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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

Parasitic Indicators of Foraging Strategies in Wading Birds

Gumbleton, Sarah 24 July 2018 (has links)
Feeding ecology and trophic interactions of six species of wading birds were explored through a combined analysis of stable isotope profiles and endoparasite communities. Stable isotopes broadly characterize the feeding preferences and geographic information, while parasite communities reflect long-term trends in feeding ecology. Deceased birds were obtained from four South Florida wildlife rehabilitation organizations. Of the 81 birds dissected, 73 contained parasites. Parasites were predominately found within the gastrointestinal tract. Host and range extensions were noted for several parasite taxa. Bird host species had a significant effect on the parasite community (P=0.001) while wildlife center location and maturity status did not. Stable nitrogen (δ15N) values for pectoral muscle tissues, representing approximately 24 days, ranged from 6.44 to 13.48‰ while stable carbon (δ13C) values ranged from -33.39 to -11.66‰. δ13C varied significantly among location (P=0.0002) and δ15N varied significantly among species (P15N and δ13C was analyzed in combination; bird species (P=0.001) and location (P=0.001) were significantly different. By using this combined approach of stable isotope analysis and parasite identification, it was possible to elucidate more components of bird feeding ecology. Stable isotope analysis provided knowledge on trophic interactions based on δ15N values, while δ13C was used to determine the differences in geographic foraging location. As endoparasites are acquired trophically via food-web interactions, identifying the parasite community allowed for trophic links to be drawn between organisms present within the same environment. Combining these two techniques allows for an abundance of information on feeding ecology and trophic interactions to be obtained.
2

Problemas taxonômicos da família Threskiornithidae: filogenia molecular e o caso de Eudocimus

Malaver, Jorge Luis Ramirez 01 March 2011 (has links)
Made available in DSpace on 2016-06-02T20:21:26Z (GMT). No. of bitstreams: 1 3664.pdf: 2255481 bytes, checksum: 8606405322631d7b23133954708544a6 (MD5) Previous issue date: 2011-03-01 / Financiadora de Estudos e Projetos / The family Threskiornithidae includes 13 genera and 32 species, but the relationships among genera, species or subspecies have been little studied. This family is traditionally divided into two subfamilies: Plataleinae and Threskiornithinae. One of the more interesting taxonomical questions within this group is the case of the species Eudocimus ruber and Eudocimus albus. They are usually considered as separate species, but they show similar behavior and there are also records of hybridization in nature. This study aims to reconstruct the phylogenetic relationships within the family Threskiornithidae as well as assess the level of genetic differentiation between Eudocimus albus and E. rubber, using mitochondrial and nuclear gene sequences. DNA was extracted from blood and tissue samples from 13 species of Threskiornithidae (seven genera) and two outgroups. For the Eudocimus study were extracted 10 individuals of each species. We sequenced the 16S rRNA and the intron 7 of β- Fibrinogen for all species. For Eudocimus Cytochrome B, Cytochrome Oxidase I, intron 11 of Glyceraldehyde-3-Phosphate Desidrogenase, intron 4 of the Myelin Proteolipid Protein and intron 2 of Myoglobin were also sequenced. Sequences for other five species of the family were obtained from GenBank. Phylogenetic trees were constructed using Neighbor-Joining, Maximum Parsimony, Maximum Likelihood, Bayesian inference and Bayesian inference of species tree. Networks and genetic distances were determined for Eudocimus haplotypes. Several approaches for species delimitation using multilocus data were applied. All analyses strongly supported the family Threskiornithidae (18 species) as a monophyletic group. However, the current classification of two subfamilies was not supported by our data: Plataleinae formed a monophyletic group, but nested within Threskiornithinae (a paraphyletic group). Tests of monophyly rejected the hypothesis of monophyly of Threskiornithinae. The family Threskiornithidae also showed a division into two groups: one with only genera endemic to the American continent (Theristicus and Eudocimus) and another with the remaining species. Within the latter clade, species of genus Plegadis are observed in a basal position, while subfamily Plataleinae was grouped with the remaining species. This pattern of species distribution suggests an initial Gondwana division and subsequent colonization by species from the Old to the New World. The divergence within the family was estimated at 35-40 million years, which is before the separation between America and Antarctica. Mitochondrial genetic analysis showed Eudocimus species as two different lineages. Multilocus analysis based on nuclear genes revealed a strong signal of speciation despite the polyphyly found in three of the four markers. / A família Threskiornithidae inclui 13 gêneros e 32 espécies e suas relações interespecíficas, assim como as designações dos gêneros, espécies ou subespécies foram pouco estudadas. A família tem sido dividida em duas subfamílias: Plataleinae e Threskiornithinae. O caso de Eudocimus ruber e Eudocimus albus é uma das questões interessantes da taxonomia do grupo, pois têm sido consideradas como espécies, mas mostram similaridades no comportamento e há registros de hibridização na natureza. Os objetivos do presente estudo foram reconstruir as relações filogenéticas dentro da família Threskiornithidae e avaliar o nível de diferenciação genética entre Eudocimus albus e E. ruber, baseando-se nos dados de sequências de genes mitocondriais e nucleares. DNA foi extraído de amostras de sangue e de tecidos de 13 espécies de Threskiornithidae, representantes de sete gêneros da família e de dois grupos externos. Para o estudo do caso de Eudocimus foram analisadas amostras de 10 indivíduos de cada espécie. Foram sequenciados os genes 16S rRNA e o íntron 7 do β-fibrinogênio para todas as espécies. Nos indivíduos de Eudocimus foram sequenciados também os genes Citocromo B, Citocromo Oxidase I, o íntron 11 da Gliceraldeído-3-Fosfato Desidrogenase, o íntron 4 da Proteína Proteolipídica da Mielina e o íntron 2 da Mioglobina. Sequências para outras cinco espécies da família foram obtidas do GenBank. Árvores filogenéticas foram construídas pelos métodos de inferência de Neighbor-Joining, Máxima Parcimônia, Máxima Verossimilhança, Análise Bayesiana e Estimativa Bayesiana de árvore de espécies. Redes de haplótipos e distâncias genéticas foram determinadas para as sequências de Eudocimus. Diversas abordagens de delimitação de espécies usando informação multilocus foram realizadas. A família Threskiornithidae com 18 espécies se apresentou como grupo monofilético fortemente sustentado em todas as análises. A classificação atual das duas subfamílias não foi corroborada: Plataleinae se apresentou como grupo monofilético, mas agrupada dentro dos Threskiornithinae, sendo este último um grupo parafilético. Os testes de monofilia rejeitaram a hipótese de Threskiornithinae ser um grupo monofilético. A família Threskiornithidae pode ser dividida em dois grupos: o primeiro agrupando somente gêneros endêmicos do continente americano (Theristicus e Eudocimus) e o outro com as demais espécies. Dentro deste ultimo clado, observa-se em posição basal as espécies do gênero Plegadis e a subfamília Plataleinae agrupada com o restante das espécies. Este padrão de distribuição de espécies concorda com uma divisão inicial Gondwânica e uma posterior colonização por espécies do velho ao novo mundo. A divergência da família foi estimada em 35 40 milhões de anos, data anterior à separação do continente Americano da Antártica. As análises genéticas mitocondriais mostraram as espécies de Eudocimus como duas linhagens diferentes. Nas análises multilocus baseadas nos genes nucleares foi possível recuperar um forte sinal de especiação apesar da polifilia encontrada em três dos quatro marcadores.

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