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Geology topics

J. T. Lokemoen

Publications and source records attributed to J. T. Lokemoen.

At least 19 recordsLinked to original sources
USGS1994

Locating and managing peninsulas for nesting ducks

The purpose of this extension bulletin is to guide the management of nesting ducks on peninsulas on public and private lands. Managing peninsulas for ducks is a relatively new strategy that was developed in the grassland region of western North America. Information contained in this bulletin is primarily from studies conducted by biologists working at the Northern Prairie Wildlife Research Center.

Report↗
USGS1993

Increasing waterfowl nesting success on islands and peninsulas

Waterfowl that nest in uplands in the prairie pothole region have had low recruitment rates in recent decades, primarily because of predation. The loss of breeding waterfowl and their progeny has generated interest in management techniques that safeguard incubating hens and their eggs. Developing islands and peninsulas for nesting waterfowl has potential because these sites are naturally attractive to breeding ducks and geese. In fact, dense nesting colonies of ducks developed on some islands when successful females and a portion of their female progeny returned in subsequent years. Managers have successfully duplicated the beneficial attributes of islands by developing various nesting habitats that are protected by water barriers. This chapter addresses the management of existing islands, the creation of new islands, and the modification of peninsulas into islands to increase nesting success in waterfowl.

Fish and Wildlife Leaflet↗
USGS1986

Nest sites of ducks in grazed mixed-grass prairie in North Dakota

Habitat use and nesting success of seven species of dabbling ducks were evaluated in five vegetative associations within grazed mixed-grass prairie in central North Dakota. During 1976-80, 548 nests were found on 412 ha of grazed prairie for an annual average density of 27 nests/100 ha. Numbers of nests found ranged from 1/100 ha in 1977 (a drought year) to 58/100 ha in 1979 (a very wet year), reflecting the variability that may be expected in a dynamic prairie wetland environment. Nesting success ranged from an average of 23% in the western snowberry (Symphoricarpos occidentalis) association to 34% in the mixed-grass association. Forty-two percent of the mallard (Anas platyrhynchos) nests and 35% of the gadwall (A. strepera) nests were in patches of western snowberry and/or Wood's rose (Rosa woodsii) that made up 2% of the available cover. Numbers of nests of blue-winged teal (A. discors) and northern shoveler (A. clypeata) were highest in cool-season grasses, especially green needlegrass (Stipa viridula) and western wheatgrass (Agropyron smithii). Height/density (HD) of residual cover decreased exponentially with increased grazing pressure. Use of grazed prairie by blue-winged teal was maximized when the HD of residual cover was 0.5 dm or higher, as could be maintained under light grazing. Results of this study indicated that properly grazed mixed-grass prairie can provide adequate nesting habitat for dabbling ducks. We recommend that preservation and sound ecological management be focused on large tracts of mixed-grass prairie with complexes of seasonal and semipermanent wetlands.

North Dakota↗
USGS1982

Electric fences to reduce mammalian predation on waterfowl nests

We evaluated electric fences as predator barriers to reduce high losses of waterfowl nests to mammalian predation at Waterfowl Production Areas (WPAs). The work was done in 1978-81 on 3 paired sites in central North Dakota and western Minnesota. Resident mammalian predators were trapped from inside the exclosures. All 3 fences operated during the study period with few major maintenance problems. Nest success in the exclosures was 65% in North Dakota and 55% in Minnesota vs. 45 and 12% in the respective controls. Cover inside the electric fence produced 7.8 more young/ha than cover in control plots in North Dakota during the 3 years. Cover inside the 2 electric fences in Minnesota yielded 9.5 and 4.3 more young/ha than cover in control plots during the 3 years. Using construction costs only we estimated that each additional duckling produced in cover protected by electric fencing cost $0.65 in North Dakota and $0.87 in Minnesota.

Wildlife Society Bulletin↗
USGS1976

Duck nesting in fields of undisturbed grass-legume cover

A study of dabbling duck ( Anatinae ) nesting was conducted during 1971-73 on nine 12- to 54-ha Cropland Adjustment Program fields in the prairie pothole region of north-central South Dakota. The tall, dense vegetation was comprised of introduced cool-season grasses and legumes, primarily smooth bromegrass ( Bromus inermis ), intermediate wheatgrass ( Agropyron intermedium ), and alfalfa. Complexes of temporary, seasonal, and semipermanent wetlands surrounded the fields at densities of 1.5-8.1 basins/km2 and areas of 9.4-17.2 ha/km2. Of the 620 nests studied, 38 percent were of blue-winged teal ( Anas discors ), 24 percent were of mallards ( A. platyrhynchos ), and 24 percent were of gadwalls ( A. strepera ). Densities of nests of all species averaged 67, 114, and 47 nests/km2 (3-yr av 77/km2). Calculated hatching rates were 69, 58, and 32 percent (av 56) for the 3 years. Hatchability of eggs in successful nests averaged 97.1 percent. Averages of 4.0, 6.2, and 1.2 ducklings were hatched per hectare in 1971, 1972, and 1973, respectively (3-yr av 3.7/ha).

South Dakota↗