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.

My master's thesis deals with monitoring of giraffes group (mainly three members - male Johan, cow Berta and young cow Laura) in Prague zoological garden in the period from summer 2012 till spring 2013. Behavior of three chosen individuals is presented in the form of graphs and charts for better clarity. Overview of all Giraffidae Family, its description and living area, is included in the thesis. Zoological gardens breeding giraffes and conditions of their breed are included in this project.

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.

No description available.

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.

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.

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

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 / 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 / Doctor of Science / Kyoto University / DGAM

I en komplex miljö som skärgårdar väntar en del utmaningar. Detta tillsammans med den teknik som finns idag inom UAV området skapar nya hotbilder. Ett av fartygen som den svenska flottan använder är Visbykorvetten, som är ett komplext system med kompetent förmåga som ska kunna lösa många uppgifter. Rapporten avser att analysera vilket hot som drönare kan utgöra mot Visbykorvetten.   Några UAV som används i kriget i Ukraina är Switchblade 300, 600 och Shahed-136. Arbetet syftar till att undersöka dessa UAV och vilket hot de kan utgöra mot en Visbykorvett, i syfte för att se om korvettens skydd är tillräckligt.  Fartyget har ett bra egenskydd mot ankommande hot från luften, dock på grund av vapensystemens placering på fartyget uppstår en begränsning i möjligheterna att erhålla ett eget skydd runt hela fartyget. Detta kan även försvåras av den komplexa miljö som skärgården medför. Begränsningen i egenskyddet bedöms en UAV kunna nyttja och på så sätt få möjligheten att skada fartygets sensorer som sitter relativt oskyddade. Vilket medför att fartyget inte fullt ut kan lösa tilldelade uppgifter utan är behov av att repareras. För att undvika detta kan fyra olika åtgärder vidtas. Undvika trånga sund om det är möjligt, fråga externa marina förband om eskortmöjligheter, eller installera vapenstation på akterdäck för att öka egenskyddet, och ge fartyget signalstörningsförmåga. / The complex environments that the archipelago provides, alongside the technical developments of drones, create a new form of threat. The Visby class corvette is a complex platform that can fulfil many different tasks both above and below the surface. This thesis will look closer at its surface-to-air defense system, and capability to defend against drones. Some of the drones that are used in the Russo-Ukrainian war, are Switchblade 300, 600 and Shahed-136. The thesis aims to investigate these drones and what threat they may pose against a Visby Corvette, to see if the ship’s protection is sufficient.  The ship has good self-protection against incoming threats from the air, but due to the location of the weapon systems on the ship, there is a limitation in obtaining full protection. The protection can also be hampered by the complex environment that the archipelago entails. A drone can exploit this limitation of self-protection and obtain the possibility of damaging the sensors of the ship that are relatively unprotected. This means that the ship cannot fully solve the assigned tasks due to its need for repairs.  In conclusion, to prevent this, four different actions can be taken. Avoid narrow straits, if possible. Ask external units for escort. Install a weapon station in the stern to increase self-protection and provide the vessel with signal interference technology.

Försvarsmakten är under en återuppbyggnad och står inför en stor nyanskaffning av materiel till samtliga delar av organisationen. 161. Stridsledning- och luftbevakningsbataljonen skall utöka och ersätta delar av den befintliga sensorkedjan med nya system där det finns utrymme för anskaffning av rörliga markbaserade radarsystem.  Tidigare forskning och rapporter från bland annat FOI och Försvarsmakten kopplat mot framtidens radarsensorer tyder på att AESA-radarer är väl lämpliga vid en framtida anskaffning. Arbetet är av tekniskt beskrivande karaktär och använder teorin om militär nytta samt analysverktyget multimålmetoden. Arbetets syfte är att undersöka om de framtagna värderingskriterierna kostnad, rörlighet, masthöjd och målupptäckt skulle kunna användas vid en svensk anskaffning av ett rörligt markbaserat radarsystem. Slutsatsen är att värderingskriterierna som tagits fram i arbetet kan och bör användas vid en anskaffning av ett rörligt markbaserat radarsystem. Dock behöver värderingskriterierna fördjupas ytterligare för att i framtida användning få fram ett mer precist resultat. / The Swedish Armed Forces are undergoing a re-establishment and are facing a major new acquisition of equipment for all parts of the organization. 161. Combat Control and Air Surveillance Battalion will increase and replace parts of the existing sensor chain with new systems where there is room for the acquisition of mobile ground-based radar systems.  Previous research and reports from, among others, FOI and the Swedish Armed Forces related to future radar sensors indicate that AESA radars are well suited for in a future acquisition. This report is of a technical descriptive type and uses the theory of military utility and the analysis tool multi-criteria decision. The purpose of the report is to investigate whether the valuation criteria’s cost, mobility, mast height and target detection should be used as criteria in a Swedish acquisition of a mobile ground-based radar system. The conclusion is that the evaluation criteria concluded in the report can and should be used in the acquisition of a mobile ground-based radar system. However, the evaluation criteria need to be further deepened to obtain a more precise result in future use.