Wintering and Migration Areas
Setting hunting aside, the survival of migrating and wintering waterfowl appears to depend mainly on food supplies. Thus, as a first approximation, changes in available foraging habitat can be used to measure progress in meeting the needs of nonbreeding waterfowl. By this standard, many joint ventures have produced substantial gains in foraging habitat since 1986, including those that winter a significant percentage of North America’s hunted waterfowl. For example, joint ventures in both the lower Mississippi Alluvial Valley and the Central Valley of California have reported large increases in foraging habitat, with food supplies now able to support 1970s populations in all but the driest winters.
The plan’s success in many wintering and migration areas stems from a combination of biological and economic factors. First, relatively small areas can support large numbers of nonbreeding waterfowl, whereas on breeding areas, ducks naturally space themselves at low densities. Second, combining public programs like the Wetlands Reserve Program and the North American Wetlands Conservation Act with private resources provided by DU and other joint venture partners has made it possible to achieve net wetland gains in many, though not all, nonbreeding areas.
While wetland restoration has helped provide gains in foraging habitat, much of the food needed by wintering waterfowl still occurs on unprotected agricultural lands. Joint ventures have worked with landowners to promote waterfowl-friendly practices like winter flooding of harvested rice fields. Although these habitats are likely to be important in the near future, changing farm practices and agricultural markets are largely beyond joint venture control. Continued efforts to restore and protect wetlands that provide waterfowl with natural foods will increase the long-term reliability of wintering and migration habitat.