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Wetlands of the United States

Their Extent and Their Value To Waterfowl and Other Wildlife

Public Waterfowl Areas

The Fish and Wildlife Service and most State fish and game departments have wetland-improvement programs. Public waterfowl refuges or management areas have been established because good habitat is a fundamental requirement of waterfowl management. The availability and adequacy of wetlands, more than any other factors, govern the abundance and distribution of our waterfowl resource. This is becoming increasingly true as the destruction of waterfowl habitat continues throughout the country. Although there were a few public refuges before the drought years of the thirties, this abnormally dry period sounded the warning that a substantial amount of wetlands would have to be preserved and developed by public agencies to help alleviate the effects of future droughts on waterfowl populations.


The first objective of all waterfowl refuges is to protect and manage the resource so it can be continually used and enjoyed by all the people. The accomplishment of this goal requires the concerted effort not only of Federal and State agencies, but also of the private custodians of wetlands. As the Federal agency vested with the responsibility of managing waterfowl on a nationwide basis, the Fish and Wildlife Service believes the primary purpose of a Federal waterfowl refuge system is the preservation and improvement of waterfowl habitat in sufficient quantity and availability to perpetuate stable or increasing populations of waterfowl.

National Wildlfe Refuge

Although it is possible that several hundred major national waterfowl refuges could prevent the extinction of our waterfowl species, the maintenance of a harvestable annual crop can be assured only with the assistance of State refuges or management units and privately owned wetlands. The national refuge system is geared specifically to the protection of waterfowl habitat in strategic locations, whereas most State management areas are designed to supplement these refuges and provide for hunting opportunities on a sustained basis.

Waterfowl production attributable to wetlands lying within the United States is estimated at about 20 percent of the annual continental production. The maintenance of the 80 percent in Canada and Alaska is therefore an even greater problem, but the preservation of wetlands habitat needed for waterfowl reproduction, regardless of its location, is of utmost importance if waterfowl and waterfowling are to be perpetuated.

The value of public refuges within the breeding range of waterfowl in the United States increases appreciably with the advent of droughts. During these emergency periods, most of the smaller wetlands, normally preferred by nesting waterfowl, are devoid of water and are rendered useless to waterfowl. Then, public refuges in the breeding sections of the country provide a good share of the remaining acceptable nesting habitat because these areas are designed and managed to maintain adequate water.

The majority of the waterfowl produced in the arid regions of the country are from publicly managed areas. Refuges often prevent loss of production from surrounding wetlands by providing extensive marsh areas where adult birds can spend the flightless period safely and where young of the year can retreat when smaller nearby wetlands go dry late in the summer.

More than half of the national waterfowl refuges include wetlands used as nesting habitat, and most State waterfowl areas in the northern tier of States are valuable production areas. Production from public refuges will increase significantly as new refuges are established and as additional private wetlands are lost. However, it should be understood that privately owned marshes still produce the vast majority of the ducks raised in this country. Even with a vastly expanded refuge system, both State and Federal, breeding areas remaining under private ownership must continue to produce about the same number of ducks as at present if waterfowl populations are to remain near the present level.

Intermediate and wintering refuges are becoming more essential each year, especially in States where natural or man-made forces have seriously reduced the quality and quantity of good waterfowl wetlands. An increase in such refuge areas with attractive and adequate food supplies will help to distribute the birds equitably and to prevent crop depredations.


There are now 205 national refuges established primarily for waterfowl; they cover about 3 1/2 million acres. Wetlands comprise 1,350,000 acres, and 540,000 acres are of permanent water. Thus, nearly three-fifths of the total area of Federal waterfowl refuges is aquatic waterfowl habitat. The remaining acreage, consisting of uplands essential for protection and effective management of aquatic habitats, is utilized for growing supplemental food and meeting other needs.

Fifty-one Federal refuges are established primarily for purposes other than waterfowl management. These contain 350,000 acres of wetlands and 245,000 acres of permanent water. In total, there are preserved on national wildlife refuges 1,700,000 acres of wetlands and 790,000 acres of permanent water.

In addition, at least 1,500,000 acres in waterfowl areas are now administered by the States.


The role of public refuges in the distribution and utilization of waterfowl during the hunting season is becoming increasingly important because these areas attract waterfowl and materially influence the distribution of the birds. The present trend seems to be toward narrower flight paths. This condition is not only detrimental to the birds -- creating depredation and disease problems -- but it restricts the areas where waterfowl hunting can be profitably undertaken. Future refuges and wetland-development projects, then, should be selected with a view to dispersing the birds more widely.

The need for sanctuary units on management areas open to hunting has been abundantly demonstrated. Sanctuaries that provide adequate food and cover will hold waterfowl in the general region for a longer period and will improve waterfowl-hunting opportunities on surrounding lands. Most of the management areas where hunting is permitted have sanctuary areas, and many privately managed hunting marshes have a place where waterfowl can retreat unmolested. Sanctuary areas are extremely important where the hunting pressure is excessive in relation to the availability of waterfowl habitat.

The task of providing an increasing number of gunners with an opportunity to harvest waterfowl is growing more difficult each year. Not long ago, sufficient hunting sites were available to accommodate the hunting pressure. In many sections of the country this is not so today. Some waterfowl habitats have been changed to dry-land uses, and others are closed to public access. If the sport of waterfowl hunting is to be extended in response to public demand, public agencies apparently will have to acquire and manage additional public hunting grounds.

The States have logically taken the lead in acquiring public hunting areas, and in the future this phase of their management program will receive increased attention.

The success of the present combined Federal-State projects points the way to future development of wetlands, especially where large areas are involved. On such joint endeavors, the Fish and Wildlife Service manages the sanctuary area and the State administers the public hunting area.

Although national waterfowl refuges have been established primarily to protect a basic breeding population, portions of more than 30 refuges were open to public hunting in 1955. Where the harvest of surplus birds is warranted, the Fish and Wildlife Service permits public waterfowl hunting on as many refuges as possible, consistent with applicable laws.


Basically, there are three components of waterfowl habitats -- water, food, and cover. Public refuges are developed and managed to produce the maximum of these three essentials from each acre. Land-use practices on refuges vary with their primary function. Refuges where waterfowl nesting is the primary function strive for maximum interspersion of nesting habitat requirements. On intermediate and wintering refuges, development for food production and cover receives primary attention.

There are no set rules for increasing the attractiveness of waterfowl habitats. Ecological conditions and the seasonal availability of water will govern the methods used. Because the quality of any waterfowl habitat is chiefly dependent upon the quality of the vegetation, both aquatic and upland, refuge management is largely plant management. Waterfowl utilization of a refuge -- the only true measure of its value -- is directly related to the abundance and availability of desirable food and cover plants.

By proper manipulation of water levels, plant successions may be controlled to obtain the maximum yields of desirable plants. Other marsh-management techniques used to control weed plants and to improve the value of desirable plants are controlled burning, use of herbicides, and removal of undesirable plants by mechanical means. The muskrat, properly managed, helps to create open-water areas in dense cattail marshes.

Land practices on upland areas of refuges are also geared to increase the carrying capacity for waterfowl. In some cases, controlled cattle grazing is helpful in maintaining suitable cover on nesting and territorial areas, particularly along shorelines. This is favorable to producing the desired "edge effect" without seriously impairing brood cover and food supplies. On migration and wintering refuges, moderate grazing that makes fresh, green shoots available to waterfowl (especially geese) is often beneficial. Removal of rank vegetation by controlled burning is also employed to improve nesting habitats and feeding areas.

To the chagrin of farmers, some species of waterfowl now seem to prefer cultivated crops to native foods. The mallard and pintail, especially, prefer cereal crops, and geese have taken a liking for green-row and forage crops. To prevent local depredation on adjacent farms and, in some cases, to supplement a shortage of natural foods, arable lands on many public refuges are devoted to crop production. Nearly 90,000 acres of land on national refugees today are farmed.


In the face of the ever-expanding conversion of wetlands to agricultural, industrial, and urban uses, the importance of preserving the remaining high-quality wetlands for waterfowl use is clear. The loss of each valuable wetland area, large or small, means one less unit where waterfowl can breed, rest, or winter; it may also mean one less hunting site.

It is estimated that, if our waterfowl population is to be maintained somewhere near the present level of abundance, at least 12.5 million acres of intesively managed habitat under State and Federal ownership will be required to provide sufficient habitat for the birds that now migrate and winter within the United States. This habitat will also produce hundreds of thousands of young birds each year, but most production must continue to come from north of the Canadian border.

The acreage of land and water in Federal waterfowl refuges must be more than doubled if the Fish and Wildlife Service is to meet its responsibility for the protection of waterfowl populations. With 3,270,000 acres now in Federal refuges, about 4 million additional acres are needed to reach the Service's share of the 12.5 million acre objective. It is the desire of the Service to have an important waterfowl refuge every 200 miles along the north-south axis of each of the four flyways.

There are approximately 100 areas in this country where a Federal refuge should be located. These include problem areas where essential waterfowl habitats must be protected or provided, where crop depredation problems are acute, or where disease abatement is necessary. Many of the new Federal refuges will be superimposed on other Federal water-use projects to develop optimum conditions for waterfowl.

The States, with approximately 1,500,000 acres of waterfowl refuges at present, will need to preserve and manage an additional 3,500,000 acres in order to reach their share of the minimum goal of 12.5 million acres of waterfowl habitat in public ownership.

It should be clearly understood that while the postulated 12.5 million acres of publicly managed habitat will preserve waterfowl populations for future generations, the future of waterfowl hunting as an important American sport is dependent largely on what happens to privately owned wetlands, particularly the duck-nesting marshes in the North Central States and in Canada and Alaska.

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