By Chad Manlove
Have you ever wondered what ducks do during the cold winter months? Experience might lead many of us to believe that the birds spend most of their time skirting decoy spreads and flaring from duck calls. But what really determines a duck's daily routine on the wintering grounds?
Ducks spend most of their time during winter actively searching for food and resting to conserve energy (fat reserves) for use during periods of harsh weather when feeding time is limited. For some species, including mallards, important activities like courtship and pair-bond formation also occur in winter. So it should come as no surprise that Ducks Unlimited's habitat conservation efforts in priority waterfowl areas like the Central Valley of California, the Gulf Coast prairies, the Mississippi Alluvial Valley, and the mid-Atlantic coast focus on providing optimal foraging habitat for migrating and wintering waterfowl. DU's conservation programs in these areas help the birds survive during winter and return to northern nesting areas in good physical condition the following spring.
Winter Habitat Needs
By the middle of December, most waterfowl have reached their wintering grounds across the southern half of the United States. The most important biological need of wintering ducks is food. Wintering areas offer a diversity of habitats that ducks use to meet their food or energy needs, including moist-soil emergent wetlands, forested wetlands, coastal marshes with beds of submerged aquatic vegetation, and flooded agricultural fields. Habitat needs vary over winter by species and location. Daily energy demands differ by species, but a typical mallard-sized duck generally requires about 290 kilocalories of food per day throughout winter. For that reason, wintering waterfowl congregate in areas with an abundance of foods that will provide them with the energy they need to survive.
The availability of waterfowl foods on many wintering areas is often determined by the amount of rainfall. Heavy rains can suddenly flood thousands of acres of agricultural fields and river bottoms. Dabbling ducks will flock to these areas to exploit new food resources. Such natural winter flooding typically occurs during fall and winter in one of DU's highest priority areas for waterfowl, the Mississippi Alluvial Valley (MAV).
To better understand how habitat conditions change over winter and how they vary among years, conservation planners at Ducks Unlimited's Southern Regional Office performed a landscape analysis of winter waterfowl habitat in the MAV. DU biologists used satellite imagery and remote sensing techniques to quantify available foraging habitat in the MAV for waterfowl during winter from 1999 through 2005. Information gathered during the analysis was summarized by state into specific habitat categories including public managed habitat, private managed habitat, and unmanaged naturally flooded habitat (that is, flooded agricultural fields or bottomland hardwood forests).
The research showed that during years of average to heavy precipitation, the MAV provides abundant feeding opportunities for ducks, especially mallards, pintails, and wood ducks. "In years of abundant precipitation, it's not uncommon to witness natural flooding in the MAV that provides more than 1.5 million acres of flooded bottomland hardwoods," says Dr. Tom Moorman, director of conservation planning at DU's Southern Regional Office. "In addition, we've observed 500,000 acres of flooded agricultural fields and moist-soil wetlands," he continues. "We believe it is the large amount of naturally flooded wetland that attracts and holds significant numbers of ducks in the MAV, but managed moist-soil wetlands and agricultural fields provide important habitat, particularly in years when natural flooding is reduced by drought."
Wetlands Conservation, Waterfowl Habitat, and the Farm Bill
The Wetlands Reserve Program (WRP), a federally funded program that is part of the Farm Bill, has been a major driver in the restoration of wetlands in the MAV and many other regions of the United States. DU works in partnership with the Natural Resources Conservation Service (NRCS) to restore wetlands under this program. WRP provides financial and technical assistance to landowners who want to restore wetland habitat on marginal, flood-prone farmland on their property. Landowners typically provide a perpetual easement to the NRCS in exchange for a one-time easement payment and payment of restoration costs.
Restoration of forested wetlands is an important aspect of DU's conservation activities in the MAV because DU-supported research indicates that waterfowl prefer these areas in winter. Mallards, wood ducks, and gadwalls in particular make extensive use of these habitats in the MAV. Under WRP, restoration activities include reforestation that incorporates a suite of bottomland hardwood tree species. The species mix for each site is determined by careful consideration of the site's elevation, flood frequency, soil type, and other factors that influence which trees are suited to the area. "More than 70 species of trees occur naturally in bottomland hardwood forests," says Phil Covington, regional biologist for Ducks Unlimited in Arkansas. "Our plan is to plant several species of oak such as nuttall, overcup, willow, water, and more. We'll also plant sugarberry, green ash, and many other soft mast species. Bottomland hardwood forests provide a great service within the MAV because they ultimately filter out sediments and nutrients that would otherwise end up in our rivers."
DU's role in WRP is to complete reforestation and restoration of hydrology on lands enrolled by the NRCS. DU biologists work with the NRCS to complete tree-planting activities, and DU engineers design levees and water-control structures to restore wetlands. "Our primary interest is to ensure that these conservation projects are designed and restored to best provide wetland functions and values for waterfowl and other wildlife species, while meeting overall program requirements and landowners' desires," Covington says.
WRP is offered nationwide, but its greatest impact has been in the MAV, where DU with the NRCS has reforested approximately 125,000 acres over the last 10 years. In addition, more than 42,500 acres of moist-soil wetlands have been restored through managed seasonal flooding on private lands. With annual management, these wetlands produce an abundance of seeds and aquatic invertebrates, ultimately providing various proteins and amino acids essential to the survival of waterfowl late in winter.
While WRP has been extremely successful on private lands in the MAV, several well-known public areas have also benefited from WRP restoration activities. The Steve N. Wilson/Raft Creek Wildlife Management Area in Arkansas is one example of how Farm Bill programs are helping to restore public lands open to hunting.
In 2000, an obscure 4,200-acre parcel of land in Arkansas was considered marginal farmland because of its susceptibility to spring and summer flooding. As a result, this property was enrolled in WRP. DU and its partners recognized an excellent opportunity to restore this area to seasonally flooded wetlands of great value to wintering waterfowl. Thus, DU helped the Arkansas Game and Fish Commission purchase the property.
Following the acquisition of Raft Creek WMA, DU and NRCS quickly went to work restoring various wetland complexes. DU engineers invested considerable time conducting topographic surveys with satellite equipment to identify subtle elevation changes on the landscape. By August 2003, partners had successfully restored 1,500 acres of moist-soil wetlands and reforested 2,700 acres of bottomland hardwood trees. "This was truly a partner-driven restoration project made possible by WRP funding," says Craig Hilburn, director of conservation programs for DU in Arkansas. "The Steve N. Wilson/Raft Creek WMA winters thousands of ducks each year, and when weather conditions are right, it provides outstanding hunting opportunities for waterfowl hunters."
Together, WRP lands in the MAV states of Louisiana, Arkansas, and Mississippi constitute the single largest bottomland hardwood restoration effort anywhere in the United States. "The Wetlands Reserve Program is a vitally important wetland restoration program in the MAV that enables restoration of forested wetlands of value to waterfowl, other wildlife, and people at a scale that is truly meaningful," says Dr. Curtis Hopkins, director of conservation programs for DU's Southern Regional Office. "The forested wetlands restored under WRP will provide excellent habitat for mallards, wood ducks, and other waterfowl, and they will also provide a host of other functions important to people, including natural flood storage, enhancements to water quality, and other ecological functions."
In addition to conservation activities in the MAV, DU has partnered with the NRCS through WRP to restore approximately 40,000 acres of wetlands along the Red River in portions of Oklahoma, Texas, Arkansas, and Louisiana. The Red River meanders through an important region commonly referred to as the West Gulf Coastal Plain (WGCP). Bottomland forests and associated moist-soil wetlands support substantial populations of migrating and wintering waterfowl in the WGCP including mallards, gadwalls, green-winged teal, and wood ducks. Additionally, a significant number of wood ducks breed in forested wetlands throughout this conservation region.
Landowners and farmers in this area have used Farm Bill programs like WRP to restore marginal, flood-prone agricultural land back to bottomland hardwoods and emergent wetlands. In the WGCP, DU has reforested more than 25,000 acres of bottomland hardwood wetlands through WRP. In addition to foraging habitat, bottomland hardwoods provide thermal refuge and pair-isolation habitat for wintering waterfowl. These ecosystems provide crucial habitat for millions of migrating and wintering waterfowl every year.
DU biologists and engineers also restore hydrology of moist-soil and emergent wetlands through WRP. Along the Red River, DU has restored more than 15,000 acres of moist-soil wetlands. "Typically, DU uses state-of-the-art GPS satellite equipment to conduct detailed topographic surveys for landowners," says Eric Held, regional engineer for DU in Oklahoma. "We then design wetland impoundments using earthen levees and water-control structures to maximize foraging opportunities for wintering waterfowl. Moist-soil impoundments provide plant and animal foods that are a critical component of food resources during the winter period."
Public lands in the WGCP also benefit from wetland restoration efforts through Farm Bill programs like WRP. Red Slough Wildlife Management Area in McCurtain County, Oklahoma, is a prime example. In an era of aggressive wetlands conversion, Red Slough was drained, cleared, and farmed beginning in the 1960s. "DU partnered with the Oklahoma Department of Wildlife Conservation, U.S. Forest Service, NRCS, and Trust for Public Lands to restore 3,200 acres of moist-soil wetlands and 1,700 acres of bottomland hardwoods back to their original condition," says Scott Manley, director of conservation programs for DU in Oklahoma. "The wetlands provide outstanding waterfowl hunting opportunities for local hunters and play a key role in forest regeneration, wildlife habitat, water quality, and flood control."
WRP has also made a significant contribution to wetland restoration efforts in the West, especially in the Central Valley of California where more than 60 percent of all Pacific Flyway waterfowl spend the winter in some years. Since 1992, approximately 100,000 acres of wetlands and wildlife habitat have been restored and protected in California through WRP. The majority of this acreage has been enrolled in the Central Valley, where only about 350,000 acres of wetlands remain intact.
How You Can Help
North America has lost more than half its original wetlands, and every year at least 80,000 more acres are lost. Restoring drained wetlands and protecting those that remain are the only ways to reverse this trend. The implications of continued habitat loss are alarming for all of us who have a passion for ducks. However, much can be done to ensure that waterfowl continue to find critically important wetland habitats on wintering grounds throughout the United States. DU is working closely with conservation partners and congressional staff to ensure that adequate WRP funding is maintained in the next Farm Bill, where they can continue to benefit ducks and other wildlife.
When Congress begins working on the next Farm Bill, it will be critically important for all who have an interest in Farm Bill programs like WRP to make their voices heard by calling or writing their congressional representatives. Regular updates and opportunities to take action will be posted on the DU website.
WRP is a critically important tool with which DU, NRCS, private landowners, and other program partners are able to restore, manage, and conserve wetlands across the nation. Many landowners want to conserve wetlands through this program, but funding is often limited. It is vital that support for WRP be maintained and expanded to benefit waterfowl and waterfowl hunting.