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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.
91

Confronting the challenges of tidal flat conservation spatial patterns and human impacts in a Marine Protected Area in southern NSW, Australia /

Winberg, Pia Carmen. January 2008 (has links)
Thesis (Ph.D.)--University of Wollongong, 2008. / Typescript. CD-ROM contains full thesis, appendix II database and abstract. Includes bibliographical references: p. 169-198.
92

A rede de marca??o e recaptura: o caso de borboletas do g?nero heliconius

Cunha, Maria do Socorro Mariano da 27 January 2010 (has links)
Made available in DSpace on 2014-12-17T14:10:20Z (GMT). No. of bitstreams: 1 MariaSMC_DISSERT.pdf: 2542892 bytes, checksum: bb7b11247ce7668feb164d1de842f43d (MD5) Previous issue date: 2010-01-27 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / (The Mark and Recapture Network: a Heliconius case study). The current pace of habitat destruction, especially in tropical landscapes, has increased the need for understanding minimum patch requirements and patch distance as tools for conserving species in forest remnants. Mark recapture and tagging studies have been instrumental in providing parameters for functional models. Because of their popularity, ease of manipulation and well known biology, butterflies have become model in studies of spatial structure. Yet, most studies on butterflies movement have focused on temperate species that live in open habitats, in which forest patches are barrier to movement. This study aimed to view and review data from mark-recapture as a network in two species of butterfly (Heliconius erato and Heliconius melpomene). A work of marking and recapture of the species was carried out in an Atlantic forest reserve located about 20km from the city of Natal (RN). Mark recapture studies were conducted in 3 weekly visits during January-February and July-August in 2007 and 2008. Captures were more common in two sections of the dirt road, with minimal collection in the forest trail. The spatial spread of captures was similar in the two species. Yet, distances between recaptures seem to be greater for Heliconius erato than for Heliconius melpomene. In addition, the erato network is more disconnected, suggesting that this specie has shorter traveling patches. Moving on to the network, both species have similar number of links (N) and unweighed vertices (L). However, melpomene has a weighed network 50% more connections than erato. These network metrics suggest that erato has more compartmentalized network and restricted movement than melpomene. Thus, erato has a larger number of disconnected components, nC, in the network, and a smaller network diameter. The frequency distribution of network connectivity for both species was better explained by a Power-law than by a random, Poissom distribution, showing that the Power-law provides a better fit than the Poisson for both species. Moreover, the Powerlaw erato is much better adjusted than in melpomene, which should be linked to the small movements that erato makes in the network / (A rede de marca??o e recaptura: O caso de borboletas do g?nero Heliconius). O ritmo atual de destrui??o dos habitats, especialmente em paisagens tropicais, tem aumentado a necessidade de se ter algum conhecimento sobre fragmentos e dist?ncia entre fragmentos como requisito m?nimo para a conserva??o das esp?cies em remanescentes de florestas. Os estudos de marca??o e recaptura t?m sido fundamentais no fornecimento de par?metros para modelos funcionais. Devido ? sua popularidade, facilidade de manipula??o e bem conhecida biologia, as borboletas tornaram-se modelos nos estudos da estrutura espacial. No entanto, a maioria dos estudos sobre o movimento de borboletas se concentraram em esp?cies de clima temperado que vivem em ambientes abertos, onde fragmentos florestais formam obst?culos para os movimentos. O presente trabalho teve como objetivo visualizar e reavaliar os dados de marca??o e recaptura como uma rede em duas esp?cies de borboleta (Heliconius erato e Heliconius melpomene). Um trabalho de marca??o e recaptura das esp?cies foi realizado em uma reserva de mata Atl?ntica localizada a cerca de 20 km da cidade de Natal (RN), durante um per?odo de tr?s anos, nos meses mais secos e chuvosos do ano, com tr?s visitas semanais. As capturas foram comuns nas duas partes da estrada de terra, com coleta m?nima na trilha de floresta e a dispers?o espacial das capturas tamb?m foi semelhante nas duas esp?cies. Por?m, as dist?ncias entre as recapturas parecem ser maiores para H. melpomene que para H. erato. Al?m disso, a rede erato ? mais desligada, sugerindo que esta esp?cie precisa viajar caminhos mais curtos. Em rela??o ?s medidas de rede, ambas as esp?cies t?m n?mero similar de conex?es (N) e v?rtices n?o considerando os pesos (L). No entanto, melpomene tem uma rede com liga??es que pesou 50% mais que erato. Essas medidas sugerem que erato tem uma rede mais compartimentada e de dispers?o mais restrita do que melpomene. Assim, erato tem um n?mero maior de componentes desconectados, nC, na rede, e um menor di?metro de rede. A distribui??o de freq??ncia de conectividade de rede para ambas as esp?cies foi mais bem explicada pela lei de pot?ncia do que pela distribui??o de Poisson, mostrando que a lei de pot?ncia prev? um ajuste melhor que o de Poisson para ambas as esp?cies. Al?m disto, a lei de pot?ncia de erato ? bem melhor ajustada do que a de melpomene, que deve estar ligado aos pequenos movimentos que erato faz na rede
93

Área de vida e uso de habitat por fêmeas de veado-campeiro (Ozotoceros bezoarticus) nos diferentes períodos reprodutivos, no Pantanal Sul-Matogrossence / Home-range and habitat use by females of Pampas Deer (Ozotoceros bezoarticus) in different reproductive periods, in Pantanal Sul-Matogrossense

Natalia Fraguas Versiani 20 May 2011 (has links)
As populações de veado-campeiro vêm sofrendo constantes ameaças, principalmente pela caça excessiva e destruição de seu habitat. A escassez de conhecimento sobre a biologia da espécie dificulta a elaboração de diferentes formas de manejo. Assim, há necessidade de estudos básicos para a instituição de programas para a conservação do veado-campeiro, principalmente no Brasil. O presente estudo teve como objetivos estimar o tamanho da área de vida de fêmeas de veado-campeiro, além de quantificar e comparar o uso de habitat pelas mesmas nos períodos reprodutivos e não-reprodutivos no Pantanal Sul-Matogrossense. Foram utilizadas quatro fêmeas de veado-campeiro em vida livre marcadas com colares de GPS modelo ATS® G2110, as quais tiveram suas localizações registradas a cada 13 horas por um período de aproximadamente 12 meses. Os cálculos para área de vida foram feitos através do programa ArcView® GIS versão 3 Extensão Animal Movement, usando os métodos do Mínimo Polígono Convexo (MPC) com 100% das localizações, e Kernel fixo com 95%, 70% e 50% de probabilidade de uso, sendo os dois últimos para estimativas dos centros de atividade. As fêmeas tiveram uma área de vida anual média de 549,88ha ± 124,76 quando estimado pelo MPC e 258,69ha ± 34,54 quando estimado por Kernel com 95% de probabilidade de uso. Quanto às áreas de uso mensais por status reprodutivo, não houve diferença significativa entre os meses (p > 0,05), evidenciando apenas uma pequena diminuição no tamanho das áreas de vida durante o período de aleitamento e um aumento nas épocas de acasalamento. Os habitats foram estabelecidos pelo tipo de vegetação predominante na área e foram caracterizados por imagem de satélite Landsat-5 e verificação in loco da região de estudo. Para verificar se houve uso desproporcional entre as categorias de habitats em relação à disponibilidade em suas respectivas áreas de vida foi usado o teste qui-quadrado de qualidade de ajustamento (chi-square goodness-of-fit test) e posterior estimativa do intervalo simultâneo de confiança de Bonferroni. Na análise anual, os habitats campo e baía foram selecionados, apesar deste último ser o menos abundante, enquanto floresta e caronal foram evitados pelas fêmeas de veado-campeiro. No entanto, ao analisarmos a seleção de habitat mensalmente para comparar o uso entre os diferentes status reprodutivos, o habitat campo tendeu a ser preferido, mas seu uso foi igual ao disponível em todos os períodos. Sendo assim, este estudo elucidou algumas informações sobre a ecologia do veado-campeiro, a fim de facilitar o desenvolvimento de programas de conservação para a espécie. / The pampas deer populations have been under constant threats, mainly by excessive hunting and habitat destruction. The lack of knowledge about the biology of the species hampers the development of different forms of management. Thus, there is a need for basic studies of establishment of conservation programs, mainly in Brazil. This study aimed to estimate the size of home-range, to quantify and compare the habitat use by females in reproductive and non-reproductive periods rights in Pantanal Sul-Matogrossense. Four females of pampas deer were marked with GPS collars, model ATS® G2110, which had recorded their locations every 13 hours for approximately 12 months. The calculations for home-range were made using the Arcview® GIS version 3 Extension Animal Movement, using the methods of the minimum convex polygon (MPC) with 100% of the locations, and fixed Kernel 95%, 70% and 50% of probability, being the last two for estimating the activity centers. The females had an annual home-range average of 549.88 ± 124.76 ha when estimated by MPC and 258.69 ± 34.54 ha when estimated by Kernel with 95% of probability. For the monthly home-ranges for reproductive status, no significant difference among months (p > 0.05), showing only a slight decrease in the size of home-range during the suckling period, increasing in the mating seasons. The habitats were established by the type of dominant vegetation and characterized by landsat-5 imaging satellite and in loco verification of the study area. To determine if there was disproportionate use of habitats between the categories regarding availability in their respective home-range, was used the chi-square goodness-of-fit test and subsequent estimation of Bonferroni simultaneous confidence intervals. In annual analysis, field and bay habitats were selected, despite the last being the less abundant, while forest and caronal were avoided by females of pampas deer. However, when analyzing the monthly habitat selection to compare the use between the different reproductive status, the habitat field tended to be preferred, but its use was equal to that available in all periods. Thus, this study clarified some informations about the ecology of pampas-deer, facilitating conservation programs development for the species.
94

Reef Fish Assemblage Biogeography Along the Florida Reef Tract

Ames, Cory 29 November 2017 (has links)
Understanding the biogeography of reef fish assemblages is paramount to reef conservation, management, and conducting appropriate population survey designs. Reef fish assemblages are a multispecies complex of reef-associated fish and are shaped by multiple environmental and biological factors (e.g. temperature, depth, benthic habitat, and topographic relief), which determine the species constituents residing in an area. Assemblages typically change with latitude where the number of families, genera, and/or densities of species specific to warmer climates decrease poleward into colder climate regimes. The Florida Reef Tract (FRT) extends for 595 km from the Dry Tortugas in the south-west to Martin County in the north, crossing a sub-tropical to temperate climate transition. This study investigates the biogeography of reef fish assemblages throughout the FRT to determine if they correspond to previous regional delineations that were primarily based on coastal geomorphology. Multivariate density analyses show that depth, habitat, relief, and region are major factors in determining the assemblages. Four main ecoregions were evident based on depth, benthic habitat, relief and latitudinal region: Dry Tortugas (DT), Florida Keys (FK), Southeast mainland (SE), and Bahamas Fracture Zone (BF). DT split into four biogeographic assemblage regions primarily based on depth, and relief. FK split into five biogeographic assemblage regions with a sixth extending through Broward County primarily based on depth, habitat type, and relief. SE split into four biogeographic assemblage regions primarily based on depth, and region. BF split into three biogeographic assemblage regions primarily based on depth, and region. These sixteen assemblages represent the current composition of reef fish based on four factors. Numerous other factors also affect reef fish assemblages (e.g. past and present fishing pressure, mangrove nursery habitat, and coral death) that were not part of the analysis but are discussed. The final reef fish assemblage regions were associated with previous benthic habitat maps in order to view their spatial extent. Having a map of current biogeographic reef fish assemblages serves as a baseline and allows more accurate management and monitoring of future reef fish populations.
95

Movement ecology and spatial distribution of Tayassu pecari in heterogeneous tropical landscapes /

Oshima, Júlia Emi de Faria. January 2019 (has links)
Orientador: Milton Cezar Ribeiro / Resumo: Modificações da cobertura do solo, perturbações antropogênicas e mudanças climáticas na região Neotropical têm sido associadas à crise da biodiversidade. Nesta tese, o objetivo principal foi investigar os efeitos que a estrutura da paisagem (incluindo a perturbação antropogênica) e a qualidade do habitat têm na distribuição espacial, nos padrões de movimento e na seleção de habitat da queixada - Tayassu pecari. Esta espécie é o único ungulado florestal Neotropical que forma grandes bandos e é uma espécie-chave nos ecossistemas florestais, pois sua extinção local pode causar perdas adicionais de biodiversidade por meio de efeitos em cascata. Ainda assim, pouco se sabe sobre uso do espaço e movimentos de queixadas em escala fina. Para tanto, estudamos a distribuição e movimentação da espécie em diferentes escalas e biomas do Brasil, investigando quais variáveis de paisagem influenciaram a mesma em diferentes escalas e ordens de seleção. Nossos resultados mostram fortes efeitos negativos da modificação da paisagem e fragmentação do habitat na distribuição de queixadas, restando apenas 47% do território brasileiro com áreas adequadas para a espécie. Verificamos que menos da metade de todas as áreas protegidas nos biomas Cerrado e Mata Atlântica têm um habitat adequado para a queixada. Para a análise do movimento, rastreamos 30 indivíduos com colares de GPS de julho de 2013 a outubro de 2016 no Pantanal e no Cerrado do estado do Mato Grosso do Sul. Nossos principais resultados mos... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Land cover modifications, anthropogenic disturbances and climate change in the Neotropical region have been linked to the biodiversity crisis. This thesis proposal was to investigate the effects that landscape structure (including anthropogenic disturbance) and habitat quality have in the spatial distribution, in the movement patterns and in the habitat selection of the white-lipped peccary - Tayassu pecari (WLP). This species is the only Neotropical forest ungulate that forms large herds, and it is a keystone species in forest ecosystems because its local extinction may cause additional biodiversity losses through cascading effects. Still, little is known about WLPs space use and fine-scale movement. For that aim we studied the species distribution and movements in different scales and biomes of Brazil, investigating which landscape variables would influence the species in different scales and orders of selection. Our findings show strong negative effects of landscape modification and habitat fragmentation on white-lipped peccary distribution, with only 47% of the Brazilian territory with suitable areas for the species. We also found that less than half of all protected areas in the Cerrado and the Atlantic Forest biomes have suitable habitat for WLP. For the movement analysis we tracked 30 individuals with GPS collars from July 2013 to October of 2016 in the Pantanal and in the Cerrado of Mato Grosso do Sul state. Our main results showed a positive selection of WLP for fore... (Complete abstract click electronic access below) / Doutor
96

Predicting Glass Sponge (Porifera, Hexactinellida) Distributions in the North Pacific Ocean and Spatially Quantifying Model Uncertainty

Davidson, Fiona 07 January 2020 (has links)
Predictions of species’ ranges from distribution modeling are often used to inform marine management and conservation efforts, but few studies justify the model selected or quantify the uncertainty of the model predictions in a spatial manner. This thesis employs a multi-model, multi-area SDM analysis to develop a higher certainty in the predictions where similarities exist across models and areas. Partial dependence plots and variable importance rankings were shown to be useful in producing further certainty in the results. The modeling indicated that glass sponges (Hexactinellida) are most likely to exist within the North Pacific Ocean where alkalinity is greater than 2.2 μmol l-1 and dissolved oxygen is lower than 2 ml l-1. Silicate was also found to be an important environmental predictor. All areas, except Hecate Strait, indicated that high glass sponge probability of presence coincided with silicate values of 150 μmol l-1 and over, although lower values in Hecate Strait confirmed that sponges can exist in areas with silicate values of as low as 40 μmol l-1. Three methods of showing spatial uncertainty of model predictions were presented: the standard error (SE) of a binomial GLM, the standard deviation of predictions made from 200 bootstrapped GLM models, and the standard deviation of eight commonly used SDM algorithms. Certain areas with few input data points or extreme ranges of predictor variables were highlighted by these methods as having high uncertainty. Such areas should be treated cautiously regardless of the overall accuracy of the model as indicated by accuracy metrics (AUC, TSS), and such areas could be targeted for future data collection. The uncertainty metrics produced by the multi-model SE varied from the GLM SE and the bootstrapped GLM. The uncertainty was lowest where models predicted low probability of presence and highest where the models predicted high probability of presence and these predictions differed slightly, indicating high confidence in where the models predicted the sponges would not exist.
97

Microhabitat Use by Blanding’s Turtles (<i>Emydoidea blandingii</i>) and Wood Turtles (<i>Glyptemys insculpta</i>) in a Shared Landscape

Reine K Sovey (8812556) 08 May 2020 (has links)
<p>Understanding and adequately protecting habitat is at the forefront of modern conservation concerns. Turtles are especially vulnerable to habitat loss, and are therefore a top priority for habitat research. To help meet this need, I used radio telemetry to collect microhabitat data from two imperiled species of turtles that occupy a military base in Michigan. Preliminary data exploration was carried out with principal components analysis (PCA). Microhabitat use was then modeled for each species using conditional logistic regression (CLR), with a generalized estimating equation (GEE) element to limit bias due to individual variation. Finally, I compared habitat use between sympatric Blanding’s and Wood Turtles using Mann-Whitney U tests and Mood’s median tests to investigate the degree of overlap in microhabitat use when these species occur in sympatry. Evidence for microhabitat selection in Blanding’s Turtles was weak, suggesting that they likely do not make habitat decisions at this level. Wood Turtles selected sites that were farther from water and had fewer trees, less overstory canopy cover, and more ground cover. Additionally, the two species differed in several aspects of microhabitat use; Wood Turtles were more terrestrial and more tolerant of tree cover than Blanding’s Turtles. Patterns of microhabitat use found in this study match previously observed behavior of turtles in high quality habitat, suggesting that managers should work to maintain the habitat currently available at Camp Grayling. Additionally, because both turtle species were associated with open canopy, selective logging could benefit turtles provided care is given to timing and methods. </p>
98

Reptilian Activity, Movements and Spatial Ecology within the Oak Openings Region

Martin, Amanda K. 29 April 2020 (has links)
No description available.
99

Multi-Scale Habitat Selection of Antillean Manatees (Trichechus manatus manatus) in Sian Ka'an Biosphere Reserve, Southeastern Mexico

Gagnon, Émilie 06 September 2023 (has links)
The distribution of organisms across the globe forms non-random patterns that are based on their selection for certain environmental features. Habitat selection is the study of how organisms choose where they live. It is a fundamental behavior shaping several ecological and evolutionary processes. The hierarchical nature of the environment makes it imperative to consider multiple scales in habitat selection studies. Even though there is extensive coverage of scaling in habitat selection literature, most published papers only consider one scale. To our knowledge, habitat selection studies of the Antillean manatee (Trichechus manatus manatus) have never included more than one spatial scale. Hence, we modeled Antillean manatee habitat selection in the Sian Ka'an Biosphere Reserve, in Mexico, at two spatial scales: study area and 1 km buffer. We used GPS coordinates of opportunistic encounters (n = 102) recorded since 2009. We randomly generated 500 pseudo-absences per presence point for both scales, and extracted the environmental conditions from each point: seagrass abundance (leaf area index or LAI), water depth, and shortest distance to land, closest river and closest resting hole. We fitted a binomial regression of the probability of presence as a function of the environmental parameters using a Bayesian approach. Our results show that the probability of manatee presence increases in proximity to resting holes for both scales and increases with land proximity at the large-scale. Overall, we showed that proximity to resting holes is the most important feature of habitat selection for Antillean manatees in Sian Ka'an, followed by proximity to land. This study demonstrates the importance of multi-scale designs in habitat selection and highlights the need for more studies looking at the use and ecological implications of manatee resting holes.
100

Socioecology of the Guianan bearded saki, Chiropotes sagulatus

Gregory, L Tremaine 21 March 2011 (has links)
No description available.

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