers. Total duck numbers in this region were down 19 percent from last year's estimate, but remained 20 percent above the long-term average.
Although waterfowl production was poor on the grasslands of southern Saskatchewan, DU Canada biologist Dr. Michael Hill reports that breeding ducks fared better in the parklands, where wetland conditions were more favorable. "Summer rains helped maintain water levels in many areas of the parklands," he says. "Good numbers of broods were observed by our field staff in these areas, with mallard, gadwall, blue-winged teal, and northern shoveler broods being most common."
As on the prairies of Saskatchewan, dry weather prevailed across much of the U.S. Great Plains when waterfowl returned this spring. May pond numbers in the north-central United States were down 30 percent in 2008. Populations of most duck species declined across this region as well. Roughly 3.4 million breeding ducks were surveyed in South Dakota, a number similar to last year's estimate but 54 percent above the long-term average. North Dakota's breeding population estimate of approximately 3.8 million ducks was down 22 percent from last year but remained 25 percent above the long-term average. Approximately 550,000 breeding ducks were surveyed in Montana in 2008, a 42 percent decline from last year and a level 39 percent below the long-term average.
"With the exception of a few areas like far eastern South Dakota, breeding ducks were limited by a lack of suitable wetland habitat," says DU biologist Dr. Scott Stephens. "In North Dakota, for example, our research crews found only about half as many duck nests as we did last year on the same sites. We did receive much needed precipitation in late spring and early summer, benefiting late nesters like gadwalls and bluewings, but production appears to have been down considerably overall compared to the past several years."
The outlook was much brighter for Central Flyway goose populations. Favorable spring weather resulted in average to above-average production on many northern breeding areas, and most goose populations should have a fall flight similar to or larger than that of last year. Midcontinent lesser snow, Ross's, and white-fronted geese appear to have had a good hatch, and fall populations of these species should be up this year in the flyway.
Mississippi Flyway
Most Mississippi Flyway waterfowl are raised on the prairies of the United States and Canada, as well as in Ontario, the Great Lakes states, western boreal forest, and Arctic. In southern Manitoba, extremely dry spring weather caused a 27 percent decline in May pond numbers. Breeding duck numbers were similar to last year, but were 21 percent below the long-term average.
DU Canada biologist Mark Francis reports that late spring and early summer rains improved wetland conditions in southwestern Manitoba after waterfowl surveys were completed. "Cool, wet weather had a positive effect on what were shaping up to be pretty bleak conditions for breeding waterfowl in the Manitoba pothole region," he says. "The much needed precipitation recharged some seasonal wetlands and delayed hay harvesting. DU staff observed good brood numbers in areas where water was available, and new broods continued to appear through the last week of July, indicating there was a strong renesting effort."
Waterfowl breeding habitat was more abundant in neighboring Ontario, where parts of the province received record June rainfall. "Good wetland conditions were present across much of the province this spring, and breeding pairs were widely distributed across the abundant habitat," says DU Canada biologist Scott Muir. "Frequent rains delayed hay harvesting, benefitting renesting birds, and sightings of broods of various sizes and ages confirmed there was a protracted breeding effort typical of waterfowl in Ontario."
In the Great Lakes states, duck numbers and habitat conditions were variable. Abundant runoff from heavy snow accumulations and above-average spring precipitation generally improved wetland conditions across Minnesota and Wisconsin. In both states, total breeding duck numbers were well above last year's estimates and the long-term average. Waterfowl habitat conditions were less favorable in Michigan, where mallard numbers declined 40 percent this year and were at the lowest level since surveys began in 1992.
Breeding success among Mississippi Flyway goose populations was also mixed. Harsh weather in the north reduced production among Mississippi Valley Population Canada geese, while Eastern Prairie Population and Southern James Bay Population Canada geese appear to have had average production. A good hatch was reported among midcontinent lesser snow, Ross's, and white-fronted geese, and fall populations of these species should be up in the flyway this year.
Atlantic Flyway
The majority of Atlantic Flyway waterfowl are raised in the eastern United States and Canada, with the exception of certain species such as canvasbacks and redheads that are largely produced on the prairies. In the eastern survey area, (eastern Ontario, Quebec, the Maritime Provinces, Maine, and northern New York) the abundance of most duck species—including mallards, black ducks, green-winged teal, and ring-necked ducks—was statistically similar to last year's estimate and the long-term (1990-2007) average.
In the northeastern United States, breeding ducks declined 20 percent in 2008 and were 16 percent below the long-term average. Mallards were down 10 percent from last year's estimate and were 21 percent below the long-term average, while wood duck numbers were similar to last year's estimate and the long-term average. On a positive note, the midwinter black duck index in the Atlantic Flyway was up 33 percent in January 2008 and was 15 percent higher than the 10-year mean.
DU Canada biologist Wade Lewis reports that weather and habitat conditions were generally favorable for breeding waterfowl in the provinces of New Brunswick, Nova Scotia, and Prince Edward Island. "Although rain was less frequent than in past summers, there was no apparent effect on waterfowl production," he says. "Reports of broods of various sizes and ages indicate that production was in line with previous years. Water levels in DU-managed wetlands have remained favorable for breeding waterfowl, even in areas with below-average precipitation. Overall, waterfowl production and brood habitat conditions appeared to be good over the entire region."
Most Atlantic Flyway goose populations also had good breeding success. In northern Quebec, biologists surveyed an estimated 170,000 breeding pairs of Atlantic Population Canada geese—similar to last year's estimate. In addition, an early thaw and mild spring temperatures fostered an unusually strong nesting effort, and record clutch sizes were observed, likely resulting in a larger fall flight. Favorable spring weather also benefitted breeding Atlantic brant and greater snow geese, and fall populations of these species should be up this year as well.
Looking Ahead
While duck production declined on the prairies this year, most species remain at healthy levels. Many goose populations are also near or above their management goals and will provide excellent hunting opportunities this fall. Looking ahead, it's important to remember that droughts are temporary, but habitat loss is often permanent. If grassland and wetland habitats remain intact on the prairies, duck populations will bounce back quickly when water returns. By providing waterfowl with a "balanced portfolio" of high-quality habitat, DU is helping to ensure the birds will continue to have strong growth potential in the future.
For more information on waterfowl populations and habitat conditions on the breeding grounds, go to flyways.us.