Northern Prairie Wildlife Research Center
U.S. Prairie Pothole Joint Venture
Implementation Guidelines for Management Strategies
Develop monitoring and evaluation methods to document population responses
of other wildlife to habitat and management for waterfowl, and incorporate those
methods into PPJV monitoring and evaluation plans.
Evaluate in each state all waterfowl management practices for potential adverse
effects on other wildlife, especially those targeted under Objective
#2. Determine means of avoiding, offsetting, or mitigating these effects
to ensure at least a neutral cumulative effect.
Obtain, and where practical, develop information on population limiting factors
and population responses to waterfowl habitat development and management actions
for species to be managed under Objective #2.
Support development of quantitative population objectives by agencies and
organizations with management interests and responsibilities for other species
of wetland dependant wildlife and other declining wildlife endemic to the PPR.
- Exclosures are designed to separate nesting hens and nests from ground predators.
Electric fences are the most commonly used barrier. Exclosures represent an
intensive management effort that requires initial expense and regular maintenance
throughout the nesting season. Mallards and gadwalls are the primary duck
species attracted to fenced areas, but other species of birds, including non-waterfowl
migratory birds, also benefit. A density of 1 - 2 duck nests per acre should
- Locate near good wetland habitat, preferably where 10 - 20 percent of
the land within 1/2 to 1 mile of the exclosure is wetland.
- Within one-half mile of 60+ acres of semipermanent wetlands and as many
seasonal wetlands as possible.
- Avoid fresh or slightly brackish permanent or semipermanent wetlands,
stock dams, dugouts, and streams. Avoid building adjacent to areas to
be fenced. These situations increase occurrences of mink. If unavoidable,
place exclosure ≥220
yards from such mink habitat.
- Surrounding area (up to 1 mile radius) should have relatively poor nesting
cover, and low nest success (use Mallard Model).
- Terrain inside fence should be level to gently rolling and soil should
be high quality, and stable.
- Fenced area should be void of features that attract predators such as
trees, rock piles, buildings, and wetlands.
- Secure brood travel cover should be available between exclosure and
brood water. Small grain cover will usually be adequate (dense cover is
likely not available if area is appropriate for fence).
- 20 - 80 acres. Areas less than 20 acres will probably not attract enough
duck pairs to justify cost. It takes almost as much effort to maintain
a 20-acre fenced area as it does an acre one.
- Exclosures should be 3 or 4 sided with no inside (concave) corners.
- Fences should be designed to allow deer to exit
- Establish dense cover with minimum residual Robel value of 1.5 decimeters.
Cool season grass (such as intermediate wheatgrass/legume mix is suitable.
Buckbrush and wild rose are also suitable cover.
- Close exclosure and remove predators just prior to nesting in spring.
Use track sign to determine if predators are inside when gates are closed.
Do not trap outside exclosure.
- Check fence and maintain predator control regularly (daily/weekly) through
- Open fence at end of season to prevent prey buildup and to allow free
access in and out by deer.
- In dry years consider that exclosures may not be worth maintenance effort.
- Consult Ducks Unlimited, Inc., or Service for fence design.
- For peninsulas > 5 acres in size located on semipermanent or permanent
- Brackish and alkaline wetlands are preferred
- Substantial pair and brood habitat nearby
- Other guidelines similar to stand-alone exclosures
- This treatment creates a water barrier that in essence converts a peninsula
into an island. Gadwall, mallards, and blue-winged teal are the principal
species nesting on cutoffs. Other duck species, such as pintail and lesser
scaup, are found in lesser proportions.
- Select large brackish or alkali wetlands because they are likely to
have low use by raccoons and mink (cutoffs are not 100 percent predator
- Near ≥60 acres semipermanent brood wetlands
with emergent vegetation and large numbers of seasonal wetlands within
1/2 to 1 mile to attract pairs.
- Where surrounding attractive nesting cover is minimal.
- Cut-off channel should create ≥100 yard
water barrier with trench not deeper than surrounding bottom, but not
less than 2 feet.
- Slope edge of trench to not create a cut-off bank that attracts muskrat
and consequently mink.
- Avoid areas with substantial emergent vegetation near cut-off.
- Peninsula size is site specific, but because of expense > 5 acres is
- Trap peninsulas annually just prior to nesting season and check occasionally
(search for tracks) to see if predator removal was complete.
- Establish nesting cover with Robel value of 1 - 1.5 decimeters if existing
cover is inadequate. Brush type cover is suitable and should require no
annual maintenance. Seeding grass/legume cover in winter when construction
is completed has worked well.
- Remove trees, tall shrubs > 1.5 m, rock piles, debris, etc., that may
provide cover/attraction for predators.
- Consult with Ducks Unlimited, Inc. or Service for techniques and specifications
for creating cut-offs.
- Properly designed nest structures provide nest sites for mallards that are
secure from ground predators if properly placed. Hay bales may not provide
adequate protection from raccoon and mink.
- In Class III (Stewart and Kantrud) or semipermanent wetlands. Semipermanent
wetlands are preferred.
- ≤6 feet from
- Where water depth is 18 inches minimum (when wetland is at normal level).
- Avoid areas with trees nearby.
- Where the attractiveness of surrounding cover is marginal for duck nesting
(cropland and grazed pasture dominate).
- Where nest success in existing cover is low.
- Areas with high density of wetlands and mallard pairs.
- No more structures than the number of mallard pairs in the area (maximum
density = 1 per acre).
- Culvert type nest structures should be filled with soil to anchor in
place and provide base for vegetative growth (culvert type structures
are low maintenance compared to some other types).
- Baffle may have to be installed to allow mallard hen and Canada geese
- For information on availability and installation of nest structures, contact
Service, ND Game and Fish Department, SD Department of Game and Parks.
- Small, man-made islands provide secure nesting sites that are used particularly
by mallards, gadwall, and lesser scaup. Other duck species and Canada geese
will also use islands in lower concentrations. Some islands attract extremely
large numbers of nesting ducks (> 30 nests per acre).
- Large (≥25 acres) alkali wetlands with water
depth of about 2 feet (shallow depth minimizes construction cost).
- Where numerous wetlands exit in surrounding area to provide pair habitat
and brood cover.
- Where nest predation in mainland cover is known or expected to be high.
- In areas where competing cover is minimal.
- Where a minimum water gap ≥100 yards from
shore can be maintained.
- Generally, islands should be constructed at 3/4 to 1 acre surface area
above water. Smaller islands have been made and used successfully by ducks,
but are subject to more rapid loss due to wave and ice erosion than large
islands. Islands are expensive to build, so only the most suitable sites
should be used. In general, ten 1 acre islands are better than one 10
acre island from duck use and success standpoint.
- Numerous islands can be created in a single wetland but islands should
be separated so they are within the breeding territories of more breeding
- Islands should be covered with a minimum of 4 inches of top soil and
planted with vegetative cover (intermediate or tall wheat/legume mix is
preferred). Shrubs such as buckbrush and rose require some effort to plant,
but require little maintenance and are very attractive to ducks. Shrubs
should be planted in small patches in the center of the island where grass/legume
mix was purposely not planted.
- Visit islands annually in the spring and trap predators that are present.
Maintain predator control through nesting season.
- Gulls can cause problems on some islands, but may be deterred by planting
dense cover to eliminate bare areas.
- Consult with Ducks Unlimited, Inc. or Service for information on construction
techniques, permits, etc., that are involved in island creation.
- Natural islands occurring in wetlands often represent "ready made" secure
nesting sites that are attractive to several duck species. While some islands
are adequate "as is," most require some form of enhancement or management
to obtain maximum benefits. These efforts can be costly, so prioritizing sites
- Any natural island may have potential, however, certain characteristics
may be associated with the greatest benefits; alkali - best, brackish,
- ≥100 yards from shore.
- Near good wetland complex with ample pair and brood habitat.
- One-tenth acre and larger.
- Each island is unique and may require different levels of attention.
- Establish cover on islands if it currently does not exist.
- Remove debris, trees, tall shrubs > 1.5 m, etc.
- Trap in spring to remove predators. Especially in wet years.
- Minimize human disturbance.
- Island characteristics will vary. Some islands may consistently be free
of predators. Still, this needs to be determined and an annual visit is
recommended. Island use by nesting ducks is extremely important for prioritizing
efforts. Monitoring use will allow maximizing benefits per effort and
provide information that can be used to identify other potential sites
or management strategies.
- Some islands are suitable only in wet years when high water inundates
connecting spit. Dry years may provide opportunity to "disconnect" islands
- The Habitat and Population Evaluation Team (HAPET) office will investigate
the use of an automated system using remote sensed data and Geographical
Information System techniques to identify and maintain a register of islands
in the prairie pothole region.
- Skunks are the primary nest predator in some areas. Skunks are easy to trap
in early spring (April) and, when combined with other management effort, skunk
removal can provide an extra margin of security for nesting hens.
- In areas where the predator community is simple and skunk densities
are not extremely high (otherwise, alternate predators and adjacent skunk
populations will quickly fill voids created).
- Target areas where coyotes are the primary canine predator as opposed
to red fox.
- Concentrate effort near areas treated by other enhancement methods such
as islands, planted cover, delayed haying, etc, or alternately implement
a broad scale intensive effort over a large area (township, county).
- Prior to whelping, April 1 to May 1.
- Red fox are a major cause of nest loss and kill many nesting hens in some
parts of the Prairie Pothole Region of North America. Broad scale control
of fox is generally not practical. However, special circumstances may warrant
fox removal that benefit ground nesting ducks. Data should be collected to
establish the effectiveness of the effort in each case.
- In areas where the predator community is simple and fox densities are
- Near areas treated by additional enhancement measures such as on islands,
delayed haying, planted cover, etc. This practice is probably beneficial
only where fox densities are low or where complete control can be obtained.
- Field studies indicate that areas dominated by coyotes will generally have
higher nest success than similar areas dominated by red fox. Coyotes tend
to displace red fox, yet coyote densities are usually lower in the areas they
dominate (in the PPJV). It is not clear whether densities will increase as
coyotes become better established.
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