Glen Sargeant
Science and Products
Effects of population density on prevalence of chronic wasting disease, physical condition, and vital rates of elk at Wind Cave National Park, South Dakota
CWD is a degenerative neurological disease caused by infectious proteins called prions. Although documented cases are invariably fatal, infected elk commonly survive for several months or longer, passing prions directly to other individuals and into the environment, where they bind to surfaces or soils and can persist for years. CWD reached Wind Cave National Park about 1997 and rapidly...
Integrated conservation of bison and native prairie at Badlands National Park, South Dakota
Badlands National Park contains the largest contiguous bison range in the core of the species’ historic range on the northern Great Plains. The park nevertheless is too small to accommodate natural movements of free-ranging bison. As a result, continual grazing by resident bison has supplanted intense-but-ephemeral grazing by nomadic bison. The herd also is currently too small to prevent...
Population and harvest dynamics of midcontinent sandhill cranes
Sandhill cranes (Antigone canadensis) inhabiting the midcontinent of North America have been hunted since the 1960s under management goals of maintaining abundance, retaining geographic distribution, and maximizing sustainable harvest. Some biologists have raised concerns regarding harvest sustainability because sandhill cranes have lower...
Pearse, Aaron T.; Sargeant, Glen A.; Krapu, Gary; Brandt, David A.
Chronic wasting disease—Research by the U.S. Geological Survey and partners
IntroductionChronic wasting disease (CWD) is the only transmissible spongiform encephalopathy, a class of invariably fatal neurodegenerative mammalian diseases associated with a misfolded cellular prion protein found in wild free-ranging animals. Because it has a long incubation period, affected animals in Cervidae (the deer family; referred to as...
Hopkins, M. Camille; Carlson, Christina M.; Cross, Paul C.; Johnson, Christopher J.; Richards, Bryan J.; Russell, Robin E.; Samuel, Michael D.; Sargeant, Glen A.; Walsh, Daniel P.; Walter, W. David Ecotypic variation in population dynamics of reintroduced bighorn sheep
Selection of bighorn sheep (Ovis canadensis) for translocation historically has been motivated by preservation of subspecific purity rather than by adaptation of source stocks to similar environments. Our objective was to estimate cause‐specific, annual, and age‐specific mortality of introduced bighorn sheep that originated at low elevations in...
Bleich, Vernon C.; Sargeant, Glen A.; Wiedmann, Brett P.
Potential effects of energy development on environmental resources of the Williston Basin in Montana, North Dakota, and South Dakota—Species of conservation concern: Chapter D in Potential effects of energy development on environmental resources of the Williston Basin in Montana, North Dakota, and South Dakota
The ecosystems of the Williston Basin provide direct and indirect benefits to society. These benefits include carbon sequestration, flood control, nutrient rich soils for agricultural productivity, and habitat for wildlife. This chapter’s main focus is on the effects of energy development on species that occupy the ecosystems in the Williston...
Post van der Burg, Max; Symstad, Amy J.; Igl, Lawrence D.; Mushet, David M.; Larson, Diane L.; Sargeant, Glen A.; Harper, David D.; Farag, Aïda M.; Tangen, Brian A.; Anteau, Michael J. Timing of spring surveys for midcontinent sandhill cranes
The U.S. Fish and Wildlife Service has used spring aerial surveys to estimate numbers of migrating sandhill cranes (Grus canadensis) staging in the Platte River Valley of Nebraska, USA. Resulting estimates index the abundance of the midcontinent sandhill crane population and inform harvest management decisions. However, annual changes in the index...
Pearse, Aaron T.; Krapu, Gary L.; Brandt, David A.; Sargeant, Glen A. Use of water developments by female elk at Theodore Roosevelt National Park, North Dakota
Development of water sources for wildlife is a widespread management practice with a long history; however, needs of wildlife and availability of water depend on myriad interacting factors that vary among species and localities. Benefits are therefore situational, establishing a need for evaluation of water use in varied settings. We used global-...
Sargeant, Glen A.; Oehler, Michael W.; Sexton, Chad L. Ecotypic variation in recruitment of reintroduced bighorn sheep: implications for translocation
European settlement led to extirpation of native Audubon's bighorn sheep (formerly Ovis canadensis auduboni) from North Dakota during the early 20th century. The North Dakota Game and Fish Department subsequently introduced California bighorn sheep (formerly O. c. californiana) that were indigenous to the Williams Lake region of British Columbia,...
Wiedmann, Brett P.; Sargeant, Glen A. Determinants of mallard and gadwall nesting on constructed islands in North Dakota
Constructed islands with adequate nesting cover provide secure nesting sites for ducks because islands restrict access by mammalian predators. These islands are costly to construct and should be placed in areas that ensure the greatest use by nesting ducks. We studied mallard (Anas platyrhynchos) and gadwall (A. strepera) nesting on constructed...
Shaffer, Terry L.; Dahl, Ann L.; Reynolds, Ronald E.; Baer, Kathy L.; Johnson, Michael A.; Sargeant, Glen A. Markov Chain Monte Carlo estimation of species distributions: a case study of the swift fox in western Kansas
Accurate maps of species distributions are essential tools for wildlife research and conservation. Unfortunately, biologists often are forced to rely on maps derived from observed occurrences recorded opportunistically during observation periods of variable length. Spurious inferences are likely to result because such maps are profoundly affected...
Sargeant, Glen A.; Sovada, Marsha A.; Slivinski, Christiane C.; Johnson, Douglas H. Demographic response of black bears at Cold Lake, Alberta, to the removal of adult males
Previous reports described an increase in population density following the removal of 23 adult male black bears (Ursus americanus) from a 218-km2 study area near Cold Lake, Alberta (the CLSA). This finding plays a central role in continuing debates over population regulation in bears, but has recently been criticized because density estimates were...
Sargeant, Glen A.; Ruff, Robert L. Survival of postfledging mallards in northcentral Minnesota
Effective, economical management of waterfowl populations requires an understanding of age-, sex-, and cause-specific forces of mortality. We used radio telemetry to estimate survival rates of immature mallards (Anas platyrhynchos) from fledging to autumn migration in northcentral Minnesota. We monitored 48 females and 42 males during 1972-74 and...
Kirby, Ronald E.; Sargeant, Glen A. An improved method for determining the distribution of swift fox in Kansas
During 1997 and 1998 we tested a new method for determining the distribution of swift foxes (Vulpes velox) in Kansas. From a sampling frame of 30 counties in western Kansas, we selected a systematic sample of alternate townships in a checkerboard pattern. During September and October 1997 and August 1998, experienced observers delineated suitable...
Roy, Christiane C.; Roy, Christiane C.; Sovada, Marsha A.; Sargeant, Glen A.