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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.
211

Approaches towards a critical evaluation and update of the red list of South African Butterflies

Ball, Johathan Bradford 03 1900 (has links)
Thesis (MScConsEcol (Conservation Ecology and Entomology))--University of Stellenbosch, 2006. / Using the World Conservation Union’s (formerly the International Union for the Conservation of Nature) IUCN 2001 categories and criteria, the conservation status of the South African butterfly fauna has been reassessed. This study includes an assessment of the 62 globally threatened South African taxa and 1 that has a marginal distribution in this region.
212

Ecology of capercaillie within a managed pine forest

Canham, Lois January 2009 (has links)
The capercaillie is a rare species of forest bird which is once again facing extinction in Britain. Working pine forests are thought to represent the future for capercaillie in Scotland. However, few studies have focused on capercaillie within working forests and as a result current management recommendations are based on studies conducted within semi-natural pinewoods. Therefore study of the ecology of capercaillie within working forests is vital for the survival of the species in Scotland. The present study investigated the ecology of capercaillie, based on indirect measures of capercaillie use, within Morangie Forest, a pine plantation managed by the Forestry Commission. Monthly dropping counts were collected over a 30 month period to gain insight into the capercaillie population at Morangie Forest, and to explore the use of faecal counts as a non-invasive monitoring tool. Habitat analysis, dietary analysis of droppings and genetic analysis of feathers were further conducted to fully explore ecology of capercaillie within Morangie Forest. Results showed that the capercaillie population in Morangie Forest was subject to seasonal movements and that movements were not confined to the bounds of the forest. Substantial mixing occurred with capercaillie from neighbouring Novar Forest. In addition, capercaillie within Morangie Forest selected habitat at a radius of 50m and beyond. The population of capercaillie at Morangie Forest was estimated at around 65 individuals based on measures from dropping counts and genetic determination of individuals from feathers. Results also suggested that winter dropping counts could represent a useful tool for forest managers to monitor the size and movement of capercaillie populations frequenting their forests. In addition winter dropping counts could be used in conjunction with habitat data to plan management of habitat for capercaillie. The present study contributes towards future management strategies for the conservation of capercaillie within working forests and suggests further research priorities for capercaillie in Scotland, particularly those focused at a landscape scale.
213

Biodiversity conservation and evolutionary models

Hartmann, Klaas January 2008 (has links)
Biodiversity conservation requires a framework for prioritising limited resources to the many endangered species. One such framework that has seen much attention and is considered extensively in this thesis, is the Noah's Ark Problem (NAP). The NAP combines a biodiversity measure (Phylogenetic Diversity; PD) with species survival probabilities and conservation costs. The aim of the NAP is to allocate the limited conservation resources such that the future expected PD is maximised. Obtaining optimal solutions to the NAP is a computationally complex problem to which several efficient algorithms are provided here. An extension to the NAP is also developed which allows uncertainty about the survival probability estimates to be included. Using this extension we show that the NAP is robust to uncertainty in these parameters and that even very poor estimates are beneficial. To justify using or promoting PD, it must produce a significant increase in the amount of biodiversity that is preserved. We show that the increase attainable from the NAP is typically around 20% but may be as high as 150%. An alternative approach to PD and the NAP is to prioritise species using simple species specific indices. The benefit of these indices is that they are easy to calculate, explain and integrate into existing management frameworks. Here we investigate the use of such indices and show that they provide between 60% and 80% of the gains obtainable using PD. To explore the expected behaviours of conservation methods (such as the NAP) a distribution of phylogenetics trees is required. Evolutionary models describe the diversification process by which a single species gives rise to multiple species. Such models induce a probability distribution on trees and can therefore be used to investigate the expected behaviour of conservation methods. Even simple and widely used models, such as the Yule model, remain poorly understood. In this thesis we present some new analytic results and methods for sampling trees from a broad range of evolutionary models. Lastly we introduce a new model that provides a simple biological explanation for a long standing discrepancy between models and trees derived from real data -- the tree balance distribution.
214

The Effects of Inbreeding on Fitness Traits in the Critically Endangered Attwater’s Prairie-chicken

Hammerly, Susan C. 08 1900 (has links)
The goals of captive breeding programs for endangered species include preserving genetic diversity and avoiding inbreeding. Typically this is accomplished by minimizing population mean kinship; however, this approach becomes less effective when errors in the pedigree exist and may result in inbreeding depression, or reduced survival. Here, both pedigree- and DNA-based methods were used to assess inbreeding depression in the critically endangered Attwater’s prairie-chicken (Tympanuchus cupido attwateri). Less variation in the pedigree-based inbreeding coefficients and parental relatedness values were observed compared to DNA-based measures suggesting that errors exist in the pedigree. Further, chicks identified with high parental DNA-based relatedness exhibited decreased survival at both 14- and 50-days post-hatch. A similar pattern was observed in later life stages (> 50 days post-hatch) with birds released to the wild; however, the pattern varied depending on the time post-release. While DNA-based inbreeding coefficient was positively correlated with mortality to one month post-release, an opposite pattern was observed at nine months suggesting purging of deleterious alleles. I also investigated whether immunocompetence, or the ability to produce a normal immune response, was correlated with survival; however, no significant correlation was observed suggesting that inbreeding was a more important factor influencing survival. Pairing individuals for breeding by minimizing DNA-based parental relatedness values resulted in a significant increase in chick survival. This study highlights the importance of using DNA-based methods to avoid inbreeding depression when errors exist in the pedigree.
215

Právní úprava mezinárodního obchodu s ohroženými druhy / Legal regulation of international trade in endangered species

Ambrožová, Magdalena January 2011 (has links)
The subject of my thesis is the regulation of international trade in endangered species. An excessive trade in endangered species is one of the main causes of biodiversity loss on the Earth. The biodiversity loss constitutes a serious worldwide problem and threatens the stability of all the ecosystems. It is becoming more urgent by the fact that the speed of species extinction or at least their inclusion in the lists of endangered species is getting faster. Especially an illegal trade in endangered species is considered one of the largest and the most profitable. I have chosen this topic with the aim to show legal methods and ways of the regulation of the excessive exploitation of wildlife. The question of the regulation of the international trade is examined from the international perspective, the perspective of the European Union law and as well from the czech law perspective. A considerable stress is put on the description and explanation of the operation of the international trade regulation system regarding that an effective slowdown of the biodiversity loss phenomenon or its stop can be only possible by the international cooperation of the countries. The remaining levels of the regulation must be in compliance with the international level of the regulation. The thesis is consisted of six...
216

Právní úprava ochrany rostlinstva a živočišstva / Legal regulation of the protection of plants and animals

Futterová, Alice January 2017 (has links)
Legal regulation of the protection of plants and animals The subject of this thesis by the title " Legal regulation of the protection of plants and animals" are selected, the most significant legal standards, laying out the problematic of fauna and flora protection and their analysis in order to create a comprehensive scope of fauna and flora legal regulation in situ both on international, European and domestic level of law. The thesis is divided into four parts. The first chapter introduces the structure and extensity of the fauna and flora protection problematic, whereas it contemplates over the term biological diversity. The next chapters successively describe the legal regulations of fauna and flora on the international, European and domestic level of law. The introduction is always there to mention historical development and related standards that have given the present legal regulation its form. It is followed by summary of the most significant standards of the legal regulation in effect. To conclude my thesis, I am summarizing and determining whether the system of legal standards in effect truly results in the objective of legal regulations of fauna and flora protection, primarily in stopping the decrease of biological diversity and its restoration in the future.
217

Incentives for Ecosystem Services on Rangelands: Institutional Design and Stakeholder Attitudes

Lien, Aaron Matthew, Lien, Aaron Matthew January 2017 (has links)
Payments for ecosystem services (PES), or conservation incentives, are an increasingly popular approach to encouraging natural resources conservation on private lands. The goal of PES approaches is to motivate conservation by private landowners that would not otherwise take place by providing an economic incentive. To achieve this goal, incentive programs must be available to landowners who can provide the desired services; supportive policy structures must be in place; landowners must be willing to participate as sellers of ecosystem services; and the program itself must have an institutional structure that effectively regulates the production, sale, and maintenance of targeted ecosystem services. This dissertation uses a combination of case study and comparative research methods to develop new knowledge and tools for assessing each of these necessary conditions for success. The potential development of an incentive program to conserve habitat for endangered jaguars in southern Arizona and southwestern New Mexico is used as a case study to understand the attitudes of ranchers toward participation in PES programs and related policies and regulations. Results show that ranchers have strong intrinsic conservation motivations unrelated to economic incentives, coupled with significant concerns about the impacts of government regulations that could accompany participation in a PES program. Comparative research of the institutional structures of existing PES programs is carried out using the Institutional Analysis and Development framework. Focusing on water quality trading, one of the most common types of PES program, a classification system for PES program institutional arrangements is developed and the utility of the classification system for analyzing institutional diversity is demonstrated. Together, the case study and comparative research provide a means of linking empirical assessment of PES governance models with the preferences of targeted participants, increasing the likelihood of successful conservation outcomes.
218

Lidské preference živočišných druhů a jejich vliv na druhovou ochranu / Human preference to animal species and its impact on species conservation

Marešová, Jana January 2012 (has links)
The dissertation thesis deals with human aesthetic preference to other species and its anthropological and conservation aspect. The aesthetic preference to animal species has rarely been systematically studied before and quantitative analyses, especially on a fine taxonomic scale did not exist. On the other hand, it was known that attractive species often receive more support for their conservation. From these simple facts rose the idea to test human aesthetic preference to snake species (and consequently to species across major vertebrate taxa) and use this quantified preference to explain the conservation effort devoted to captive breeding worldwide (measured as size of zoo populations). We confirmed that the perceived attractiveness (preference and/or species' body size) succesfully predicts the size of zoo populations across mammal, bird and reptile taxa. On contrary, we found no effect of the IUCN listing of the species. To find out whether we work with Czech students' preference only or we may generalize to other populations, we carried out the same experiment to determine human preference to boas and pythons in eight cultures of five continents. Despite profound differences of the studied ethnics, we revealed a considerable agreement. Moreover, we found an agreement between pre-school...
219

Pequenos mamíferos da Mata Atlântica do Planalto Atlântico Paulista: uma avaliação da ameaça de extinção e da resposta a alterações no contexto e tamanho dos remanescentes / Small mammals of the Atlantic Forest of the Atlantic Plateau of São Paulo: an evaluation of the threat of extinction and the response to alterations in context and remnant size

Bueno, Adriana de Arruda 19 September 2008 (has links)
Por meio de uma amostragem padrozinada de longa duração, realizamos levantamentos de pequenos mamíferos com armadilhas de interceptação e queda em 68 sítios distribuídos em seis paisagens de 10.000 ha (três em mata contínua e três em paisagens fragmentadas) localizadas em três regiões do Planalto Atlântico Paulista. As paisagens fragmentadas compreendem diferentes quantidades de matas remanescentes, 50%, 30% e 10%, porcentagens acima e próximas dos limites superior e inferior do limiar teórico de fragmentação (10-30%). A presente tese de doutoramento foi dividida em quatro capítulos e duas abordagens principais. A primeira delas (Capítulo 2) teve por objetivo avaliar se os pequenos mamíferos listados como ameaçados de extinção são afetados pela fragmentação e pela qualidade dos remanescentes de Mata Atlântica do Planalto Atlântico Paulista. Para isso, utilizamos os dados coletados nos 68 sítios amostrados, os quais estavam distribuídos em oito categorias: nove em matas maduras contínuas, nove em matas secundárias contínuas, quatro em fragmentos grandes e 11 em fragmentos pequenos da paisagem com 50% de remanescentes, sete em fragmentos grandes e 13 em fragmentos pequenos da paisagem com 30% de remanescentes, e quatro em fragmentos grandes e 11 em fragmentos pequenos da paisagem com 10% de remanescentes. Avaliamos se 10 espécies de pequenos mamíferos listados como ameaçados de extinção e cinco espécies endêmicas comuns nas mata contínuas e ausentes das listas vermelhas são afetados igualmente pela fragmentação, na escala da paisagem e da mancha, e pela qualidade dos remanescentes de Mata Atlântica. Nenhuma das espécies analisadas, independentemente do grau de ameaça ou de raridade, respondeu a variação do estádio de regeneração das matas contínuas. Por outro lado, nossos dados mostraram que as espécies endêmicas comuns respondem de forma mais congruente e negativamente à perda e fragmentação da Mata Atlântica do que as ameaçadas, as quais tanto podem não ser afetadas quanto ser positivamente ou negativamente afetadas pela fragmentação. Assim, sugerimos a separação das espécies em dois grupos nas listas vermelhas (naturalmente raras versus afetadas pelas ações antrópicas) e a utilização de outros critérios para avaliar o status de ameaça das espécies mais comuns, como a resposta à perda e fragmentação do habitat e a especificidade ao habitat na forma de endemismos e de grau de tolerância a matriz. A segunda abordagem (Capítulo 3) teve como objetivo verificar a influência do contexto (paisagem) e do tamanho do fragmento em paisagens com quantidades diferentes de remanescentes sobre a riqueza e abundância de espécies endêmicas e não-endêmicas. Para isso, utilizamos dados de 50 dos 68 fragmentos amostrados, localizados nas três paisagens 114 fragmentadas com 50%, 30% e 10% de remanescentes. A partir da avaliação da plausibilidade de oito modelos de regressão, que expressam visões teóricas alternativas da importância do contexto e da área dos fragmentos, investigamos se a influência positiva da área das manchas de floresta é mais forte (1) para as espécies endêmicas e (2) na paisagem próxima ao limite superior do limiar de fragmentação (sensu Andrén, 1994), já que em contexto de muita mata remanescente, fragmentos pequenos e grandes poderiam abrigar populações viáveis, e em contexto de pouca mata remanescente, espécies sensíveis já teriam desaparecido. Com exceção da riqueza de espécies não-endêmicas, modelos que incluem o contexto foram as hipóteses mais plausíveis para descrever a variação da riqueza e abundância das espécies de pequenos mamíferos. Como esperado, a influência positiva da área do fragmento foi mais importante na paisagem com 30% de floresta para a maioria das espécies de pequenos mamíferos endêmicos, enquanto que os modelos que incluem a influência da área do fragmento não estiveram entre os mais plausíveis para as espécies não-endêmicas. Nossos resultados corroboram a existência de um limiar de fragmentação e indicam que, ainda que os limiares variem entre espécies, é possível identificar grupos com respostas semelhantes à perda e fragmentação do habitat, auxiliando as políticas de manejo e conservação. / A long-term standardized survey of the Atlantic Forest small mammals was conducted using pitfall traps in 68 sites distributed in six 10.000-ha landscapes (three in continuous forest and three in fragmented landscapes) located in three regions in the Atlantic Plateau of São Paulo. The fragmented landscapes harbored different amounts of remnants, 50%, 30% and 10%, percentages above or within the superior and inferior limits of the theoretical fragmentation threshold (10-30%). This thesis was divided in four chapters e two main approaches. The first approach (Chapter 2) aimed to evaluate if small mammals listed as threatened were affected by forest fragmentation and quality in the Atlantic Plateau of São Paulo state. For this, we used data from 68 sites distributed in eight categories: nine in mature continuous forests, nine in secondary continuous forests, four in large and 11 in small patches in the landscape with 50% of remnants, seven in large and 13 in small patches in the landscape with 30% of remnants and four in large and 11 in small patches in the landscape with 10% of remnants. We investigated if 10 threatened small mammals and five non-threatened endemic species commonly found in continuous forests were equally affected by fragmentation, at the landscape and patch scales, and by forest quality. Regardless of threat or rarity level, no analyzed species responded to differences in the regeneration stage in continuous forests. On the other hand, our data showed that common endemic species respond more strongly and negatively to the loss and fragmentation of the Atlantic Forest than threatened species, which either may not be affected by fragmentation, or be positively or negatively affected. we suggest separating species in two groups (naturally rare versus affected by human impact) in the Red Lists and including different criteria to evaluate common species such as response to habitat loss and fragmentation as well as habitat specificity in terms of endemism and level of matrix tolerance. The second approach (Chapter 3) aimed to evaluate the effects of context (landscape) and patch area in landscapes with different amounts of remnants on the richness and abundance of the endemic and non-endemic species. We used data from 50 sites located in the three fragmented landscapes. By analyzing the plausibility of eight regression models, which express alternative theoretical hypothesis about the importance of context and patch area, we investigate if the positive influence of patch area was stronger (1) for endemic species and (2) in the landscape within the superior limit of the fragmentation threshold (sensu Andrén, 1994), since in a context of high proportion of remnants, small and large patches could harbor viable populations and in a context of low proportion of remnants, sensitive species would have gone extinct. Except for the non116 endemic species richness, the models including context were the most plausible hypothesis to describe small mammal richness and abundance variations. As expected, the positive influence of patch area was more important in the landscape with 30% of remnants for the majority of the endemic small mammals, whereas the models including patch area were not among the most plausible ones for the non-endemic species. Our data corroborate the existence of a fragmentation threshold and point out that, although thresholds vary among species, it is possible to identify groups with similar response to habitat loss and fragmentation, directing management and conservation policies.
220

Distribuição e abundância de Amazona vinacea (Papagaio-de-peito-roxo) no oeste de Santa Catarina

Zulian, Viviane January 2017 (has links)
Esse trabalho oferece uma avaliação da abundância do papagaio-de-peito-roxo (Amazona vinacea) para 2016 e 2017, combinando contagens em dormitórios ao longo de toda a distribuição da espécie, em escala global, com amostragens replicadas em dormitórios na região oeste de Santa Catarina (WSC), em escala local, Brasil. As contagens em escala global resultaram em 3888 e 4066 indivíduos em 2016 e 2017, respectivamente. As estimativas para o WSC foram de 945 ± 50 e 1393 ± 40 para os mesmos dois anos. Não foi observada nenhuma evidência de crescimento populacional de 2016 para 2017, pois o acréscimo no número de indivíduos foi acompanhado por aumento do esforço amostral em ambas escalas. Quando extrapolamos a abundância no WSC para toda a área de distribuição da espécie, segundo a IUCN, e pressupondo densidade homogênea, obtivemos valores que estão acima da contagem na escala global, mas dentro da mesma ordem de magnitude. Nosso resultado oferece uma base sólida para afirmar que o tamanho populacional global de A. vinacea é de milhares de indivíduos, mas não dezenas de milhares. Realizamos um esforço sistemático para considerar as principais fontes de incerteza na estimativa de abundância da espécie. Cada contagem, tanto na escala local quanto na global, incluíram visitas em todos os dormitórios conhecidos dentro de um intervalo de 10 dias, evitando duplas contagens devido ao movimento dos papagaios entre dormitórios. No WSC, a abundância foi estimada usando um N-Mixture Model implementado em contexto Bayesiano. Apesar de nossa estimativa de tamanho populacional e de área de distribuição serem maiores do que as consideradas pela IUCN, sugerimos que A. vinacea permaneça na categoria “Em Perigo”, até que sejam realizados estudos sobre tendência populacional. / We offer an assessment of Vinaceous parrot (Amazona vinacea) abundance in 2016 and 2017, combining roost counts over the whole range of the species, with a replicated survey of roosts at the local scale, in western Santa Catarina state (WSC), Brazil. The whole range counts amounted to 3888 and 4066 individuals in 2016 and 2017, respectively. The WSC estimates were 945 ± 50 and of 1393 ± 40 individuals, for the same two years. We found no evidence of population growth from 2016 to 2017 because the increase in numbers is accompanied by an increase in observation effort both in WSC and at the whole-range scale. When extrapolating the WSC abundance estimate to the whole IUCN extant range of the species under the simplifying assumption of homogenous population density, we obtain values above the whole-range counts, but within the same order of magnitude. Such result offers a sound basis for putting the global population size of A. vinacea in the thousands of individuals, but not in the tens of thousands of individuals. We made a systematic effort to address key sources of uncertainty in parrot abundance estimation. Each count, at the local or whole-range scale, includes visits to all relevant roosts within less than ten days time to avoid double counting due to movement between roosts. At the local scale, we estimated abundance using an N-Mixture Model of replicated count data, implemented in a Bayesian framework. Even though we estimate a larger population size and a bigger geographic range that those currently reported by the IUCN, we suggest that A. vinacea should remain in the ‘Endangered’ IUCN threat category, pending further investigation of population trends.

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