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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Habitat selection by calving caribou of the central arctic herd, 1980-95

Wolfe, Scott Adrian. January 2000 (has links) (PDF)
Thesis (M.S.)--University of Alaska Fairbanks, 2000. / Title from PDF t.p. (viewed on Dec. 12, 2000). Includes bibliographical references (leaves 58-83).
42

An environmental controversy how newspapers framed coverage of the Bush administration's proposal to drill for oil and gas in the Arctic National Wildlife Refuge (Alaska) /

Dudo, Anthony David. January 2005 (has links)
Thesis (M.A.)--University of Delaware, 2005. / Principal faculty advisor: Nancy Signorielli, Dept. of Communication. Includes bibliographical references.
43

Landscape genetics of black bears (Ursus americanus) on the Kenai Peninsula, Alaska : phylogenetic, population genetic and spatial analyses /

Robinson, Stacie Joy. January 2007 (has links) (PDF)
Thesis (M.S.)--University of Idaho, 2007. / Includes bibliographical references. Also available electronically on the Internet.
44

Investigations of the West Nile virus transmission cycle at Medicine Lake National Wildlife Refuge, Montana, 2006-2006

Hale, Kristina Marjorie. January 2007 (has links) (PDF)
Thesis (M.S.)--Montana State University--Bozeman, 2007. / Typescript. Chairperson, Graduate Committee: Gregory D. Johnson. Includes bibliographical references (leaves 60-66).
45

Development of an Interpretive Document for the Bear River Migratory Bird Refuge

Burbridge, William R. 01 May 1972 (has links)
Since its inception, the National Wildlife Refuge System has been administered for management and restoration of habitat essential to the propagation and welfare of resident and wintering wildlife species. Acquisition of additional System units has been primarily directed to the benefit of the migratory bird resource. As of July 1, 1968 about 250 of the 321 refuge units were managed for the waterfowl resource (U. S. Department of Interior, 1968a). However, this growth of the System has been accompanied by an increase in recreational use of the refuges. In 1962, Public Law 87-714, the Refuge Recreation Act, was passed to provide direction for recreational development. The Act recognized that recreation must be limited in type and scope to avoid conflict with the primary wildlife management objectives. Although the primary function of the Refuge System is to meet the needs of wildlife, the entire System is based on the philosophical precept that the wildlife on these refuges is for the enjoyment of the public. It thus follows that refuges should provide for some public use. In recent analyses of America's resource picture, the fastest rising curves and projection are those of travel and the recreational use of wildlands (Clawson, 1963). Attendance records at our wildlife Refuges have grown at a rate of 12 percent annually. Except for boating and fishing at reservoir sites, the fastest growth in outdoor recreation since World War II has been in the use of National Wildlife Refuges (Clement, 1964).
46

Avian Affairs: A Study of the Occurrence and Benefits of Extra-pair Breeding Behavior in Eastern Kingbirds (Tyrannus Tyrannus)

Dolan, Amy Catherine 01 June 2006 (has links)
Over three consecutive breeding seasons I examined the breeding system of Eastern Kingbirds in Malheur National Wildlife Refuge in SE, Oregon. To assess genetic paternity, I optimized seven microsatellite markers and determined that extra pair paternity was common. Extra-pair young were present in approximately 60% of nests, representing 47% of young. I examined implications of extra-pair paternity from three perspectives. First, I examined the impact of extra-pair paternity on the opportunity for sexual selection within a socially monogamous system and identified correlates of male reproductive success. Some males were successful at the expense of others, and 24% of males did not sire any young. Thus, variance in male reproductive success was more than nine times greater than female variance, indicating that sexual selection operates strongly in this system. Extra-pair success was positively related to tarsus length and inversely dependent upon dawn song start time. Within-pair success was positively related to nest defense intensity during the incubation period. Second, I assessed the four genetic hypotheses proposed to explain female cooperation in extra-pair copulations. Extra-pair young were not distributed randomly among broods. Cuckolded within-pair males were not more closely related to females than were extra-pair sires. Pair wise comparisons indicated males with specific song and morphological traits were chosen as sires. Brood success (proportion of brood to fledge and recruit) was unrelated to thenumber of males who sired young in the brood. Extra-pair young were larger and heavier than their within-pair half-siblings. These results unambiguously support the 'good genes' hypothesis of female extra-pair mating. Last, I examined the influence of breeding date and parental condition (mother, social father and genetic sire) on offspring sex ratio. Given that male variance in reproductive success is much greater than that of females, I predicted the characters of genetic sires would be the most important factor influencing offspring sex ratio. Contrary to my prediction, male traits did not influence offspring sex ratio. However, more males hatched early in the season and females in better condition produced more sons. I also found that male nestling survival to the next breeding season was inversely related to date.
47

Impacts of nutrient loads on the invasion potential of Butomus umbellatus L. on Ottawa National Wildlife Refuge diked wetlands

Forstater, Erica L. 10 August 2020 (has links)
No description available.
48

The Impacts of Feral Horses on the Use of Water by Pronghorn on the Sheldon National Wildlife Refuge, Nevada

Gooch, Amy Marie 01 December 2014 (has links) (PDF)
Feral horses occupy 31.6 million acres throughout western North America. Feral horses share similar habitats with a wide range of animal species, including pronghorn. Since horses are larger and often more aggressive than other animals of this region, they are generally socially dominant over all other native ungulate species. Pronghorn share water sources with horses in areas where both occur. In situations where horses exclude pronghorn from water, pronghorn fitness may be impaired, especially during the hottest months of the year when water is limited. The purpose of this study was to investigate interference competition between pronghorn and feral horses at water sources. During spring and summer 2010-11, we placed motion-sensitive cameras at water sources across the Sheldon National Wildlife Refuge in northwest Nevada. Cameras were used to examine the overlap of water use by pronghorn and horses and to determine the occurrence of spatial or temporal partitioning of water between these species. Additionally, we made direct observations of horses and pronghorn at high-use water sources to record the occurrences and outcomes of pronghorn/horse interactions as well as differences in pronghorn behavior in the presence and absence of horses. Pronghorn spent more time on vigilance behavior and less time foraging or drinking in the presence of horses than in their absence. Nearly half of pronghorn/horse interactions at water resulted in pronghorn exclusion from water. Our data also suggest that temporal partitioning of water between horses and pronghorn on an hourly basis may be occurring.
49

"Access Points"

Dye, Aaron Charles 08 1900 (has links)
Access Points explores the different relationships that humans have to land, focusing on the various ways that the area known as the Wichita Mountains Wildlife Refuge is used, appreciated, and preserved by disparate groups. The natural beauty of this Wildlife Refuge and its striking appearance amidst encircling plains makes it a popular destination for many groups of people, including the local rock-climbing community and generations of indigenous peoples whose connection with this land is as deep as it is longstanding. While climbing organizations have long had to negotiate access and rules regarding climbing within the park, members of the Kiowa community negotiate a much different relationship to a natural area that is now managed by the United States government. These disparate voices, identities, and ways of thinking about land all impact the modern-day Wildlife Refuge in terms of its appearance, individuals' access to the land, and the conservation efforts happening there.
50

Factors Limiting Native Species Establishment On Former Agricultural Lands

Weiler-Lazarz, Annalisa M 01 January 2012 (has links)
Restoration of abandoned, nonnative species-dominated agricultural lands provides opportunities for conserving declining shrubland and grassland ecosystems. Land-use legacies, such as elevated soil fertility and pH from agricultural amendments, often persist for years and can favor nonnative species at the expense of native species. Understanding the factors that limit native species establishment on abandoned agricultural lands can provide important insights for restoration and conservation of native species on human-modified lands. I conducted two field experiments on abandoned agricultural lands: a former pasture on Martha’s Vineyard, MA and a former citrus grove at Merritt Island National Wildlife Refuge (MINWR) in Titusville, FL. In these experiments I tested how soil chemical properties affect native and nonnative species abundance and how different methods of removing nonnative, invasive species affect native and nonnative species abundance. In the first experiment, specifically I tested how restoration treatments affect competition between existing nonnative agricultural plant species and native plant species that are targets for sandplain grassland restoration on Martha’s Vineyard, MA. At MINWR, I examined how lowering soil fertility with carbon additions and lowering soil pH by applying sulfur affects nonnative species richness and cover (in two former citrus groves that were historically scrub/ scrubby flatwoods. Overall, I found that biotic factors, such as competition with nonnative species, play a stronger role in limiting native species establishment than soil chemical properties. Likewise, control of nonnative, invasive species is most effective with mechanical treatments to physically reduce cover, rather than altering soil chemical properties

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