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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.
231

Risk assessment of the nonnative Argentine black and white Tegu, Salvator merianae, in South Florida

Unknown Date (has links)
The Argentine black and white tegu, Salvator merianae, is a nonnative species that has invaded parts of Florida. The potential impacts of this species on native Florida wildlife are not yet known. This study looks at the stomach contents of 169 S. merianae captured between 2011 and 2013 in south Florida to infer potential impacts of S. merianae and spatial or seasonal shifts in diet. Analysis of 169 GI tracts showed that S. merianae is an omnivorous, terrestrial forager with a broad dietary range which includes insects, fruits, plants, snails, crayfish, carrion, birds, small mammals, turtles, snakes, lizards, frogs and eggs. S. merianae diet composition varied with capture habitat, the fattest tegus were collected from disturbed/agricultural areas and these samples contained, primarily, gastropods and insects. Tegu dietary habits threaten local endangered and state listed species such as the American crocodile, Crocodylus acutus, and the Cape Sable seaside sparrow, Ammodramus maritimus mirabilis. Dedicated funds and efforts need to be focused on this species to limit its further spread and future impact on native species. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2015. / FAU Electronic Theses and Dissertations Collection
232

Anatomia, taxonomia e distribuição geográfica dos caracóis gigantes do \"Complexo Megalobulimus granulosus\" (Mollusca, Gastropoda, Pulmonata). / Anatomy, taxonomy and geographical distribution of the giant snails \"complex Megalobulimus granulosus\" (Mollusca, Gastropoda, Pulmonata)

Fontenelle, Jose Heitzmann 07 November 2012 (has links)
Neste estudo foram comparadas anatomicamente as espécies de gastrópodes terrestres pertencentes ao \"complexo Megalobulimus paranaguensis\" (M. paranaguensis, M. granulosus, M. abbreviatus, e M. foreli) e as espécies M. cf. haemastomus e M. aff. gummatus, utilizadas como comparativo externo. Todas foram comparadas conquiliologicamente entre si e com M. ovatus, M. sanctipauli, M. yporanganus, e M. gummatus. O complexo apresenta uma distribuição geográfica contígua entre o litoral sul de São Paulo e o nordeste do Rio Grande do Sul, mas não possuem embasamento morfológico que o sustente. Todas as espécies possuem um conjunto exclusivo de caracteres que as individualizam. M. paranaguensis e a simpátrica M. aff. gummatus compartilham caracteres na cavidade palial, sistema digestivo e reprodutivo, diferenciando-se morfologicamente das demais espécies e consideradas como espécies-irmãs. A esculturação de M. foreli e M. abbreviatus similares a M. sanctipauli infere que estas espécies sejam transferidas para o complexo homônimo. M. granulosus, com ocorrência para o litoral de Santa Catarina, possui uma concha singular, mas apresenta uma anatomia interna similar a M. abbreviatus. M. cf. haemastomus distribuiu-se pela depressão central do Rio Grande do Sul e Uruguai, com simpatria na região de Porto Alegre com M. abbreviatus diferenciando-se por caracteres na borda do manto e sistemas digestivo e reprodutivo. O confronto de M. aff. gummatus, com ocorrência no Vale do Ribeira em São Paulo, e M. gummatus de distribuição no Rio de Janeiro, evidenciou que a primeira é uma espécie independente / This study compares anatomically species of the terrestrial gastropods belonging to the \"complex Megalobulimus paranaguensis\" (M. paranaguensis, M. granulosus, M. abbreviatus and M. foreli). M. aff. gummatus and M. cf. haemastomus was analyzed as outgroup. They also were conchologically compared with M. ovatus, M. sanctipauli, M. yporanganus and M. gummatus. The complex has a contiguous geographical distribution, between the south of São Paulo and northeastern Rio Grande do Sul States, but lacks morphological foundation supports. The species of the complex have a unique set of characters that individualizes it. M. paranaguensis and sympatric M. aff. Gummatus share characters in the palial cavity, digestive and reproductive systems, differing morphologically from other species, they are regarded as sister species. The shell sculpture of M. foreli and M. abbreviatus is similar to M. sanctipauli, infering that these species may be transferred to the complex M sanctipauli. The M. granulosus, occurring in Santa Catarina coastal zone, has a singular shell, but presents an internal anatomy similar to M. abbreviatus. The M. cf. haemastomus, distributed in the central depression of the Rio Grande do Sul State and Uruguay, sympatric in the region of Porto Alegre with M. abbreviatus, possesses different characters on the edge of the mantle and digestive and reproductive systems. The confrontation of M. aff. Gummatus, occurring in Vale do Ribeira, São Paulo, with M. gummatus, from Rio de Janeiro, showed that the first is an independent species
233

Microbial Aspects of Plant Invasion: An Analysis of Soil Microbial Communities Associated with the Invasive Plant - (Schinus terebinthifolius) Brazilian Pepper Tree Across South-Eastern Florida.

Unknown Date (has links)
The Brazilian pepper tree (BP, Schinus terebinthifolius), introduced to the United States in the 1800s, has since become a category one invasive plant in Florida, aggressively spreading to 3000 km2 of prime habitat. There is a serious dearth of knowledge on whether the rhizobiome plays any roles in the displacement of native flora and the range expansion of BP. This thesis discusses the well-established plant invasion mechanisms of the BP and highlights key emerging mechanisms and gaps in (a) the current understanding of the molecular, below-ground processes of BP invasion and (b) studies on the potential role of microbial interactions in the success of BP invasion already established for other select invasive species, and the intervention of soil metagenomic studies to elucidate plant invasive mechanisms. These poorly studied mechanisms could further explain the aggressive spread and resilience of BP and contribute significantly to the development of effective and sustainable control measures, enabling appropriate strategies for restoring native plants. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2016. / FAU Electronic Theses and Dissertations Collection
234

A habitat suitability model for wading birds in a large subtropical lake: linking hydrologic fluctuations and nesting

Unknown Date (has links)
Anthropogenic hydrologic alterations can affect the quality of lake littoral zone habitats for wading birds, such as the great egret (Ardea alba), snowy egret (Egretta thula), and white ibis (Eudocimus albus). One such lake in Florida, Lake Okeechobee, has experienced a marked decline in wading bird nesting since the 1970’s, concomitant with changes in lake level management. It’s hypothesized that a reduction in foraging habitat has led to the nesting decline; however, there is little quantitative evidence of this link. A habitat suitability model was developed for Lake Okeechobee wading birds that incorporate the spatial and temporal dynamics of environmental factors that affect wading bird foraging and tests whether foraging habitat is linked to numbers of nests. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection
235

Taxonomia e distribuição geográfica do complexo Penelope superciliaris Temminck, 1815 (Aves: Galliformes: Cracidae) / Taxonomy and geographic distribution of Penelope superciliaris complex Temminck, 1815 (Aves: Galliformes: Cracidae)

Vargas, Oscar Diego Evangelista 09 May 2017 (has links)
Penelope superciliaris Temminck, 1815, comumente conhecido como jacupemba, é o jacu com a mais ampla área de distribuição, ocorrendo no Brasil, Paraguai, Argentina e Bolívia, sendo também uma das sete espécies do gênero Penelope distribuída no Brasil. Suas subespécies foram descritas com base na largura e a tonalidade das bordas das penas, no desenvolvimento da linha superciliar, pigmentação das partes nuas, coloração geral da plumagem e tamanho. A taxonomia deste táxon é complexa e até hoje muitos autores nunca chegaram a um consenso sobre a validade dos táxons subordinados, a maioria deles reconhece apenas três subespécies: P. s. superciliaris, P. s. jacupemba e P. s. major, outras populações propostas como novas subespécies geográficas são atualmente sinonimizadas com as três anteriores. Para este complexo nenhuma revisão foi realizada nos últimos 70 anos, é por isso que, com coletas recentes de material novo, estamos realizando uma revisão taxonômica com base em caráteres morfológicos externos. O objetivo deste trabalho é verificar quantos táxons estão no nível de espécie no complexo Penelope superciliaris e delimitar suas respectivas distribuições geográficas, de acordo com o bioma em que eles ocorrem. Para atingir esses objetivos, realizamos análises qualitativas de carácteres morfológicos externos como coloração da plumagem, pigmentação das partes nuas, e também foram testadas variações inter- e intra-populacionais de acordo com esses caráteres. Para a análise estatística foram realizados testes univariados e multivariados para avaliar o dimorfismo sexual e a variação geográfica. De dezoito grupos geográficos formados, as análises qualitativas revelam que não há dimorfismo sexual, e a maioria delas tem um alto grau de variação individual. As análises estatísticas não discriminaram os sexos e populações com base nas oito medidas corporais utilizadas, porém os táxons foram discriminados pela coloração da plumagem e a pigmentação das regiões nuas. De acordo com o Conceito Filogenético de Espécies (PSC), consideramos que o complexo Penelope superciliaris deve ser dividido em quatro espécies: Penelope pseudonyma Neumann, 1933, uma população de jacus de cara azul restrita ao interflúvio Madeira-Tapajós na floresta amazônica; Penelope ochromitra Neumann, 1933, da Caatinga e Cerrado que limita com este bioma; Penelope alagoensis Nardelli, 1993, do Centro de Endemismo Pernambuco; e Penelope superciliaris Temminck, 1815, que ocorre no resto da distribuição do complexo. / Penelope superciliaris Temminck, 1815, known as Rusty-margined Guan, is a forest guan with the widest distribution, occurring in Brazil, Paraguay, Argentina and Bolivia, being also one of the seven species of the genus Penelope distributed in Brazil. Its subspecies have been described based on the width and shade of edges of feathers, the development of the superciliary stripe, naked parts pigmentation, general plumage coloration and size. The taxonomy of this taxon is complex and even today many authors never reached a consensus on the validity of the subordinate taxa; most of them recognize only three subspecies: P. s. superciliaris, P. s. jacupemba and P. s. major; other populations proposed as new races are currently synonymized with the previous three. For this complex, no review was conducted in the last 70 years that is why, with recent collection of new material, I performed a taxonomic revision based on external morphological characters. The aim on this work is to verify how many taxa exist at the species level in the Penelope superciliaris complex, and delimit their respective geographic distributions. To achieve these goals, we performed qualitative analyzes of external morphological characters as plumage coloration, naked parts pigmentation, and were tested inter- and intra-populational variations according to these characters. For statistical analyzes we performed univariate and multivariate tests to evaluate the sexual dimorphism and geographical variation. From eighteen geographic groups formed, the qualitative analyzes reveals that there is no sexual dimorphism, and most of them have a high degree of individual variation. Statistical analyzes did not discriminate the sexes and populations based on the eight body measurements used, but the taxa were discriminated by plumage coloration and naked parts pigmentation. According to the Phylogenetic Species Concept (PSC), we consider that the Penelope superciliaris complex must be divided in four species: Penelope pseudonyma Neumann, 1933, a blue-faced guans population restricted to the Madeira-Tapajós interfluvium in the Amazon forest; Penelope ochromitra Neumann, 1933, from the Caatinga and Cerrado that borders with this biome; Penelope alagoensis Nardelli, 1993, from the Pernambuco Center of Endemism; and Penelope superciliaris Temminck, 1815, which occurs in the rest of the distribution of the complex.
236

Using DNA Fingerprinting to Assess Genetic Structure of the Vernal Pool Amphibian Rana sylvatica

Beatini, Salvatore J. 28 April 2003 (has links)
In this study, I used restriction fragment length polymorphism (RFLP) analysis (DNA fingerprinting) to study the genetic population structure of wood frogs, Rana sylvatica, collected as egg masses from vernal pools within the Massachusetts Audubon Society Lincoln Woods Wildlife Sanctuary in Leominster, MA. The average genetic relatedness of sibling individuals, non-sibling individuals from within the same pool, and individuals from pools of close (5 m), far (200 m) and distant (40 km) spatial separations was calculated. The goal was to use genetic relatedness to estimate the breeding patterns of R. sylvatica and use that information to make general management recommendations that could be applied to other vernal pools breeders. I detected relative differences in genetic similarity between individuals from pools only 5 meters apart, however over a larger distance of 200 meters no significant genetic differences were present. This suggests that although wood frogs are known to be highly philopatric, they may use information other than simply proximity to their natal pool when choosing breeding sites. Factors such as species composition, water chemistry and heterogeneity of the landscape between pools may influence breeding site choice. Also, contrary to the findings of recent studies, the distance between vernal pools may not be the best indicator of the genetic similarity of the individuals they host. Pools in close proximity to one another may host genetically distinct populations, and therefore management decisions should be made on a pool-by-pool basis. Consequently, when managing populations of R. sylvatica, and possibly other vernal pool breeders, taking into account parameters other than simply the spatial separation of pools within an array may avoid decisions that could result in the loss of genetic diversity.
237

Pequenos mamíferos não-voadores do Planalto Atlântico de São Paulo: identificação, história natural e ameaças / Non-volant small mammals of the Atlantic Plateau of São Paulo: identification, natural history and threats

Rossi, Natália Fernandes 13 June 2011 (has links)
Roedores Cricetidae e Echimyidae e marsupiais Didelphidae formam o grupo dos pequenos mamíferos não-voadores das florestas neotropicais, o qual engloba boa parte da diversidade de mamíferos do Brasil, exerce papel ecológico importante na regeneração e dinâmica das florestas, e funciona como indicador de alterações da paisagem e da estrutura local dos habitats. No entanto, a identificação das espécies do grupo é difícil já que a taxonomia é baseada principalmente em caracteres cranianos e cromossômicos, muitas espécies ainda vêm sendo descritas, e faltam listas recentes para muitos biomas e regiões brasileiras. Além disso, apesar de sua importância numérica e ecológica, existe uma carência de informações, e de sínteses e compilações, sobre a diagnose, história natural, distribuição geográfica e ameaças para as espécies deste grupo. Esta dissertação apresenta uma compilação do conhecimento atualmente existente sobre os caracteres diagnósticos, distribuição, uso de habitats e respostas às alterações humanas, dieta, uso do espaço, reprodução e ameaças das espécies de pequenos mamíferos não-voadores de uma das regiões mais ricas da Mata Atlântica, o Planalto Atlântico de São Paulo, encontro entre duas áreas de endemismo adjacentes, que abriga respectivamente cerca de 22 e 32% das espécies de roedores Cricetidae e marsupiais Didelphidae com ocorrência no Brasil. A diagnose das espécie foi baseada na comparação e descrição das mesmas características para todas as espécies, focando principalmente em caracteres externos, passíveis de serem analisadas nos animais vivos e algumas características cranianas e dentárias mais relevantes para os grupos analisados. Já a descrição de características ecológicas foi baseada em extenso banco de dados coletados em 155 sítios com 118.322 armadilhas-noite de esforço no Planalto pelos projetos do Laboratório de Diversidade e Conservação de Mamíferos do Departamento de Zoologia do Instituto de Biociências da Universidade de São Paulo, e revisão padronizada da literatura. Para cada uma das 53 espécies, são apresentadas informações sobre: 1- \"Identificação\" que inclui medidas corporais externas (mínimo, máximo e média), um texto de diagnose que descreve características morfológicas externas e cranianas ilustradas em figuras e pranchas, e cariótipo; 2- \"Distribuição\" onde é descrita a distribuição geográfica seguida por informações sobre a ocorrência em biomas e estados brasileiros, e a distribuição e abundância nas matas do Planalto Atlântico de São Paulo; 3- \"História Natural\" onde são descritas a preferência por florestas ou áreas abertas de agricultura, a resposta à fragmentação florestal e regeneração da floresta, a capacidade de ocupar diferentes tipos de ambientes alterados, dieta, hábito, reprodução, uso do espaço e outras informações importantes; e 4- \"Ameaças\" onde se ressalta a presença em listas de espécies ameaçadas estaduais, nacional e internacional e se apresenta uma consideração sobre as ameaçadas sofridas, com base nas informações detalhadas obtidas no Planalto Atlântico de São Paulo. / Rodents from the families Cricetidae and Echimyidae and Didelphidae marsupials represent the non-volant small mammals from Neotropical forests, a group that encompasses much of the diversity of mammals in Brazil, play important ecological roles in forest regeneration and dynamics, and indicates changes in both landscape and local habitat structure. However, species identification is difficult since taxonomy is mainly based on cranial and chromosomal characters, many species are still being described, and recent lists for many biomes and regions are lacking. Moreover, despite their numerical and ecological importance, there is a lack of information, syntheses and compilations on the diagnosis, natural history, distribution and threats to the species of this group. This dissertation presents a compilation of the current knowledge about the diagnostic characters, distribution, habitat use and responses to human disturbances, diet, use of space, reproduction and threats for the non-volant small mammals from one of the richest regions of the Atlantic Forest, the Atlantic Plateau of São Paulo, where two adjacent areas of endemism meet, and which harbors about 22 and 32% of Cricetidae rodents and Didelphidae marsupials occurring in Brazil. Species diagnosis were based on the comparison and description of the same characteristics for all species, focusing mainly on external characters, which can be analyzed in live animals and some dental and cranial features most relevant to the analyzed groups. The description of ecological characteristics was based on an extensive database collected at 155 sites with an effort of 118.322 traps-night by the projects of the Laboratory of Diversity and Conservation of Mammals, Department of Zoology, Institute of Biosciences, University of São Paulo, and a standardized review of the literature. For each of the 53 species, I present information on: 1- \"Identification\" that includes external body measurements (minimum, maximum and mean), a text on diagnosis that describes the external morphological and cranial characteristics illustrated in figures and plates, and karyotype; 2- \"Distribution\" that describes the geographical distribution followed by information on the occurrence in Brazilian biomes and states, and the distribution and abundance in forests of the Atlantic Plateau of São Paulo; 3- \"Natural History\" where the preference for forests or open areas of agriculture, the response to forest fragmentation and regeneration, the ability to occupy different types of altered habitats, diet, habit, reproduction, use of space and other important information are described; and 4- \"Threats\" that highlights the presence in state, national and international lists of endangered species and presents a consideration of the threats, based on the detailed information obtained in the Atlantic Plateau of São Paulo.
238

Multiscale assessment of thermal patterns and the distribution of chinook salmon in the John Day River Basin, Oregon

Torgersen, Christian E. 08 July 1996 (has links)
This study examined the distribution and behavior of adult spring chinook salmon (Oncorhynchus tshawytscha) related to patterns of stream temperature and physical habitat at channel unit, reach, and basin-wide spatial scales in both a wilderness stream and a disturbed stream in the John Day River basin in northeastern Oregon. Thermal remote sensing of holding and spawning reaches in the upper subbasins of the North Fork and Middle Fork John Day River provided spatially continuous maps of stream temperature. Multiscale associations between salmon and cool-water areas were assessed by overlaying thermal imagery with fish locations mapped during distributional surveys. Chinook salmon were distributed non-uniformly throughout each study area, indicating that salmon selected certain reaches within each subbasin. The coldest reaches available to salmon within the Middle Fork study areas were low gradient, unconstrained reaches where the cooling influence of groundwater flow was the most apparent. In the Middle Fork, the stream currently managed for grazing and timber harvest, water temperature differences were typically 1-2��C within riffle-pool sequences and 3-4��C among reaches. The reach level association between salmon distribution and stream temperature patterns at channel unit and reach level spatial scales was strongest in the warmest study reach, the Middle Fork, and weakest in the coldest study reach, the North Fork. Pools were the preferred habitat for adult spring chinook in both subbasins; however, riffles were used more in the North Fork, the coldest subbasin. This study identified the problems and also the benefits associated with stream temperature patchiness, or discontinuity, both in currently disturbed and in recovering riverine ecosystems. Connectivity among system components in aquatic ecosystems is generally considered necessary for maintaining long-term ecological health. However, it is heterogeneity in the landscape/hydrogeologic template that creates refuge patches in disturbed stream ecosystems, such as those in the John Day River basin. Our observations of thermal refugia occurring at multiple spatial scales, particularly in the Middle Fork John Day River, indicate that, although discontinuity may be an ecological warning sign, refuge patches in streams should also be viewed as expressions of restoration potential because they are functioning remnants of a once continuous, intact hydrologic system. / Graduation date: 1997
239

The population genetics and phylogeography of the hairy woodpecker (Picoides villosus) / Brendan A. Graham

Graham, Brendan A., University of Lethbridge. Faculty of Arts and Science January 2011 (has links)
This thesis examines the effects that Pleistocene glaciation had on the population structure and contemporary genetic patterns of the hairy woodpecker (Picoides villosus). A combination of molecular markers, revealed reduced levels of gene flow among groups of hairy woodpeckers. Microsatellite analyses suggest barriers to gene flow have influenced contemporary population structure, with higher structure found in western North America where barriers to gene flow are more prevalent. MtDNA analyses revealed three distinct genetic lineages, two in North America and a third in Central America. Results indicate these lineages separated prior to the Wisconsin glaciation (~100 kya) and that contemporary population structure is the result of post-glacial expansion from multiple refugia following deglaciation. Current taxonomy recognizes 17 subspecies (Jackson et al., 2002), but molecular analyses in this study do not support current subspecies designations. / xii, 117 leaves ; 29 cm
240

Spatial patterns of vegetation and soil fertility along a grazing gradient in a desert steppe in Inner Mongolia, China

Lin, Yang Unknown Date
No description available.

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