By Virginia Getz, James Callicutt, Cassidy Lejeune, and Dale James, Ph.D.
Wildlife biologists often refer to winter as the "pinch" period because food and cover can be scarce for many species, especially in northern latitudes. Waterfowl and other migratory birds avoid harsh winter conditions by flying south to areas that have warmer weather and an abundance of food. Most waterfowl complete the fall migration and arrive on their wintering grounds by the middle of December. Here waterfowl spend much of their time resting and feeding to conserve energy and build fat reserves. Some waterfowl species, including mallards, also select their mates on the wintering grounds.
Ducks Unlimited and its partners are actively working to conserve wetlands and agricultural lands on key waterfowl wintering areas in the United States and Mexico. These efforts focus on providing sufficient feeding habitat to allow waterfowl to survive the winter and return to their breeding grounds in good physical condition. Although DU works in every state that supports wintering waterfowl and in Mexico, our highest-priority landscapes are the Gulf Coast Prairies and Marshes, the Mississippi Alluvial Valley, and the Central Valley of California. Collectively, these regions support more than 50 percent of the continent's dabbling ducks during the winter months. Following is an overview of DU's conservation programs in these high-priority waterfowl wintering areas.
Gulf Coast Prairies and Marshes
The remarkably productive wetlands of the Gulf Coast are among the most important—and threatened—waterfowl habitats in North America. The region is a vital wintering area for several species of waterfowl, including northern pintails, gadwalls, American green-winged teal, redheads, lesser scaup, and white-fronted geese. The Gulf Coast also provides crucial migration habitat for blue-winged teal that winter in Mexico and Central and South America, and supports nearly the entire western Gulf Coast population of mottled ducks.
Coastal marshes remain the backbone of the Gulf Coast's wetland habitats, providing more than 90 percent of the foraging needs of wintering waterfowl in the region. Sadly, more than 1.4 million acres of coastal marsh have already been lost in Louisiana and Texas, and these losses continue due to a variety of natural and man-made causes, including subsidence, sea-level rise, hydrological alterations, erosion, and saltwater intrusion. Wetland losses along the Gulf Coast have had a direct impact on the region's ability to support wintering waterfowl. For example, estimates suggest that south Louisiana has lost nearly 40 percent of its capacity to support wintering waterfowl since the 1970s.
Ducks Unlimited is working with several partners in the Gulf Coast Joint Venture to restore, enhance, and protect the region's most important waterfowl wintering habitats. This partnership's objective is to conserve sufficient habitat to support 13.7 million ducks and 1.6 million geese—roughly 20 percent of the wintering waterfowl in the United States. A primary focus of DU and its partners is the conservation of high-quality coastal marshes. These efforts include hydrological restoration, shoreline protection, bank stabilization, and sediment and freshwater delivery (including diversion projects) as well as the construction of earthen terraces and the acquisition of threatened habitats.
A good example of DU's work along the Louisiana Gulf Coast is a recently completed project on Pass-a-Loutre Wildlife Management Area (WMA), located at the mouth of the Mississippi River in Plaquemines Parish. A hydraulic dredge was used to clean out an old channel, increasing the flow of sediment-laden river water throughout the 1,500-acre project area. These efforts have created new wetlands and nourished existing marsh to produce more food for wintering waterfowl. As an added benefit, dredge material taken from the channel was used to create a nesting island for several species of waterbirds, such as black skimmers and terns. The project, which was completed this past spring, also provides improved opportunities for hunting, fishing, and bird-watching on this popular WMA. DU's partners in this effort included the North American Wetlands Conservation Council (NAWCC), which provided a matching grant for the project; the Louisiana Department of Wildlife and Fisheries; and the Coastal Protection and Restoration Authority.
Given the widespread loss of coastal marsh and inland prairie wetlands, flooded rice fields now play a vital role in supporting the millions of ducks and geese that winter along the Gulf Coast. In south Louisiana, working rice lands provide more than one-third of the energy needs of ducks wintering in the region. Through the Rice Stewardship Partnership, DU has teamed up with private landowners, USA Rice, the USDA Natural Resources Conservation Service (NRCS), Nestlé Purina, and many other partners to implement conservation practices on working rice lands. For example, DU assists farmers in obtaining technical and financial assistance through Farm Bill cost-share programs for the installation of "pipe drop" structures, which help control erosion and improve water-management capabilities in rice fields. In return, landowners agree to manage their fields to provide habitat for wintering waterfowl. This program annually provides more than 2,000 acres of high-quality habitat for wintering waterfowl and other wetland-dependent birds in south Louisiana.
Since 1991, Ducks Unlimited, the Texas Parks and Wildlife Department, U.S. Fish and Wildlife Service (USFWS), and NRCS have partnered to conserve crucial waterfowl habitat through the Texas Prairie Wetlands Project (TPWP). Delivered in a 28-county focus area, this partnership was established to meet waterfowl population objectives established by the Gulf Coast Joint Venture. Rice production has declined significantly along the Texas Gulf Coast, primarily due to urban sprawl and a lack of reliable and affordable water supplies. With funding provided by a variety of government and private sources, DU and its partners work with rice farmers and other private landowners to restore and enhance shallow wetlands and improve the management of rice lands for agricultural production and wildlife. To date, the TPWP has conserved more than 80,000 acres of waterfowl habitat along the Texas Gulf Coast.
Mississippi Alluvial Valley
The Mississippi Alluvial Valley (MAV) spans nearly 25 million acres in seven states, from the confluence of the Mississippi and Ohio Rivers to the Gulf of Mexico. This region supports approximately 40 percent of Mississippi Flyway waterfowl during migration and in winter, including upwards of 4 million mallards during cold winters. However, only about 30 percent of the MAV's original bottomland hardwood forest remains intact and less than 10 percent of the historical floodplain is still connected to the Mississippi River. These impacts have greatly reduced the quantity and quality of waterfowl habitat in the MAV and contributed to declines in local and regional water quality.
To help address these issues, DU and its partners in the Lower Mississippi Valley Joint Venture are working to conserve the MAV's most important habitats for waterfowl and other wildlife. Among DU's top priorities is improving waterfowl habitats on public lands. For example, DU and the Mississippi Department of Wildlife, Fisheries, and Parks (MDWFP) recently restored and enhanced an extensive complex of managed wetland impoundments on Indianola WMA. When the MDWFP purchased the property in 2010, the area consisted of more than 1,000 acres of drained aquaculture ponds. With funding provided by two grants from the North American Wetlands Conservation Act, DU and the MDWFP worked together to improve water-delivery and management capabilities on more than 20 impoundments, which collectively encompass over 800 acres. Consisting of a mix of moist-soil habitats, emergent wetlands, and flooded agricultural crops, Indianola WMA is intensively managed by the MDWFP not only to help support healthy populations of wintering waterfowl but also to provide improved public hunting opportunities for waterfowlers.
Since nearly 80 percent of the MAV's remaining bottomland hardwood forest and other wetlands are under private ownership, DU works with landowners to protect key waterfowl habitats with conservation easements and to reforest former agricultural lands through the NRCS's Wetland Reserve Easement (WRE) program. This Farm Bill conservation program has restored and protected nearly 800,000 acres of wetland habitat in the MAV, including nearly 30 percent of the 1.2 million acres that have been reforested in this region. These same habitats also provide approximately 34 percent of the food energy available to waterfowl on private lands in the region. DU is a key partner in the delivery of WRE tracts, providing expertise in wetland engineering and design as well as overseeing reforestation efforts.
In addition, DU partners with farmers to enhance waterfowl habitat on working agricultural lands in the region. In the MAV, as along the Gulf Coast, rice fields provide vital food resources for wintering waterfowl. Through Rice Stewardship, DU helps farmers implement best management practices to enhance waterfowl habitat on rice lands and improve farm profitability, water quality, and other environmental conditions.
California's Central Valley
The Central Valley of California is the most important waterfowl wintering area in the western United States, supporting approximately 60 percent of the Pacific Flyway's migrating and wintering waterfowl. In an average winter, this region hosts up to 6 million ducks and 3 million geese, including 35 percent of North America's northern pintails and 75 percent of the Pacific Flyway's white-fronted geese. Historically, the region contained more than 4 million acres of wetlands and annually supported an estimated 20 million to 25 million ducks. However, more than 95 percent of the Central Valley's original wetlands have been lost, primarily to agriculture and urban sprawl. Today, just over 205,000 acres of managed wetlands remain in the region, and two-thirds of them are under private ownership. Most of these wetlands are owned and managed by private duck clubs in areas with rich waterfowling traditions, such as the Butte Sink and the Grasslands.
Because of the widespread loss of the Central Valley's natural wetlands, wintering waterfowl are now heavily dependent on agricultural lands, which provide almost 70 percent of the food resources available to the birds. In fact, the acreage of post-harvest flooded rice fields and the quantity of waste grain that is available in those fields largely drives the Central Valley's capacity to support wintering waterfowl. Unfortunately, intense competition for limited water supplies threatens both agriculture and wildlife in this region. DU has been actively working to conserve crucial waterfowl habitats in the Central Valley for more than 30 years. DU's efforts focus primarily on restoring and enhancing wetlands and improving large-scale water conveyance infrastructure and water-use efficiency on managed wetlands and rice lands. DU and its partners in the Central Valley Joint Venture also support public policies that help conserve wetlands and rice lands and ensure adequate water supplies for these vital waterfowl habitats.
The Willow Creek Ranch (WCR) Water Distribution System Improvement Project is a good example of DU's work in the Central Valley. WCR includes more than 100 private landowners and consists of about 5,105 acres of seasonally managed wetlands and 1,945 acres of rice lands. DU is working with Willow Creek Mutual Water Company, the USFWS, the California Wildlife Conservation Board, and numerous private landowners to conduct a comprehensive assessment and upgrade of the WCR's water distribution system. These efforts will help improve water-use efficiency, enhance habitat conditions on important private wetlands by improving water- and vegetation-management capabilities, increase the capacity of the system to handle additional water if it becomes available in the future, and reduce water delivery and drainage conflicts between rice agriculture and wetlands. The upgraded system will also capture drain water from rice lands and wetlands to be reused for habitat management and agricultural production. DU has already completed the first three phases of this project and will complete the fourth during 2017. A large portion of the funding for these efforts was provided by grants from the NAWCC.
Ducks Unlimited's conservation programs on high-priority wintering areas focus on providing waterfowl with the food resources they need to survive the winter and return to their breeding grounds in good condition. These efforts also help ensure that the wintering period isn't a limiting factor in the growth of waterfowl populations. Only by conserving sufficient wetlands and other key habitats to sustain the birds throughout their annual life cycle can we succeed in our mission of filling the skies with waterfowl today, tomorrow, and forever.
Virginia Getz is manager of conservation programs in DU's Western Region. James Callicutt is a regional biologist, Cassidy Lejeune is manager of conservation programs, and Dr. Dale James is director of conservation planning in DU's Southern Region.