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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

COMPARATIVE ECOLOGY OF THE GOLDEN-WINGED WARBLER AND BLUE-WINGED WARBLER ON RECLAIMED MINES IN SOUTHEASTERN KENTUCKY

Patton, Laura L. 01 January 2007 (has links)
The golden-winged warbler (Vermivora chrysoptera) inhabits lower elevations on reclaimed surface mines in Kentucky, an indication of recent range expansion in this imperiled species. In 2004 and 2005, I compared breeding habitat between the golden-winged warbler and blue-winged warbler (V. pinus) in eastern Kentucky at landscape, territory, and nest site scales. Distance to forest edge averaged 38 m for the golden-winged warbler and 33 m for the blue-winged warbler. Maximum territory size averaged 1.5 ha for the golden-winged warbler and 2.1 ha for the blue-winged warbler. The golden-winged warbler occurred at higher elevations (up to 912 m) than the blue-winged warbler (up to 693 m). Golden-winged warblers occurred on flatter slopes when coexisting with bluewinged warblers. A higher percentage of grass cover occurred in golden-winged warbler territories where blue-winged warblers were absent compared to territories of either species where the two coexisted. Golden-winged warblers coexisting with blue-winged warblers were more often found in shrub cover than when they established territories in absence of blue-winged warblers. Management for the golden-winged warbler should focus on enhancement of transition zones between forest edges and open grasslands, especially at higher elevations.
2

Factors influencing avian community structure in bottomland hardwood forests of the southeastern United States

Husak, Michael Scott 05 May 2007 (has links)
Bottomland hardwood forests (BHF) are a disappearing habitat of importance to numerous migratory and non-migratory birds of conservation concern. Thus, understanding variables of bottomland hardwood forests that affect avian assemblage patterns are of great interest. I examined factors influencing avian assemblage and guild patterns in BHF of Noxubee National Wildlife Refuge in east-central Mississippi by conducting winter and spring fixed-radius avian point counts and vegetation surveys from 2002 ? 2004. The goals of this project were to 1) determine effects of greentree reservoir (GTR) management on breeding and wintering non-game bird community structure, 2) test hypotheses regarding plant structural complexity and avian assemblage patterns, and 3) examine the effects of landscapes on local bird assemblages within BHF. Greentree reservoirs have subtle effects on avian communities. Sites within GTRs, sites in BHF adjacent to GTRs, and random, unimpounded BHF sites differed significantly in breeding bird diversity, richness, and evenness. However, the patterns exhibited were a decreasing continuum of these variables with sites peripheral to GTRs demonstrating intermediate values. No differences were found among abundance, conservation status, or habitat specialization of breeding birds. Guild parameters did not differ except for a decreasing continuum in species richness among unimpounded BHF, BHF to GTRs, and GTR sites. The canopy nesting and ground gleaning foraging guilds were the only guilds found to differ among sites. Patterns could indicate that given the inherent structural variation of BHF, GTRs are within the expected range of variation, or GTR management could be indirectly affecting the surrounding landscape. GTR management did not affect community parameters for wintering birds, and only the bark gleaning foraging guild varied among sites (higher in GTRs). These results reflect the ubiquitous nature of wintering birds in east-central Mississippi forests. There was direct support for the structural vertical heterogeneity hypothesis; however, regression analyses of principal component scores derived from sixty structural descriptor metrics suggest that avian communities and guilds are more directly influenced by overall local plant structural complexity, as predicted by the spatial heterogeneity hypothesis. Avian community and guild parameters did not differ among the three landscape contexts defined by 1,000 and 1,500m buffers.
3

Análise temporal da comunidade de aves em um fragmento de vegetação natural em unidade de manejo florestal /

Silva, Guilherme Lima da January 2019 (has links)
Orientador: Renata Cristina Batista Fonseca / Resumo: A fragmentação é uma das principais causas da perda de biodiversidade. Conciliar as atividades produtivas e a conservação dos recursos naturais é um dos principais desafios das empresas do setor florestal. Poucos estudos avaliam a composição e estrutura das comunidades em longo prazo, sendo o monitoramento de aves uma ferramenta eficaz para tal finalidade. Este estudo foi conduzido num fragmento de vegetação natural em unidade de manejo florestal no município de Agudos, interior de São Paulo, Brasil. Tem como objetivo verificar se houve alteração na comunidade de aves de um fragmento de no intervalo de 35 anos. Nesse intervalo o fragmento que no estudo inicial era isolado foi conectado a outras áreas de vegetação natural por meio de corredores ecológicos. A captura das aves foi realizada com o auxílio de redes de neblina, dispostas em cinco pontos, com quatro redes por ponto. As amostras foram realizadas por dois dias consecutivos/mês/ponto sendo o estudo inicial, realizado de março de 1982 a janeiro de 1983 e o atual, de novembro de 2017 a dezembro de 2018. No estudo inicial foram capturados 368 indivíduos, distribuídos em 16 famílias e 32 espécies. A diversidade foi de H’ = 2,7. Não houve dominância significativa entre as espécies (J = 0,77). No atual foi constatada diminuição significativa na riqueza e diversidade, sendo capturados 142 indivíduos, de 12 famílias e 18 espécies. A diversidade foi de H’ = 2,2. Não houve dominância significativa entre as espécies (J = 0,78). A... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Fragmentation is a major cause of biodiversity loss. Reconciling how productive activities and conservation of natural resources is one of the main challenges for companies in the forest sector. Few studies assess long-term community composition and structure, and bird monitoring is an effective tool for such use. This study was conducted on a fragment of natural vegetation in the forest unit in Agudos, São Paulo State, Brazil. It aims to verify if there was alteration in the bird community of a 35 years interval fragment. In this interval the fragment that in the initial study, was connected to other areas of natural vegetation through ecological corridors. The birds were captured with the aid of five point mist nets with four nets per point. Samples were taken for two consecutives days/month/point with the initial study conducted from March 1982 to January 1983 and the current study from November 2017 to December 2018. No initial study captured 368 individuals, distributed in 16 families and 32 species. The diversity was H '= 2.7. There was no significant dominance between species (J = 0.77). At the moment, there was a significant reduction in richness and diversity, and 142 individuals from 12 families and 18 species were captured. The diversity was H '= 2.2. There was no significant dominance between species (J = 0.78). A collector curve in the current study is not stabilized and an estimated 26 species (Jackknife1). The results show that despite the strategies adopted by... (Complete abstract click electronic access below) / Mestre

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