Overall, the MAV is most important as migration and winter habitat, but it is also a primary breeding area for wood ducks. The primary limiting factor for populations of migrating and wintering waterfowl is assumed to be foraging habitat. Ducks Unlimited, in an effort to continually refine conservation programs through adaptive management, set about assessing the amount of foraging habitat potentially available to waterfowl in the MAV. In addition, during the course of this effort, DU also collected information on within and among year variation in winter habitat conditions in the MAV. This is complex evaluation effort was initiated in 1997 and remains a work in progress. However, information gained to date from this study as well as others recently completed by other researchers have allowed DU to refine conservation programs.
Following are some conclusions based upon data gathered from 1997 through the winter of 2003-2004:
- The absolute quantity of potential foraging habitat and associated estimates of duck-use-days provided are in excess of what is required by LMVJV population objectives in all but the driest of winters in the MAV.
- The bulk of the foraging habitat in the MAV consists of privately managed harvested agricultural habitat.
- Natural flooding of cleared agricultural land and forested wetlands remain a vital, viable component of the winter habitat complex in the MAV, and in most years, provides substantial potential foraging habitat.
- There remain questions about foraging habitat quality, the role of refuges and the need for additional refuges in the MAV to enable birds to maximize use of potential foraging habitat.
While foraging habitat currently does not appear to limit the population of birds wintering in the MAV, it should be noted that the bulk of foraging habitat has no long-term protection. Indeed, much of the potential foraging habitat in the MAV is agricultural in nature and subject to the whims of changes in agricultural policy, agribusiness and other factors. However, given the current estimated level of foraging habitat in excess of that needed to support desired populations, an opportunity exists to shift the emphasis of conservation programs, as discussed below, from short term effort aimed at adding to the foraging habitat based, to long-term efforts aimed at protecting and securing the foraging habitat based indefinitely.