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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.
11

The role of gopher tortoise (Gopherus polyphemus) burrows in shaping herpetofaunal diversity in the sandhills of southeast Georgia

Gaskell, Amy Dawn. January 2007 (has links) (PDF)
Thesis (M.S.)--Georgia Southern University, 2007. / "A thesis submitted to the Graduate Faculty of Georgia Southern University in partial fulfillment of the requirements for the degree Master of Science." In Biology, under the direction of Lance D. McBrayer. ETD. Electronic version approved: December 2007. Includes bibliographical references (p. 42-46) and appendix.
12

Bone growth strategies and skeletochronological age estimates of desert tortoise (Gopherus agassizii) populations /

Curtin, Amanda Jane. Spotila, James R. January 2006 (has links)
Thesis (Ph. D.)--Drexel University, 2006. / Includes abstract and vita. Includes bibliographical references (leaves 167-179).
13

Ecological genetics of the Mojave desert tortoise

Hagerty, Bridgette E. January 2008 (has links)
Thesis (Ph. D.)--University of Nevada, Reno, 2008. / "December, 2008." Includes bibliographical references. Online version available on the World Wide Web.
14

How elusive behavior and climate influence the precision of density estimates and desert tortoise populations

Inman, Richard D. January 2008 (has links)
Thesis (M.S.)--University of Nevada, Reno, 2008. / "May 2008." Includes bibliographical references. Online version available on the World Wide Web.
15

The physiological effects of relocation on gopher tortoises (Gopherus polyphemus)

Kahn, Paula Faith, Mendonça, Mary T. January 2006 (has links) (PDF)
Dissertation (Ph.D.)--Auburn University, 2006. / Abstract. Vita. Includes bibliographic references.
16

Pre- and post-copulatory sexual selection in the tortoise beetle Acromis Sparsa (Coleoptera Chrysomelidae)

Trillo, Paula Alejandra. January 2008 (has links) (PDF)
Thesis (Ph.D.) -- University of Montana, 2008. / Title from author supplied metadata. Description based on contents viewed on July 15, 2009. Includes bibliographical references.
17

Blood cell histology of Homopus areolatus: effects of season and cohort

Sparks, Sharna January 2015 (has links)
Magister Scientiae (Biodiversity and Conservation Biology) / Homopus areolatus is an endemic terrestrial tortoise that resides in a Mediterranean type of climate, which is characterised by winter rainfall and mild winter temperatures. Within ectotherms, such as H. areolatus, physiological changes are elicited by changes in the ambient temperature. These physiological changes are evident in the blood profile of reptiles. I described the morphology of immature and mature erythrocytes, leukocytes as well as thrombocytes of H. areolatus. Additionally, I evaluated erythrocytes, leukocytes and thrombocytes to assess the effects of season and cohort on these cells. Blood samples were collected in 2000 and 2001 at Elandsberg Nature Reserve in the Western Cape from H. areolatus cohorts (female, male, juvenile) in all seasons (spring, summer, autumn, winter). Blood smears were made and stained with modified Giemsa stain. SigmaStat was used for all statistical analysis. Immature erythrocyte types within H. areolatus included basophilic rubricytes, polychromatophilic rubricytes and polychromatophilic erythrocytes. Upon my evaluation, I encountered evidence to suggest that small and large immature erythrocytes possibly developed from two distinctive lineages. Further research is required to discern which lineage gave rise to which immature erythrocyte type. Cohort had no effect upon immature erythrocytes. Erythropoiesis was most prevalent during winter and spring within H. areolatus. Aberrant features of erythrocytes appeared to be more prevalent during autumn, which signified the driest season with limited food and water. Mature erythrocytes play a huge role in oxygen transport and metabolism in individuals. Factors such as size and shape are relevant since small, mature, ellipsoidal erythrocytes transport oxygen more efficiently than large, spherical erythrocytes. In H. areolatus small, mature, ellipsoidal erythrocytes appeared to be most prevalent during spring and summer. During winter however, large, spherical erythrocytes appeared to be most prevalent. Thrombocytes and seven types of leukocytes were observed within H. areolatus, namely heterophils, lymphocytes, eosinophils, basophils, monocytes, plasma cells and azurophils. Among cohort and season heterophils were most prevalent overall, followed by lymphocytes and eosinophils respectively. Basophils, monocytes, plasma cells and azurophils were present but overall, were relatively few. H. areolatus appeared to be healthy, and leukocyte counts as well as its dimensions appeared to be in accordance with other reptilian studies. This study serves as the first baseline haematological reference forH. areolatus. The study forms the second of its kind on South African tortoises, only one other haematological study has been done namely, P. geometricus which is a sympatric species to H. areolatus.
18

Metabolic energy relations in the Eastern Cape Angulate Tortoise (Chersina Anguluta)

Setlalekgomo, Mpho Rinah January 2010 (has links)
The daily oxygen consumption (VO2) pattern, the effects of varying ambient temperatures, season and mass on the resting oxygen consumption (RVO2) of Chersina angulata of the Eastern Cape were investigated. The RVO2 was measured using flow-through respirometry and specific resting oxygen consumption (sRVO2) calculated. To determine the daily pattern in the VO2 of C. angulata, the tortoises were acclimated in an environmentally controlled room (ECR) to an ambient temperature of 26 ± 1°C and a light regime of 14 hours of light and 10 hours of darkness (14L:10D) for at least a week prior to the RVO2 measurements. The RVO2 was measured at a constant temperature of 26 ± 1°C, and at three different light regimes, namely: 14L:10D, constant darkness (DD) and constant light (LL). There were no significant effects of mass or gender on the sRVO2 of the tortoises used. Rhythms in the sRVO2 were detected under all three light regimes. The amplitudes of the rhythm were largest at 14L:10D, followed by DD and smallest at LL regime. The persistence of the rhythmic pattern under constant conditions suggests the existence of an endogenous circadian rhythm in the sRVO2 for adult C. angulata. To test for the effect of ambient temperature on the sRVO2 of adult C. angulata, the tortoises were acclimated to 22 ± 1°C and a 14L:10D light regime prior to the RVO2 measurements. RVO2 was measured at eight experimental temperatures; 14°C, 18°C, 22°C, 26°C, 30°C, 35°C, 38°C and 40°C. The sRVO2 was not influenced by gender and increased with experimental temperatures, but this did not happen consistently over the whole range of temperatures tested. A plateau, possibly a thermal preferendum zone, was detected within the temperature range of 26 - 38°C. Determination of seasonal effect on the sRVO2 of adult C. angulata was accomplished by acclimating tortoises to standard summer and winter conditions. Seasonal effects were tested in the appropriate seasons. Winter experiments were conducted in winter and summer experiments conducted in summer. The RVO2 was measured at experimental temperature 14°C, 18°C and 22°C. In addition RVO2 of iv winter-acclimated tortoises was also measured at 10°C. The sRVO2 increased significantly with increasing temperature within the temperature range tested. No distinct pattern was observed in the seasonal acclimation of adult C. angulata. The metabolic rate-temperature curves of the summer and the winter-acclimated tortoises cross each other. Season and temperature had no significant effects on the mass-scaling exponent of the sRVO2. The exponent ranged from 0.48 to 0.73 within the temperature range of 22 - 38°C. Below and above this temperature range, the exponent ranged from 1.47 to 1.67. An inverse relationship was observed between sRVO2 and body mass over the temperature range of 22 - 38°C. At 14°C and 18°C, sRVO2 increased with body mass, while at 10°C and at 40°C the slope was 1.01.
19

Investigating vertebrate relationships of the south Florida gopher tortoise: a study of vertebrate species within scrub, pine rockland, coastal hammock and grassland habitats

Unknown Date (has links)
The gopher tortoise is a keystone species that creates networks of underground burrows that are home to an additional 350 species, where 60 are vertebrates. Vertebrates have been shown to differ between habitat types and seasonally, but limited information is known about vertebrate associates in our region. This study was one of the first to investigate this in our region of south Florida. This study was designed to investigate factors that may affect the presence of vertebrates at gopher tortoise burrows. Camera data was collected to determine vertebrate presence and if specific vertebrate groups elicit a territorial response from the tortoise, while habitat vegetation surveys and weather data were collected to evaluate seasonality. Statistical analysis showed variation in vertebrate presence both seasonally and by habitat type. Few territorial interactions were observed overall. This study acts as a starting point to increase our understanding of local tortoise populations. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2021. / FAU Electronic Theses and Dissertations Collection
20

Interferência da variação sazonal de fatores ambientais no perfil hematológico e bioquímico metabólico de 'Chelonoidis carbonarius' /

Cornacini, Fernando Henrique January 2020 (has links)
Orientador: Claudia Regina Bonini-Domingos / Resumo: O “jabuti-piranga” (Chelonoidis carbonarius) é um jabuti brasileiro, amplamente distribuído entre os estados do Nordeste, ocorrendo em áreas de Cerrado e campo aberto, mas também presente em recintos de zoológicos e aquários, distribuídos por todo o território nacional. São animais ectotérmicos, cujo metabolismo e fisiologia são influenciados por condições ambientais (como temperatura, umidade relativa da atmosfera e luminosidade) em magnitudes superiores aos dos animais endotérmicos, como aves e mamíferos, por exemplo. O atual trabalho tem por objetivo avaliar como esses fatores ambientais influenciam no perfil hematológico e bioquímico de “jabuti-pirangas” em cativeiro durante o período de um ano. Foi observado que machos e fêmeas diferiram no perfil hematológico, em que os primeiros apresentaram maiores valores para hematócrito, hemoglobina e eritrócito; enquanto que no perfil bioquímico, machos obtiveram maiores valores para glicose e as fêmeas para colesterol e triglicérides. Entre os meses do ano, foi possível observar menores valores para concentração de hemoglobina circulante e correspondentes índices hematimétricos nos meses de outubro e dezembro; enquanto que a concentração de colesterol e triglicérides teve aumento significativo em dezembro e junho, para machos e apenas em dezembro, para as fêmeas. Foi possível concluir que: a variação sazonal dos fatores ambientais influencia diretamente nos parâmetros hematológicos, reduzindo a concentração de hemoglobinas circul... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The “red-footed tortoise” (Chelonoidis carbonarius) is a Brazilian tortoise, widely distributed among the states of the Northeast, occurring in areas of Cerrado and open fields, but also present in enclosures of zoos and aquariums, distributed throughout the national territory. They are ectotermal animals, whose metabolism and physiology are more influenced by environmental conditions (such as temperature, relative humidity and luminosity) than they are in endothermic animals, such as birds and mammals, for example. The aim of the current study is to evaluate how these environmental factors influence the hematological and biochemical profile of “redfooted tortoises” in captivity during the period of one year. It has been observed that males and females differed in the hematological profile, in which the former had higher values for hematocrit, hemoglobin and erythrocyte; whereas in the biochemical profile, males obtained higher values for glucose and females for cholesterol and triglycerides. Between the months of the year, it was possible to observe lower values for circulating hemoglobin concentration and corresponding hematimetric indices in the months of October and December; while the concentration of cholesterol and triglycerides increased significantly in December and June, in males and only in December, in females. It was possible to conclude the following: the seasonal variation of the environmental factors directly influences the hematological parameters, reducing t... (Complete abstract click electronic access below) / Mestre

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