Ecology and Management of Islands, Peninsulas and Structures for Nesting
Waterfowl
The Effects Of Cover Manipulation and Electric Predator Barrier On Lake
Albert In South Dakota
Gay Simpson and Dan Limmer South Dakota Department of Game, Fish and Parks
The Central Flyway Mallard Management Plan identified summer survival of hens
and nest success as the two population parameters which could have the greatest
impact on recruitment rates of mallards (Anas platyrhynchos). Electric
fence barriers had been shown to increase those two parameters, but had not been
tested in South Dakota. Neither had electric fence barriers been tested in association
with established dense-nesting populations. Chain-drag nest searches were conducted
on a peninsula in Lake Albert, Kingsbury County, South Dakota, in 1985 and again
in 1987 and 1988, to determine duck nest density and success, to evaluate the
peninsula for construction of a predator barrier fence, and to evaluate the effectiveness
of the barrier once constructed. Nest density increased from 0.58 nests per ha
in 1985 to 5.83 nests per ha in 1987 and 1988, respectively, after construction
of the fence. Nest success increased from 0 in 1985 to 65.4 and 44.5 percent in
1987 and 1988, respectively. This dramatic response of ducks, principally mallards,
was due to several factors. First, the proximity of Lake Albert Island, a known
dense-nesting island for mallards, insured a supply of nesting hens. Second, burning
and grazing on the peninsula prior to barrier construction resulted in an increase
in snowberry (Symphoricarpos occidentalis) and intermingled stinging nettle
(Urtica procera), the preferred nesting cover on the island. Third, the
barrier successfully excluded predators due to the suitability of the site, and
finally the barrier eliminated human disturbance on the area, which had been frequent.
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and Barriers Return to Contents Next Section -- Prairie Pothole Project Predator-Fenced
Cover Plot Evaluations