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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.
71

Revealing structure in vocalisations of parrots and social whales

Noriega Romero Vargas, Maria Florencia 07 August 2017 (has links)
No description available.
72

Beastly spaces : geomorphism in the literary depiction of animals

Paddock, Alexandra Angharad January 2016 (has links)
In 2010, Simon Estok observed that, "the most immediate question ecocriticism can ask is about how our assumptions about animals affect the natural environment". In this thesis, I respond to this challenge by generating a sustained conversation between the hitherto surprisingly distinct fields of animal studies and ecocriticism. I do this by formulating a new critical concept, that of the geomorphic animal, which I use to show how literary representations of animals often expose the many complex ways in which they constitute space rather than simply inhabiting it. This, in turn, should make them central to future ecocritical readings. I focus on two periods, medieval and modern; the broad historical and generic scope of this thesis is intended to demonstrate the conceptual validity and robustness of geomorphic readings. Chapter One shows how concerns with death and symbiosis are expressed through the earth-bound activities of the geomorphic animals of the Exeter Book riddles. Chapter Two examines geomorphic whales in texts deriving from two related traditions: the Book of Jonah and the Physiologus. Chapters Three and Four focus on modern theatre, which affords distinctive ways of articulating the spatial implications of geomorphism. Chapter Three discusses the literary representation of museums and zoos in terms of the interpretative complexities generated by staging and spectacle. Chapter Four, focusing on mediation, discusses the interplay between animals, viewpoints and place in theatre, also taking into account particular issues arising from the adaptation of plays into films. This argument paves the way to addressing the geomorphic depiction of marginalised humans and human groups, suggesting the critical potential of geomorphism as a means of furthering feminist and post-colonialist aims.
73

Effects and added drag on cetaceans : fishing gear entanglement and external tag

Van der Hoop, Julie M January 2017 (has links)
Thesis: Ph. D., Joint Program in Applied Ocean Science and Engineering (Massachusetts Institute of Technology, Department of Biology; and the Woods Hole Oceanographic Institution), 2017. / Cataloged from PDF version of thesis. / Includes bibliographical references (pages 283-314). / Animal movement is motivated in part by energetic constraints, where fitness is maximized by minimizing energy consumption. The energetic cost of movement depends on the resistive forces acting on an animal; changes in this force balance can occur naturally or unnaturally. Fishing gear that entangles large whales adds drag, often altering energy balance to the point of terminal emaciation. An analog to this is drag from tags attached to cetaceans for research and monitoring. This thesis quantifies the effects of drag loading from these two scenarios on fine-scale movements, behaviors and energy consumption. I measured drag forces on fishing gear that entangled endangered North Atlantic right whales and combined these measurements with theoretical estimates of drag on whales' bodies. Entanglement in fishing gear increased drag forces by up to 3 fold. Bio-logging tags deployed on two entangled right whales recorded changes in the diving and fine-scale movement patterns of these whales in response to relative changes in drag and buoyancy from fishing gear and through disentanglement: some swimming patterns were consistently modulated in response. Disentanglement significantly altered dive behavior, and can affect thrust production. Changes in the force balance and swimming behaviors have implications for the survival of chronically entangled whales. I developed two bioenergetics approaches to estimate that chronic, lethal entanglements cost approximately the same amount as the cost of pregnancy and supporting a calf to near-weaning. I then developed a method to estimate drag, energy burden and survival of an entangled whale at detection. This application is essential for disentanglement response and protected species management. Experiments with tagged bottlenose dolphins suggest similar responses to added drag: I determined that instrumented animals slow down to avoid additional energetic costs associated with drag from small bio-logging tags, and incrementally decrease swim speed as drag increases. Metabolic impacts are measurable when speed is constrained. I measured the drag forces on these tags and developed guidelines depending on the relative size of instruments to study-species. Together, these studies quantify the magnitude of added drag in complementary systems, and demonstrate how animals alter their movement to navigate changes in their energy landscape associated with increased drag. / by Julie M. van der Hoop. / Ph. D.
74

Population Genetics of St. Lawrence Beluga Whales, Assessment of Inbreeding by DNA Fingerprinting and Assessment of Biopsy Darting Factors for Minimal Wounding and Effective Sample Retrieval / Population Genetics of St. Lawrence Beluga Whales

Patenaude, Nathalie J. 12 1900 (has links)
The endangered St. Lawrence beluga (Delphinapterus leucas) population is not recovering from severe depletion despite its protected status over the past 20 years. DNA fingerprinting analysis of St. Lawrence beluga whales with three minisatellite probes (Jeffreys 33.6, 33.15 and Ml3) indicate a reduced level of genetic variability compared to Mackenzie Delta animals. The average band-sharing between individuals of the St. Lawrence beluga population for the three probes (0.534, 0.573, 0.478) was significantly higher than the average band-sharing of the Mackenzie Delta beluga population for the same probes (0.343, 0.424, 0.314). Higher levels of mean homozygosity in the isolated St. Lawrence belugas (0.33 vs 0.21) as well as a high degree of relatedness suggest that this population is inbred and that inbreeding depression is a factor in the lack of recovery of the St. Lawrence beluga population. Because sampling of some beluga populations may be biased, there is the need of alternative sampling procedures such as biopsy darting. To evaluate the impact of biopsy darting on beluga whales, different combinations of dart and stop sizes were tested on fresh beluga carcasses and the effect of different factors on the success of retrieval and the extent of wounding were evaluated. Tips with smaller diameters were more likely to retrieve a sample than those with larger diameters (p <0.05) and longer tips were also more likely to retrieve a sample than shorter tips (p < 0.10). The force of impact, a function of draw weight and distance, had a significant effect on the severity of wounding (p<0.05). The samples obtained from all biopsy darts tested yielded sufficient amounts of DNA for genetic analysis. / Thesis / Master of Science (MS)
75

Modelling distributions of rare marine species : the deep-diving cetaceans / Modéliser les distributions des espèces marines rares : les cétacés grands plongeurs

Virgili, Auriane 11 January 2018 (has links)
Les cétacés grands plongeurs, cachalots Physeteridae et Kogiidae, et baleines à bec Zipiidae, sont des espèces marines rares. Leur faible densité, aire de distribution étendue et faible disponibilité en surface génèrent de faibles taux d’observations. Cette particularité constitue un défi pour la modélisation d’habitat de ces espèces, préalable à leur conservation. Les modèles doivent gérer l’abondance de zéros qui limitent leur capacité à inférer des résultats écologiquement cohérents. Cette thèse vise donc à trouver une méthodologie adaptée aux jeux de données abondants en zéros, à déterminer comment les variables environnementales influencent la distribution des grands plongeurs et à prédire les zones potentielles qu’ils utilisent. Tester la capacité de prédiction de différents modèles d'habitat confrontés à un nombre décroissant d’observations a permis de souligner la pertinence d’un modèle, même si un minimum de 50 observations est nécessaire pour fournir des prédictions fiables. Des données issues de différentes campagnes visuelles ont été assemblées afin de produire les premières cartes de densités de grands plongeurs à l’échelle de l’océan Atlantique Nord et la mer Méditerranée. Les densités les plus élevées sont prédites dans les eaux entre 1500 et 4000 m de profondeur et près des fronts thermiques, particulièrement le long des pentes continentales et à l'ouest de l'océan Atlantique Nord. Par ailleurs, l’analyse de la transférabilité des modèles a montré une variation des habitats préférentiels en fonction des écosystèmes. Finalement, cette thèse permet de discuter les défis de la modélisation statistique appliquée aux espèces rares et les applications de gestion associées. / Deep-diving cetaceans, sperm- and beaked whales Physeteridae, Kogiidae and Ziphiidae, are rare marine species. Due to their low densities, wide distribution ranges and limited presence at the water surface, visual surveys usually result in low sighting rates. This paucity of data challenges the modelling of their habitat, prerequisite for their conservation. Models have to cope with a great number of zeros that weakens the ability to make sound ecological inferences. Consequently, this thesis aimed at finding a methodology suitable for datasets with a large number of zeros, determining how environmental variables influence deep-diver distributions and predicting areas preferentially used by these species. By testing the predictive performance of various habitat models fitted to decreasing numbers of sightings, I selected the most suitable model and determined that at least 50 sightings were needed to provide reliable predictions. However, individual surveys can rarely provide sufficient deep-diver sightings thus I merged many visual survey datasets to produce the first basin-wide deep-diver density maps in the North Atlantic Ocean and the Mediterranean Sea. Highest densities were predicted in waters from 1500-4000 m deep and close to thermal fronts ; hotspots were predicted along the continental slopes, particularly in the western North Atlantic Ocean. In addition, a model transferability analysis highlighted that habitat drivers selected by the models varied between contrasted large ecosystems. Finally, I discussed challenges related to statistical modelling applied to rare species and the management applications of this thesis.
76

Investigating fin whale (Balaenoptera physalus) sightings in Skjálfandi Bay, Iceland, and potential migratory movements through photo-identification

Lundström, Hanna January 2023 (has links)
In studies of migration and life-history of many large whales, photo-identification has proven a very powerful tool. Unfortunately, photo-identification is not as established and common when it comes to the second largest animal on earth, the fin whale (Balaenoptera physalus).Despite the massive size of the creatures many things remain unknown about them, such asmigration patterns, the geographical and temporal locations of wintering and individual seasonal range. This study aimed to investigate when fin whales normally visit Skjálfandi Bay, Iceland, and if they migrate between Skjálfandi Bay and Ireland, using photo-identification. The results showed somewhat that the fin whale visits in Skjálfandi Bay were most common in March and April which could be connected to arrival of schooling fish such as capelin (Mallotus villosus) early spring, and that visits have not changed noticeably over the years, suggesting that the fin whales will keep coming to Skjálfandi Bay. One possible fin whale match was found between Skjálfandi Bay and Ireland, suggesting but not confirming migration between the two locations. Further investigation is needed to understand fin whale migration patterns. Because of typical fin whale behavior, similar dorsal fins and unreliable weather, the photo-identification system was discussed, and improvements suggested. A more established photo-identification system could include fin whale photo-ID catalogues with pictures from dorsal view and from the left and right side. However, the photo-identification methods need further investigating to improve even more and to find the best possible way to identify and photograph fin whales. / Foto-identifiering har visat sig vara ett användbart verktyg för att studera migration men även livshistoria hos många stora valar. Tyvärr är fotoidentifiering inte lika etablerat och vanligt när det gäller det näst största djuret vår jord, sillvalen (Balaenoptera physalus). Trots valens massiva storlek finns det en stor kunskapsbrist kring dess migrationsmönster, de geografiska och tidsmässiga platserna för övervintring och individuellt säsongsutbrednings-område bland annat. Denna studie syftade till att undersöka när sillvalarna normalt kommer till Skjálfandi Bay, Island, och om de migrerar mellan Skjálfandi Bay och Irland, med hjälp av foto-identifiering. Resultaten visade delvis att sillvalarna oftast besöker Skjálfandi Bay i mars och april, vilket kan vara kopplat till att stimfiskar såsom lodda (Mallotus villosus) kommer dit tidig vår, och att besökssiffrorna inte har ändrats mycket över åren vilket tyder på att sillvalarna kommer fortsätta komma till Skjálfandi Bay. En möjlig matching hittades mellan en identifierad sillval i Skjálfandi Bay och en identifierad sillval i irländska vatten, vilket tyder på men inte bekräftar migration mellan de två platserna. På grund av det typiska sillvalbeteendet och derasliknande ryggfenor samt det opålitliga vädret som en faktor, diskuterades fotoidentifieringssystemet och förbättringar föreslogs. Ett mer etablerat fotoidentifieringssystem hade kunnat inkludera fotoidentifieringskataloger med bilder på sillvalar från ovan sida och från båda sidor. Däremot behöver fotoidentifieringsmetoderna vidare undersökning för ytterligare förbättringar och för att hitta det bästa sättet att identifiera och fotografera sillvalar.
77

Estimating whale abundance using sparse hydrophone arrays

Harris, Danielle V. January 2012 (has links)
Passive acoustic monitoring has been used to investigate many aspects of marine mammal ecology, although methods to estimate absolute abundance and density using acoustic data have only been developed in recent years. The instrument configuration in an acoustic survey determines which abundance estimation methods can be used. Sparsely distributed arrays of instruments are useful because wide geographic areas can be covered. However, instrument spacing in sparse arrays is such that the same vocalisation will not be detected on multiple instruments, excluding the use of some abundance estimation methods. The aim of this thesis was to explore cetacean abundance and density estimation using novel sparse array datasets, applying existing methods where possible, or developing new approaches. The wealth of data collected by sparse arrays was demonstrated by analysing a 10-year dataset collected by the U.S. Navy's Sound Surveillance System in the north-east Atlantic. Spatial and temporal patterns of blue (Balaenoptera musculus) and fin whale (Balaenoptera physalus) vocal activity were investigated using generalised additive models. Distance sampling-based methods were applied to fin whale calls recorded by an array of Ocean Bottom Seismometers in the north-east Atlantic. Estimated call density was 993 calls/1000 km².hr⁻¹ (CV: 0.39). Animal density could not be estimated because the call rate was unknown. Further development of the call localisation method is required so the current density estimate may be biased. Furthermore, analysing a single day of data resulted in a high variance estimate. Finally, a new simulation-based method developed to estimate density from single hydrophones was applied to blue whale calls recorded in the northern Indian Ocean. Estimated call density was 3 calls/1000 km².hr⁻¹ (CV: 0.17). Again, density of whales could not be estimated as the vocalisation rate was unknown. Lack of biological knowledge poses the greatest limitation to abundance and density estimation using acoustic data.
78

Direito internacional do mar, sistema e regime jurídico de proteção às baleias : a proibição de utilização de métodos letais em pesquisas científicas com baleias em alto-mar

Subtil, Leonardo de Camargo January 2016 (has links)
A presente tese pretende analisar uma possível proibição de utilização de métodos letais em pesquisas científicas com baleias em alto-mar, no sistema de Direito Internacional do Mar, inserida em um contexto marcado por uma binariedade ou dualidade normativa entre Estados pró e contra a pesca internacional da baleia. A fim de responder esse problema de pesquisa estabelecido, a tese desenvolve, em um primeiro momento, a noção inovadora do Direito Internacional do Mar como sistema. Para tanto, partiu-se da noção do Direito Internacional como um sistema social de validação normativa, onde as noções de técnica positiva de resolução de controvérsias internacionais, função, processo, comunicação social e tempo, tornamse a sua gramática comum. Em tal perspectiva sistêmica e social do Direito Internacional, são demonstradas as comunicações normativas e institucionais para caracterizar o Direito Internacional do Mar como um sistema funcional de regulação global dos oceanos. Tal compreensão, desenvolvida na primeira Parte da tese, levará a um segundo momento de análise em torno da proteção jurídica das baleias no sistema de Direito Internacional do Mar. Baseada na observação do regime tradicional de proteção jurídica das baleias, enquanto fenômeno de produção de sentido normativo, a tese desenvolve as principais controvérsias estabelecidas antes e após a Segunda Guerra Mundial – entre estabilidade e transformação –, bem como o regime jurídico da Convenção Internacional para a Regulamentação da Pesca da Baleia de 1946. Em uma leitura da proteção jurídica das baleias vinculada ao sistema de Direito Internacional do Mar, serão reveladas as (in)suficiências normativas do Artigo VIII, parágrafo 1º, da Convenção de 1946 e as suas relações com o julgamento do Whaling in the Antarctic pela Corte Internacional de Justiça (ICJ), em 2014. Por fim, a partir de uma metodologia sistêmico-pragmática de análise, será desenvolvida a tese da proibição de utilização de métodos letais em pesquisas científicas com baleias em alto-mar, vinculada ao sistema de Direito Internacional do Mar e, mais especificamente, com base na Convenção das Nações Unidas sobre o Direito do Mar (UNCLOS). / This thesis analyses the possibility of prohibition against the use of lethal methods in scientific whaling on the high seas under the current International Law of the Sea system, which is marked by a normative binarity or duality between states both for and against international whaling. In order to answer the research question proposed, this thesis develops, at first, the innovative notion of the International Law of the Sea as a system. For such purpose, this thesis initiates with the notion of International Law as a social system for normative validity, whereby the elements of positive technique for international settlement of disputes, function, process, social communication and time become its common syntax. In such a systemic and social perspective of International Law, this thesis demonstrates the normative and the institutional conveyance for characterizing International Law of the Sea as a functional system for the global regulation of the oceans. Such understanding, developed within the first part of this thesis, will lead to the analysis of the legal protection of whales within the International Law of the Sea system. Based on the observation of the traditional regime of legal protection of whales as a normative phenomenon, this thesis examines the main controversies that were established both before and after the Second World War – amid stability and transformation – as well as the legal regime of the 1946 International Convention for the Regulation of Whaling. Within the scope of the legal protection of whales attached to the normative system of the International Law of the Sea, this thesis reveals the normative (in)sufficiency of the paragraph 1 of Article VIII of the 1946 Convention and its relationship to the 2014 Whaling in the Antarctic judgment of the International Court of Justice (ICJ). Lastly, within a systemic-pragmatic methodology of analysis, this thesis develops the prohibition theory of the use of lethal methods in scientific whaling on the high seas as established through the International Law of the Sea system and, more specifically, on the basis of the United Nation Convention on the Law of the Sea (UNCLOS).
79

The ideological dimensions of whale bone use in Thule winter houses /

Patton, A. Katherine B. (Anna Katherine Berenice) January 1996 (has links)
This study attempts to demonstrate symbolic whale bone patterning within 31 Thule winter houses along the southeast coast of Somerset Island, Northwest Territories, Canada. All visible architectural whale bone incorporated within the dwellings was mapped. Trends towards particular patterns of whale bone distribution were demonstrated using Spearman's Rank-order Correlation Coefficient. The potential symbolic nature of such patternings was determined within the context of north Alaskan ethnographic and oral historical sources. The extensive use of whale bone in some Thule entrances suggests that their builders sought to create a distinction between the entrance tunnel and main room, not unlike the Inupiat dwellings in 19th-century Tikigaq. The significance of this architectural phenomenon is rooted in the Inupiat, and to some extent Inuit, association between women, the house and the bowhead whale. It is also suggested that whaling status may be reflected in differential access to bowhead whale bone.
80

All’s Whale that Ends Whale: How Correctly Identifying Antarctic-Feeding Grounds of Oceania Humpbacks Could Save an Endangered Population

Holmes, Davey 01 January 2016 (has links)
Although major whaling practices have ceased, increasing human involvement and influence in the world’s marine ecosystems continue to adversely effect global whale populations. It is a major concern throughout Antarctic waters, where endangered Oceania Humpback Whales (Megaptera novarangliae) annually feed. This study analyzes the extent to which a proposed marine protected area within the Ross Sea may indirectly harm the last remaining endangered population of Humpbacks. Using current satellite tracks of southern Humpback migrations, this model maps the effects of displaced Toothfish fisheries, and suggests further conservations efforts, based on New Zealand’s Precautionary Approach, to protect these vulnerable whales.

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