Northern Prairie Wildlife Research Center
Differential Effects of Coyotes and Red Foxes
on Duck Nest Success
Study Areas
We collected data from 36 areas in the Prairie Coteau, Missouri Coteau, and
Drift Plain physiographic regions (Stewart 1975, Van Bruggen 1976, Kantrud et
al. 1989) of North Dakota and South Dakota during 1990-92. We changed location
each year to increase number of study areas and for geographic dispersal of
sampled areas. Because of drought, annual site selection was based on water
levels in the preceding fall. In 1990, 12 areas were in LaMoure, Logan, McIntosh,
and Stutsman counties of south-central North Dakota. In 1991, 13 areas were
in Ward and McLean counties of central North Dakota, and in 1992, 11 areas were
in Brown, Day, Marshall, McPherson, Roberts, and Spink counties of northeastern
South Dakota (Sovada 1993). Each area was 60-200 ha and was all or part of a
federal Waterfowl Production Area or part of a national wildlife refuge; uplands
on all areas were managed for nesting ducks.
The Coteau regions were moderately to steeply rolling glacial moraine. The
Drift Plain was relatively flat to moderately rolling. All 3 regions contained
high densities of wetlands and were farmed, intensively in most places (Higgins
1977, Cowardin et al. 1983). In the locations of our areas, most upland was
cultivated annually for crops, primarily small grain; untilled uplands were
pastures, hayland, and idle grassland. Much idle grassland was in the Conservation
Reserve Program (Bjerke 1991).
The climate at the study locations was continental and average monthly temperature
ranged -13-26 C (U.S. Dep. of Commer. 1990, 1991, 1992). Annual precipitation
at study locations was 44-48 cm (U.S. Dep. of Commer. 1990, 1991, 1992). We
conducted the study during a period of drought; many temporary and seasonal
wetlands near areas studied were dry early in spring each year.
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