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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.
1

Epidemiology of black rhinoceroses (Diceros bicornis) in captivity in the United States

Dennis, Patricia Marie. January 2004 (has links)
Thesis (Ph. D.)--Ohio State University, 2004. / Document formatted into pages; contains xiii, 126 p. Includes bibliographical references. Abstract available online via OhioLINK's ETD Center; full text release delayed at author's request until 2007 Sept. 21.
2

Factors affecting the impact of invasive mussels on native freshwater mussels

Jokela, Anneli. January 2006 (has links)
Biological invasions are among the leading causes of species diversity loss; however, the impacts of invasion are context-dependent and can vary with the local environment. The mechanisms governing variation in impact and their relationship to specific abiotic and biotic factors remain largely unexplored. Recent local declines in native unionid mussels have been attributed to the invasion of North American lakes and rivers by the Eurasian zebra mussel ( Dreissena polymorpha), as a result of intense fouling of unionid shells by zebra mussels. My research investigated the role of abiotic and biotic factors in mediating the impact of zebra mussels on native mussels. I examined the impact of zebra mussels on unionids in a habitat thought to be suboptimal for zebra mussels and compared this to the impact observed in other invaded habitats. A predictive model relating fouling intensity to local environmental variables (calcium concentration, sediment particle size) was developed, and a predator-exclusion experiment was conducted to investigate the role of predation in mediating fouling intensity. Overall, I found that two abiotic factors of the local environment were significant predictors of fouling intensity and that relationships used to predict the impact of zebra mussels could be extended to a broader range of habitats.
3

Factors affecting the impact of invasive mussels on native freshwater mussels

Jokela, Anneli. January 2006 (has links)
No description available.
4

Threats to native aquatic insect biodiversity in Hawaiʻi and the Pacific, and challenges in their conservation

Englund, R. A (Ronald A.) January 2005 (has links)
Thesis (Ph. D.)--University of Hawaii at Manoa, 2005. / Includes bibliographical references. / Also available by subscription via World Wide Web / ix, 202 leaves, bound ill., map 29 cm
5

On the ecology of invasive species, extinction, ecological history, and biodiversity conservation

Donlan, Charles Joseph. January 2008 (has links) (PDF)
Thesis (Ph. D.)--Cornell University, 2008. / Title from PDF t.p. (viewed on Apr. 20, 2009). Vita. Includes bibliographical references. Mode of access: World Wide Web.
6

Predação de ninhos artificiais: aplicações, desafios e perspectivas para as áreas tropicais / Artificial nest predation: application, challenges and perspectives for the tropical areas

Alvarez, Ariane Dias 26 July 2007 (has links)
A predação de ninhos naturais vem sendo sugerida a principal causa do declínio de populações de aves, influenciando na estrutura e no funcionamento das comunidades. Devido à dificuldade de localização e monitoramento dos ninhos naturais, os ninhos artificiais são utilizados como uma rápida alternativa para avaliar o sucesso reprodutivo da avifauna. Os estudos com ninhos artificiais são amplamente difundidos em ambientes temperados e o que conhecemos sobre a predação de ninhos são provenientes destes ambientes. Nos trópicos, os estudos com ninhos artificiais ainda são escassos e no Brasil são quase inexistentes. O presente trabalho tem como objetivo suprir a carência de informações sobre as aplicabilidades e limitações do uso de ninhos artificiais e buscar por padrões de predação de ninhos em um ambiente tropical. O primeiro capítulo foi desenvolvido na Ilha Anchieta que apresenta uma alta densidade de mamíferos e répteis predadores de ninhos. Alguns aspectos metodológicos foram investigados referentes à localização dos ninhos artificiais e o comportamento seletivo dos predadores, por diferentes tipos de ovos utilizados, nos experimentos de predação. Os mamíferos foram os principais predadores de ninhos e os ovos sintéticos foram bons substitutos dos ovos das aves silvestres. No segundo capítulo foi analisada a variação na predação de dois tipos de ninhos artificiais (aéreo e solo) em diferentes ilhas, fragmentos e aéreas continuas. As ilhas apresentaram a maior predação de ninhos, especialmente naquelas que possuem espécies introduzidas, que os fragmentos e as áreas contínuas. Em relação ao tipo de ninho (aéreo e solo) verificamos que os ninhos no solo foram mais vulneráveis a predação nas ilhas e nas áreas contínuas. As ilhas e os fragmentos, apesar de estarem isolados geograficamente, não apresentaram um padrão semelhante na predação de ninhos no solo. Sugerimos que diferentes fatores podem influenciar nos padrões de predação das ilhas e dos fragmentos, como o histórico e a permeabilidade da matriz em que se insere o fragmento. O uso de ninhos artificiais, apesar da sua limitação, é uma ferramenta importante para a compreensão dos padrões de predação de ninhos na avifauna silvestre e pode auxiliar no diagnóstico do estado de conservação nesses ambientes. / The natural predation of the nests has been suggested as the principal cause to the decline of bird population, acting on the performance and community structure. Due to the difficulty of natural nest localization and monitoring, the artificial nests are used as a fast alternative to check the avian reproductive success. The artificial nest studies are widely known in temperate environments where most of the nest predation information has been gotten. In the tropics, the artificial nest studies have still been scarce and in the Brazil, there are few studies about this subject. This work has as a goal to give information about the use and the limitation of artificial nest predation. It also checks some nest predation patterns in tropical environments. The first chapter had been developed in Anchieta Island which has a higher density of mammal and lizard nest predators. Some methodological aspects were investigated related to the artificial nest localization and the selective behavior of the predators by different kinds of eggs used in the predation experiments. The mammals had been the main predators of nests and the plasticine eggs had been good egg substitute of the natural wild eggs. The second chapter, the variation in the predation, of two kinds of artificial nests (on the ground and shrub) in the different islands, fragments and continue areas, had been studied. The islands showed a higher level of nest predation, mainly in those which have exotic species, than the fragments and continue areas. Related to the kind of nest (shrub and ground), it was checked that the ground nests were more vulnerable to depredation in the islands and in the continues areas. The islands and the fragments, besides being geographically isolated, didn?t show the similar pattern in the ground nest predation. It is suggested that different factors can interfere in the predation patterns of the islands and the fragments, as the historical and permeability of the matrix where the fragment is located. The use of artificial nest, besides its limitation; it is a useful tool to understand wildlife avifauna nest predation patterns and can help checking the situation of conservation in different environments.
7

A kind of wild

Vizcarrondo, Nina Leigh 24 February 2015 (has links)
Gemsbok, ibex, sitatunga, nyala. Their names may be unfamiliar, but these rare species, originally from Africa and Asia, now roam Texas ranches in numbers close to 1 million. In an irony as big and as rich as Texas, however, their proliferation has depended on their popularity with hunters. Enthusiasts will pay anywhere from $2,000 to $20,000 to hunt these so-called “texotics.” While this flourishing micro-economy and sub-culture has gone unrecognized by most of the world, “A Kind of Wild” is a 22 minute documentary that puts forth a portrait of the industry as illustrated through a cross-section of individuals with different roles in the system: an amateur breeder, a researcher, a ranch hand and a hunter. The film explores the paradoxical relationship between these people and the animals they care for, between economics and conservation. It is intended to spread awareness about this obscured phenomenon and to encourage audiences to reflect upon their own values concerning humans increasingly complicated impact on the natural world around us. This report chronicles the process of making the film and expounds on its challenges and lessons. / text
8

Rendimentos de abate e aspectos tecnológicos de Javaporco (Sus scrofa javaporco)

Silva, Julyanna Andrade [UNESP] 25 January 2011 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:23:28Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-01-25Bitstream added on 2014-06-13T19:29:31Z : No. of bitstreams: 1 silva_ja_me_sjrp.pdf: 532607 bytes, checksum: fa6463333af7dc34ef59d3dc24603f96 (MD5) / O presente trabalho teve como objetivo avaliar as características do javaporco (Sus scrofa javaporco) por meio dos parâmetros zootécnicos e tecnológicos. Os dados zootécnicos foram medidos pela avaliação do consumo de ração, do ganho de peso e da conversão alimentar desse animal. Quanto aos aspectos nutricionais, foram realizadas análises da composição centesimal básica (umidade, proteínas, lipídeos, cinzas e carboidratos) e análises quanto à presença/ausência de Salmonella sp.. Para tais estudos, os animais foram divididos em quatro lotes, cada um contendo três indivíduos, machos e castrados, abatidos na idade de 4 (Lote A), 6 (Lote B), 8 (Lote C) e 10 (Lote D) meses. Em relação ao ensaio de crescimento, os javaporcos apresentaram peso vivo no abate variando entre 14, 50 kg a 57,66 kg em 300 dias de avaliação. Os lotes B e C, foram os que apresentaram melhores valores de conversão alimentar correspondendo a 3,49 e 3,72, respectivamente. Os rendimentos das carcaças variaram entre 54,75 a 75,15%, com uma média de produção de carne em relação ao peso da carcaça de 33,13% para todos os animais. Quanto à composição química básica o percentual de umidade para os lotes A, B e C variou de 73,90 a 74,23%, já o lote D apresentou valor inferior a este, 70, 96%. Os valores de proteínas variaram de 17,35 a 18,33% em todos os lotes. O percentual lipídico apresentou valores médios de 3,31 a 4,34% e os mineiras oscilaram entre 1,17 a 1,84%. No estudo da estabilidade microbiológica, em relação à presença/ausência de Salmonellas sp. somente o lote A encontrou em não conformidade com a legislação, tendo 2 amostras contaminadas. Diante destas observações, a adoção de estudos quanto ao manejo mais adequado e uma alimentação balanceada e especifica para esses animais tornam-se necessárias para que os interessados tenham sucesso na criação deste animal... / The present research was focused in the evaluation of the characteristics of the javaporco (Sus scrofa javaporco) by means of zootechnical and technological parameters. The zootechnical data had been provided by the evaluation of the consumption of ration, the gain of body weight and the feed conversion of this animal. Regarding the nutritional aspects, analyses of basic proximate composition was carried out (humidity, proteins, lipids, leached ashes and carbohydrate) and analysis for the presence/absence of Salmonella sp was performed as an indicative of microbial contamination. For such studies, the animals were divided into four lots, each of them containing three male animals which were slaughter at the age of 4 months (Lot A), 6 months (Lot B), 8 months (Lot C) and 10 months (Lot D). Regarding the growth trial, the javaporcos presented a live weight, before slaughtering, between 14,50 kg to 57,66 kg in 300 days of evaluation. Lots B and C, were the ones that presented better values of feed conversion, 3,49 and 3,72, respectively. The carcasses yield varied between 54,75% to 75.15%, with an average productivity of meat in relation to the carcass weight of 33,13% for all animals evaluated. Regarding to the basic chemical composition of the meat, the percentage of humidity for lots A, B and C varied from 73.90% to 74.23% although Lot D presented a lower value of 70, 96%, however the protein values varied from 17.35% to 18.33% in all lots. The percentage lipid values were on average 3.31% to 4.34% and the minerals varied from 1.17% to 1.84%. In the study of microbiological stability in relation to the presence/absence of Salmonella sp. the lot A was the only that met in disagreement with the legislation, having two contaminated samples. Having said that an appropriate studies and a balanced and vii 20 specific diet for these animals become necessary for parties interested in order... (Complete abstract click electronic access below)
9

Rendimentos de abate e aspectos tecnológicos de Javaporco (Sus scrofa javaporco) /

Silva, Julyanna Andrade . January 2011 (has links)
Resumo: O presente trabalho teve como objetivo avaliar as características do javaporco (Sus scrofa javaporco) por meio dos parâmetros zootécnicos e tecnológicos. Os dados zootécnicos foram medidos pela avaliação do consumo de ração, do ganho de peso e da conversão alimentar desse animal. Quanto aos aspectos nutricionais, foram realizadas análises da composição centesimal básica (umidade, proteínas, lipídeos, cinzas e carboidratos) e análises quanto à presença/ausência de Salmonella sp.. Para tais estudos, os animais foram divididos em quatro lotes, cada um contendo três indivíduos, machos e castrados, abatidos na idade de 4 (Lote A), 6 (Lote B), 8 (Lote C) e 10 (Lote D) meses. Em relação ao ensaio de crescimento, os javaporcos apresentaram peso vivo no abate variando entre 14, 50 kg a 57,66 kg em 300 dias de avaliação. Os lotes B e C, foram os que apresentaram melhores valores de conversão alimentar correspondendo a 3,49 e 3,72, respectivamente. Os rendimentos das carcaças variaram entre 54,75 a 75,15%, com uma média de produção de carne em relação ao peso da carcaça de 33,13% para todos os animais. Quanto à composição química básica o percentual de umidade para os lotes A, B e C variou de 73,90 a 74,23%, já o lote D apresentou valor inferior a este, 70, 96%. Os valores de proteínas variaram de 17,35 a 18,33% em todos os lotes. O percentual lipídico apresentou valores médios de 3,31 a 4,34% e os mineiras oscilaram entre 1,17 a 1,84%. No estudo da estabilidade microbiológica, em relação à presença/ausência de Salmonellas sp. somente o lote A encontrou em não conformidade com a legislação, tendo 2 amostras contaminadas. Diante destas observações, a adoção de estudos quanto ao manejo mais adequado e uma alimentação balanceada e especifica para esses animais tornam-se necessárias para que os interessados tenham sucesso na criação deste animal... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The present research was focused in the evaluation of the characteristics of the javaporco (Sus scrofa javaporco) by means of zootechnical and technological parameters. The zootechnical data had been provided by the evaluation of the consumption of ration, the gain of body weight and the feed conversion of this animal. Regarding the nutritional aspects, analyses of basic proximate composition was carried out (humidity, proteins, lipids, leached ashes and carbohydrate) and analysis for the presence/absence of Salmonella sp was performed as an indicative of microbial contamination. For such studies, the animals were divided into four lots, each of them containing three male animals which were slaughter at the age of 4 months (Lot A), 6 months (Lot B), 8 months (Lot C) and 10 months (Lot D). Regarding the growth trial, the javaporcos presented a live weight, before slaughtering, between 14,50 kg to 57,66 kg in 300 days of evaluation. Lots B and C, were the ones that presented better values of feed conversion, 3,49 and 3,72, respectively. The carcasses yield varied between 54,75% to 75.15%, with an average productivity of meat in relation to the carcass weight of 33,13% for all animals evaluated. Regarding to the basic chemical composition of the meat, the percentage of humidity for lots A, B and C varied from 73.90% to 74.23% although Lot D presented a lower value of 70, 96%, however the protein values varied from 17.35% to 18.33% in all lots. The percentage lipid values were on average 3.31% to 4.34% and the minerals varied from 1.17% to 1.84%. In the study of microbiological stability in relation to the presence/absence of Salmonella sp. the lot A was the only that met in disagreement with the legislation, having two contaminated samples. Having said that an appropriate studies and a balanced and vii 20 specific diet for these animals become necessary for parties interested in order... (Complete abstract click electronic access below) / Orientador: Pedro Fernando Romanelli / Coorientador: José Francisco Lopes Filho / Banca: Maria Luiza Poiatti / Banca: Luis Fernando Fertonani / Mestre
10

Predação de ninhos artificiais: aplicações, desafios e perspectivas para as áreas tropicais / Artificial nest predation: application, challenges and perspectives for the tropical areas

Ariane Dias Alvarez 26 July 2007 (has links)
A predação de ninhos naturais vem sendo sugerida a principal causa do declínio de populações de aves, influenciando na estrutura e no funcionamento das comunidades. Devido à dificuldade de localização e monitoramento dos ninhos naturais, os ninhos artificiais são utilizados como uma rápida alternativa para avaliar o sucesso reprodutivo da avifauna. Os estudos com ninhos artificiais são amplamente difundidos em ambientes temperados e o que conhecemos sobre a predação de ninhos são provenientes destes ambientes. Nos trópicos, os estudos com ninhos artificiais ainda são escassos e no Brasil são quase inexistentes. O presente trabalho tem como objetivo suprir a carência de informações sobre as aplicabilidades e limitações do uso de ninhos artificiais e buscar por padrões de predação de ninhos em um ambiente tropical. O primeiro capítulo foi desenvolvido na Ilha Anchieta que apresenta uma alta densidade de mamíferos e répteis predadores de ninhos. Alguns aspectos metodológicos foram investigados referentes à localização dos ninhos artificiais e o comportamento seletivo dos predadores, por diferentes tipos de ovos utilizados, nos experimentos de predação. Os mamíferos foram os principais predadores de ninhos e os ovos sintéticos foram bons substitutos dos ovos das aves silvestres. No segundo capítulo foi analisada a variação na predação de dois tipos de ninhos artificiais (aéreo e solo) em diferentes ilhas, fragmentos e aéreas continuas. As ilhas apresentaram a maior predação de ninhos, especialmente naquelas que possuem espécies introduzidas, que os fragmentos e as áreas contínuas. Em relação ao tipo de ninho (aéreo e solo) verificamos que os ninhos no solo foram mais vulneráveis a predação nas ilhas e nas áreas contínuas. As ilhas e os fragmentos, apesar de estarem isolados geograficamente, não apresentaram um padrão semelhante na predação de ninhos no solo. Sugerimos que diferentes fatores podem influenciar nos padrões de predação das ilhas e dos fragmentos, como o histórico e a permeabilidade da matriz em que se insere o fragmento. O uso de ninhos artificiais, apesar da sua limitação, é uma ferramenta importante para a compreensão dos padrões de predação de ninhos na avifauna silvestre e pode auxiliar no diagnóstico do estado de conservação nesses ambientes. / The natural predation of the nests has been suggested as the principal cause to the decline of bird population, acting on the performance and community structure. Due to the difficulty of natural nest localization and monitoring, the artificial nests are used as a fast alternative to check the avian reproductive success. The artificial nest studies are widely known in temperate environments where most of the nest predation information has been gotten. In the tropics, the artificial nest studies have still been scarce and in the Brazil, there are few studies about this subject. This work has as a goal to give information about the use and the limitation of artificial nest predation. It also checks some nest predation patterns in tropical environments. The first chapter had been developed in Anchieta Island which has a higher density of mammal and lizard nest predators. Some methodological aspects were investigated related to the artificial nest localization and the selective behavior of the predators by different kinds of eggs used in the predation experiments. The mammals had been the main predators of nests and the plasticine eggs had been good egg substitute of the natural wild eggs. The second chapter, the variation in the predation, of two kinds of artificial nests (on the ground and shrub) in the different islands, fragments and continue areas, had been studied. The islands showed a higher level of nest predation, mainly in those which have exotic species, than the fragments and continue areas. Related to the kind of nest (shrub and ground), it was checked that the ground nests were more vulnerable to depredation in the islands and in the continues areas. The islands and the fragments, besides being geographically isolated, didn?t show the similar pattern in the ground nest predation. It is suggested that different factors can interfere in the predation patterns of the islands and the fragments, as the historical and permeability of the matrix where the fragment is located. The use of artificial nest, besides its limitation; it is a useful tool to understand wildlife avifauna nest predation patterns and can help checking the situation of conservation in different environments.

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