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 37 for “"tortoises"”.
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Influence of Diet on Growth and Health of Captive Hatchling Gopher Tortoises (Gopherus polyphemus)
<p>Accelerated growth in tortoises has traditionally been associated with potential health risks, however empirical evidence in the literature is lacking. In captivity, growth rates of tortoises are generally expected to exceed those of natural populations and the main cause is probably due to …
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Understanding predation of tortoises by nesting Pied Crows (Corvus albus) in western South Africa
… have come observed accounts of large numbers of tortoises being found depredated under Pied Crow nests, raising concerns over their impact on tortoises in these areas. Southern Africa has the richest biodiversity of tortoises in the world and a high rate of endemism. The endemic species are …
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Patterns in the Presence of Respiratory Tract Mycoplasmas in Four Species of North American Tortoises
… tract disease (URTD) in some species of tortoises. Here, we sought to determine the presence and frequency of these bacteria among four North American tortoise species: Gopherus polyphemus (gopher tortoise), G. berlandieri (Texas tortoise), G. morafkai (Sonoran desert tortoise), and G. …
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ENVIRONMENTAL GEOMETRY IN FISHES AND TORTOISES: EFFECT OF LANDMARKS, BEHAVIOURAL METHODOLOGIES, AND SENSORY CHANNELS ON SPATIAL REORIENTATION
… environmental geometry and landmarks in fish and tortoises (Chapter 2), the studies were carried out within several apparatuses, that is, a rectangular opaque arena or two different sized square opaque arenas or a transparent square arena, with conspicuous or local landmarks: Study 1, Conspicuous …
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A Comparison of Movements and Burrow Usage Between Indigenous and Relocated Gopher Tortoises (Gopherus polyphemus) in a Fall Line Sandhills Community
… indigenous to the relocation site) adult gopher tortoises {Gopherus polyphemus) were followed during the late spring, summer and early autumn in Talbot County, Georgia. The objectives of this study were to determine whether relocated gopher tortoises developed fidelity to a relocation site, and …
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Maternal Effects and Offspring Behavior: Potential Contributors to the Lack of Recruitment in Mississippi Gopher Tortoises (<i>Gopherus polyphemus</i>)
… hatchlings. Overall, the poor survival of gopher tortoises may be more strongly linked to environmental variables such as soil structure than physiological ones.</p>
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Seasonal variation in population location of the Galapagos tortoise, geochelone elephantopus vandenburghi, on Volcan Alcedo, Isabela Island, Galapagos archipelago
<p>Twenty tortoises, 10 adult males and 10 adult females, were tagged with radio transmitters. Numbers were painted on each carapace to aid in visual sighting. The tortoises were released, and their movement was monitored over a one year period.</p> <p>The percent recovery of tagged tortoises along …
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The genes must flow: using movement ecology to understand connectivity of Mojave desert tortoise (Gopherus agassizii) populations in altered landscapes
… I study the movement ecology of Mojave desert tortoises to understand how natural and anthropogenic features contribute to patterns of connectivity in the species. Corridors are important areas of a landscape that allow movement of animals between population centers through areas of unsuitable …
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Parasite Burden and Potential Virus Exposure in the Gopher Tortoise <em>(Gopherus polyphemus)</em>
… To assess this hypothesis, a survey of gopher tortoises from areas in southeastern Georgia where EEEV is present was conducted from May 2001 to August 2002. In this survey, tortoise blood samples were tested for the presence of antibodies to EEEV, and blood-borne, intestinal, and ectoparasite …
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Conservation Genetics of Threatened Gopher Tortoises, <i>Gopherus polyphemus</i>: An Assessment of Genetic Variation and Parentage in Two Populations in South Mississippi
<p>Despite the protection of gopher tortoises, <em>Gopherus polyphemus</em>, in the western portion of their range for over twenty years, populations of the De Soto National Forest (DNF) in southern Mississippi experience low recruitment and lower hatching success than populations in the eastern …
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Habitat use and activity patterns of Gopher Tortoises (Gopherus polyphemus) inhabiting military test ranges and forested sandhills at Eglin Air Force Base, Florida
… sub-populations on base are small, and many tortoises currently inhabit treeless military testing and training ranges (test ranges) rather than typical forested sandhill. My objectives were therefore to identify factors that may have been influencing use of test ranges as habitat by gopher …
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Nachweis von Salmonella spp. bei Landschildkröten
… procedure for detecting salmonellas in feces of tortoises should be established. First of all a survey of occurrence of salmonellas in reptiles and their importance for reptiles as well as for man is given. Next an appropriate incubation temperature for multiplying salmonellas of reptilian origin …
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Tortoise mortalities along fences in the southeastern Karoo, South Africa
… practices. Recent studies found that leopard tortoises (Stigmochelys pardalis) are more prone to dying from electrocution along electric fences than any other taxa. However, no studies have quantified tortoise mortality along non-electric fences or assessed the impact of fence structure. With …
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Ecology and morphology of the Kalahari tent tortoise, Psammobates oculifer, in a semi-arid environment
… habitat, morphology and ecology of Kalahari tent tortoises over 13 months in semi-arid Savanna at Benfontein farm, Northern Cape Province, South Africa. In order to allow continuous monitoring of individuals, I attached radiotransmitters to males and females, split equally between two habitats, …
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Seasonal Variation in Desert Tortoise Immune Function
… cell numbers in a colony of captive, healthy tortoises. Bacteriocidal assays measured the ability of constitutive natural antibodies and complement proteins to kill a standard strain of Escherichia coli. Ratios of heterophils to lymphocytes were used to infer relative levels of chronic stress …
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Home Range, Reproduction, and Habitat Characteristics of the Female Gopher Tortoise (Gopherus Polyphemus) in Southeast Georgia
… Army Reserve (FSAR) in southeast Georgia. Tortoises were studied in four sectors or regions on Ft. Stewart that contain the longleaf pine/wiregrass ecosystem. Vegetation characteristics were consistent between the different areas that tortoises inhabited. Soil types were similar between …
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Effects of Habitat Quality on Reproduction in Two Georgia Populations of Gopherus Polyphemus
… affecting adult size and age to sexual maturity? Tortoises were captured by bucket trapping and hand trapping. Radio-graphs were used to obtain information about female body size, clutch size and egg size. In order to assess the effect of habitat quality on tortoises, hatchlings from both …
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Determination of the Presence of <i>Rickettsia</i> Spp. and <i>Borrelia</i> Spp. Carried by Tortoise Ticks from Madagascar
… were removed from three species of Malagasy tortoises, <em>Astrochelys</em> <em>yniphora</em>, <em>A. radiata</em>, and <em>Pyxis arachnoides</em> (comprising two subspecies <em>P. a. arachnoides</em> and<em> P. a. oblonga</em>), between 2012 and 2015. The ticks were presumed to be from the …
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Spatial Ecology of the Desert Tortoise: Sampling Frequency and Biological Influences
… an intensive sampling regime. This suggests that tortoises may require more land than previously thought. Males and females demonstrated very different patterns of space and burrow use, suggesting these variables affect estimates for each sex differently. I conclude that a combination of these …
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Gopher tortoise nest-site selection at burrows and the influence of nest environment on hatching success
… predictors of nest presence at burrows, with tortoises in the sites nesting at burrows with lower understory and canopy cover. Furthermore, there was an interaction between the understory vegetation and canopy cover effects, where the effect of understory cover decreased as canopy cover …
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