An overview of North America's most important waterfowl landscapes and DU's efforts to conserve them
Edited by Dale Humburg
Waterfowl managers in North America must ensure that more than 40 species of ducks, geese and swans find landscapes with sufficient habitat to sustain them throughout the year. The diversity of species and habitats, the great number of birds and the continental scale involved make this a daunting conservation challenge. Ducks Unlimited and its partners have identified and prioritized the landscapes that are most important to continental waterfowl populations. These designations help ensure that we spend our supporters' hard-earned dollars in the places that will give us the biggest bang—and most ducks—for the buck.
Defining these high-priority conservation areas, however, requires a balance of perspectives and science-based judgments. For conservation planners, "life-history" events that impact waterfowl production and survival are primary considerations. For example, research indicates that events that occur on the breeding grounds—especially nesting success and hen and brood survival—are the most important limiting factors for prairie ducks. In other cases, the availability of food resources and wetland habitat on key migration and wintering areas are pressing concerns. Following are DU's five highest-priority landscapes, their importance to waterfowl and our efforts to conserve them for present and future generations.
The Prairie Pothole Region (PPR) of the United States and Canada is the most important breeding area for ducks in North America. In 2011, 29 million breeding ducks were surveyed in the PPR—nearly two-thirds of the birds in the traditional survey area. The PPR is also the most important breeding area for several individual duck species, including mallards, northern pintails, blue-winged teal, northern shovelers, gadwalls, canvasbacks and redheads.
Unfortunately, widespread conversion of grasslands and wetlands has diminished this region's productivity for breeding waterfowl. Despite these losses, the PPR continues to produce impressive numbers of waterfowl when environmental conditions are favorable. To ensure healthy waterfowl populations now and in the future, DU has determined that at least 6 million acres of wetlands and 25 million acres of adjacent upland nesting cover must be conserved in the PPR.
Across much of this continent, waterfowl must share the landscape with agriculture and this is especially true in the PPR. As a result, DU works closely with the ranching community to protect large tracts of native prairie with conservation easements and directly acquires properties of high waterfowl habitat value that are threatened with imminent development. In addition, DU helps prairie landowners restore wetlands and grasslands on former croplands through agricultural conservation programs, such as the Conservation Reserve Program (CRP) and Wetlands Reserve Program (WRP) and by partnering with agribusiness providers. DU also offers agricultural extension assistance to help farmers grow winter wheat on intensively cultivated prairie landscapes, which provides more secure nesting cover for pintails and other dabbling ducks. In the public policy arena, DU is working to secure sufficient funding for Farm Bill conservation programs in the United States and to strengthen state, provincial and federal wetland protections in the United States and Canada to prevent further losses of high-quality waterfowl breeding habitat on the prairies.
—Dr. Johann Walker and Dr. Karla Guyn
Encompassing 1.5 billion acres from western Alaska to Canada's Atlantic Coast, North America's boreal forest is the largest remaining intact forest and wetland ecosystem on earth. Of particular importance to waterfowl is the western boreal forest, which annually supports 12 million to 14 million ducks during the breeding season. More than half the surveyed populations of 10 duck species and a quarter of the surveyed populations of another seven duck species occur in the western boreal forest. Population trends among boreal waterfowl vary considerably by region and species. In Alaska, populations of most dabbling ducks have increased in recent decades, while in Canada, the most abundant species in the western boreal forest (scaup, mallards, American wigeon and scoters) have declined by 25 percent to 60 percent from historical levels.
Waterfowl biologists have known for decades that boreal wetlands provide vital habitat for millions of waterfowl, but due to the region's remoteness and great size, it was not considered a high conservation priority until recently. That perception has changed as many forms of development have begun to impact boreal wetlands and other wildlife habitats on a vast scale. In Canada, the energy, forestry and agriculture sectors are growing rapidly, particularly in the southern boreal forest, where deforestation is occurring at one of the highest rates on earth. Recent analyses suggest that these activities may have reached a level that is limiting duck populations.
Ducks Unlimited has been instrumental in mapping more than 350 million acres of wetlands and associated uplands in the western boreal forest of Alaska and Canada. DU and its partners are using these maps as well as data from waterfowl distribution and habitat studies to promote sustainable land-use practices that conserve key wetland habitats for waterfowl and other wildlife. In partnership with the Pew Charitable Trusts and a consortium of aboriginal, federal, provincial and territorial governments; other nongovernmental organizations; and visionary industries, DU is working to permanently protect 50 percent of Canada's boreal forest and ensure that sustainable land-use practices are implemented throughout the region.
Already more than 70 million acres of the western boreal forest have been conserved, largely in protected areas or via sustainable development planning.
—Dr. Stuart Slattery and Dr. Fritz Reid
California's Central Valley and coastal habitats support up to 60 percent of the Pacific Flyway's wintering waterfowl, including nearly 6 million ducks and 1 million geese. Roughly 40 percent of this continent's pintails winter in the Central Valley. Significant numbers of American wigeon, mallards, green-winged teal, shovelers and tundra swans as well as nearly the entire continental population of tule white-fronted geese also winter here.
Conservation planners use "waterfowl use days" as a measure of a landscape's capacity to support migrating and wintering waterfowl. Specifically, a waterfowl use day is defined as the energy needed by one bird for a day during the nonbreeding period. The Central Valley provides close to 1 billion waterfowl use days from the time ducks and geese arrive in fall to their departure in spring. This is truly remarkable given that 95 percent of the Central Valley's historical wetlands have been lost. As in other regions, waterfowl that winter in the Central Valley now rely heavily on agricultural habitats to meet their biological needs. Of the many crops grown here, rice is the most important to wintering waterfowl. In fact, rice fields that are flooded after harvest currently provide more than half of all the food energy available to wintering ducks and geese in this region.
Most of the wetlands managed for waterfowl in the Central Valley are in public ownership or protected with conservation easements. But the number of people living in the Central Valley is expected to more than double during the next 30 years, which will place even greater demands on the region's open space and limited water supplies. Nearly all the region's agricultural land is unprotected and, in many areas, vulnerable to urban sprawl. As a result, DU and its partners hope to add more than 100,000 acres to the region's managed wetland base over the next 25 years. Maintaining sufficient funding for WRP and other Farm Bill conservation programs will be essential to achieving this objective. DU will also continue to work with the agricultural community, private duck clubs, government agencies and other partners to protect wetlands and secure water supplies for key waterfowl habitats in this vital, yet threatened waterfowl wintering area.
—Dr. Mark Petrie and Dr. Fritz Reid
A key migration and wintering area for midcontinent waterfowl, the Mississippi Alluvial Valley (MAV) supports peak populations of 7 million to 8 million ducks and geese. This includes up to 4 million mallards as well as significant numbers of pintails, wood ducks, green-winged teal, shovelers, white-fronted geese and lesser snow geese. In total, the MAV provides nearly a half-billion waterfowl use days for ducks and geese during fall and winter.
The timing and amount of winter precipitation, which affects the extent of natural flooding, has a large impact on the availability of waterfowl habitat in this region. Research indicates that in wet winters, waterfowl weigh more on average and survive at higher rates than in dry winters. During wet years, the MAV provides up to 3 million acres of naturally flooded forested wetlands and agricultural land, including more than 500,000 acres of managed private land, about 75,000 acres of restored managed wetlands on WRP land and 150,000 acres of flooded managed public land.
DU's conservation efforts in the MAV focus on providing a secure habitat base that will sustain migrating and wintering waterfowl in the region under variable environmental conditions. Top priorities include protecting seasonally flooded forested wetlands, enhancing the quality of intensively managed foraging habitat on private lands and continuing to restore and enhance the quantity and quality of managed habitat on public land. Studies suggest that more active and effective management of private lands enrolled in WRP could increase foraging potential in the MAV to support up to 500,000 additional wintering waterfowl.
—Dr. Dale James and Dr. Tom Moorman
Nearly 14 million ducks and 2 million geese have historically wintered along the Gulf Coast, distinguishing this ecosystem as North America's most important waterfowl wintering area.
Eighty percent or more of this continent's gadwalls, green-winged teal and redheads winter in this region. Two species of concern, pintails and lesser scaup, also winter in large numbers along the Gulf Coast and more than 90 percent of the world's mottled ducks live here year-round. In total, this region annually provides more than 2 billion waterfowl use days for ducks and geese.
Sadly, the loss of Gulf coastal wetlands threatens this region's capacity to sustain desired populations of wintering waterfowl. About one-third of Louisiana's coastal marsh—nearly 1,900 square miles—has already been lost and losses continue at a rate of nearly 17 square miles a year. In neighboring Texas, coastal wetland loss is occurring at a rate of nine square miles a year. In addition, recent declines in rice production have further reduced the Gulf Coast region's capacity to support wintering waterfowl. As a result, DU and its partners are working to ensure that policy and management actions along the Gulf Coast help sustain agricultural practices and water resources that provide vital habitat for waterfowl.
The Deepwater Horizon oil spill brought national attention to the Gulf Coast and the rich culture, traditions and economic significance of its wetlands. Potential funding from Clean Water Act penalties could provide the foundation for the long-term recovery of the Gulf Coast's expansive wetlands. This will require a significant long-term commitment to restoring the marsh-building processes that created and historically sustained this region's diverse and productive wetland systems.
—Dr. Tom Moorman and Dr. Dale James
While current research suggests that the availability of high-quality breeding habitat, especially on the prairies and in the western boreal forest, is the greatest limiting factor influencing many waterfowl populations, landscapes that support the birds during migration and in winter are also important to sustaining healthy numbers of waterfowl. During the nonbreeding period, wetlands and agricultural habitats provide the food and cover necessary to allow waterfowl to survive and remain in good physical condition until they return to their breeding grounds. But rather than distinguishing between migration and wintering habitat requirements, it is more biologically accurate to view the fall-to-spring habitat needs of waterfowl as a continuum. Dynamic weather, precipitation and seasonal flooding result in dramatic differences in where the birds find resources each year.
In contrast to the breeding season, waterfowl are gregarious and concentrated during the nonbreeding period. Therefore, waterfowl managers can support significant numbers of birds on relatively small pieces of real estate compared to the extensive habitats required by breeding waterfowl. Waterfowlers are familiar with the spectacular concentrations of ducks and geese that gather each year on the Great Lakes, Upper Mississippi River, Mid-Atlantic Coast, Rainwater Basin, Platte River and other well-known staging areas. Many of the waterfowl that rely on DU's highest-priority conservation areas also depend on key habitats in these regions. In addition, large numbers of certain species such as black ducks, sea ducks and Arctic geese breed, migrate, or winter beyond DU's main conservation focus areas. Consequently, a comprehensive approach across seasons and landscapes will be required to ensure the long-term sustainability and enjoyment of all of North America's waterfowl populations.
—Dr. John Coluccy
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