Ducks Unlimited Special Report—2004 Waterfowl Forecast
Duck numbers are down from last year, but populations of most species remain near or above their long-term averages
By Matt Young
Waterfowlers have always watched events in the Prairie Pothole Region of the United States and Canada with a combination of hope and downright anxiety. Much like farmers whose livelihoods depend on favorable weather during the growing season, the fortunes of waterfowl populations and, by extension, duck hunters are heavily influenced by how much snow and rain fall on the breeding grounds each year.
In 2004, precipitation and habitat conditions on the prairies were unusually variable—even for a region with notoriously unpredictable weather. Large areas of the prairies received substantial snowfall over the winter, but much of the moisture soaked directly into the parched soil rather than running off and filling wetland basins during the spring thaw. As a result, many seasonal and temporary wetlands, which provide critical habitat for breeding pairs, were dry when waterfowl returned this spring.
According to the U.S. Fish and Wildlife Service (USFWS), the number of May ponds—the primary indicator of waterfowl breeding habitat on the prairies—declined 24 percent, from 5.2 million in 2003 to 3.9 million in 2004. Not surprisingly, breeding populations of many duck species declined in the survey area (see chart on page 62). The total breeding duck index in the traditional survey area was 32.2 million birds—an 11 percent decline from the previous year, but a level roughly equivalent to the long-term (1955-2003) average.
Mallard numbers also declined slightly in the traditional survey area. In comparison, this year's mallard population of 7.4 million birds was almost identical to the 2002 estimate and was similar to mallard numbers during the late 1970s (see graph on page 60). An additional 932,000 breeding mallards were surveyed in the Great Lakes states ( Minnesota , Wisconsin , and Michigan )—a slight increase from last year's total of 840,000. Mallard numbers also increased slightly in the northeastern United States and eastern Canada , with a total of roughly 1.1 million birds.
In mid-May, a rare spring blizzard dumped from six to 18 inches of snow across northern North Dakota and southern Saskatchewan and Manitoba . While this precipitation brought welcomed moisture to drought-stricken areas, the harsh weather likely disrupted early waterfowl nesting efforts, especially among mallards and pintails. As spring progressed, a series of storms soaked much of the Prairie Pothole Region, with some areas receiving more than 200 percent of normal precipitation for the season. Heavy rains filled many wetland basins that had been dry earlier in the spring and fostered lush growth of upland nesting cover, providing improved habitat for hens and broods. Goose production also varied considerably across northern breeding areas, but most populations remain near or above their management objectives.
DU's chief biologist, Dr. Bruce Batt, says the unusual weather this past spring has made it difficult to project overall waterfowl production and the status of the fall flight in 2004. “The late, cold spring likely delayed migration to the breeding grounds for some duck species, especially the later nesters, and the dry weather caused very tentative settling patterns by the early-nesting species. The widespread improvement in habitat conditions that took place after the May survey assured that duck production wasn't a bust this year. But we are not likely to see a bumper crop either,” Batt says.
Annual waterfowl breeding population and wetland habitat estimates are compiled during extensive air and ground surveys conducted by the USFWS, Canadian Wildlife Service, and state and provincial wildlife agencies. Waterfowl hunting regulations are determined each year by the USFWS, in consultation with the flyway councils, and not by Ducks Unlimited. What follows is a comprehensive waterfowl forecast for each flyway, based upon reports from government and DU biologists in the field.
Pacific Flyway
The Pacific Flyway receives most of its waterfowl from the western United States and Canada, with the largest numbers of birds coming from Alberta, Alaska, British Columbia, and the Northwest Territories. In Alberta, minimal runoff and dry spring weather produced generally fair to poor habitat conditions for breeding waterfowl. Total breeding ducks declined 7 percent across the southern Alberta survey area. Most species, including pintails and mallards, declined from last year's levels and were well below their long-term averages.
DU biologist Dr. Jonathan Thompson reports that wetland conditions improved markedly in June and July across the Alberta parklands, where waterfowl habitats have suffered from several consecutive years of drought. “This area has had one of the coolest and wettest summers in more than a decade. Unfortunately, the rainfall came too late to benefit most breeding ducks, but it has helped set the stage for better habitat conditions next year if we receive sufficient snowfall over the winter months.”
Dry spring weather plagued breeding waterfowl throughout central British Columbia and the western United States. In Washington and Oregon, total duck numbers and mallard populations were similar to last year, but remained below their long-term averages. In California, the abundance of breeding mallards declined 22 percent, from 337,000 birds in 2003 to 262,000 this year—the smallest mallard population recorded in the state since surveys began there in 1992.
Duck numbers also declined overall in central and northern Alberta, northeastern British Columbia, and the Northwest Territories. However, the abundance of some species—including pintails, gadwalls, redheads, and blue- and green-winged teal—increased in these areas from last year's population estimates. The USFWS reports that wetlands in the western boreal forest experienced an unusually late thaw this spring, which likely delayed—and may have reduced—waterfowl breeding activity in the region.
The waterfowl production outlook was much brighter in Alaska. Mild spring weather and excellent wetland conditions set the stage for above-average production of mallards, pintails, wigeon, canvasbacks, green-winged teal, scaup, and several other species. Pacific Flyway goose populations also had generally good breeding success in Alaska and the western Canadian Arctic, and fall populations of all species should be similar to or above 2003 levels.
Central Flyway
The majority of Central Flyway waterfowl are raised in the Prairie Pothole Region, as well as in the western boreal forest and central Canadian Arctic. The province of Saskatchewan is an especially important breeding area for waterfowl in the Central and Mississippi flyways. A disappointing runoff in southern Saskatchewan left wetland habitat conditions in only fair shape when breeding waterfowl returned this spring. May pond numbers in the prairie-parkland region declined 32 percent from 2003. Total ducks were down 38 percent, with all major species showing significant declines.
In May and early June, much of southern Saskatchewan received above-average precipitation, improving habitat conditions for breeding waterfowl in many areas. DU's Dr. David Howerter reports: “A major snowstorm came through southeastern Saskatchewan and Manitoba in the middle of May, which probably caught some birds on their nests and caused some nest failures. However, as habitat conditions improved, our research crews observed large numbers of breeding ducks and a very strong late nesting effort.”
As in southern Canada, generally dry habitat conditions prevailed across the Great Plains states when waterfowl returned to the region this spring. In South Dakota, total duck numbers declined 20 percent relative to last year's estimate and were at the lowest level since 1992. In contrast, overall duck numbers in North Dakota increased by 15 percent, possibly reflecting a partial redistribution of breeding waterfowl from South Dakota. Populations of all major duck species were up in the state, except for blue-winged teal. Pintails had the biggest jump, increasing 104 percent above the 2003 estimate.
Dr. Jim Ringelman reports that DU research crews in North Dakota also observed a strong response from breeding waterfowl to improved habitat conditions after the May surveys had been completed. “Although several counties in North Dakota had good water conditions early in the spring,” he says, “most of the state was dry when mallards and especially pintails came through, and many of these birds continued north into Canada. In mid-May, it started raining, and the wet weather continued through mid-June, which filled up a lot of the seasonal wetlands. The mallards and pintails that did settle in the state had a strong breeding effort, and the mid- and late nesters—such as gadwalls, blue-winged teal, and scaup—did quite well. Our nest-monitoring crews found comparable numbers of nests as they did last year, and nest success appears to have been pretty good overall. Our crews also saw lots of broods again this year, but they were later in hatching than the year before.”
The outlook for Central Flyway goose populations is mixed. The USFWS reported that harsh spring weather on northern breeding areas likely reduced production among lesser snow, Ross's, and white-fronted geese, as well as small subspecies of Canada geese. Larger Canada geese that breed on the prairies had much better success, and another large fall flight of these birds is expected this year.
Mississippi Flyway
The Mississippi Flyway receives most of its waterfowl from the prairies of the United States and Canada, as well as from Ontario, the Great Lakes states, and boreal forest. In southern Manitoba, runoff from substantial snow accumulations produced a 10 percent increase in May pond numbers. Total duck numbers in the prairie-parkland region were slightly below the 2003 estimate and were similar to the long-term average. Pintails, gadwalls, shovelers, redheads, and canvasbacks increased in the survey area, while mallards, wigeon, scaup, and blue- and green-winged teal declined, compared to last year's levels.
Waterfowl populations were up this year in Ontario, a critical breeding area for Mississippi and Atlantic flyway waterfowl. In western Ontario, the USFWS surveyed 1.7 million breeding ducks, a level 101 percent above the long-term average and the third-highest population recorded since 1955. All major duck species increased in the survey area, including mallards (+19 percent), black ducks (+167 percent), and green-winged teal (+14 percent). Significant increases in dabbling duck populations also were surveyed in central Ontario.
DU biologist Mike Gendron reports: “Ample early summer rains maintained wetlands and delayed hay cutting in southern Ontario, providing good habitat for breeding waterfowl and broods. Numerous brood sightings of various age classes of ducklings suggests there was an extended breeding effort. Duckling survival appears to have been normal, and we expect production was average to slightly above average this year.”
Duck numbers also increased in the Great Lakes states. Mallard numbers in Minnesota and Michigan were up by 34 percent and 12 percent, respectively. The abundance of breeding mallards in Wisconsin declined slightly, relative to last year, but total duck numbers in the state increased 22 percent and were 58 percent above the long-term average.
The outlook isn't as bright for Mississippi Flyway goose populations. A cold, late spring and inclement weather took a toll on goose production on major breeding areas across the central Canadian Arctic and the Hudson Bay Lowlands. Among Canada geese, a reduced fall flight is expected for the Southern James Bay, Mississippi Valley, and Eastern Prairie populations this year. Midcontinent light goose numbers remain high, but reduced gosling production on northern breeding areas will result in fewer juvenile birds flying south this fall.
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, which are largely produced on the prairies. Total breeding duck numbers in the eastern survey area increased 7 percent from the 2003 estimate. Populations of black ducks, ring-necked ducks, and green-winged teal increased, while wigeon, lesser scaup, goldeneye, and buffleheads declined. Mallard numbers were at a level similar to last year. In the heartland of the black duck breeding range, in the Maritime Provinces and Maine, black duck numbers increased 24 percent over last year's estimate, boding well for this highly prized species.
Wood duck populations in the Atlantic Flyway also appear to be either stable or increasing. According to the North American Breeding Bird Survey, conducted by volunteers during May and June each year, wood duck numbers in the Atlantic Flyway have grown at the rate of nearly 5 percent a year over the long term (1966-2003) and have increased by slightly more than 4 percent annually over the short term (1980-2003).
In northern Quebec, the breeding population of Atlantic Canada geese was up 11 percent, from 156,900 pairs in 2003 to 174,800 this year. Unfortunately, harsh spring weather delayed nesting activity and reduced breeding success, and a decreased fall flight of these birds is expected. Atlantic brant production also may have been adversely affected by a late spring thaw in the eastern Canadian Arctic. However, greater snow geese appear to have fared better on their breeding grounds, and a fall flight similar to last year's is expected.
Looking Ahead
Many waterfowl populations de-clined this year, largely in response to drier habitat conditions across the Prairie Pothole Region. Most duck species, however, including mallards, remained near or above their long-term averages, despite below-average May pond numbers on the prairies. DU's Executive Vice President, Don Young, offers some perspective: “Waterfowl hunters have weathered conditions much worse than this many times in the past. Just a few years ago, we enjoyed some of the best fall flights in the last several decades. But now, as we are in a drier period on the breeding areas, waterfowl hunters and managers are facing a different reality. As always, it remains critical to maintain the nesting habitat base, especially our prairie grasslands, through the drier times so we can witness the ‘boom' that has always recurred with the return of water.”