Dissertations / Theses: 'Giraffe'

1

Van, Sittert Sybrand Jacobus. "Ontogenetic allometry of the postcranial skeleton of the giraffe (Giraffa camelopardalis) with application to giraffe life history evolution and palaeontology." Thesis, University of Pretoria, 2015. http://hdl.handle.net/2263/53314.

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Giraffes (Giraffa camelopardalis) have evolved into a unique and extreme shape. The principle determinant of its shape is the skeleton and the overarching theme of the study was to describe how this shape is achieved throughout ontogeny. Accordingly, the study had three main objectives: 1) To describe the growth of the giraffe postcranial skeleton allometrically, 2) To interpret the allometric patterns described in an evolutionary and functional sense and 3) To reconstruct the size and shape of the extinct Giraffa sivalensis using, if feasible, allometric equations obtained in this study. Secondary objectives were to a) establish if sexual dimorphism was evident in G. camelopardalis and b) determine if growth patterns in the foetus differed from those in postnatal G. camelopardalis. Data were collected from giraffes culled as part of conservancy management in Zimbabwe. The sample included 59 animals from which vertebral dimensions were taken in 48 animals and long bone dimensions in 47 animals. Body masses ranged from 21 kg to 77 kg in foetuses and 147 kg to 1412 kg postnatally, representing 29 males and 30 females. In addition to body mass, external body dimensions were recorded from each animal. Each vertebra and unilateral long bone was dissected from the carcasses and cleaned, after which dimensions were measured with a vernier calliper, measuring board or measuring tape. Vertebral dimensions measured included body (centrum) length, height and width as well as vertebral spinous process length. Long bone dimensions included length, two midshaft diameters and circumference. Allometric equations (y=bxk) were constructed from the data, with special interest in the scaling exponent (k) to illustrate regions of positively allometric, isometric or negatively allometric growth. In the first series of analyses the growth patterns of the components of the postcranial axial skeleton were analysed. The adaptations in vertebral growth to create and maintain extraordinary shape were identified as disproportionate elongation of the cervical vertebrae after birth, increasing cross sectional diameters of the cervical vertebrae from cranial to caudal and positively allometric spinal process growth. The theory of sexual selection as a driver for neck elongation in giraffes was brought into question by showing that male and female vertebral elongation rates are similar relative to increases in body mass. The second series of analyses described the growth pattern of the long bones of the appendicular skeleton. The allometric exponents seemed unremarkable compared to the few species described previously, and it was shown that the giraffe appendicular skeleton does not elongate in the dramatic way the neck does. Limbs at birth, after lengthening with positive allometry in utero, are already elongated and slender in shape and a further increase in the gracility of the bones is either not possible or not desirable. This result implies that it is neck elongation rather than leg elongation that is the dominant factor in the evolution of the giraffe shape. Nevertheless, the front limb bones and especially the humerus may show responsiveness to increasing high loads and/ or bending moments, which may be caused by the neck mass which increases with positive allometry, or with behaviours such as splaying the forelegs during drinking. In the third component of the study ontogenetic allometric equations in extant giraffes were applied to the remains of an extinct giraffid, G. sivalensis. The procedure was unusual as it employed ontogenetic regressions instead of the more commonly used interspecific regressions. The appropriateness of each equation to estimate body mass was evaluated by calculating the prediction error incurred in both extant giraffes and okapis (Okapia johnstoni). It was concluded that, due to body shape, ontogenetic equations were adequate and perhaps preferable to interspecific equations to estimate proportions in Giraffa species. This analysis showed that G sivalensis was smaller than extant giraffes and weighed around 400 kg (range 228 kg 575 kg), with a neck length of about 147 cm and a height of 390 cm. There may be evidence of sexual dimorphism in this species, with males being about twice the body weight of females. However, if sexual dimorphism was not present and all the bones were correctly attributed to this species, then G. sivalensis had a slender neck with a relatively stocky body. In conclusion, this study established ontogenetic regression equations for the skeleton of an animal of which the body shape seems to be at the extreme limits of mammalian possibility. The value of the current study lies especially in its sample size and quality, which included an unprecedented number of giraffe body masses, vertebral and long bone dimensions. This dataset had applications in the giraffe s evolutionary biology, palaeontology and even ecology. Future studies still need to compare the findings from giraffe growth with similar data from other taxa, especially those with long legs and necks. Specifically, it would interesting to determine if positively allometric neck growth combined with isometric leg growth is found in other mammalian species. In addition, the strength of giraffe long bones and vertebrae needs to be investigated with more accuracy using parameters like second moment of area. Lastly, further palaeontological studies on other giraffid sizes are necessary to validate the current and future interpretations of fossil giraffid findings.
Thesis (PhD)--University of Pretoria, 2015.
tm2016
Production Animal Studies
PhD

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2

Fennessy, Julian Thomas. "Ecology of desert-dwelling giraffe Giraffa camelopardalis angolensis in northwestern Namibia." Thesis, The University of Sydney, 2004. http://hdl.handle.net/2123/910.

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The population size and range of giraffe Giraffa camelopardalis have been greatly reduced in Africa in the past century, resulting in geographical isolation of local populations and some herds surviving at the edge of the species’ preferred range. Numerous factors have contributed to these declines, but historical analysis indicates that habitat loss and fragmentation, human encroachment, disease and poaching are the main threatening processes. These processes can be expected to continue to impact on giraffe populations, particularly as human populations grow and needs for land and resources increase. This study used field data and laboratory analyses to investigate the taxonomy, behaviour and ecology of desert-dwelling giraffe Giraffa camelopardalis angolensis in the northern Namib Desert. This population resides at the extreme of the giraffe’s range. My research also complements the community-based natural resource management (CBNRM) program of the Namibian government, and provides baseline data on the current population status and structure of giraffe in the Kunene Region. The field data, genetic, habitat and forage samples used in this study were collected by myself and a number of research assistants over a period of two years (2001 to 2003), following preliminary research that I undertook between 1999 and 2001. Laboratory analysis of genetic samples was conducted by Dr R. Brenneman and his team at Henry Doorly Zoo, Omaha, NB., as well as by Mr D. Brown at UCLA, CA. Mr W. Gawa!nab and his team at the agricultural laboratory, Ministry of Agriculture, Water and Rural Affairs, Namibia, conducted chemical analyses on plant samples that form part of the giraffe’s diet. The genetic architecture of Namibian giraffe was investigated, including the samples from the desert-dwelling giraffe of the northern Namib Desert and giraffe from Etosha National Park. The results were compared with genetic profiles of giraffe subspecies throughout Africa, but in particular with G. c. giraffa which is the currently-accepted nomenclature of the Namibian giraffe. Results indicated that the Namibian giraffe has five unique haplotypes and is genetically distinct from G. c. giraffa or any other extant subspecies; it is considered here, tentatively, to represent G. c. angolensis. Furthermore, the Namibian Abstract iv giraffe has been separated from other populations for an extended period. Some gene flow has occurred between the desert-dwelling and Etosha NP giraffe population, and can be attributed to recent translocations between these regions. Within the study region, a sharing of haplotypes between three studied subpopulations indicated gene flow among giraffe throughout the northern Namib Desert, and this was confirmed by field-based monitoring. Taken together, these findings suggest that Namibian giraffe should be viewed as important for the conservation of overall genetic variation within Giraffa camelopardalis, although further investigation into the taxonomy of the Namibian form is warranted. Following these findings, I then investigated the behaviour and ecology of the desert-dwelling giraffe. As no previous study has been published on the ecology of G. c. angolensis, there is an information gap in our knowledge of this subspecies. One hundred and fifty six giraffe were identified individually using field-based identification methods and digital imagery. An assessment of the population structure and dynamics indicated marked variation in numbers, sex and age structure, herd structure and densities between three study areas. These variations possibly arose from differences in study area size, aridity, availability of forage and human impacts. I also investigated levels of associations between giraffe within the population using a simple ratio technique, and observed that increased association occurred in smaller populations; there appeared to be a matrilineal social structure. In one bull-biased population, a higher degree of association between bulls was observed compared to bulls in the other two populations. To gain further insight into the distribution and range of giraffe, I collected GPS locations from a combination of field-based monitoring and GPS satellite collars. The GPS satellite collars were the first trial of this technology on giraffe in Africa. Using Range Manager, a MapInfo animal location analysis extension program, I estimated 100% and 95% minimum convex polygon for daily, monthly and annual home range sizes of giraffe in the northern Namib Desert. Giraffe were observed to have large home ranges, with the largest individual range for a bull, Africa-wide, being recorded in this study. Large home ranges correlated with low population density, reduced diversity of forage and, in bulls, increased search areas for receptive cows. Giraffe movements occurred predominantly along riparian woodlands, although seasonal use of other habitats was recorded. Observations Abstract v Abstract vi and data from four GPS satellite-collared giraffe provided high-resolution data on daily movements, and indicated a pattern of highly biphasic movement behaviour that correlated with ambient temperatures. Diurnal activity budgets varied between the sexes, with cows spending more time feeding and resting, while bulls walked and ruminated more frequently. Juveniles rested more often than other giraffe. Seasonal variation in activity budgets was evident, perhaps reflecting use of an energy maximiser strategy for cows and an energy minimiser strategy for bulls. The establishment of artificial water points in the Hoanib River during the study period appeared to alter the seeming independence of giraffe on water in the northern Namib Desert, and also resulted in small-scale shifts in use of the riparian woodland by elephant. To investigate the diet of giraffe, I observed animals feeding in the field and also carried out laboratory analyses of the chemical content of preferred plant species. Seasonal changes in the abundance, moisture and protein content of available food plants correlated with shifts in the diet of giraffe. Giraffe impacted on their preferred forage source, Faidherbia albida, causing distinct structural changes in the individual plants and the F. albida population. This impact, combined with elephant damage and seasonal flood events, has resulted in a shift in the age structure and dynamics of the F. albida population over the past two decades. Finally, I present a brief overview on the history of conservation and management in the Kunene Region. The established CBNRM program provides a baseline for future wildlife conservation and management, of which the desert-dwelling giraffe could be an integral component for non-consumptive tourism. Long-term research on the population’s status, range, behaviour, social structure, habitat requirements, and ecology would help to provide a better understanding of the giraffe’s adaptation to the arid environment, while focussed legislation would enable increased control of communal lands and continue to benefit community-based conservancies.

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3

Fennessy, Julian Thomas. "Ecology of desert-dwelling giraffe Giraffa camelopardalis angolensis in northwestern Namibia." University of Sydney, 2004. http://hdl.handle.net/2123/910.

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Doctor of Philosophy
The population size and range of giraffe Giraffa camelopardalis have been greatly reduced in Africa in the past century, resulting in geographical isolation of local populations and some herds surviving at the edge of the species’ preferred range. Numerous factors have contributed to these declines, but historical analysis indicates that habitat loss and fragmentation, human encroachment, disease and poaching are the main threatening processes. These processes can be expected to continue to impact on giraffe populations, particularly as human populations grow and needs for land and resources increase. This study used field data and laboratory analyses to investigate the taxonomy, behaviour and ecology of desert-dwelling giraffe Giraffa camelopardalis angolensis in the northern Namib Desert. This population resides at the extreme of the giraffe’s range. My research also complements the community-based natural resource management (CBNRM) program of the Namibian government, and provides baseline data on the current population status and structure of giraffe in the Kunene Region. The field data, genetic, habitat and forage samples used in this study were collected by myself and a number of research assistants over a period of two years (2001 to 2003), following preliminary research that I undertook between 1999 and 2001. Laboratory analysis of genetic samples was conducted by Dr R. Brenneman and his team at Henry Doorly Zoo, Omaha, NB., as well as by Mr D. Brown at UCLA, CA. Mr W. Gawa!nab and his team at the agricultural laboratory, Ministry of Agriculture, Water and Rural Affairs, Namibia, conducted chemical analyses on plant samples that form part of the giraffe’s diet. The genetic architecture of Namibian giraffe was investigated, including the samples from the desert-dwelling giraffe of the northern Namib Desert and giraffe from Etosha National Park. The results were compared with genetic profiles of giraffe subspecies throughout Africa, but in particular with G. c. giraffa which is the currently-accepted nomenclature of the Namibian giraffe. Results indicated that the Namibian giraffe has five unique haplotypes and is genetically distinct from G. c. giraffa or any other extant subspecies; it is considered here, tentatively, to represent G. c. angolensis. Furthermore, the Namibian Abstract iv giraffe has been separated from other populations for an extended period. Some gene flow has occurred between the desert-dwelling and Etosha NP giraffe population, and can be attributed to recent translocations between these regions. Within the study region, a sharing of haplotypes between three studied subpopulations indicated gene flow among giraffe throughout the northern Namib Desert, and this was confirmed by field-based monitoring. Taken together, these findings suggest that Namibian giraffe should be viewed as important for the conservation of overall genetic variation within Giraffa camelopardalis, although further investigation into the taxonomy of the Namibian form is warranted. Following these findings, I then investigated the behaviour and ecology of the desert-dwelling giraffe. As no previous study has been published on the ecology of G. c. angolensis, there is an information gap in our knowledge of this subspecies. One hundred and fifty six giraffe were identified individually using field-based identification methods and digital imagery. An assessment of the population structure and dynamics indicated marked variation in numbers, sex and age structure, herd structure and densities between three study areas. These variations possibly arose from differences in study area size, aridity, availability of forage and human impacts. I also investigated levels of associations between giraffe within the population using a simple ratio technique, and observed that increased association occurred in smaller populations; there appeared to be a matrilineal social structure. In one bull-biased population, a higher degree of association between bulls was observed compared to bulls in the other two populations. To gain further insight into the distribution and range of giraffe, I collected GPS locations from a combination of field-based monitoring and GPS satellite collars. The GPS satellite collars were the first trial of this technology on giraffe in Africa. Using Range Manager, a MapInfo animal location analysis extension program, I estimated 100% and 95% minimum convex polygon for daily, monthly and annual home range sizes of giraffe in the northern Namib Desert. Giraffe were observed to have large home ranges, with the largest individual range for a bull, Africa-wide, being recorded in this study. Large home ranges correlated with low population density, reduced diversity of forage and, in bulls, increased search areas for receptive cows. Giraffe movements occurred predominantly along riparian woodlands, although seasonal use of other habitats was recorded. Observations Abstract v Abstract vi and data from four GPS satellite-collared giraffe provided high-resolution data on daily movements, and indicated a pattern of highly biphasic movement behaviour that correlated with ambient temperatures. Diurnal activity budgets varied between the sexes, with cows spending more time feeding and resting, while bulls walked and ruminated more frequently. Juveniles rested more often than other giraffe. Seasonal variation in activity budgets was evident, perhaps reflecting use of an energy maximiser strategy for cows and an energy minimiser strategy for bulls. The establishment of artificial water points in the Hoanib River during the study period appeared to alter the seeming independence of giraffe on water in the northern Namib Desert, and also resulted in small-scale shifts in use of the riparian woodland by elephant. To investigate the diet of giraffe, I observed animals feeding in the field and also carried out laboratory analyses of the chemical content of preferred plant species. Seasonal changes in the abundance, moisture and protein content of available food plants correlated with shifts in the diet of giraffe. Giraffe impacted on their preferred forage source, Faidherbia albida, causing distinct structural changes in the individual plants and the F. albida population. This impact, combined with elephant damage and seasonal flood events, has resulted in a shift in the age structure and dynamics of the F. albida population over the past two decades. Finally, I present a brief overview on the history of conservation and management in the Kunene Region. The established CBNRM program provides a baseline for future wildlife conservation and management, of which the desert-dwelling giraffe could be an integral component for non-consumptive tourism. Long-term research on the population’s status, range, behaviour, social structure, habitat requirements, and ecology would help to provide a better understanding of the giraffe’s adaptation to the arid environment, while focussed legislation would enable increased control of communal lands and continue to benefit community-based conservancies.

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4

Bredin, Ian Peter. "Phosphorus and calcium extraction from bone digestion in the rumen of sheep (Ovis aries)." Diss., Electronic thesis, 2006. http://upetd.up.ac.za/thesis/available/etd-05042007-180754/.

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5

Parker, Daniel Matthew. "The feeding biology and potential impact of introduced giraffe (Giraffa camelopardalis) in the Eastern Cape Province, South Africa." Thesis, Connect to this title online, 2004. http://eprints.ru.ac.za/48/.

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6

Cornelius, Andri Judith. "The management of extralimital giraffe (Giraffa Camelopardalis) in the mosaic thicket of Southern Cape, South Africa." Thesis, Nelson Mandela Metropolitan University, 2010. http://hdl.handle.net/10948/1345.

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The giraffe at Nyaru were found to be browsers who made little use of graze during the study period. They utilized a diversity of 20 browse species. Two species, Acacia karroo and Acacia cyclops, formed the bulk of the giraffe diet throughout the year. A definite seasonal dietary shift was evident. A. karroo was favoured in summer and autumn and formed the main food species in spring, summer and autumn. A. cyclops was favoured throughout the study, but its contribution to the diet increased during winter when less A. karroo was consumed. This seasonal shift is related to the deciduous nature of Acacia karroo. Although a seasonal shift in species contribution to giraffe diet has been observed in many other giraffe feeding studies, no studies on giraffe feeding have been done in the Mosaic Thicket of the southern Cape. The ecological browsing capacity for giraffe in thicket was estimated to be between 0.020 BU/ha and 0.095 BU/ha. The browsing capacity for giraffe at Nyaru, based on the available phytomass 2–5 m above the ground, was estimated using those species that formed the bulk of the giraffe diet, and amounted to 0.063 BU/ha. A maximum of three giraffe could thus be stocked on the 157 ha of suitable giraffe habitat on Nyaru. This stocking rate recommendation lies within the range commonly recommended by local consultants for giraffe introductions into the southern Cape. Their recommendations are, however, not based on quantitative assessments such as performed in this study. The recommendation of this study should not be applied as a fixed ecological capacity for giraffe in thicket, but should be seen as a starting point in the adaptive management cycle. Ongoing monitoring of parameters, such as herbaceous composition and phytomass; as well as the condition of key browse species, is strongly advocated. A. karroo was browsed significantly more and carried significantly fewer pods per tree at a heavily used site compared to a lightly used site. Heavy browsing thus appears to affect the reproductive success of A. karroo significantly. Fewer pods are likely to lead to lower regeneration and thus reduced density of A. karroo. Whether A. karroo will maintain its dominance within the thicket vii community in the long run will be related to how individual plants survive and reproduce and if some can escape from herbivory. Fewer G. occidentalis were clumped with other species at the heavily used site compared to the lightly used site. This could possibly be attributed to the fact that intense browsing pressure at the heavily used site caused protective clumps to be eaten away, thus exposing G. occidentalis to higher ungulate browsing. Previous studies have found that nurse shrubs protect G. occidentalis against ungulate browsing. G. occidentalis was browsed significantly more at the heavily used site compared to the lightly used site. There was a general trend of fewer fruits at the heavily used site compared to the lightly used site, while fruits were absent on G. occidentalis growing alone at the heavily used site. This suggests a negative effect of heavy browsing on plant reproductive success and emphasizes the importance of nurse plants for the successful recruitment and hence long term prevalence of G. occidentalis in Mosaic Thicket.

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7

Van, Schalkwyk Ockert Louis. "Bone density and calcium and phosphorus content of the giraffe (Giraffa camelopardalis) and African buffalo (Syncerus caffer) skeletons." Diss., University of Pretoria, 2004. http://hdl.handle.net/2263/28860.

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Apart from its slender appearance, four main factors lead to questions regarding the bone density, mineral content and morphology of the giraffe skeleton: X A rapid vertical growth rate ¡V especially in the neck and metapodials X Biomechanical considerations pertaining to the tall and slender shape of the skeleton X A proportionally larger skeleton in relation to body mass X A seemingly abnormal mineral balance in their diet with possible signs of mineral deficiency (i.e. osteophagia) In this study the skeleton of the giraffe was compared with that of the African buffalo with regards to bone density, skeletal calcium (Ca) and phosphorus (P) content and certain femoral and metacarpal morphological characteristics. The aim was to establish if, compared to buffalo, the features of the giraffe skeleton differed in any unique way. Fourteen similar bones or parts of bones were collected from carcasses of six adult giraffe bulls and nine adult buffalo bulls. These bones were cleaned, weighed and their volume determined through water displacement, from which their density could be calculated. Hereafter, Ca and P content were analysed in 10 bones from each carcass. Morphological characteristics of cross-sections from femoral and metacarpal shafts were also measured. No significant differences between the density or mineral content of bones in the two species could be found. In both species 19,5% Ca and 9,5% P were measured in defatted bone. Although similar in mineral concentration, the giraffe skeleton contains three times more absolute Ca and P, which translates into a 1,5-2-fold higher dietary requirement for these minerals compared to buffaloes. A gradation in the volume and weight of cervical vertebrae was also seen in giraffes. This could hold biomechanical advantage for the carriage and manoeuvrability of the long neck. Bone wall thickness of the giraffe femur and metacarpus is increased compared to buffaloes. This could hold biomechanical advantage for the slender legs that are subjected to increased vertical forces. Adequate Ca seems to be acquired through very specific browse selection, which seems to be of evolutionary origin, while the acquisition of adequate P seems to be critical and a possible cause for osteophagia. This study is the first of its kind in these species and therefore also provide valuable baseline data for future work in this field.
Dissertation (MSc (Veterinary Science))--University of Pretoria, 2004.
Production Animal Studies
unrestricted

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8

Reeves, Max. "Implementing GLib CollectionTypes in the Giraffe Library." Thesis, Uppsala universitet, Institutionen för informationsteknologi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-324974.

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Only a few graphical user interface (GUI) toolkits for Standard ML are available to thepublic and they are in general old and do not seem to be actively maintained. Theinability to create modern GUIs can be seen as one of the greater drawbacks ofapplication development in Standard ML (SML). The Giraffe library provides a Poly/MLand MLton interface for GObject based C libraries that have GObject introspectionrepository information available, using language bindings. Development of the Giraffelibrary is far gone, but currently there is no support for GLib collection types. Thisthesis presents a simple implementation of support for the GSList collection type forthe Giraffe library, as well as performance results of a number of different approachesto the conversion between GSLists and SML lists.

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9

Seymour, Russell. "Patterns of subspecies diversity in the giraffe, Giraffa camelopardalis (L. 1758) : comparison of systematic methods and their implications for conservation policy." Thesis, University of Kent, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.275008.

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This thesis examines the subspecific taxonomic status of the giraffe and considers the role of formal taxonomy in the formulation of conservation policy. Where species show consistent. geographically structured phenotypic variation such geographic patterns may indicate selective forces (or other population-level effects) acting . upon local populations. These consistent geographic patterns may be recognised formally as subspecies and may be of interest in single or multi-species biodiversity or biogeography studies for delimiting areas of conservation priority. Subspecies may also be used in the formulation of management policies and legislation. Subspecies are, by definition, allopatric. This thesis explicitly uses methodology of systematic biology and phylogenetic reconstruction to investigate patterns of variation between geographic groups. The taxonomic status of the giraffe is apposite for review. The species provides three independent data sets that may be analysed quantitatively for geographic structure; pelage patterns, morphology and genetics. Museum specimens. grouped according to geographic origin, were favoured for study as more than one type of data was often available for an individual. Population aggregation analysis of forty pelage pattern characters maintained six separate subspecies, while agglomerating some neighbouring populations into a subspecies. A 'traditional' morphometric approach, using multivariate statistical analysis of adult skull measurements, was complemented by a geometric morphometric approach; landmarkrestricted eigenshape analysis. Four morphologically distinct groups were recognised by both morphological analyses. Phylogenetic analysis of mitochondrial DNA control region sequences indicates five major cIades. Nested cIade analysis identifies population fragmentation, range expansion and genetic isolation by distance as contributing to the genetic structure of the giraffe. The results of the analyses show remarkable congruence. These results are discussed in terms of the formulation of conservation policy and the differing requirements of'blological and legal classification systems. The value of a formal taxonomic framework to the recognition, and subsequent conservation, of biodiversity is emphasised.

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10

Salvatore, Ludovica. "Lignocellulose-degrading enzymes from the gut of giraffe and zebra." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2021.

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In the present thesis the gut microbiome of large herbivores was targeted to identify the presence of active lignocellulose-degrading enzymes. As there are essentially no protocols for the cultivation of these microbiomes, which may differ from animal to animal, this study aimed at developing a reliable protocol for their cultivation, using the giraffe and zebra as target animals in order to compare a foregut and hindgut fermenter. Gut microbiome inocula were incubated with pure substrates (either cellulose, hemicellulose or lignin) or animal feed. Fermentation kinetics in terms of biogas and volatile fatty acids (VFAs) production, cell count, pH analysis and production of biosurfactants and bio-emulsifiers were performed. Giraffe gut microbiomes were more active on hemicellulose than on other portions of lignocellulose. This may be due to the fact that the retention time of the ingesta is just 40 hours. This may suffice to access and break down hemicellulose, that is, the external matrix in the complex lignocellulose structure. As for the zebra, the gut microbiome was particularly active on the feed to which it was adapted rather than the pure substrates. In the second part of the experiments, the characterization of the enzymatic activity of the samples obtained at the end of the fermentation was performed to detect the presence of enzymes in the gut of the two animals through an initial calorimetric and chromatographic investigation by HPLC, followed by anion exchange column fractionation and SDS-Page analysis. The results obtained from the enzymatic characterization do not clearly identify an enzymatic activity in the gut microbiome of both animals. Changes to the original protocol are needed, such as, for example, a change in the enzyme concentration to be analyzed and the sampling times.

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11

Douda, Nikolaus. "The conditio humana and George Saiko's anthology Giraffe unter Palmen." Thesis, University of Reading, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.240184.

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12

Bashaw, Meredith J. "Social behavior and communication in a herd of captive giraffe." Diss., Available online, Georgia Institute of Technology, 2004:, 2003. http://etd.gatech.edu/theses/available/etd-04082004-180020/unrestricted/bashaw%5Fmeredith%5Fj%5F200312%5Fphd.pdf.

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13

Monson, Michael L. Jr. "The Effects of Increased Hay-Grain Ratio on Masai Giraffe Behavior, Health Indicators and Fecal Microflora Diversity." Cleveland State University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=csu1475530272039469.

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14

Kearney, Celeste. "Effects of dietary physical form and carbohydrate profile on captive giraffe." [Gainesville, Fla.] : University of Florida, 2005. http://purl.fcla.edu/fcla/etd/UFE0009468.

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15

Jacobs, Evert Philippus. "Diet and feeding effects of introduced giraffe in the Eastern Cape." Thesis, Nelson Mandela Metropolitan University, 2008. http://hdl.handle.net/10948/964.

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This study presents the results of a study on introduced giraffe diet and feeding effects within the Eastern Cape Province of South Africa. Five sites were selected over a moisture gradient from the mesic east to the arid west of the Eastern Cape to describe giraffe diet and provide baseline data for feeding effect experiments. At each site faecal samples were collected seasonally and diet composition determined by microhistological analysis. Plant species availability was measured using the point intersect method in order to compare plant availability to plant consumption to determine diet preferences. Giraffe diet across the sites showed a unimodal response to rainfall by utilising fewer species in drier areas where plant availability is low and increasing the number of species consumed as the rainfall increases. In higher rainfall areas, giraffe reduced the number of plant species fed upon because of the high availability of important species that reduces the need for a varied diet. Across all sites, plant availability was dominated by woody plant species (more than 90 percent at each site). A total of 57 plants species were recorded as being eaten across the five sites. Several PDI (Principle Diet Items) plant species (Acacia karroo, Schotia afra, Pappea capensis and Euclea undulata) were eaten across sites. Over all the sites, significantly preferred species were Asparagus striatus, Schotia latifolia, Asparagus suaveolens, Commelina benghalensis, Viscum rotundifolium, and Acacia cyclops. Acacia karroo, Schotia afra, Pappea capensis, Rhus crenata, A. tetracantha, and Grewia robusta were utilised in proportion to their availability. Euclea undulata, Rhus longispina and Putterlickia pyracantha were avoided. Feeding effects were tested by erecting exclosures around trees, covering one half of each tree. Ten trees were selected for these manipulative experiments which ran from September 2003 to February 2005. The number of branches, number of leaves, branch orders, branch diameter, branch length, leaf length and leaf width were measured for ten samples per side (enclosed vs. exposed) and analysed using a Wilcoxon matched pairs test and tested for effect size using Cohen’s d. Although no significant differences were detected between the sides measured, the effect size indicated differences in all measurements between sides ranging from low to moderate. Leaf length was greater on the outside of exclosures and showed a moderate difference between the sides in terms of the d-value with the p-value (0.059) tending towards significance. Although leaf width was higher on the inside of exclosures, it only showed a moderate difference for d with no statistical significance. Leaf area was higher on the inside of exclosures and tended to significance (p = 0.059) and similarly the d value indicated moderate differences between the sides in terms of effect size. Similarly branch length was higher on the inside of exclosures although not significantly, the p-value (0.07) approached significance. The effect size for branch length also showed a moderate difference between the sides. The number of branches and the number of leaves showed no statistical differences between the sides although the p-value (0.059) for the number of branches, as well as number of leaves (p = 0.07) approached significance. For both these variables, effect size showed a moderate difference. Giraffe showed diversity in their diet selection across sites but mainly fed upon available species. Some preferred species were however less available and this preference could possibly result in increased pressure on the selected plant species Exclosure experiments showed no significant differences in leaf and shoot characteristics although all measurements showed differences in terms of effect size meriting further investigation. It is concluded that giraffe impact on sites may be reduced if populations are properly managed however, high densities of giraffe could lead to similar vegetation impacts as observed in other areas where giraffe have been introduced and potentially change vegetation structure and plant community composition.

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Basu, Christopher Kumar. "The evolution of locomotor form and function in the giraffe lineage." Thesis, Royal Veterinary College (University of London), 2018. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.766331.

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17

Soutschka, Nadine. "Does tree size matter? : giraffe influence on African savanna ecosystem properties." Bachelor's thesis, University of Cape Town, 2010. http://hdl.handle.net/11427/25765.

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Trees alter the environment by affecting microclimate, soil properties and adding structural complexity to an otherwise single stratum system. It is known that the herbaceous understory of Savanna ecosystems is most productive at intermediate tree density, where the shade and nutrients from the tree are more influential than the competition with the tree. Tree density varies in savannas due to disturbances, such as fire and herbivory. Yet, disturbances do not only alter density but can affect entire tree structure. It has been found that chronic ungulate browsing influences whole tree size, as well as canopy size and shape. Giraffe in south of Kruger National Park browse heavily on Acacia nigrescens found on basalt-derived soils. I studied the influence of trees above the giraffe browse trap (>6 m) as opposed to trees in the browse trap (< 6 m) on savanna ecosystem properties. I compared grass biomass, soil moisture, soil organic matter, soil carbon and soil nitrogen beneath tall trees vs. short trees, as well as in the open vs. underneath trees. Ecosystem properties were estimated and compared between a giraffe impacted to a giraffe absent area. Giraffe impacted area overall yielded lower grass biomass, soil moisture, soil nitrogen and soil carbon. The consequence is a trophic cascade of events from increased giraffe decreasing fires and in tum increasing tree density and hence carbon sequestration. As giraffes replace a single large tree by several small trees, shows that their population size is key determinant of ecosystem properties.

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Saito, Miho. "The social and ecological significance of nursery groups in wild giraffe." Kyoto University, 2019. http://hdl.handle.net/2433/242651.

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付記する学位プログラム名: 霊長類学・ワイルドライフサイエンス・リーディング大学院
Kyoto University (京都大学)
0048
新制・課程博士
博士(理学)
甲第21613号
理博第4520号
新制||理||1649(附属図書館)
京都大学大学院理学研究科生物科学専攻
(主査)教授伊谷原一, 教授村山美穂, 教授平田聡
学位規則第4条第1項該当

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19

Neumann, Gaby. "Bestimmung von Sexualzyklus und Trächtigkeit mit Hilfe des Nachweises von Gestagenen im Kot von im Zoo gehaltenen Giraffen (Giraffa camelopardalis) und Spitzmaulnashörnern (Diceros bicornis)." Doctoral thesis, Universitätsbibliothek Leipzig, 2004. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-37516.

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Da die afrikanischen Spitzmaulnashörner in ihrer Heimat vom Aussterben bedroht sind, besitzt ihre Nachzucht in Zoologischen Gärten große Bedeutung. Zwar sind die Bestände der Giraffen in der Wildnis noch nicht besonders gefährdet, die Verlustrate dieser empfindlichen Tierart in menschlicher Obhut ist jedoch zu hoch. Die Gestagen-konzentrationen im Kot wurden bestimmt, um detailliertere Kenntnisse der Fortpflan-zungsphysiologie dieser beiden Spezies, die für eine erfolgreiche Reproduktion notwendig sind, zu erlangen. Die nichtinvasive Methode erwies sich als geeignet zur Überwachung der Fortpflanzung sowohl bei den Giraffen als auch den Spitzmaulnas-hörnern. Die Gestagenbestimmung im Kot erfolgte in 3 Schritten: Einwiegen des Kotes, Extraktion der Gestagene mit Hilfe von Methanol und ihre Bestimmung mittels Radioimmunoassay. Im methodischen Teil der Arbeit ergaben sich innerhalb einer Tierart (Giraffen, Spitzmaulnashorn und zusätzlich Damagazellen) nur geringfügige Schwankungen der Trockenmasse des Kotes von maximal 5 %, so dass sich auch bei unterschiedlichem Wassergehalt des Kotes ohne vorherige Trocknung der Proben gut vergleichbare Gestagenwerte in verschiedenen Kotproben der gleichen Tierart ermitteln lassen. Nach 24- bzw. 48-stündiger Lagerung bei Raumtemperatur waren im Kot von Giraffen und Nashörnern die Gestagenwerte im Vergleich zum sofortigen Einfrieren der Proben signifikant erhöht. Bei Nashörnern und Gazellen wurden nach längerer Lagerzeit (1 und 3 Monate) bei 20 °C keine signifikanten Veränderungen der niedrigen Gestagen-konzentrationen im Kot festgestellt. Im Gegensatz dazu zeigte sich bei Kotproben von Giraffen mit hohen Ausgangskonzentrationen eine signifikante Erniedrigung (durchschnittlich 45 %). Im Vergleich zu einmaligem führte mehrmaliges Auftauen der Proben zum signifikanten Absinken der Gestagenkonzentrationen im Kot von Spitzmaulnashörnern und Gazellen. Im Ergebnis dieser Voruntersuchungen wurde für das weitere Vorgehen eine standardisierte Behandlung der Kotproben bis zur Bestimmung ihrer Gestagenkonzentrationen eingehalten. Bei 13 Giraffen und 8 östlichen Spitzmaulnashörnern aus 7 deutschen Zoos (insgesamt 2618 Kotproben) erfolgte zwischen 1997 und 2002 eine Zyklus- und/ oder Graviditäts-diagnostik mittels Gestagenbestimmungen im Kot. Dabei zeigten die Konzentrationen an Progesteronmetaboliten im Kot von 6 adulten, ingraviden Giraffen zyklische Schwankungen mit einer Zykluslänge von ca. 14 Tagen. Die Follikelphase dauerte im Mittel 6,9 Tage mit Gestagengehalten von durchschnittlich 259 ± 49 ng/g Kot und die Lutealphase hatte eine Länge von im Mittel 7,6 Tagen bei Konzentrationen an Progesteronmetaboliten von durchschnittlich 1163 ± 223 ng/g Kot. Brunstsymptome und/ oder Paarungen fielen immer mit dem Ende der Lutealphase zusammen. Am Beginn von 8 Graviditäten kam es bei den Giraffen zum Anstieg der Hormonkonzen-trationen auf Werte, die auch während der Lutealphase erreicht werden. Danach blieb die Gestagenausscheidung mit dem Kot zwischen der 58. und 1. Woche a. p. auf hohem Niveau. Eine Rückkehr auf Basalwerte, die während der Follikelphase auftreten, erfolgte erst 3 Tage p. p. Nach der Geburt konnten bei einigen Tieren postpartale Östren mit einer kurzfristigen Erhöhung der Hormonausscheidung im Kot festgestellt werden. Bei 7 adulten, ingraviden Spitzmaulnashörnern konnte mit der angewandten Methode kein Sexualzyklus ermittelt werden. Diese Tiere zeigten nur geringe Schwankungen der Gestagenausscheidung auf niedrigem Niveau (im Mittel 74 ± 18 ng/g Kot). Im Rahmen von 4 Graviditäten kam es bei den Spitzmaulnashörnern zunächst zu einer langsamen Erhöhung der Ausscheidung von Progesteronmetaboliten mit dem Kot, gefolgt von einem starken Anstieg ab der 56. Woche a. p. auf maximale Konzentrationen von ca. 674 ng/g Kot zwischen der 40. und 36. Woche a. p. Im weiteren Verlauf der Gravidität schwankten die Gestagengehalte zwischen 450-600 ng/g Kot. Eine Rückkehr auf das Niveau der Gestagenausscheidung von ingraviden Tieren war erst 3 Tage p. p. zu verzeichnen. Durch Festlegung eines Schwellenwertes von 200 ng/g Kot konnte eine Graviditätsdiagnose bei den Spitzmaulnashörnern ab etwa 52 Wochen vor der Geburt erfolgen. Eine Vorhersage des Geburtszeitpunktes war durch die Bestimmung der Gestagene im Kot weder bei Giraffen noch bei Spitzmaulnashörnern möglich
Since the African black rhinoceros is threatened to become extinct in its homeland, its offspring in zoological gardens possesses great importance. The existence of the giraffe is not yet particularly endangered in the wild, the loss of this sensible species in captivity is however very high. Gestagen concentrations in the faeces were determined in order to get more knowledge on the reproduction physiology of these two species, which is necessary for a successful reproduction. These non-invasive method was shown to be suitable for monitoring of the reproduction both in giraffes and black rhinoceroses. The gestagens in the faeces were analyzed in 3 steps: weighing of faeces specimens, gestagen extraction with methanol and their determination by means of radioimmunoassay. In the methodical part of the study the dry mass of the faeces showed only small variations up to 5 % within one species (Baringo giraffe, black rhinoceros and also dama gazelle). Thus, it was possible to estimate comparable gestagen levels from several faecal samples within one species without drying, in spite of their different amounts of water. After storage at room temperature for about 24 and/ or 48 hours gestagen concentrations in the faeces of giraffes and rhinoceroses were significantly increased in comparison to samples frozen immediately. After prolonged storage time (1 and 3 months) at 20 °C no significant changes of low gestagen concentrations were stated in the faeces of rhinoceroses and gazelles. In opposite to this, in the faeces of giraffes with high initial gestagen concentrations a significant decrease (average 45 %) was evident. Repeated thawings of the samples led to a significant dropping of the gestagen levels in the faeces of rhinoceroses and gazelles compared to single thawing. As a result of these preceding investigations a standardized treatment of the faeces samples prior to determination of their gestagen concentrations was observed. Control of reproduction cycle and pregnancy respectively by means of faecal gestagen monitoring was carried out in a total of 2618 faecal samples of 13 giraffes and 8 eastern black rhinoceroses, collected in 7 German zoos from 1997 to 2002. Concentrations of progesterone metabolites in the faeces of 6 adult, nonpregnant giraffes showed cyclic fluctuations with a cycle length of approximately 14 days. The follicular phase took 6.9 days on an average with a mean gestagen concentration of 259 ± 49 ng/g faeces and the luteal phase had a length of 7.6 days on an average with a mean concentration of 1163 ± 223 ng/g faeces. Oestrus behaviour and/ or mating was observed always at the end of the luteal phase. A rise of hormone concentrations to a level, which is characteristic for the luteal phase, was evident at the beginning of 8 pregnancies in giraffes. Afterwards the excretion of faecal gestagens remained on a high level between week 58th and 1st a. p. Basal values, which are characteristic for the follicular phase, were detected 3 days p. p. After parturition some animals showed oestrus behaviour with a short increase of hormone excretion by the faeces. In 7 adult, nonpregnant black rhinoceroses no reproduction cycle could be ascertained by determination of gestagens in the faeces. Only small fluctuations of the gestagen excretion on a low level (on an average 74 ± 18 ng/g faeces) were evident in these animals. Within 4 pregnancies of black rhinoceroses a slow increase of the excretion of faecal progesterone metabolites could be detected, followed by a massive rise from week 56th a. p. to maximum concentrations of approximately 674 ng/g faeces between week 40th and 36th a. p. In the ongoing pregnancy the gestagen concentrations varied between 450-600 ng/g faeces. A return to the level of the gestagen excretion of nonpregnant animals was noticed 3 days p. p. Diagnosis of pregnancy of black rhinoceroses was possible approximately 52 weeks prior to parturition by defining a threshold value of 200 ng/g faeces. Prediction of the day of delivery by means of gestagen determination in the faeces was neither possible in giraffes nor in black rhinoceroses

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20

Loffell, D. A. "Interactions between acacias and giraffe in Ithala Game Reserve; : a study in landscape change." Bachelor's thesis, University of Cape Town, 1999. http://hdl.handle.net/11427/26720.

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21

Suraud, Jean-Patrick. "Identifier les contraintes pour la conservation des dernières girafes de l’Afrique de l’Ouest : déterminants de la dynamique de la population et patron d’occupation spatiale." Thesis, Lyon 1, 2011. http://www.theses.fr/2011LYO10339/document.

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Le défi de la protection des espèces menacées en Afrique est de concilier de façon durable les objectifs de conservation de la nature, et la nécessité de développement économique des populations humaines. Au Niger, survivent aujourd'hui les dernières girafes d'Afrique de l'Ouest (Giraffa camelopardalis peralta). Ces girafes sont unique à plusieurs titres : (i) elles constituent les seules représentantes de la sous espèce peralta (ii), elles vivent dans une région fortement anthropisée (iii) elles vivent dans une zone non protégée, (iv) et elles ne cohabitent avec aucun prédateur. En 1996, la population était au bord de l'extinction avec seulement 50 individus. Malgré des signes de restauration observés ces dernières années, la sous-espèce est inscrite depuis 2008 dans la liste rouge des espèces menacées de l'UICN (Union Internationale pour la Conservation de la Nature) avec le statut « en danger ». Quels sont les facteurs qui pourraient limiter le taux de croissance maximum récemment observé dans cette population? Est-ce que les conjonctures favorables à l'augmentation de la population sont durables? Aborder les questions de conservation des populations met en avant le besoin de connaitre les paramètres démographiques de la population concernée, et les paramètres environnementaux qui conditionnent sa distribution spatiale. Nous avons réalisé une analyse de l'historique des comptages, puis, nous avons déterminé les paramètres démographiques de la population grâce à une approche par Capture Marquage Recapture. Une analyse spatiale à plusieurs échelles nous a permis de caractériser la distribution des girafes aux niveaux de la population et du troupeau (à partir d'observations directes), et de mesurer la sélection de l'habitat au niveau individuel (à partir d'un suivi par colliers GPS)
One of the main challenges for endangered species protection in Africa is to find a sustainable way of integrating objectives of nature conservation with the economic development needs of the local human population. Last West African giraffe population, Giraffa camelopardalis peralta, lives in Niger. These giraffe are unique for several reasons: (i) they represent the only population of peralta sub-species, and (ii) they live in an area densely populated by humans, (iii) which is unprotected and (iv) without predators. In 1996, this giraffe population was almost extinct, with only 50 individuals remaining. Despite signs of population recovery, the sub-species has been classified as “endangered” according to the IUCN Red List assessment criteria. What are the limiting factors for the maximum annual growth rate that has been recorded over the last years in the population? Are favorable conjunctures to this population increasing sustainable? Assessing population conservation requires knowledge of demographic parameters and understanding of the environmental factors driving its spatial distribution. Census data from 1996 to 2009 were analyzed and then demographic parameters through a capture-markrecapture method were determined. A multi-scale spatial analysis allowed me to determine giraffe distribution at both population and herd level (through observations), and to measure habitat selection at the individual level (through GPS satellite collars). Census results, almost exhaustive from 2005 to 2008 highlited an annual growth rate of 12%. This is the maximum growth rate for a giraffe population, and fits with the theoretical maximum growth rate for the species. At the population and herd level, giraffe distribution patterns are driven by food availability. These food resources are seasonally distributed and impacted by human activities. Habitat selection shows that during dry season, giraffe avoid village proximity, where disturbance is high. However, at night giraffe move closer to villages where food resource quantity and quality are higher (tree density, granaries). The use of bean field crop suggests that some cultivated crops gain in attraction and even become favourable to giraffe. This might explain the increase of human-giraffe conflicts. My results clearly show the importance of taking human activities and perception into account, when assessing wildlife conservation strategies

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22

Brand, Rachel. "Evolutionary ecology of giraffes (Giraffa camelopardalis) in Etosha National Park, Namibia." Thesis, University of Newcastle Upon Tyne, 2007. http://hdl.handle.net/10443/1461.

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The giraffe (Giraffa camelopardalis) occupies a variety of habitats across sub- Saharan Africa. It is characterised by a loose social organisation, and a dominancedriven polygynous mating system. This project sought to explain biogeographic and inter-sexual variation in pelage colouration in the context of natural and sexual selection. I also sought to test the hypothesis that in a semi-arid environment, limited resources (food and water) would predictably concentrate females, increasing the potential for dominant males to monopolise matings. I analysed photos from across Africa, and reveal that where yearly bright sunshine is greater, female giraffe in particular tend to be lighter, resulting in sexual dichromatism in high insolarity locations. I hypothesised that dark pelage colour is maintained in males through sexual selection for a costly status signal. Field work was carried out in Etosha NP, Namibia. Using photographic records, I identified 431 individual giraffe. I surveyed the study area regularly and collected data on group composition and behaviour upon locating giraffe. I carried out focal watches, and recorded all observations of agonistic and mating behaviour. Darker males tended to be older and more dominant than lighter males, associated less with females, but had greater success in courting females. Food and water affected female movements on both a spatial and temporal scale. At waterholes, encounter rates were increased and consequently mating and agonistic interactions more frequent. Paler males had a greater chance of interacting with females at waterholes because of higher intruder pressure, but when present, darker males always monopolised courtship opportunities. Mature males demonstrated a diversity of ranging strategies that affected association with females. These individual differences are assumed to relate to status and probably affect individual reproductive success. Evidence suggests male reproductive success is skewed towards mature dark males, but may also vary among dark males, with some potentially being excluded from mating.

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23

Paulse, Jamie. "The behaviour and feeding ecology of extralimital giraffe within Albany Thicket vegetation in the Little Karoo, South Africa." University of the Western Cape, 2018. http://hdl.handle.net/11394/6747.

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Magister Scientiae (Biodiversity and Conservation Biology) - MSc (Biodiv and Cons Biol)
Due to their popularity for tourism, giraffes are being introduced into Thicket areas within the Little Karoo region of the Western Cape. However, information regarding the activity budgets and diet selection of these giraffes is lacking. Therefore, this study aimed to achieve three objectives; to determine the diurnal activity budget, diet composition and browsing levels, and the estimated browsing capacities of extralimital giraffe. The study was conducted on two privately owned farms, namely Kareesbos Private Game Reserve and Tsumkwe Private Game Reserves. Observations were completed on both study sites using the interval scan method, whereby observations were conducted on all visible individuals from 6 am – 6 pm for four days every 3 months (winter, spring, summer and autumn). Observations found browsing to be the most dominant activity displayed by both populations, with walking and rumination being the second and third most dominant activity. Females browsed more than males in both study sites. Dietary observations showed four species (Pappea capensis, Portulacaria afra, Euclea undulata and Searsia longispina) and five species (Searsia longispina, Euclea undulata, Pappea capensis, Vachellia karroo and Grewia robusta) to comprise approximately 90% and 80% of their diet in Kareesbos and Tsumkwe respectively. The importance of flower bearing species (Lycium spp. and Rhigozhum obovatum) increased during the spring and summer seasons in both study sites. In addition to the diet selection, browsing by both giraffe populations was shown to occur mostly below 2 m. Estimated browsing capacities for Kareesbos and Tsumkwe were 25 and 21, and 107 and 88 ha per giraffe, respectively, for the respective browse height strata of less than two metres and five metres. It is suggested that browsing capacities of less than two metres be considered when stocking giraffe and the number of individuals adjusted accordingly on each farm, due to the continuous low browsing of giraffe at less than two metres. Furthermore, results indicate that these giraffes have adapted to take advantage of forage available in ecosystems outside their natural ranges. Low foraging heights suggests possible niche overlap with other browsers, which may result in increased competition for food when it becomes limited. Long term ecological monitoring of extralimital populations and appropriate management procedures are therefore required to avoid the displacement and degradation of indigenous fauna and flora within the Little Karoo, and possible mortalities amongst the giraffe populations.

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Muller, Zoe. "The social behaviour and conservation of Rothschild's giraffes, Giraffa camelopardalis rothschildi, in Kenya." Thesis, University of Bristol, 2018. http://hdl.handle.net/1983/f2157a75-f1a8-4d3c-9365-5b5ae814e023.

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An increasing number of species are declining in the wild. Giraffes have suffered an estimated 36-40% decline in the past ten years and are now listed as Vulnerable on the IUCN Red List of Threatened Species (Muller, 2016). Given this rate of decline, there is an urgent need for the development of conservation plans and practices for giraffes. However, giraffes have been understudied in relation to other large African mammals and even basic aspects of their behaviour and ecology are still unknown or misunderstood. Understanding a species’ social organisation and behaviour is critical to developing suitable conservation and management plans. In this thesis I provide a thorough investigation of giraffe social behaviour and the factors which influence association patterns and discuss how these may be related to fitness and impact upon the survival of the species. My results show that giraffes live in complex social systems which are composed of non-random associations, the patterns of which are influenced by age and sex of individual, behavioural state, reproductive state, and environmental factors such as disturbance and habitat structure. My results have contributed knowledge to understanding the complex social behaviour of giraffes and have demonstrated how generic conclusions about the behaviour of a species should not be drawn from studies of single populations. My study provides an important starting point from which to develop the comparative study of networks and determine the relative influence of environmental factors on network structure and provides comprehensive information that can be used for the management of giraffe populations in the wild.

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Semaan, Thierry. "Caractéristiques spectrales et pulsationnelles d'étoiles Be à l'aide de données sol (VLT/GIRAFFE et X-SHOOTER) et espace (CoRoT)." Observatoire de Paris (1667-....), 2012. https://hal.science/tel-02095134.

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Les étoiles Be sont des étoiles chaudes à rotation quasi-critique qui sont entourées d'un disque circumstellaire alimenté par des éjections discrètes de matière. Les étoiles Be sont de bons laboratoires pour étudier l'impact de la rotation rapide sur les pulsations stellaires et aussi du rôle des pulsations sur le phénomène récurrent des éjections de matière. Au cours de cette thèse nous nous sommes intéressé à l'étude des étoiles Be observées dans les premiers champs d'exoplanètes du satellite CoRoT. La première étape de ce travail a été d'identifier les étoiles Be parmi toutes les étoiles variables observées par le satellite. Nous avons constitué ainsi une liste d'une quarantaine d'étoiles Be. Grâce à des observations spectroscopiques obtenues au VLT avec les instruments GIRAFFE et X-SHOOTER nous avons pu étudier les propriétés spectrales d'une vingtaine de ces objets et déterminer leurs paramètres fondamentaux en tenant compte des effets de la rotation rapide. Nous avons étudié ensuite les courbes de lumières CoRoT de ces étoiles pour déterminer les fréquences et les amplitudes des pulsations qui les caractérisent. Nous avons étudié la variation des fréquences et amplitudes dans le temps. Cette étude porte une attention particulière aux nouvelles étoiles découvertes présentant des sursauts de lumière, signes d'éjections récurrentes de matière. Grâce à nos études spectroscopiques et photométriques nous avons pu établir de nouvelles caractéristiques des spectres de fréquences en fonction de la position des étoiles dans le diagramme HR, et mettre en évidence quelques comportements communs parmi les étoiles Be étudiées
Be stars are early-type stars having near critical rotation. They are surrounded by an equatorial disc fed by discrete mass-loss ejections from the central star. Be stars are good laboratories to study, on one hand, the impact of rotation on pulsations and, on the other hand, the role of pulsation on the recurrent mass ejections. During this thesis we focused on faint Be stars located in the first exoplanetary fields CoRoT satellite. In a first step we have identified the stars presenting the Be phenomenon among all the variable stars observed by CoRoT. We have thus been able to provide a sample of forty Be stars. Thanks to ground-based spectroscopic observations at VLT with GIRAFFE and X-SHOOTER instruments we have studied th spectral properties of half of them and determined their fundamental parameters by taking into account the effects of rapid rotation. Using the CoRoT light curves we have determined the frequencies and amplitudes of the pulsations that characterize the treated stars and studied their temporal variations. We have studied attentively the newly discovered stars presenting light outbursts. Thanks to the carried spectroscopic and photometric studies we have been able to investigate the properties of pulsations according to the stellar location in the HR diagram, and could identify some common properties among the Be stars of our sample

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Winter, Sven [Verfasser], Axel [Gutachter] Janke, and Paul [Gutachter] Dierkes. "Gene flow, population structure and genetic specification of giraffe have implications for their conservation / Sven Winter ; Gutachter: Axel Janke, Paul Dierkes." Frankfurt am Main : Universitätsbibliothek Johann Christian Senckenberg, 2020. http://d-nb.info/1225793165/34.

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Shadwell, Eleanor. "Top-down or bottom-up?: Impacts of giraffe browse and water abstraction on two keystone tree species of the Kgalagadi Transfrontier Park." Master's thesis, University of Cape Town, 2016. http://hdl.handle.net/11427/22908.

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In this thesis I determine how an emphasis on tourism may have both a top-down and bottom-up affect on the two most dominant tree species in the southern Kalahari Desert of central southern Africa. Both tree species are considered as keystone species especially along ephemeral rivers. My focus is on the impact of the introduction of an extralimital megaherbivore, Giraffa camelopardalis, (top-down) and anthropogenic water abstraction (bottom-up) on the reproductive output and vegetation structure of Acacia erioloba and Acacia haematoxylon in the Kgalagadi Transfrontier Park. I determine the impact of giraffe on canopy structure and reproductive potential of the two tree species by comparing three zones of giraffe density (high, medium and low) along the Auob River. I do this through a series of transects through the river to determine both giraffe and tree density and also photographed several trees to determine change in canopy width, percentage canopy death and change in the number of flowers and pods between the three zones and between species. My results show a significant negative impact of giraffe browse on canopy structure, specifically for A. haematoxylon. I did not however find any significant differences in recruitment between the different giraffe density zones. However, a noticeable decrease in numbers of flowers and pods in the giraffe browse height of trees (2 - 5 m) between zones suggest that giraffe will have a negative effect on the A. haematoxylon population but not the A. erioloba population in the future. I use stable hydrogen and oxygen isotope ratios to determine the water source for the two tree species. I do this relative to the stable isotope ratio of the water extracted from nearby boreholes. I also determine how close to physiological stress the trees are (using specific leaf area, leaf δ¹³C values, canopy death and midday xylem pressure potentials) both upstream and downstream of active boreholes used for two tourist camps. One camp, Nossob, in the Nossob River is abstracting at a high rate while the other camp, Urikaruus, in the Auob River is abstracting at a lower rate. My results for water isotope ratios show that both A. erioloba and A. haematoxylon are using deep groundwater. My results also show that in the dry season, A. erioloba in the Nossob are losing contact with groundwater and have to rely on some as yet unmeasured water source in the soil profile. This 'stress' is not reflected in canopy dieback as yet. The trees continue to transpire in the dry season suggesting that they are physiologically able to adapt to fluctuations in the water table of between 4.5 - 5.2 m between the wet and dry season by closing their stomata but are prone to drought-induced carbon starvation, specifically for trees in the Nossob. Overall, my results show that the impact of giraffe on vegetation structure is already evident for A. haematoxylon, indicative of future negative effects on reproduction. My research also shows that although current levels of water abstraction are as yet not affecting vegetation structure below the abstraction points, the trees are edging closer to thresholds of water stress that would be exacerbated with drought. These findings are discussed within the context of ecosystem health and management implications for the giraffe population and water use within the Park.

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Malavolta, Luca. "Data reduction, radial velocities and stellar parameters from spectra in the very low signal-to-noise domain." Doctoral thesis, Università degli studi di Padova, 2013. http://hdl.handle.net/11577/3423130.

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Large astronomical facilities usually provide data reduction pipeline designed to deliver ready-to-use scientific data, and too often as- tronomers are relying on this to avoid the most difficult part of an astronomer job Standard data reduction pipelines however are usu- ally designed and tested to have good performance on data with av- erage Signal to Noise Ratio (SNR) data, and the issues that are related with the reduction of data in the very low SNR domain are not taken int account properly. As a result, informations in data with low SNR are not optimally exploited. During the last decade our group has collected thousands of spec- tra using the GIRAFFE spectrograph at Very Large Telescope (Chile) of the European Southern Observatory (ESO) to determine the ge- ometrical distance and dynamical state of several Galactic Globular Clusters but ultimately the analysis has been hampered by system- atics in data reduction, calibration and radial velocity measurements. Moreover these data has never been exploited to get other informa- tions like temperature and metallicity of stars, because considered too noisy for these kind of analyses. In this thesis we focus our attention on data reduction and analysis of spectra with very low SNR. The dataset we analyze in this thesis comprises 7250 spectra for 2771 stars of the Globular Cluster M 4 (NGC 6121) in the wavelength region 5145 − 5360Å obtained with GIRAFFE. Stars from the upper Red Giant Branch down to the Main Sequence have been observed in very different conditions, including nights close to full moon, and reaching SNR ≃ 10 for many spectra in the dataset. We will first review the basic steps of data reduction and spec- tral extraction, adapting techniques well tested in other field (like photometry) but still under-developed in spectroscopy. We improve the wavelength dispersion solution and the correction of radial veloc- ity shift between day-time calibrations and science observations by following a completely different approach with respect to the ESO pipeline. We then analyze deeply the best way to perform sky sub- traction and continuum normalization, the most important sources respectively of noise and systematics in radial velocity determination and chemical analysis of spectra. The huge number of spectra of our dataset requires an automatic but robust approach, which we do not fail to provide. We finally determine radial velocities for the stars in the sample with unprecedented precision with respect to previous works with similar data and we recover the same stellar atmosphere parameters of other studies performed on the same cluster but on brighter stars, with higher spectral resolution and wavelength range ten times larger than our data. In the final chapter of the thesis we face a similar problem but from a completely different perspective. High resolution, high SNR data from the High Accuracy Radial Velocity Planet Searcher spectro- graph (HARPS) in La Silla (Chile) have been used to calibrate the at- mospheric stellar parameters as functions of the main characteristics of Cross-Correlation Functions, specifically built by including spec- tral lines with different sensitivity to stellar atmosphere parameters. These tools has been designed to be quick and to be easy to imple- ment in a instrument pipeline for a real-time determination, neverthe- less they provide accurate parameters even for lower SNR spectra.
Telescopi di grandi dimensioni usualmente rendono disponibili dei programmi per la riduzione dati che restituiscono all’astronomo dati già pronti per l’analisi scientifica, e sempre più spesso gli astronomi si appoggiano a questi programmi per evitare un lavoro lungo e diffi- cile. I programmi di riduzione dati standard sono però progettati per restituire buoni risultati su dati con buon Rapporto Segnale Rumore (RSR), e spesso i problemi legati alla riduzione di dati a basso RSR non sono presi in considerazione, con il risultato che le informazioni che contengono non sono adeguatamente utilizzate. Negli ultimi anni il nostro gruppo di ricerca ha collezionato migli- aia di spettri osservati con lo strumento GIRAFFE collegato al Very Large Telescope dell’Osservatorio Europeo del Sud in Cile, con lo scopo di determinare la distanza geometrica e lo stato dinamico di diversi Ammassi Globulari Galattici, ma in definitiva l’analisi è stata ostaco- lata da errori sistematici nella riduzione e calibrazione dei dati e nella misura delle velocità radiali. Inoltre questi dati non sono mai stati uti- lizzati per determinare altre informazioni come temperatura e metal- licità delle stesse, poiché considerati troppo rumorosi per questo tipo di analisi. In questa tesi concentriamo la nostra attenzione sulla riduzione dati ed analisi di spettri con bassissimo RSR. Il set di dati che analizziamo in questa tesi è composto da 7250 spettri per 2771 stelle dell’ammasso globulare M 4 (NGC 6121) ottenute con GIRAFFE nell’intervallo spet- trale 5145 − 5360Å. Stelle della parte superiore del Ramo delle Giganti Rossi fino alla Sequenza Principale sono state osservate in condizioni molto differenti, comprese notti con luna piena, fino ad raggiungere un valore limite di RSR ≃ 10 per molti spettri. La nostra analisi incomincia con i passi di base della riduzione dati ed estrazione degli spettri, adattando tecniche ben testate in altri campi (come la fotometria) ma ancora non ben sviluppate in spettroscopia. Continuiamo con il migliorare la soluzione della dispersione in lunghezza d’onda la correzione per piccoli spostamenti nelle velocità radiali di riferimento tra i dati di calibrazione presi durante il giorno e le osservazioni scientifiche seguendo un approccio completamente differente rispetto a quello ESO. Analizziamo poi la miglior maniera per effettuare la sottrazione del cielo e la normalizzazione del continuo, le due più importanti fonti rispettivamente di rumore ed errori sistematici nella misura delle velocità radiali nell’analisi chimica degli spettri. L’alto numero di spettri del nostro dataset richiede un approccio automatico ma robusto, che non manchiamo di fornire. Determiniamo infine per il nostro campione di stelle velocità radiali con una precisione mai vista in precedenza per dati di questo tipo e ritroviamo gli stessi parametri atmosferici di altri lavori svolti su stelle più brillanti, con dati a risoluzione spettrale maggiore e su intervalli di lunghezza d’onda dieci volte superiori a quello dei nostri dati. Nell’ultimo capitolo della tesi affrontiamo una problematica simile ma da una prospettiva completamente differente. Spettri ad alta risoluzione e ad alto RSR ottenuti con lo spettrografo HARPS sono stati usati per calibrare i parametri atmosferici stellari in funzione delle caratteristiche di funzioni di cross-correlazione specificatamente costruite includendo linee spettrali con diversa sensibilità ai parametri atmosferici stellari. Questi strumenti sono stati progettati per essere facilmente implementati un programma di riduzione dati, pur tuttavia senza sacrificare l’accuratezza dei parametri determinati anche per spettri a basso Rapporto Segnale Rumore.

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Gussek, Isabel Ruth [Verfasser]. "Nutrition of giraffes (Giraffa camelopardalis) in captivity : Evaluation of feeding practice and analysis of rations in European zoos / Isabel Ruth Gussek." Bonn : Universitäts- und Landesbibliothek Bonn, 2016. http://d-nb.info/111001418X/34.

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Neumann, Gaby. "Bestimmung von Sexualzyklus und Trächtigkeit mit Hilfe des Nachweises von Gestagenen im Kot von im Zoo gehaltenen Giraffen (Giraffa camelopardalis) und Spitzmaulnashörnern (Diceros bicornis)." [S.l.] : [s.n.], 2002. http://dol.uni-leipzig.de/pub/2003-17.

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Sicks, Florian [Verfasser], Günther [Akademischer Betreuer] Fleissner, Manfred [Akademischer Betreuer] Kössl, and Klaus [Akademischer Betreuer] Scheibe. "Paradoxer Schlaf als Parameter zur Messung der Stressbelastung bei Giraffen (Giraffa camelopardalis) / Florian Sicks. Gutachter: Günther Fleissner ; Manfred Kössl ; Klaus Scheibe. Betreuer: Günther Fleissner." Frankfurt am Main : Univ.-Bibliothek Frankfurt am Main, 2013. http://d-nb.info/1044276150/34.

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Battran, Martin [Verfasser], Uwe [Gutachter] Hoßfeld, Georgy S. [Gutachter] Levit, and Thomas [Gutachter] Junker. "Der Hals der Giraffe oder: Jean-Baptiste de Lamarck (1744-1829), seine Transformationstheorie sowie die Bedeutung und Wirkungsgeschichte des Lamarckismus in Deutschland / Martin Battran ; Gutachter: Uwe Hoßfeld, Levit Georgy S., Thomas Junker." Jena : Friedrich-Schiller-Universität Jena, 2016. http://d-nb.info/1177612461/34.

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Graic, Jean-Marie. "Sexual Dimorphism In Areas of the Brain of Cetartiodactyla." Doctoral thesis, Università degli studi di Padova, 2018. http://hdl.handle.net/11577/3425869.

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Comparative neuroanatomy studies have helped us see the major structures and similarities between mammals, and allowed for the confirmations of hypotheses via direct observation. Variety in brain specialization can be seen in Cetartiodactyla, between the terrestrial artiodactyls and aquatic cetaceans. Compared to the primate brain, adapted to grasp using articulated fingers with opposable thumbs, the pure quadrupedal locomotion of ungulates and the absence of articulated movements in the limbs of cetaceans most certainly shows variations in the related brain areas. From this principle, the study of the brain of the swine, bovine, sheep or any other cetartiodactyl can help understand the basic organization coding the brain of mammals. Some species have been used more than others among cetartiodactyls. The sheep Ovis aries has been the subject of a fair amount of cytoarchitectural studies and functional investigations of the cortex, but also the hypothalamus. Other more exotic terrestrial species like the giraffe Giraffa camelopardalis, have much more rarely had their brain thoroughly studied and published. For this reason we studied the cortical folding of the giraffe brain, its brain weight and encephalization quotient (EQ), and we reviewed the literature concerning its encephalon as far as 1839. This showed that, although a relatively very small absolute number of specimen have been collected over the years, the giraffe brain was quite typical of ungulates, with a deep gyrification, and an absolute weight of 720 g. The brain of the swine Sus scrofa received comparatively little attention, regarding even basic data. To provide weighed data on the brain of the pig, we weighted the brain of 48 animals to reach a robust value for the average brain weight of the domestic swine a different age categories. The average adult brain weight was 135 g, which was compared to the literature, as well as published EQs. The relatively low EQ (0.38) could be related to the domestication and heavy breeding that meat production necessitated to improve body weight. One of the findings of the cyctochemical exploration of the mammalian brain is the existence of sexually dimorphic structures. Groups of cells were found to be much larger in volume or cell number in the brain of males or females. Although their precise function is still unknown, most of them are directly involved in reproduction behaviors. Hormones have a crucial role in shaping the developing brain, and in particular androgens. The effects of male and female steroids on the development of the brain and its sexual differentiation can be put in perspective in the study of intersex freemartin bovines. During twin pregnancy of a bovine with a male and a female fetus, male sexual hormones circulating during intrauterine development in the female fetus can masculinize its genital apparatus and alter its phenotype, resulting in an intersex animal. We investigated the hypothalamus cytoarchitecture of freemartin heifers and compared them to male and female hypothalami. We found sex differences between male and female suprachiasmatic (SCN) and vasopressin-oxytocin containing (VON) nuclei. Moreover, the freemartin hypothalamus showed differences more complex than a simple masculinized female brain. While the VON was in size and cell count between male and female values, the SCN of freemartins was larger than both males and females. Using modern multivariate statistical methods, we also investigated the cytoarchitecture of male, female and freemartin cerebellar cortex. We found differences among cellular layers in size, regularity and density of the cells, across sex categories, showing that a multivariate multi-aspect approach can yield valuable results at the cellular level for large cohorts, and that a multi-disciplinary team can produce finer studies.
La neuroanatomia comparata consente di caratterizzare le strutture nervose mettendo in luce le somiglianze e le differenze tra i mammiferi. Un aspetto interessante di questo studio comparato riguarda il cervello dei Cetartiodattili sia terrestri (artiodattili) sia marini (cetacei) in cui la locomozione quadrupedale degli ungulati e l'assenza di movimenti articolati nell’arto dei cetacei mostrano variazioni morfologiche rispetto ai primati nelle aree cerebrali correlate i quali presentano un arto specializzato con dita articolate e pollici opponibili capaci di afferrare oggetti molto piccoli con precisione. Da questo punto di vista uno studio neuroanatomico dell’encefalo di artiodattili come il suino, il bovino e la pecora può aiutarci a comprendere l'organizzazione della citoarchitettura nei diversi mammiferi. La pecora Ovis aries come modello animale è stata oggetto di una discreta quantità di studi anatomici e indagini funzionali sul ruolo della corteccia cerebrale e dell'ipotalamo. Altre specie di artiodattili terrestri come la giraffa Giraffa camelopardalis, sono state meno studiate e sono rare le pubblicazioni che ne hanno studiato il cervello. Per questo motivo, uno degli obiettivi di questa tesi è stato quello di caratterizzare le circonvoluzioni corticali dell’encefalo della giraffa, valutare il suo peso ed il suo quoziente di encefalizzazione (EQ). I risultati hanno permesso di affermare che il cervello della giraffa presenta caratteristiche comuni a quelle degli altri ungulati con una notevole girificazione e un peso medio di 720 g. Un altro obiettivo è stato quello di analizzare l’encefalo del suino Sus scrofa. Per ottenere risultati significativi, abbiamo pesato il cervello di 48 animali appartenenti a diverse categorie di età. Il peso medio del cervello adulto è risultato di 135 g. L'EQ relativamente basso (0,38) ottenuto da questo mammifero potrebbe essere spiegato con le esigenze di produzione spinta che l'allevamento intensivo comporta, incrementando la selezione di animali sempre più pesanti. Uno degli aspetti molto studiati in questi ultimi anni da un punto di vista neuroanatomia riguarda la caratterizzazione delle aree sessualmente dimorfiche nell’encefalo dei mammiferi. Il bovino Bos taurus rappresenta un modello interessante per lo studio dei dimorfismi cereberali perché questo mammifero possiede un cervello grande, altamente convoluto, una gravidanza di 9 mesi. Inoltre in questa specie si manifesta la sindrome del freemartinismo. Tale sindrome si presenta perchè durante la gravidanza gemellare di un feto maschile e uno femminile, gli ormoni maschili del maschio a causa della anastomosi plaecentare circolano nel feto femminile mascolinizzando. Così il feto femmina è un individuo intersesso interessante perché il suo cervello femminile si è sviluppato naturalmente in un ambiente ormonale maschile. L’obiettivo che ci siamo posti è stato quello di studiare la citoarchitettura dell'ipotalamo di giovenche freemartin e confrontare i dati ottenuti con quelli analizzati nell’ipotalamo di bovini maschi e femmine. Questo studio ci ha permesso di caratterizzare i dimorfismi sessuali tra maschili e femminili presenti nel nucleo suprachiasmatico (SCN) e nel nucleo contenete vasopressina-ossitocina (VON). L’ipotalamo dei freemartin mostrava per quanti riguarda il nucleo VON valori intermedi in termini di dimensioni e numero di cellule tra i valori maschili e femminili. Il SCN dei freemartins è risultato più grande rispetto a quello dei bovini maschi e femmine. Un ulteriore obiettivo è stato quello di studiare la morfologia della citoarchitettura della corteccia cerebellare tra bovini maschi, femmine e freemartin. Applicando un metodo statistico multivariato e multi-aspetto, abbiamo caratterizzato le differenze di genere tra gli strati del cervelletto in termini di dimensioni, regolarità e densità delle cellule.

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Loeillet, Benoit. "Planètes extrasolaires à courte période orbitale: De la détection à la caractérisation des Jupiter-chauds." Phd thesis, Université de Provence - Aix-Marseille I, 2008. http://tel.archives-ouvertes.fr/tel-00353240.

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Plus de 300 planètes extrasolaires ont été découvertes à ce jour. La variété et la diversité des caractéristiques qu'elles présentent sont extrêmement vastes. Et dans cette multitude, une population se distingue, les Jupiter-chauds. Ces planètes ne ressemblent, en effet, en rien à celles que l'on côtoie dans le Système Solaire. Elles ont une masse d'une à plusieurs fois celle de Jupiter et sont très proches de leur étoile parent, orbitant en seulement quelques jours. L'étude de cette population nous apporte beaucoup d'éléments quant à leur processus de formation et d'évolution. Certaines d'entre elles ont en effet la particularité de transiter devant leur étoile parent. Mes travaux de thèse m'ont mené à détecter et caractériser en densité 14 planètes extrasolaires, grâce aux programmes de recherche CoRoT et SuperWASP combinés au spectrographe SOPHIE (OHP). Parmi ces planètes figurent celles ayant la plus courte période orbitale et, autour d'une autre étoile, la plus importante masse jamais détectées en transit. Un programme novateur, que j'ai initié, nous a également permis d'explorer les capacités de détection d'un instrument de type multi-fibre (FLAMES/GIRAFFE et UVES). Nous avons montré que cet instrument peut être performant en terme de précision de mesure en vitesse radiale, et qu'il permet un très bon écrémage des cibles. L'instrument multi-fibre est utilisable également dans le cadre d'un suivi de candidats issus de programmes de recherche par photométrie, tels que la mission CoRoT , mais il nécessite dans ce cas, pour être eficace, d'un champ de vue significatif (de plusieurs degrés carrés par exemple). L'étude du transit spectroscopique de 3 systèmes planétaires m'a également permis d'apporter de fortes contraintes quant à leur processus de formation et d'évolution, et de mettre en évidence pour la première fois l'existence d'un système exotique : X0-3.

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VITALI, FRANCESCA. "THE PHYSIOLOGICAL IMPACT OF CAPTURE: STRATEGIES FOR IMPROVING IMMOBILIZATION OF WILD EAST AFRICAN MESO- AND MEGA-HERBIVORES." Doctoral thesis, Università degli Studi di Milano, 2021. http://hdl.handle.net/2434/843597.

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East African meso- and mega-herbivores have been a key part of the Earth’s ecosystem for millions of years, but are now at risk of disappearing. To ensure their conservation, operations that involve veterinary immobilization are becoming essential for wild populations. However, capture morbidity remains high, with both short- and longer-term physiological alterations that can result in acute or delayed death. In large-sized herbivores, the size and unique anatomy and physiology contribute to the high susceptibility to capture stress, drugs adverse effects and alterations due to recumbency. On top of this, the limited knowledge in the species-specific physiological response to immobilization and, as a result, the obliged practice of extrapolating drug doses and protocols from similar species, enhances the risk of complications. Improvement in capture methods and drug protocols are advocated, and as such, in order to develop targeted strategies, it is essential to gain a better understanding of the species-specific physiological impact of capture. The general objective of this thesis is to advance the knowledge of the physiological mechanism of capture morbidity, and evaluate strategies for the prevention, detection and treatment of complications arising from opioid-based immobilization of selected species of East African megaherbivores, the giraffe (Giraffa camelopardalis ssp. tippelskirchi and reticulata) and the black rhinoceros (Diceros bicornis ssp. michaeli), and in a large mesoherbivore, the African buffalo (Syncerus caffer). A key factor of this study was the collection of data through an opportunistic approach, whereas the research design was shaped for each of the study species based on targeted needs, thus different specific objectives were pursued for each species. In free-ranging Masai giraffes that were immobilized for a translocation, a combination of etorphine and azaperone was evaluated for physiological and handling safety. Early opioid antagonization – a common procedure performed to reduce etorphine’s respiratory depression – was performed at low doses to assess if it would result in smoother restraint and transport. The protocol produced safe inductions, but variable opioid-related excitement occurred and accounted for metabolic derangement. On the other hand, early antagonization with low dose naltrexone allowed calm restraints, a stable physiological function during the recumbency, and enabled smooth recoveries and loading into the chariot with resulting uneventful transport. No delayed complications or resedation were observed during a two-week post-capture boma monitoring. Although the protocol allowed safe immobilization and transport, the study highlighted that further research on techniques that reduce induction-induced excitement, which poses severe health risks in giraffe capture, is advocated. Building up on the study performed in Masai giraffe, the physiological mechanism of capture morbidity occurring in both vehicle and helicopter darted reticulated giraffes, immobilized with an etorphine-azaperone combination, was investigated in order to detect the predisposing factors for homeostatic alterations and to define and guide prevention strategies. Trends over time in blood gases, selected biochemistry variables and cardio-respiratory function were analyzed following early opioid antagonization, and the use of a non-invasive nasal capnometer was investigated. In the helicopter darted giraffes, severe metabolic alterations were observed as a result of an intense startle response, whereas in vehicle darted giraffes, these were moderate and mainly a result of etorphine-induced excitement. Intense excitement occurred when lower doses of etorphine were administered, whereas higher doses resulted in respiratory depression, severe respiratory acidosis and hypoxemia. Early antagonization produced an improvement over time of gas exchanges, but not of the acid-base status, and resulted in poor immobilization quality. Nasal capnometry proved to be a useful non-invasive monitoring tool for field ventilatory function in giraffes. The severe alterations observed suggest that advances in giraffe immobilization should focus on reducing both opioid-respiratory depression and excitement, and onto providing adequate sedation and analgesia during field immobilizations. In Eastern black rhinoceroses, two intra-anesthetic treatments, butorphanol and oxygen, or doxapram, butorphanol and oxygen - which are routinely administered to improve gas exchanges, but which efficacy has not been investigated yet in the species - were evaluated. The mechanism of physiological alterations resulting from capture was investigated, and nasal capnometry was evaluated for its accuracy in monitoring carbon dioxide. Hypoxemia and severe lactic acidosis, proportional to more intense pre-dart chase, occurred. After the administration of doxapram and butorphanol, the initial hypoxemia and acidosis improved, presumably as a result of increase in ventilation mediated by doxapram; whereas the same values worsened when butorphanol only was administered. This might suggest that, different to other rhinoceroses, increased oxygen consumption is not the primary mechanism of hypoxemia in black rhinoceros. Nasal capnometry was efficient in monitoring carbon dioxide trends, but not accurate in predicting absolute values. Although intra-anesthetic treatment with doxapram partially improved gas exchanges, and post-capture complications did not occur for at least nine months, the severe metabolic and respiratory alterations observed highlight the need of advances in black rhinoceros capture methods that focus on preventing the origin of physiological alterations. The physiological safety of two immobilization protocols, etorphine-azaperone and etorphine- medetomidine-azaperone combinations, was compared in free-ranging African buffalos. The aim was to evaluate if medetomidine’s sparing effect would have allowed to safely decrease etorphine doses, and its adverse respiratory effects, without increasing the risk of excitement or poor immobilization quality. The addition of a low dose of medetomidine allowed to decrease etorphine dose by 30 %, and resulted in quicker and smoother inductions, and significantly improved immobilization quality. Medetomidine reduced the occurrence of tachycardia and respiratory acidosis, but not of hypoxemia. Etorphine-medetomidine-azaperone combination is recommended for buffalo immobilization as it provides greater physiological and handling safety, and can help to reduce the onset of capture stress. The new knowledge acquired within the different studies of this thesis has allowed to detect and evaluate species-specific strategies for the prevention (through knowledge of factors influencing capture morbidity, and improved immobilization protocols), detection (through clinical monitoring) or treatment (intra-anesthetic drugs) of capture and drug complications in large-sized herbivores. Species- specific and intra-specific variation of physiological response to capture stress and drugs were individuated, and hence a species-specific approach needs to be endorsed when capturing large-sized herbivores. Furthermore, based on the new information gained in this thesis, further studies can now specifically focus towards targeting solutions for the specific detected physiological alterations. The advances on immobilization methods resulting from this thesis represents a first step towards the improvement of the safety of immobilization of giraffes, black rhinoceroses and buffalos, and by reducing the risk of occurrence of delayed morbidity, it also contributes to the conservation of these East African large-sized herbivores.

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Smith, Caitlin Caryl Danielle. "Giraffa camelopardalis: limb bone histology through ontogeny." Master's thesis, Faculty of Science, 2020. http://hdl.handle.net/11427/32351.

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Although there are many studies on mammalian bone histology, there are only a few that have examined the bone histology of artiodactyls, or focused specifically on osteohistological changes during ontogeny. The current study investigates the microanatomy and histology of giraffe limb bones through ontogeny. Mid-diaphyseal sections of humeri, radii, metacarpals, femora, and tibiae of 14 individuals representing individuals of known sex, as well as at different ontogenetic stages (foetal, juveniles, subadults, and adults). Thin sections were prepared for all the bones, and microanatomical (using Bone Profiler) and histological analyses were conducted on each of the sections. The study examined three main aspects, 1) Crosssectional shape changes in limb bones through ontogeny, 2) Histological changes through ontogeny in each of the limb bones, and 3) Histovariability among skeletons. The results of the study show that the foetus and juvenile individuals have round cross-sections, with small vacant medullary cavities, while cross sections of older individuals tend to be oval with variable amounts of cancellous bone surrounding the medullary cavity. The highest bone compactness values were obtained for the humerus and femur of the foetus, whereas the radius, metacarpal, and tibia bone compactness values are similar across the age classes. In terms of histology, this study found that the earlier ontogenetic stages had highly vascularised fibrolamellar bone in their cortices, which contrasts with that of the subadults and adults where more slowly deposited bone tissue occurs. These observations indicate that after rapid initial growth during early ontogeny, osteogenesis (and overall growth) slows down. This research also documents the fusion of the metacarpal III and IV, and the associated changes that occur in the histology. The study also highlights that the tibia is the only bone that has long radial vascular canals in the cortex. Overall the results of this study have provided a much better understanding of the bone histology of giraffes during ontogeny and has therefore filled an important gap in our knowledge of mammalian bone tissues. Furthermore, this study has direct implications for any future palaeohistological studies of fossil giraffids from Langebaanweg in South Africa.

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Šustrová, Andrea. "Inter-individual distances and interactions among captive giraffes." Master's thesis, Česká zemědělská univerzita v Praze, 2015. http://www.nusl.cz/ntk/nusl-257679.

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Mochon, Daniel. "Giraffes, religion and conflict : essays in behavioral decision making." Thesis, Massachusetts Institute of Technology, 2008. http://hdl.handle.net/1721.1/45331.

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Thesis (Ph. D.)--Massachusetts Institute of Technology, Sloan School of Management, 2008.
Includes bibliographical references.
Essay 1: Objective Scale Anchoring in Sequential Judgments We explore the scope and boundary conditions for anchoring when respondents render sequential judgments in the absence of an explicit comparative standard. We show that previous judgments can anchor subsequent ones, even when these are not explicitly compared. We then demonstrate that the effect is caused by the reinterpretation of objective response scales. Much like the use of the label 'very heavy' will depend on its context, we show that the use of labels such as '1000 pounds' will also depend on context. Even though the pounds scale is objectively defined, psychologically it still must be interpreted, and is subject to similar effects as those that influence subjective scales. Essay 2: The Impact of Regular Activities on Well-being Because of people's tendency to adapt, few events in life have a lasting impact on subjective well-being. We suggest that while major events may not provide lasting increases in well-being, certain seemingly minor events - such as attending religious services or exercising - may do so by providing small but frequent boosts. In two studies we demonstrate the existence of such boosts to well-being, and provide evidence that these boosts may be cumulative. We suggest that shifting focus from the impact of major life changes on well-being to the impact of seemingly minor repeated behaviors is crucial for understanding how best to improve well-being. Essay 3: The Doomsday Device: A Mechanism for Avoiding Conflict Arms races are a common occurrence in the business world. In the current paper, we propose that such arms races can be avoided by the use of commitment to an extreme response, and we test this idea experimentally.
(cont.) Our findings suggest that actual commitment is an effective but underused tool for avoiding the escalation of conflict. We also find that while cheap talk is not effective in the short run, it is useful for establishing a reputation for future interactions.
by Daniel Mochon.
Ph.D.

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Kavanagh, Kayla. "Translating Le coup de la girafe: A Register Analysis of Fictional Orality." Thesis, Université d'Ottawa / University of Ottawa, 2019. http://hdl.handle.net/10393/38840.

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This thesis examines fictional orality through the lens of register theory, and the application of these concepts in translation. Fictional orality is created by the intersection of two registers that are quite distinct in some languages and cultures: the more formal, written literary register, and the informal, spoken register. This results in an entirely new hybrid register, which seeks to balance the spontaneous, informal language of natural speech with the conventions of formal, written language. I aim to explore this hybrid register in my translation of Le coup de la girafe by Camille Bouchard. The story is told in a first-person, present-tense narration, so fictional orality is ubiquitous in the novella, and it is an excellent text to use for this purpose. In this thesis, I first lay out the theoretical framework for my translation by delving into register theory and fictional orality, and how these notions have been adapted to translation studies. Then, drawing on this framework, I discuss how I applied these concepts in my approach to the translation of Le coup de la girafe, using specific examples from the text. After this, I conclude by presenting the translation itself.

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Viljoen, Storme. "Habitat use and diet preference of extralimital giraffes in the Kgalagadi Transfrontier Park." Bachelor's thesis, University of Cape Town, 2013. http://hdl.handle.net/11427/14013.

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Extralimital giraffe introductions in the south-western region of Kgalagadi Transfrontier Park, South Africa, may result in changes to the vegetation structure for the region through overutilization of two keystone tree species in the area. In the areas where giraffe density was highest, I determine the relative abundance of giraffe; their diet preference and the potential reasons for this preference. Using both spoor and dung counts as indicators of giraffe presence, transects were carried out over approximately 20 km of the Auob River. Percentage occurrence was plotted onto a map of the river, along with the location of boreholes that supply the only surface water. Little trend could be seen, although occurrence appeared slightly higher near boreholes. The two trees that most commonly occur in the Auob duneveld, Acacia erioloba and Acacia haematoxylon, were examined for nutritional content, and both chemical and physical defences - all of which are thought to affect herbivore selection. Stable isotope analysis and linear mixing model were used to determine the proportion of each species in the diet of giraffe using the leaves of both species and giraffe dung. The majority of the giraffe's diet consists of A. haematoxylon (mean = 79 %, s.d. = 20.5 %) despite having less crude protein and similar condensed tannin content. Relative lack of physical defences appears to encourage giraffes to exploit A. haematoxylon, which has shorter, weaker thorns. Without management intervention, A. haematoxylon could suffer selective mortality through the impacts of giraffe browsing, resulting in a loss of species and structural diversity of the landscape.

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Fasoli, Sabrina <1988&gt. "Giraffe’s urine: from urinalysis to proteomics and metabolomics." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2021. http://amsdottorato.unibo.it/9655/1/Sabrina_Fasoli_Tesi.pdf.

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This thesis focused on defining the urinary reference values and investigating the urinary proteome and metabolome of captive giraffes (Giraffa camelopardalis) by using a non-invasive sampling method. Urine samples were collected with a syringe from the ground, immediately after spontaneous voiding, by aspirating the upper part of samples, to avoid them to come into contact with the soil contaminants as much as possible. To prove the sampling’s reliability, cow urines were used and the results of both types of samples (those collected in sterile urine cups and those collected from the ground with a syringe) were compared. This experiment revealed no statistical differences in the variables investigated (urine total protein, uTP; urine creatinine, uCrea; urine protein:creatinine ratio, UPC; number of protein bands and band protein quantification detected by 1D-electrophoresis-SDS-PAGE), which proved the reliability of this sampling technique. By establishing the urinary reference values as well as by identifying the urinary proteome, it was possible to obtain information about the renal function in giraffes for the first time. Just like other ruminants, urine of giraffes contains low quantity of proteins, the majority of which shows low molecular mass (MM). The proteins identified in their urines might act as a defence against microbes and play a role in the ability of giraffes to concentrate urine. A first insight into the urinary metabolome allowed to identify and quantify 39 molecules; this provided some information on some physiological adaptations of giraffes and were influenced by sex and age.

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Girard, Elodie. "Attributions causales de la maladie de patients souffrant de douleurs chroniques /." Genève : [s.n.], 2006. http://www.unige.ch/cyberdocuments/theses2006/GirardE/these.pdf.

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Silva, Adao Antonio da. "Construção e análise de um elipsômetro de compensador girante." Universidade de São Paulo, 1985. http://www.teses.usp.br/teses/disponiveis/54/54132/tde-31082009-101352/.

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Neste trabalho, descreveremos a teoria, a construção e algumas aplicações de um elipsômetro fotométrico de compensador girante e analisador fixo (RCFAE). Além disso, foram feitas medidas dos estados de polarização de um feixe de luz, bem como a medida da constante dielétrica complexa, ξ = ╭ - ╮, de um substrato de ouro, a fim de verificar o desempenho d instrumento. Também foi feita uma análise comparativa da sensibilidade (ou poder de resolução) do elipsômetro construído com a do elipsômetro de analisador girante. Além disso, mostraremos como os resultados das medidas, são independentes da intensidade da luz incidente.
In this work we describe the theory, construction and most important applications of a photometric elipsometer with routing compensator and fixed analyzer. We also analyze the procedures for measuring the polarization states of a light beam and the complex dielectric constant of a substrate of gold, in order to verify the performance of instrument. A comparative analysis of the sensibility (or resolution power) of the elipsometer built with an elipsometer of routing was also made. We show that the results of the measurements are independent of the intensity of the incident light.

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Olsen, Ricardo Lastra. "Torquímetro girante com transmissão de sinal sem contato elétrico." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 1992. http://hdl.handle.net/10183/129429.

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Este trabalho analisa aspectos de projeto e construção de um torquímetro girante para aplicações que exijam boa precisão, confiabilidade e monitoramento contínuo. Um condicionador de sinais é acoplado ao eixo girante, sendo alimentado por um transformador rotativo. A transmissão do sinal de torque, modulado em freqüência, da parte girante para a estática, é feita capacitivamente, sem a utilização de contatos elétricos. Um protótipo foi construído e testado, detalhes do seu projeto elétrico e mecânico são apresentados.
This work examines the design and manufacturing aspects of a rotating torquemeter for applications that requires good accuracy and continuous monitoring. A signal conditioner is attached to the rotating shaft, being energized by a rotary transformer. The transmission of the frequency modulated torque signal, from the rotating shaft to the stationary housing, is established in a contacless, capacitive, way. A prototype was constructed and tested, details of the electrical and mechanical designs are shown.

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Sullivan, Kathleen Elizabeth. "The Impact of Nutrition on the Development of Urolithiasis in Captive Giraffes and Meat Goats." NCSU, 2007. http://www.lib.ncsu.edu/theses/available/etd-12042006-190320/.

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Obstructive urolithiasis is a documented problem in domestic ruminants, such as the meat goat, and also in captive giraffe. A survey of the health history, feeding practices, and dietary contents in captive giraffes in North America was conducted to examine the possible connection between diet and the development of urolithiasis. Samples of urine, serum and feed were collected and analyzed for basic panels and mineral content. There appeared to be a positive correlation between diet and physiologic phosphorus levels in giraffe. This may not have been related to the ingredients of the diet but rather to the ratio of concentrate to hay eaten and the nutrient composition of the concentrate. We hypothesized that high phosphorus content in the diet and a high level of concentrate feeding would increase indicators of urolith formations including crystal formation and high urine mineral content. We followed up with a metabolic trial in meat goats, testing 2 different complete pelleted feeds and 2 complete pelleted feed to hay ratios in a 2 by 2 factorial randomized complete block design. The intent of this study was to look at the impact of type of diet (ADF-16 or Wild Herbivore complete pelleted feed) and complete pelleted feed to hay ratios (20 or 80 % hay) on the development of urolithiasis in meat goats, in the context of captive giraffe feeding practices. The four treatments had a range of fiber content and differed in mineral content, particularly Ca to P ratio and levels of P. We also measured the number of crystals in the fresh urine, as these may be considered precursors to urolith formation. The ADF-16 diet where hay was 20% of the diet had the lowest levels of fiber, lowest Ca to P ratio, and highest level of phosphorus compared to the other 3 diet treatments. From our results, it can be concluded that feeding the ADF-16 diet where hay is 20% of the diet, produced a trend of high urinary P, high serum P and a tendency for a high crystal count in the urine over the four week experimental period. These can be considered strong risk factors for the development of phosphatic uroliths. As one third of the zoos which responded to the survey fed a majority of their diets as ADF-16, this conclusion warrants further investigation.

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Gustavsson, Robin, Emil Jacobsen, and Gabriel Thomasson. "“Ett kvarter, inte ett köpcentrum” : En fallstudie om könsskillnader inom sinnesmarknadsföring på Giraffen i Kalmar." Thesis, Linnéuniversitetet, Institutionen för marknadsföring (MF), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-95971.

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Sinnesmarknadsföring är en viktigt aspekt för organisationer och påverkar alla människor medvetet eller undermedvetet. Studien fokuserar på tre sinnen, syn, doft och hörsel kopplat till den traditionella könsuppdelningen. Syftet är att kartlägga sinnesmarknadsföring på ett köpcentrum i Kalmar med namn Kvarteret Giraffen. Det är möjligt att segmentera efter könen för att på så sätt omfamna i stort sätt alla människor. Fallstudien undersöker hur Kvarteret Giraffen arbetar med sinnesmarknadsföring och om det är den rätta vägen att gå. Detta genomförs med kvalitativa intervjuer med både experter inom ämnet och personer med direkt koppling till Giraffen. Bör Giraffen använda sinnesmarknadsföring i förhållande till könen eller fortsätta med nuvarande strategi. Resultatet visar att Kvarteret Giraffen bör marknadsföra sig könsneutralt, men frågor och funderingar kring fenomenet uppmärksammas hos respondenter.
Sensory marketing is something every organization should take into consideration as it affects all people either consciously or subconsciously. The study focuses on three crucial senses, vision, scent, and hearing, in connection to the traditional gender divide. The purpose is to map sensory marketing on a shopping mall in Kalmar called Kvarteret Giraffen. It is possible to segment by gender, thus embracing virtually all people. The case study examines how Kvarteret Giraffen is working with sensory marketing and whether it is the right way to go or not. This is done with qualitative interviews with both experts in the subject and people with direct connection to Giraffen. Should Kvarteret Giraffen use sensory marketing relative to gender or continue with its current strategy. The result shows that Kvarteret Giraffen in question should use a gender-neutral marketing approach, however, questions and reflections about the phenomenon are noticeable among the respondents.

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Backelin, Kristina, Anna-Sofie Oveland, and Lena Salorinne. "När den nya tekniken knackar på, öppnar kommunen då? : Den kommunala omsorgens förhållande till Giraff och tekniska hjälpmedel." Thesis, Mälardalen University, School of Sustainable Development of Society and Technology, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-9992.

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Syftet är att få samt skapa förståelse för hur en kommun resonerar inför införskaffandet av tekniska hjälpmedel. Köpbeslutsprocessen för B2B utgör den teoretiska grunden. En kvalitativ undersökning i form av semistrukturerade telefonintervjuer genomfördes och totalt intervjuades elva respondenter. Slutsatsen är att på nämnd- och tjänstemannanivå finns ett tydligt intresse för ny teknik. Fördröjande faktorer för implementeringen av tekniska hjälpmedel är snarare personalens skepsis och ej anpassade förhandlingsdirektiv. Resultaten pekar dock på att marknaden för tekniska hjälpmedel kommer att växa.

The purpose is to gain and create an understanding of how municipalities argue at the prospect of procuring technical aids. The Buying Decision-making Process for B2B is the theoretical base. A qualitative study made up by semi-structured telephone interviews was conducted and in total there were eleven respondents. The conclusion is that on a political and managerial level there is an evident interest for new technology. Delaying factors are the scepticism of the staff and out-dated directives for negotiations. The results do however indicate that the market for technical aids will grow.

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Pereira, Marcelo José Fernandes, Sérgio Henrique Lopes Cabral, and Universidade Regional de Blumenau Programa de Pós-Graduação em Engenharia Elétrica. "Aplicação de máquina elétrica girante de imã permanente em geradores eólicos /." reponame:Biblioteca Digital de Teses e Dissertações FURB, 2012. http://www.bc.furb.br/docs/DS/2012/350517_1_1.pdf.

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Gloneková, Markéta. "Mateřské chování žiraf (Giraffidae)." Doctoral thesis, Česká zemědělská univerzita v Praze, 2016. http://www.nusl.cz/ntk/nusl-259716.

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Allomaternal care is one of the most interesting types of cooperation among females. Its most extreme form is allonursing, nursing of a non-filial young, which is still not completely understood, even though many hypotheses have been postulated. This type of cooperation among giraffes had not been expected for long time. This was based on the initial opinion that giraffes do not have social system and form only weak social bonds. However, my bachelor and master theses showed high occurrence of allonursing in captive giraffes. The first aim (1) of this thesis was to test all possible hypotheses explaining allonursing in captive giraffes. However, a lot of the information needed to test them were missing, which resulted in the formulation of further aims. The second aim (2) was to test the hierarchy in captive giraffes. The third aim (3) was to describe the growth and weight of captive giraffes. The fourth aim (4) was to compare nursing patterns in the zoo and in the nature reserve Bandia, Senegal and the last aim (5) was to test the social bonds among giraffes in the nature reserve Bandia, Senegal. (1) From 2007 to 2011, the nursing behaviour of 24 females and 37 calves was observed. Eighty-three percent of the females allonursed a nonfilial calf and 86.5% of calves allosuckled from a nonmaternal female. Allonursing in giraffes was explained by milk-theft from the point of view of the calves and possible reciprocity among females. (2) The agonistic interactions of 31 giraffes were recorded in four herds. A linear hierarchy was been found among giraffes and rank was significantly affected by age and time spent in the herd. (3) The weight data from 43 giraffes in Prague zoo were collected from 2009 to 2013 and provided the basic information about giraffe growth and weight. (4) I also observed the nursing behaviour of seven and four female-calf pairs in the fenced Bandia reserve, Senegal, and in Prague zoo, respectively, both for 22 days. The differences in nursing patterns were likely to reflect anti-predator behaviour, the population density of animals and the distribution of food resources. (5) Finally, I investigated the social preferences of 28 introduced giraffes in semi-captivity in the nature reserve Bandia, Senegal and provided the results supporting the existence of a fission fusion social system among giraffes with social preferences among adult females. The overall results provide unique findings on allonursing in general as well as changing our perspective on giraffe social behaviour.

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Arantes, André Gustavo Borges. "Alocação de reserva girante em sistemas hidrotérmicos com penetração de geração eólica." reponame:Repositório Institucional da UFPR, 2017. http://hdl.handle.net/1884/52577.

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Orientadora : Profª. Drª. Thelma S. Piazza Fernandes
Coorientador : Prof. Dr. Clodomiro Unsihuay Villa
Dissertação (mestrado) - Universidade Federal do Paraná, Setor de Tecnologia, Programa de Pós-Graduação em Engenharia Elétrica. Defesa: Curitiba, 28/04/2017
Inclui referências : f. 84-88
Resumo: Tendo em vista a crescente diversificação da matriz energética brasileira, que tem aumentado sua participação térmica e eólica, deve-se dar redobrada atenção ao provimento de reserva girante, pois a intermitência e natureza aleatória dos ventos resulta em um grande desafio para coordená-la a um sistema hidrotérmico de grande porte. Isto exige aumento da disponibilidade de reserva girante como solução para diminuir o risco de déficit nos momentos de quedas na geração eólica, o que resulta em um custo operativo maior. Assim, este trabalho propõe modelo computacional de apoio à decisão para despacho de potência e reserva para diferentes níveis de penetração de energia eólica e diversidade hidrológica. Para tanto, foi modelado um Fluxo de Potência Ótimo não linear e intertemporal, que além de realizar o despacho de potência ativa e reativa de um sistema hidrotérmico (incluindo restrições elétricas e energéticas) para um horizonte de uma semana ou um dia a frente, é capaz também de fazer alocação ótima de reserva girante (hidráulica e térmica). O modelo foi testado em um sistema de 33 barras que representa o sistema sul equivalente do Brasil. Os resultados obtidos para diferentes cenários hidrológicos e diferentes níveis de penetração eólica são capazes de identificar diferentes despachos de potência e de reserva distribuídos entre as fontes hidroelétricas e térmicas,assim como identificar diferentes custos operacionais envolvidos. Palavras chave:Reserva girante, geração eólica, despacho eólio hidrotérmico
Abstract: In view of the increasing diversification of the Brazilian energy matrix, which has increased its thermal and wind participation, attention should be paid to the provision of spinning reserve, because the intermittency and random nature of the winds result in a great challenge to coordinate it with a large hydrothermal system.This requires increasing the availability of spinning reserve as a solution to reduce the risk of deficits at times of wind power downtime, which results in a higher operating cost. Thus, this paper proposes a computational decision support model for power dispatch and reserve for different levels of wind energy penetration and hydrological diversity. In order to do so, a nonlinear and intertemporal Optimal Power Flow was modeled which, in addition to performing the active and reactive power dispatch of a hydrothermal system (including electrical and energy restrictions) for a horizon of one week or one day ahead, is capable also to allocate optimal spinning reserve (hydraulic and thermal). The model was tested in a system of 33 buses that represents the south equivalent system of Brazil.The results obtained for different hydrological scenarios and different levels of wind penetration are able to identify different power and reserve dispatches distributed between hydroelectric and thermal sources, as well as to identify different operational costs involved. Key words: Spinning reserve, wind generation, hydropower

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Dissertations / Theses on the topic 'Giraffe'

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