Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 25 for “"Top-Predator"”.
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Ecosystem Functional Consequences of Top Predator Mortality Due to the Invasive Shrub, Lonicera maackii
… to aquatic systems would increase mortality of a top amphibian predator due to the release of phenolic compounds that inhibit respiration. A mesocosm experiment was developed to characterize the cascading effects of increased top predator (Ambystoma maculatum) mortality on larval salamander …
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Temporal variation in the diet and feeding intensity of Snoek (Thyrsites atun) in the Southern Benguela upwelling system
… feeding intensity of snoek (Thyrsites atun), a top predator of commercially exploited pelagic clupeoids, was investigated in the Southern Benguela Upwelling System.
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Linking Prey to Predator: Scale Dependence and Oceanographic Influence in Marine Food Webs
… operate at multiple scales from an individual predator up to ocean basin migrations, and research across these scales is extremely difficult. More accurate and detailed understanding of prey distributions relative to physical and biological features can greatly aid in understanding top predator …
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Assessment of pesticide concentrations in environmental and biological parameters from two Kenyan Rift Valley Lakes
… on the lake was the densest in Africa. As a top predator resident in the Kenyan Rift Valley Lakes the African Fish-Eagle is a good indicator of general ecosystem health but is also highly susceptible to toxic effects of pesticide contamination...Globally, most organochlorine pesticides have …
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A paleozoological perspective on predator extermination and white-tailed deer (Odocoileus virginianus Boddaert) overabundance in central Texas.
… time-depth to ecology. In central Texas several top carnivores including prehistoric Native American hunters have been extirpated or have had their historic ranges restricted, which has resulted in pest-level white-tailed deer (Odocoileus virginianus texana) populations in some areas. Predator …
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Ecology of feral cats Felis catus and their prey in relation to shrubland fire regimes
Invasive predators are major drivers of global biodiversity loss and their impacts may be worsened by other disturbances such as fire. I examined how the fire history of shrublands influences the ecology of feral cats Felis catus, dingoes Canis dingo and their prey species in Western Australia’s …
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Spatialised ecosystem modelling to evaluate the influences of marine protected areas and provisioning ecotourism on the foraging and distributional response of top predators from Mossel Bay to Algoa Bay, South Africa
High trophic level ecosystem-regulating top predators are an important facet in the structure and functioning of the South-East coast of South Africa. This region is influenced by the warm, fast-flowing Agulhas Current, which make it a highly productive biodiversity hotspot. This consequently …
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The spatial ecology and behaviour of the broadnose sevengill shark (Notorynchus cepedianus) in South Africa
Top predators are an important component of healthy ecosystems, contributing to ecosystem stability and biodiversity through direct and indirect effects. However, significant knowledge gaps exist in our understanding of the occurrence, biology and spatiotemporal dynamics of marine predators, …
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Seasonal dietary composition of the eastern coyote (Canis latrans) on the berry college campus in Northwestern Georgia
… during the past 50 years, and its impact as the top predator is potentially influencing community dynamics via competition and/or predation. Few studies have examined coyote food habits in the southeastern United States. Our objective was to determine prey items consumed by free-ranging coyotes …
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Acoustic Telemetry Provides New Insights into the Ecology of Smallmouth Bass in Eastern Lake Ontario
Smallmouth Bass (Micropterus dolomieu) are a top predator native to the Laurentian Great Lakes, with a wide distribution in North America. Our understanding of Smallmouth Bass ecology is extensive, although primarily based on research from smaller inland lakes, rivers, and reservoirs. In Lake …
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Zur Rekonstruktion historischer Biodiversität aus archivalischen Quellen: Das Beispiel des Oderbruchs (Brandenburg) im 18. Jahrhundert
… Da der Hecht in Süßgewässern sowohl Top-Predator als auch Indikatorart repräsentiert, lassen Angaben zu seiner Häufigkeit Rückschlüsse auf die Zusammensetzung und Biomasse der Fischartengemeinschaft, als auch auf hiermit verknüpfte Parameter der Biodiversität (z. B. Habitatdiversität) …
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Effects of a Large-scale Habitat Enhancement Project on Largemouth Bass Behavior, Feeding, and Growth in Grand Lake, Texas
… structural features, may increase production of top predator sportfish populations by providing environmental conditions favorable for foraging that facilitates increases in growth.</p>
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Behavioural Ecology of Lake Trout: From Movement Ecology to Bioenergetics
… of Lake Trout (Salvelinus namaycush), a top predator fish, in four lakes that differ in the prey community that support them. The study was completed using a relatively new telemetry-transmitter that measures acceleration on two axes of the fish body; providing an added possibility for …
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EFFECTS OF ABIOTIC STRESS AND PREDATOR REFUGE ON TERRESTRIAL PREDATOR-PREY INTERACTIONS
… reduces the importance of predation because predators are more vulnerable to stress than prey, but this hypothesis has not been well-tested in terrestrial systems. The effect of refuge from stress on predation level has been studied even less, particularly in terrestrial systems. My research …
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Predicting ecological impacts of climate change and species introductions on a temperate chalk stream in Southern Britain - a dynamic food web model approach.
… after the removal of important prey nodes and top predators, no catastrophic shift was observed and, consequently, no keystone species were identified. Impacts of species introductions were assessed by adding representative model species to the food web. The largest impact was observed after …
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Assessing the effect of feather wear on carbon and nitrogen stable isotope ratios, and the use of stable isotopes to determine predator diets in the Namibian Islands marine protected area
The stable isotope (SI) approach is widely used in ecological research to tackle problems such as delineating food web structure or tracing the migratory origins of various organisms. This thesis first tested the widely accepted assumption that SI ratios are fixed in an inert tissue, and then used …
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Contemporary Assessment of Benthic Macroinvertebrates and Fish Interaction in the Truckee River, NV
… variables. In chapter 2, the competitive and predatory interactions between native and non-native fishes were examined. Diet analysis revealed younger age-class salmonid diets significantly overlap as species selected similar prey items. A bioenergetics model predicted brown trout, the top …
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Investigating the foraging ecology of black guillemots Cepphus grylle in relation to tidal stream turbines and marine protected areas
… foraging habitat for several species of marine top predator. This habitat is potentially vulnerable to alteration from the construction of tidal stream turbines. These turbines have been installed in the north of Scotland, with several hundred more planned. Tidal turbines may affect inshore …
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Caracals as sentinels for metal exposure in a human-transformed landscape
… and human health. As urbanisation increases and top predators are forced to utilise more urban spaces, they will likely be exposed to more toxic heavy metals and metalloids. As secondary and tertiary consumers, terrestrial carnivores may be at increased risk of metal exposure through …
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Seasonal and spatial patterns in nitrogen cycling and food web interactions in Lake Taupō New Zealand
… trout (Oncorhynchus mykiss: Salmonidae), the top predator in the Taupō system, is managed through a regulated recreational fishery. Coincident with a period of declining water quality between 1995 and 2005, the trout in Lake Taupō underwent a drastic decline in abundance and individual size. …
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