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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.
81

Golden-cheeked warbler nest predators and factors affecting nest predation

Stake, Mike M. January 2003 (has links)
Thesis (M.S.)--University of Missouri-Columbia, 2003. / Typescript. Includes bibliographical references. Also available on the Internet.
82

The winter ecology of piping plovers (Charadrius melodus) along the Texas Gulf Coast

Zonick, Curtis A. January 2000 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 2000. / Typescript. Vita. Includes bibliographical references (leaves 162-168). Also available on the Internet.
83

A comprehensive methodology for measuring costs and benefits of critical habitat designation under the Endangered Species Act

Slack, John Taylor. January 2003 (has links) (PDF)
Thesis (M. S.)--Public Policy, Georgia Institute of Technology, 2004. / Norton, Bryan, Committee Chair; Noonan, Douglas, Committee Member; Kirkman, Robert, Committee Member. Includes bibliography.
84

Social perceptions of nonhumans in Tombali (Guinea-Bissau, West Africa) : a contribution to chimpanzee (Pan troglodytes verus) conservation

Costa, Susana Gonçalves January 2010 (has links)
Rainforest biodiversity is particularly vulnerable to loss, since the distribution of forests is limited and the vertebrate species that live within these forests have a limited potential to re-colonize deforested areas, especially when their abundance declines to critical levels. Guinea-Bissau (West Africa) is experiencing significant loss of habitats and species diversity; as such, the establishment of an effective conservation programme is urgent in its remaining forested areas. Despite six legislated protected areas, Guinean forests and their wildlife are not safe in reality. This lack of on-the-ground protection is the case for Cantanhez National Park (Tombali region), where this research took place. The park was established in 2007 to protect remnant forests containing unique and endemic Guinean biodiversity, such as the endangered West African chimpanzees (Pan troglodytes verus). Local inhabitant’s attitudes towards protected areas and associated externallydriven conservation programmes are seldom examined in depth in relation to understanding the drivers (livelihood, socio-cultural, and local) of perceptions, which makes conservation problematic. Understanding attitudes to animals, habitats and livelihood risks were the focus of this project, specifically in order to assess perceptions of chimpanzees. Chimpanzees are currently suffering catastrophic declines due to human actions across Africa. Thus a focus on understanding, managing and enhancing people’s perceptions and attitudes towards this species could be vital to its long-term survival. The theoretical approach is based upon (i) examining the construct of sociozoologic scales in this specific socio-cultural context, (ii) elucidating issues in humanwildlife interaction (e.g. conflict such as crop-raiding and positive such as ecotourism potential), (iii) local economies (i.e. level of dependency on forest resources), and (iv) understanding people’s expectations about the future of the National Park as a potential constraint or opportunity for their welfare and livelihoods. Quantitative and qualitative methods were combined to approach these questions. 17 The Guinean sociozoologic scale of Cantanhez clearly divides vertebrate species into (i) “tame”, considered good (e.g. gazelles) and (ii) “hazardous”, considered bad (e.g. hyaenas). Chimpanzees lay exactly in the midpoint. They are considered humans’ close relatives; however, they “misbehave” as astute crop thieves sufficiently to be perceived as a competitor for resources. Since chimpanzees are also seen as very similar to humans, their meat consumption is taboo, which adds the potential for protection. Gender and religion both influence the way locals perceive of and relate to chimpanzees. Women and Muslims tend to be more negative towards this species and the protected area than are men and non-Muslims. Women never exhibited positive attitudes in relation to the protected area, while men appeared to be more engaged with “capitalized” principles, with some awareness about the importance chimpanzees might have in catalyzing the National Park and local economy. This study highlights the need for a management plan to mitigate crop-raiding and the development of sustainable strategies that provide livelihood benefits for both men and women, addressing their distinct needs, outside the protected area.
85

Restoration and management of wildflower-rich machair for the conservation of bumblebees

Redpath, Nicola January 2010 (has links)
Over the last half century, the widespread decline of bumblebees across the agricultural landscapes of Western Europe and North America has been well documented. This decline has undoubtedly been driven to a large extent by the intensification of agriculture, which has fragmented landscapes and removed large areas of suitable foraging habitat, nesting and hibernation sites. Consequently, some of the rarest Bombus species now persist only in isolated pockets of semi-natural habitat, which have been subjected to little agricultural intensification. Of the 25 Bombus species native to the UK, three species have gone extinct in recent decades and several others are severely threatened. Remaining populations of the UK’s rarest bumblebee, Bombus distinguendus, have become strongly associated with florally-rich machair grassland habitats found only in the North and West of Scotland and Western Ireland. Machair, a unique habitat that forms on soils rich in shell sand, has been maintained by rotational agricultural practices implemented by crofters. However, recent changes in crofting practices, which include the intensive grazing of machair in some areas, or conversely the abandonment of machair management all together in others, have resulted in sections of machair that have become degraded and consequently exhibit low floral abundance and species diversity. This has significant implications for species such as B. distinguendus, which have for the most part come to rely of the florally-rich swards of machair grassland. This thesis aimed to develop a greater understanding of how machair grassland habitats are utilised by foraging bumblebees, including B. distinguendus, and in turn examined the potential for restoring degraded areas of machair via a variety of methods. The research presented here examines the influence of current crofting practices on the abundance of bumblebees and their forage plant species and combines this information with a detailed exploration of the machair seed bank and potential machair restoration treatments. The specific foraging requirements of B. distinguendus were found to be similar to those of other long-tongued bumblebee species and the provision of plants from the Fabaceae family was found to be of particular importance. Current crofting practices implemented in the North and West of Scotland were, on the whole, found support low numbers of foraging bumblebees. Similarly, existing habitat management schemes, designed to provide early cover for corncrakes and foraging resources for bumblebees, were found to be largely ineffective in attracting B. distinguendus, when compared with florally-rich machair habitat. In addition, this research suggests that the existing machair seed bank is unlikely to provide a sufficient resource for reinstating florally-rich habitat to degraded areas of machair. However, this thesis has demonstrated that it is possible to implement seed mixes on machair which can reinstate species typical of machair plant communities and which also attract high numbers of foraging bumblebees. The findings of these habitat assessments and restoration trials are examined in full in the following chapters and implications for the future management of wildflower-rich machair are discussed throughout.
86

Population trends, conservation and the trade in amphibians in Asia

White, Steve January 2005 (has links)
published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management
87

Ecohydrological Conditions Associated With The Distribution And Phenology Of The Pima Pineapple Cactus

Kidder, Amí Lynne January 2015 (has links)
Climate changes in temperature and precipitation are already occurring and are projected to further exhibit increasing temperature and precipitation extremes and increasing variation. Such increased temperature variation and decreased precipitation are likely to have a profound impact on vegetation communities, particularly in regions that are dominated by extreme temperatures and strongly seasonal precipitation events. Both temperature and precipitation are tightly linked to vegetation growth and distribution, and in regions such as the U.S. desert southwest, there are a number of rare and endangered species that have a particularly tight knit relationship with their environment. Here, I examine the relationship between these ecohydrological drivers and a specific, little- researched cactus: the Pima Pineapple Cactus (Coryphantha scheeri var. robustispina). C. scheeri is a small, hemispherical cactus that resides in the Santa Cruz and Altar Valleys of Southern Arizona, and very little is known about the conditions that promote C. scheeri distribution and growth. To provide information that may aide in managing this species, I investigate aspects of the distribution and the phenology of this species. With respect to distribution, I hypothesize that (H1) C. scheeri locations are associated with spatial physical and climatic data within its geographic limits. A framework describing the climatic associations of C. scheeri would enable species managers to take advantage of suitable habitat when opportunities arise. With respect to phenology, within established C. scheeri habitat we lack a clear understanding of the impact ecohydrological factors can have on reproduction and size. Therefore, I also hypothesize (H2) that C. scheeri flowering phenology is triggered by available moisture, which may be in the form of precipitation, humidity, or soil moisture. My results indicate that through the use of the classification tree, C. scheeri habitat is strongly associated with climatic and physical variables at a state-wide scale; these associations indicate large losses of suitable habitat under future projected climate scenarios. Additionally, I find that C. scheeri flowering phenology appears to be associated with precipitation and the resulting increase of soil moisture; the data are also suggestive that bud formation might be associated with water-year growing degree day. Because the results indicate a tight coupling with climatic variables, with most suitable habitat within the current range in Arizona projected to be lost under future climate, I suggest managers may be inclined to increase monitoring C. scheeri in an ecohydrological context relative to the variables identified here and to consider conditions and locations where supplemental watering or microclimate amelioration could be beneficial for the species.
88

Competition for Conifer Cones as a Potential Mechanism of Endangerment for the Mount Graham Red Squirrel

Minor, Rebecca January 2010 (has links)
Non-native species are a major cause of endangerment for native species, but the mechanisms are often unclear. As species invasions continue to rise, it is important to understand how to mitigate this threat. Our field experiment quantified the impact of introduced Abert's squirrels (Sciurus aberti) on rates of food removal within the range of the critically endangered Mount Graham red squirrel (Tamiasciurus hudsonicus grahamensis). In the presence of Abert's squirrels, the time until 50% of cones were removed was 5.55 days faster than when Abert's squirrels were excluded (95% confidence interval 2.25 to 11.63 days). The impact on food availability as a result of cone removal by Abert's squirrels suggests the potential of food competition as a mechanism of endangerment for the Mount Graham red squirrel. Eradication of established non-native populations is rare. Management targeted at specific mechanisms by which non-natives cause endangerment is an essential tool for conservation.
89

Binational collaboration in recovery of endangered species: the Mexican wolf as a case study

Bernal Stoopen, Jose Francisco 30 September 2004 (has links)
The goal of this inductive study was to identify factors that facilitate and inhibit binational collaboration in the recovery of endangered species in the northern Mexico borderlands, focusing on the Mexican wolf (Canis lupus baileyi). A conceptual model was developed using qualitative techniques, providing the basis for design of a mail survey. The target population included participants with experience in recovery efforts for over a dozen species at risk in the region. Long interviews were recorded with 44 participants from Mexico and the United States. Thematic hierarchical analysis was used to develop a conceptual model of how interviewees talked about factors influencing binational collaboration. Issues were classified in five thematic clusters: project, organization, people, resources, culture/history. The survey was used to conduct a needs assessment, measuring respondents' attitudes about the relative priority of issues identified in the conceptual model. High priority needs were identified from each thematic cluster: (a) equitable participation in project design and implementation, (b) continuity of personnel, (c) coordination of federal, state and local efforts, (d) increased funding, managed with accountability, and (e) exchange visits to facilitate understanding of diverse perspectives. Responses to almost half the survey items indicated accord among the sample of respondents, providing a basis for shared common ground. The nature of discord was within the range of "manageable", with no clear polarization of attitudes measured. This exploratory data analysis suggested that the structure of the conceptual model developed from the Mexican wolf case study was generally a valid basis for future deductive analysis and reflection by practitioners. For 82% of 22 statements of need, priorities of participants in the Mexican wolf recovery efforts did not differ significantly from other respondents. Nationality (of respondents) significantly affected priority rankings for only 18% of the need statements. Significant effects of five demographic variables indicated that interactive effects should be examined in future multivariate analyses to determine how respondents' attitudes on issues related to priority rankings. Recommendations were provided for a more efficient and effective approach to collaborative problem-solving, engaging reflective practitioners from the private and public sectors in principled negotiation processes to better understand diverse perspectives.
90

Federal endangered species legislation in Canada : explaining the lack of a policy outcome

Amos, William Ambrose 11 1900 (has links)
This thesis attempts to uncover the reasons why Canada, unlike the United States and Australia, does not have stand alone federal endangered species legislation. In particular, I will focus upon the history of Bill C-65, the proposed federal endangered species statute which died on the Order Table in 1997. Using the "policy regime" framework developed by George Hoberg, I examine the ideas, actors, and institutions that have combined within a given set of background conditions to produce this distinctive lack of a policy outcome, assessing the relative causal importance of each variable in terms Bill C-65's failure. Using Peter Haas' epistemic community approach, the causal knowledge of conservation scientists' regarding habitat loss is found not to have influenced the policy substance of Bill C-65. However, it is argued that scientists did play an important role in the legislative failure insofar as they joined forces with environmentalists to discredit the weak scope and substance of the bill. These pro-environment actors, however, were matched throughout the interest group competition by the parallel forces of industry and private landowner groups, who criticized Bill C-65 as a litigious, punitive and "American" style of legislation. The provinces, for their part, sided with the landowners and industry groups, arguing that the federal government had overstepped its wildlife management jurisdiction. Given a context of low public concern for environmental issues, and the institutional trend towards regulatory decentralization, the federal government had very few incentives to introduce a strong bill. However, the provinces, landowners, and industry groups, all felt it was too strong, while environmentalists and scientists felt just the opposite. Bill C-65's failure, therefore, was the result of the federal government's inability to satisfy anyone on this issue. Determining who "won" this first endangered species battle, however, is quite difficult without knowing whether Cabinet felt the bill was too strong or too weak, and without knowing what the next legislative proposal will entail. In conclusion, it is found that all three regime components of ideas, actors, and institutions were equally important factors in bringing about the failure of Bill C-65, and the current policy delay that continues to this day.

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