Waterfowl

Habitat Management Suggestions for Selected Wildlife Species
By R.J. Mackie, R.F. Batchelor, M.E. Majerus, J.P. Weigand, and V.P. Sundberg

Montana waterfowl include a variety of species of migratory ducks, geese, and swans. Twenty-seven ducks or duck-like species, four species of geese, and two species of swan are included in Montana’s waterfowl family. Of this list, 20 species of ducks, one goose, and one swan are considered as nesting species in the state. The remainder are only casual visitors during spring and fall migrations.

North American ducks are divided by body structure and habit into two groups form which they get their names - puddle ducks and diving ducks. Puddle ducks or dabbling ducks are so called because they tip the front half of their body under the water’s surface when feeding in shallow water. Diving ducks, on the other hand, dive to considerably depths to feed on submergent vegetation.

Habitat Needs

Montana’s waterfowl distribution is a result of the condition of water levels and associated wetlands (habitat condition) and the season of the year. Breeding habitat should be of sufficient quality to supply needs from the time birds arrive in early spring through the time young are ready to fly in late summer. Important factors include not only the nest location but also stable water levels, good escape cover, and available food sources. Nesting habitat varies from upland, dry nesting sites located hundreds of yards from water for some puddle ducks, to nests built over the water as is the case for some diving ducks. Abundant food and good escape cover are two critical requirements of good brood rearing habitat.

Migration habitat for both spring and fall migrations centers around the needs of rest areas and food supply. Larger bodies of water associated with agricultural crops are generally preferred by migrating birds. Montana’s winter habitat is limited to river systems which maintain some open water. As expected, the extent of these wintering areas varies with the severity of the weather.

Habitat Management Suggestions

Development of New Habitat

The initial planning stage is highly important in developing new water areas for waterfowl. Stock watering ponds exhibit a high potential for waterfowl use if waterfowl needs are recognizes in the construction phase of the project. Selection of the dam site should be in an area that will provide an adequate supply of water throughout the summer. A minimum of three acres for duck species and five acres for geese is a general rule. These areas should exhibit a shoreline slope of 20 percent or less to allow for the establishment of emergent vegetation. In association with these factors water depth is critical both from a waterfowl production aspect and maintaining water throughout the summer months. If 50 to 75 percent of the pond acreage is 2 feet or less in depth, the greatest brood use will occur.

Possible sites for the construction of islands should be included in the initial planning. Canada geese highly prefer small islands as nesting sites. Peninsulas are easily cut off to form islands and are rather inexpensive when done during the initial construction phase.

Food supplies in the form of emergent vegetation develop rather quickly in most ponds if adequate shallow water depths are provided. Root stock is available from several nurseries if the natural process is slow to develop.

Maintenance of Waterfowl Habitat

Grazing

Once an area possesses the needed ingredients that make waterfowl habitat, the emphasis must be placed on maintaining the habitat in an attractive condition for waterfowl. Water in itself does not constitute attractive waterfowl habitat. Early nesting ducks such as the mallard and pintail rely on residual vegetation for nesting sites. Lack of residual cover as a result of grazing is probably the single most important factor that reduces the attractiveness of an area for breeding waterfowl. Areas under grazing systems that allow for residual vegetation during the early part of the nesting season show dramatic increases in duck production.

Fencing

Fencing of water areas produces limited results and is a highly costly operation. Some species of ducks such as the pintail and mallard may nest several hundred yards away from the water’s edge if cover is available. Fencing of a small area around the water concentrates nesting birds. These small areas are easily worked by predators and result in low nest success.

Vegetation Control

Cattail marshes which have become solid stands of vegetation can be made more attractive to waterfowl by opening up the stands and creating an open water area. Chemicals or mechanical methods generally produce short-lived results in these areas. Pothole blasting in these areas has proven to be the most economical and most desirable treatment. This technique creates a water area of sufficient depth to last several years.

Pothole blasting can create marsh habitat in areas with high water tables. Generally these sites are too wet to farm and provide an excellent opportunity to convert idle ground into productive water fowl habitat.

Water Level Control

On larger areas where water sources exist, the use of control structures to manipulate water levels will produce dividends. The slow draw-down of water over the summer months will allow vegetation to develop throughout the shallow water zone. Reflooding during the fall will provide a food source for migrating waterfowl.

Food

Nearly all waterfowl are dependent upon the naturally occurring vegetation within the marsh ecosystem as their food source during the breeding and brood rearing season. Plants such as the sedges, bulrushes, and other marsh plants make up the birds’ diet. With the advent of fall migration, pintails, mallards, and geese utilize grain crops as their main source of food. The diving ducks remain dependent upon the aquatic plant species found in the marsh

Return to regular view	Text-only	Updated: 08/29/2006