Waterfowl Management in Georgia
Management Techniques for Waterfowl
Like all species of wildlife, waterfowl need the basic necessities for life: food, water, cover, and space. By manipulating the amount and type of each of these resources, waterfowl habitat can be greatly improved. The management techniques discussed below can be used to increase the amount of desirable foods, provide the correct amount and type of cover, control water depth and timing of flooding, and create the space and refuge needed by waterfowl.
NOTE: Always check with local offices of the U.S.D.A. Natural Resource Conservation Service and/or the U.S. Army Corps of Engineers before modifying any wetland area. There are strict federal laws concerning wetlands that must not be violated.
Managing Food Resources
Providing food for waterfowl can be accomplished in one of two ways, through moist soil management to encourage the growth of desirable, native food plants or by cultivating agricultural crops such as corn or millets. In some cases, a combination of native foods and cultivated crops can be used to attract and hold waterfowl.
Moist Soil Management
Moist soil management is a management technique that stimulates the growth of beneficial native plants by controlling the water level in an impoundment or a beaver pond. If you can control the depth, duration, and timing of flooding, you can practice moist soil management. Water levels can be controlled with the use of a flashboard riser. Removing boards will allow water to drain from the impoundment, and replacing boards will keep water in the impoundment. A dependable source of water is absolutely necessary. Streamflow can be used to fill the impoundment, or a pump can be used to pull water from a nearby source, or gravity can be used to pull water from an upstream holding pond into the impoundment. Do not rely solely on rainfall and runoff to fill the pond, or the impoundment will remain empty in some years due to lack of rainfall.
Managed impoundments should be drained gradually (over a period of 2-4 weeks) around May or June, and the soil should be kept moist through the growing season. This will stimulate the germination and growth of selected wetland plants that are preferred by waterfowl, including wild millets, smartweeds, sedges, and other aquatic plants. By draining the impoundment gradually, a greater variety of wetland plants will germinate and grow, whereas a rapid drawdown will result in a very similar stand of vegetation across the impoundment. Once the seeds are mature in the fall, the impoundment can be mowed, disked, or burned before it is reflooded. This practice is legal as long as you are managing native vegetation. Mowing, disking, and burning reduce the amount of vegetative cover in the impoundment and provide open water areas for ducks to use. These techniques also help prevent perennial pest plants from becoming established, and they stimulate the preferred, early successional plant species such as wild millets and smartweeds. The impoundment should be reflooded gradually beginning in early October, and the impoundment should be full by early November, when many of the migrants begin to arrive. Ideally, water depths in managed impoundments should range from 2-4 inches up to 18 inches. These depths provide ideal foraging areas for wintering waterfowl. After waterfowl season, the water level in the impoundment can be reduced to attract migrating shorebirds, and then drained slowly in May or June, when the annual management process starts over.
In a beaver pond situation, food resources can be increased through the use of a Clemson beaver pond leveler (Adobe Acrobat Reader required). This device should be inserted into the beaver dam in early June to drain the beaver pond. Exposing the bottom or sides of the pond to air and sunlight will result in the germination of a tremendous variety of wetland plants that will attract a variety of waterfowl in the fall. In the fall, the manager must simply close the drain and allow the pond to refill. Beaver pond managers must realize that without a dependable water supply, there is a chance that the beaver pond will not be flooded prior to duck season.
Moist soil management is inexpensive because there is no seed or fertilizer to buy and no farm equipment is needed unless the manager chooses to manipulate the vegetation prior to flooding. There is normally a great diversity of plants that grow in moist soil areas, and because these plants have evolved in wet areas, their seeds are durable and won't rot after the impoundment is flooded. Because there are so many different species of plants, there is usually a very consistent seed crop every year. Native plants provide a balanced diet, including all essential nutrients. Impoundments that are managed for native vegetation usually have more aquatic invertebrates, more amphibians, more reptiles, and more mammals than impoundments that are managed in other ways.
Planting Agricultural Crops
Impoundment managers also have the option of planting agricultural crops as a means of increasing the food supply for waterfowl. Just like moist soil management, the impoundment manager must have complete control of the water level. The manager must be able to drain the impoundment completely, keep the water off during the growing season, and reflood the impoundment from a dependable water source in the fall.
There are many different crops that can be planted for waterfowl. The management scheme is very similar for most agricultural crops. The impoundment is drained in March or April, and allowed to dry completely. The impoundment must be dry enough to support a farm tractor. Once the seedbed is prepared, the crop is planted at the proper seeding rate and fertilizer and lime are added according to soil test specifications. Planting dates will vary depending on the selected crop. Once the seed has matured, the impoundment is reflooded in early November in preparation for the arrival of migrating ducks.
Agricultural crops can also be used in beaver ponds if the water level can be controlled. A quick, late drawdown in July followed by hand sowing of Japanese millet on the exposed mudflats can provide a large amount of palatable seed for waterfowl. Once the seed is mature, allow the beaver pond to reflood as described in the section above.
Before choosing to plant agricultural crops for waterfowl, there are several factors to consider. Small grains do not provide a nutritionally complete diet for waterfowl, while native plants provide essential nutrients and a greater diversity of food. Planting has many additional costs, including seed, fertilizer, lime, equipment, and the risk of a crop failure in some years. However, some plantings are highly palatable and productive and may do an excellent job of attracting and holding waterfowl.
NOTE: There are strict baiting laws that must be followed when planting agricultural crops for waterfowl management. See Georgia's current migratory bird baiting regulation. If further assistance or clarification is needed, contact your local Georgia Department of Natural Resources, Wildlife Resources Division office for assistance.
Green Tree Reservoirs
A green tree reservoir is another type of impoundment that can be managed for waterfowl. A dike is used to hold water in an impoundment that is built around a stand of mature, mast producing trees, especially water oaks, willow oaks, southern cherrybark oaks, and others.
A water control structure such as a flashboard riser is used to hold water in the fall and winter, and the boards are removed to drain the area during the spring and summer. The impoundment should be flooded only after the leaves on the trees have changed color in the fall, which normally happens about late October or November. Once the leaves change color, the trees have gone dormant for the winter, and they will not be damaged by flooding. The impoundment should be flooded to a depth of no more than 18 inches. The primary food source in a green tree reservoir is acorns, and the waterfowl that benefit the most include mallards, wood ducks, and black ducks.
In the spring, drain the impoundment when the buds on the trees begin to swell, which normally happens in late February or early March. If the impoundment remains flooded too long in the spring, the trees could be killed. Flooding a green tree reservoir every year will slowly weaken the trees, and some eventually will die. Flooding the impoundment every other year is one way to extend the life of the trees. Another option is to flood the impoundment for three years in a row, and then let it remain dry for two years in a row. This rotation will allow use of the impoundment 3 out of every 5 years.
Managing Available Cover
Cover can be loosely defined as a place to hide, but ducks need different types of cover at different times of the year. During the spring, hens need nesting cover. Once the ducklings hatch, they need brood-rearing cover that will protect them until they are able to fly, usually at about 7 weeks of age. Ducks also need loafing cover, which is simply a safe place to sit and relax.
Hens need a safe place to build their nest because a hen on an exposed nest is more prone to attract predators, which may destroy the eggs, kill the hen, or both. The only species of waterfowl that nests in significant numbers in Georgia is the wood duck. Wood duck hens normally nest in tree cavities that have been hollowed out by some other species, usually woodpeckers. In many areas, the mature hardwood trees that would normally provide nesting cavities for wood duck hens have been cut down, and there are not enough suitable natural cavities available.
In areas where natural cavities are lacking, nest boxes can be built and erected to create the necessary nesting cover for wood duck hens. These boxes not only provide additional cavities for the wood ducks, but they are also much safer than a natural cavity when a predator guard has been properly installed. Predator guards are necessary to prevent nest predators like raccoons and rat snakes from entering the box, killing the hen, and destroying the nest. Nest boxes also must be maintained annually to keep them productive. Unhatched eggs, old nesting material, and wasp nests have to be removed, and fresh shavings need to be added along with some sort of insect repellent. Wood duck nest boxes must be put up in or near available brood-rearing habitat in order to successfully increase local wood duck populations.
Too many wood duck boxes in one area may lead to a problem known as "dump nesting." In cases where the boxes are too close together, several hens may lay eggs in the same box, yet none of the hens incubate the eggs. Dump nests may contain as many as 25-30 eggs that never develop or hatch. To avoid the problem of "dump nesting," only put up about one box per acre of suitable habitat when beginning a nest box program. Check and maintain the boxes annually, and only add more boxes when the existing boxes are all being used.
To successfully raise a brood of young ducklings, the hen wood duck needs the proper type of cover to protect them. Good brood-rearing habitat contains a mixture of approximately 30% shrubs, 25% open water, 5% trees, and 40% emergent vegetation. The emergent vegetation and overhead shrub cover provide places for the ducklings to hide from predators. The emergent vegetation also provides places for the ducklings to hunt for animal foods including aquatic insects, spiders, and other invertebrates. These animal foods are part of a high protein diet that ducklings need for proper growth and development.
To be beneficial, brood-rearing habitat should be in close proximity to the nesting cover and/or nest boxes that are available to wood ducks. Brood-rearing areas should be shallow, and have a dependable water source so that the area will stay flooded until the ducklings are able to fly.
Loafing cover is another requirement of wintering waterfowl. Loafing cover is simply a safe place to sit and rest. Muskrat mounds, beaver lodges, stumps, floating logs, and tussocks of vegetation are all examples of loafing areas. Some species prefer large areas of open water to sit and loaf. Ducks often feed heavily in the morning or afternoon hours, and then loaf and preen during the middle of the day. Ducks often seek isolated spots out of the water to preen and rest, and loafing areas provide these havens.
In addition to food, water, and cover, ducks also need space. Managers can provide all of the other necessities of life, but if ducks are constantly harassed by man's activities, i.e. if they don't have the space that they need, the ducks won't stay very long.
Reducing Disturbance and Providing Refuge Areas
Limiting access to the impoundment is the best way to limit disturbances. If the manager has the capability to "close the gates" to the wetland areas that are managed for waterfowl, that is the best way to provide a quiet environment for waterfowl. If ducks are consistently flushed, they will eventually move to another area. Other options include leaving a border of vegetation around the impoundment if it is near a road, house, or other source of disturbance. If the impoundment is hunted, do not hunt too often. The manager may have to learn by experience how often the impoundment can be hunted without driving ducks away. Many public impoundments in Georgia are only hunted once per week. Morning hunting is generally believed to be less disruptive and less likely to move ducks than evening hunting, or "roost shooting" (which is illegal after sunset). In addition to reducing disturbance to the ducks on the impoundment, providing a refuge also is very important. The refuge can take two forms: a space refuge or a time refuge. A space refuge is a physical portion of the area that is not hunted. A time refuge is a limit on the days or hours when hunting is allowed. Either of these techniques provide waterfowl with a safe place to feed and loaf when hunting season is open.
By providing the essentials of life: food, cover, water, and space, land managers can enhance local wood duck populations and attract migratory waterfowl to their property. Hopefully this management guide has provided the information necessary to begin a waterfowl management program. If landowners or managers have additional questions about waterfowl management, the Georgia Department of Natural Resources, Wildlife Resources Division, has trained personnel to answer their questions and assist with the development of a waterfowl management plan. Simply call the nearest Game Management Office to seek assistance.
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