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The Republic of South Africa is rich in the species of large and small wild herbivores and ixodid ticks that infest them and the domestic livestock within its borders. The primary objective of this study was to determine the species composition and actual size of the tick burdens of a variety of small and large herbivorous animals in several localities in South Africa. To this end a total of 95 wild herbivores ranging in size from hares to giraffes and belonging to 25 species were examined at 20 various localities in South Africa. The survey localities in alphabetical sequence were the Addo Elephant National Park, “Bucklands” farm, the Eastern Shores Nature Reserve, the Hluhluwe Nature Reserve, the Karoo National Park, the Kgalagadi Transfrontier Park, a farm at Kirkwood, eight localities within the Kruger National Park, the Mountain Zebra National Park, the Tembe Elephant Reserve, the Thomas Baines Nature Reserve, the Umfolozi Nature Reserve, and the West Coast National Park. Sampling took place between 1982 and 1996. The animal species surveyed were giraffe, Giraffa camelopardalis; African buffalo, Syncerus caffer; eland Taurotragus oryx; Burchell’s zebra, Equus burchelli; black wildbeest, Connochaetes gnou; blue wildbeest, Connochaetes taurinus; tsessebe, Damaliscus lunatus; Lichtenstein’s hartebeest, Sigmoceros lichtensteinii; bontebok, Damalisus pygargus dorcas; red hartebeest, Alcelaphus buselaphus; nyala, Tragelaphus angasii; bushbuck, Tragelaphus scriptus; greater kudu, Tragelaphus strepsiceros; gemsbok, Oryx gazella; springbok, Antidorcas marsupialis; grey rhebok, Pelea capreolus; mountain reedbuck, Redunca fulvorufula; boer goats, Capra hircus; a domestic calf, Bos sp.; suni, Neotragus moschatus; steenbok, Raphicerus campestris; rock hyrax, Procavia capensis; cape ground squirrels, Xerus inauris; scrub hares, Lepus saxatilis; and Smith’s red rock rabbits, Pronolagus rupestris. Ticks were collected from the survey animals after they had been killed by a process of soaking in a tick-detaching agent followed by scrubbing and sieving, or by careful scrutiny after the animals had been chemically immobilized. Thirty ixodid tick species, namely Amblyomma hebraeum, Amblyomma marmoreum, Rhipicephalus (Boophilus) decoloratus, Haemaphysalis parmata, Haemaphysalis silacea, Hyalomma glabrum, Hyalomma marginatum rufipes, Hyalomma truncatum, Ixodes rubicundus, Ixodes pilosus group, Margaropus winthemi, Rhipicephalus appendiculatus, Rhipicephalus arnoldi, Rhipicephalus capensis, Rhipicephalus distinctus, Rhipicephalus evertsi evertsi, Rhipicephalus exophthalmos, Rhipicephalus follis, Rhipicephalus glabroscutatum, Rhipicephalus gertrudae, Rhipicephalus kochi, Rhipicephalus maculatus, Rhipicephalus muehlensi, Rhipicephalus neumanni, Rhipicephalus sp. near pravus, Rhipicephalus theileri, Rhipicephalus simus, Rhipicephalus zambeziensis, and an unidentified Ixodes and Rhipicephalus species were recovered from the animals. All the tick species recovered in this study have been tabulated according to their distributions within the climatic zone of the Republic of South Africa. A total of 64 of the abovementioned herbivores ranging in size from medium to very large, belonging to 15 various species were examined in 11 national parks, or nature reserves or farms during 1982 - 1996. The tick species infesting the medium and small-sized animals were to some extent similar to those of very large animals. The medium-sized survey animals mostly harboured A. hebraeum, R. (B.) decoloratus, R. appendiculatus, R. evertsi evertsi and R. glabroscutatum whereas the tick burdens of the very large antelopes consisted mostly of A. hebraeum, R. (B.) decoloratus, R. appendiculatus, R. maculatus and R. muehlensi. The very large hosts harboured proportionately more adult ticks than the smaller animals which harboured proportionately more immature ticks. An interesting finding was the recovery of Rhipicephalus sp. near R. pravus from giraffes in the north-eastern Mpumalanga province and these very closely resembled the true R. pravus which occurs in East Africa. A further objective of this study was to make an inventory of the ixodid tick species infesting wild animals in three of the western, semi-arid nature reserves in South Africa. To this end the tick burdens of a total of 45 animals in the Karoo National Park, the Kgalagadi Transfrontier Park and the West Coast National Park were determined. Fourteen ixodid tick species were recovered, of which H. truncatum, R. exophthalmos and R. glabroscutatum were commonly present in two reserves and the remaining species each only in one reserve. H. truncatum, R. capensis and R. glabroscutatum were the most numerous of the ticks recovered, and eland were the most heavily infested with the former two species and gemsbok and mountain reedbuck with R. glabroscutatum. Nine very small antelopes, six of which were steenbok and three were sunis and to my knowledge whose total tick burdens had never before been determined were also examined. The steenbok were examined in three nature reserves and harboured nine tick species and the sunis were examined in a fourth reserve and were infested with eight tick species. The steenbok and sunis were generally infested with the immature stages of the same tick species that infest larger animals in the same geographic regions. In addition the sunis harboured H. parmata, which in South Africa is present only in the eastern and north-eastern coastal and adjacent areas of KwaZulu-Natal Province. They were also infested with R. kochi, which in South Africa occurs only in the far north-east of the KwaZulu-Natal and Limpopo Provinces. A further objective of the study was to assess the host status of African buffaloes for the one-host tick R. (B.) decoloratus. To this end the R. (B.) decoloratus burdens of ten buffaloes examined in three north-eastern KwaZulu-Natal Province (KZN) nature reserves were compared with those of medium-sized to large antelope species in these reserves and in the southern Kruger National Park (KNP), Mpumalanga Province. The R. (B.) decoloratus burdens of the buffaloes were considerably smaller than those of the antelopes in the KNP, but not those in the KZN reserves. The life-stage structure of the R. (B.) decoloratus populations on the buffaloes, in which larvae predominated, was closer to that of this tick on blue wildebeest, a tick-resistant animal, than to that on other antelopes. A single buffalo examined in the KNP was not infested with R. (B.) decoloratus, whereas a giraffe, examined at the same locality and time, harboured a small number of ticks. In a nature reserve in Mpumalanga Province adjacent to the KNP, two immobilized buffaloes, from which only adult ticks were collected, were not infested with R. (B.) decoloratus, whereas greater kudus, examined during the same time of year in the KNP harboured large numbers of adult ticks of this species. African buffaloes would thus appear to be resistant to infestation with R. (B.) decoloratus, and this resistance is expressed as the prevention of the majority of tick larvae from developing to nymphs. / Dissertation (MSc (Veterinary Science))--University of Pretoria, 2006. / Veterinary Tropical Diseases / unrestricted

京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第20214号 / 理博第4299号 / 新制||理||1617(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)准教授 川北 篤, 教授 田村 実, 准教授 酒井 章子 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM

A raiva é uma antropozoonose com alta letalidade, acomete todos os animais de sangue quente, essa doença causa enormes prejuízos econômicos ao rebanho pecuário nacional, é impossível estimar os custos reais com controle dessa doença, em decorrência do grande número de subnotificações. O uso de ferramentas moleculares permite identificar as linhagens virais circulantes, facilitando desse modo à compreensão da epidemiologia da raiva. A técnica de RT-PCR para amplificação parcial dos genes N e G, foi aplicada em 60 amostras positivas para o vírus da raiva pelas provas de imunofluorescência direta e prova biológica, procedentes dos Estados do Pará, Tocantins, Rondônia e Acre das espécies bovina, equídea, bubalina e suína. As sequências nucleotídicas obtidas para os genes N (41 amostras) e G (17 amostras) foram analisadas pelo algoritmo Neighbor-Joining e modelo evolutivo Kimura 2-parâmetros. Essa análise permitiu identificar distintas linhagens circulantes nas regiões estudadas, foi evidenciado ainda, um padrão de distribuição geográfico dessas linhagens. Além disso, este estudo possibilitou identificar marcadores moleculares para diferentes regiões geográficas, promovendo um melhor entendimento da epidemiologia molecular da raiva das linhagens circulantes da região em estudo. / Rabies is an anthropozoonosis with high mortality, affects all warm-blooded animals, this disease causes major economic losses to livestock. It is difficult to estimate the actual costs of disease control, due to sub notification of cases. Molecular techniques allow identification of genetic viral strains circulating, improving rabies epidemiology comprehension. Sixty rabies virus isolates from bovines, equines, swine and buffaloes coming from the states of Pará, Tocantins, Rondônia and Acre were analyzed in the present study. All samples were previously submitted to direct immunofluorescence test and inoculation in mice, afterwards were submitted to RT-PCR for amplification of partial Nucleoprotein and Glycoprotein genes. Nucleotide sequences from nucleoprotein (41 samples) and glycoprotein G (17 samples) genes were analyzed by Neighbor-joining algorithm and Kimura two-parameter model. This analysis allowed to identify different genetic strains circulating and its geographic distribution patterns. Moreover this study revealed molecular markers for different geographic regions, promoting a better understanding of rabies molecular epidemiology of circulating strains of study area.

A raiva é uma antropozoonose com alta letalidade, acomete todos os animais de sangue quente, essa doença causa enormes prejuízos econômicos ao rebanho pecuário nacional, é impossível estimar os custos reais com controle dessa doença, em decorrência do grande número de subnotificações. O uso de ferramentas moleculares permite identificar as linhagens virais circulantes, facilitando desse modo à compreensão da epidemiologia da raiva. A técnica de RT-PCR para amplificação parcial dos genes N e G, foi aplicada em 60 amostras positivas para o vírus da raiva pelas provas de imunofluorescência direta e prova biológica, procedentes dos Estados do Pará, Tocantins, Rondônia e Acre das espécies bovina, equídea, bubalina e suína. As sequências nucleotídicas obtidas para os genes N (41 amostras) e G (17 amostras) foram analisadas pelo algoritmo Neighbor-Joining e modelo evolutivo Kimura 2-parâmetros. Essa análise permitiu identificar distintas linhagens circulantes nas regiões estudadas, foi evidenciado ainda, um padrão de distribuição geográfico dessas linhagens. Além disso, este estudo possibilitou identificar marcadores moleculares para diferentes regiões geográficas, promovendo um melhor entendimento da epidemiologia molecular da raiva das linhagens circulantes da região em estudo. / Rabies is an anthropozoonosis with high mortality, affects all warm-blooded animals, this disease causes major economic losses to livestock. It is difficult to estimate the actual costs of disease control, due to sub notification of cases. Molecular techniques allow identification of genetic viral strains circulating, improving rabies epidemiology comprehension. Sixty rabies virus isolates from bovines, equines, swine and buffaloes coming from the states of Pará, Tocantins, Rondônia and Acre were analyzed in the present study. All samples were previously submitted to direct immunofluorescence test and inoculation in mice, afterwards were submitted to RT-PCR for amplification of partial Nucleoprotein and Glycoprotein genes. Nucleotide sequences from nucleoprotein (41 samples) and glycoprotein G (17 samples) genes were analyzed by Neighbor-joining algorithm and Kimura two-parameter model. This analysis allowed to identify different genetic strains circulating and its geographic distribution patterns. Moreover this study revealed molecular markers for different geographic regions, promoting a better understanding of rabies molecular epidemiology of circulating strains of study area.

京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第19529号 / 理博第4189号 / 新制||理||1601(附属図書館) / 32565 / 京都大学大学院理学研究科生物科学専攻 / (主査)教授 大串 隆之, 教授 中野 伸一, 教授 曽田 貞滋 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM

Thesis (PhD)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: Understanding how divergent selection results in the evolution of reproductive isolation (i.e. speciation) is an important goal in evolutionary biology. Populations of herbivorous insects using different host plant species can experience divergent selection from multiple selective pressures which can rapidly lead to speciation. Restio leafhoppers are a group of herbivorous insect species occurring within the Cape Floristic Region (CFR) of South Africa. They are specialised on different plant species in the Restionaceae family. Throughout my thesis I investigated how bottom-up (i.e. plant chemistry/morphology of host plant species) and top-down (i.e. predation and competition) factors drive specialisation and divergence in restio leafhoppers. I also investigated interspecific competition as an important determinant of restio leafhopper community structure. In chapter 2 I quantified host specificity of restio leafhopper species within a local community for 24 months. I found that restio leafhopper species are highly host specific and potentially synchronised with the growth phases of their host plants. In chapter 3 I used a network metric, modularity, to determine whether host plant partitioning in a restio leafhopper community is non-random (i.e. driven by a deterministic process). This metric allows the identification of the components underlying host plant partitioning (modules). I then performed experiments to show that modules, and therefore host plant partitioning, can mostly be explained by preference and performance relationships (i.e. bottom-up factors). In chapter 4 I used null models to test whether niche partitioning in restio leafhopper communities is a general pattern across the landscape. I found non-random niche partitioning, which results from strong host specificity, in all investigated restio leafhopper communities. In addition, I performed binary host choice experiments in the presence and absence of interspecific competition, but found no evidence that interspecific competition narrows host preferences. These findings suggest that host specificity, the cause of niche partitioning, is likely shaped over evolutionary time. Sampling multiple interaction networks across the CFR, in chapter 5, I tested whether restio leafhopper populations are more host specific in species rich communities and regions in the CFR than in species poor communities and regions. I found no positive relationship between restio leafhopper species richness and host specificity at any scale. These findings suggest that specialisation is not driven by interspecific competition. In chapter 6 I investigated host shifts in Cephalelus uncinatus. C. uncinatus has a broader distribution than any single restio species that it can use; suggesting that host plant related divergence may result from geographic range expansion. I found that allopatric and parapatric populations, but not sympatric individuals, using different host plants have divergent host preferences. I also found evidence for morphological divergence in traits related to predator avoidance in population pairs that exhibit divergent host preferences. My findings emphasise the importance of both bottom-up and top-down factors, with the exception of interspecific competition, as determinants of specialisation and divergence in restio leafhoppers. I find no evidence that interspecific competition is an important force structuring restio leafhopper communities. Instead, strongly niche partitioned community structure appears to emerge from the speciation process. / AFRIKAANSE OPSOMMING: Die wyse waarop uiteenlopende seleksie lei tot die evolusie van seksuele isolasie (n.l. spesiasie) is ‘n belangrike vraag in evolutionêre biologie. Plantetende insekpopulasieses wat verskillende gasheerplante gebruik kan onder uinteenlopende veelvoudige seleksie wees en vinnig spesiasie ondergaan. Restio-blaarspringers is ‘n groep plantetende insekspesies wat gespesialiseerd is op verskillende plantspesies in die restio familie. In my tesis ondersoek ek die onder-op (n.l. plantchemie en morfologie) en bo-af seleksiekragte (n.l. predasie en kompetisie) wat lei tot gasheerspesialisasie en -spesiasie in restio-blaarspringers. Ek ondersoek ook die belangrikheid van tussen-spesieskompetisie in gemeenskapsorganisasie. In hoofstuk 2 het ek gasheerspesialisasie gekwantifiseer in ‘n klein restio-blaarspringergemeenskap oor 24 maande. Ek het gevind dat restio-blaarspringers hoogs gasheerspesifiek is en moontlik met die groeifase van hul hoofgasheerplante gesinchroniseerd is. Ek het in hoofstuk 3 ‘n netwerkmetriek, modulariteit, gebruik om te bepaal of restio-blaarspringers se gasheerverdeling nie-stokasties is (n.l. deur deterministiese prosesse veroorsaak is). Hierdie metriek laat ‘n mens toe om die komponente van gasheerverdeling (modules) te identifiseer. Deur middel van eksperimente het ek bepaal dat modules, en dus gasheerverdeling, deur gasheervoorkeur en prestasie (onder-op prossesse) verduidelik kan word. In hoofstuk 4 het ek ondersoek of gasheerverdeling algemeen is. Ek het deur middel van nulmodelle gewys dat gasheerverdeling algemeen is en veroorsaak is deur sterk gasheerspesifiekheid. Ek het ook voorkeureksperimente uitgevoer in die teenwoordigheid en afwesigheid van tussen-spesies kompetisie. Hier het ek geen teken gevind dat huidige tussen-spesies kompetisie gasheervoorkeur beïnvloed nie. My bevindinge in hierdie hoofstuk stel dus voor dat spesialisasie, die oorsaak van gasheerverdeling, oor evolutionêre tyd gevorm word. In hoofstuk 5 het ek ondersoek of populasies van restio-blaarspringers meer gasheerspesifiek is in restio-blaarspringerspesies ryke gemeenskappe en streke as populasies in spesies-arm gemeenskappe en streke. Ek het geen positiewe korrelasie tussen spesiesrykheid en gasheerspesialisasie gevind nie. Dit dui daarop aan dat gasheerspesialisasie, en dus gasheerverdeling, nie deur tussen-spesies kompetisie veroorsaak word nie. In hoofstuk 6 het ek gasheerplantgekoppelde divergensie ondersoek in Cephalelus uncinatus. C. uncinatus se verspreiding is breër as enige restio-spesies wat dit kan gebruik. Dit stel voor dat verspreidingvergroting gasheerverskuiwing mag veroorsaak. Ek het gevind dat populasies wat verskillende plante in allopatrie en parapatrie gebruik uiteenlopende gasheerkeuses maak, maar insekte wat verskillende plante in sympatrie gebruik wys nie ontwrigtende gasheerkeuses nie. Die populasies wat uiteenlopende gasheerkeuses getoon het, het ook verskillende morfologiese teen-predasie eienskappe getoon. Dit dui daarop aan dat predasie belangrik mag wees vir spesiasie in restio-blaarspringers. Die bevindinge van my tesis dui daarop aan dat beide onder-op en bo-af seleksie belangrik is vir gasheer-spesialisasie in divergensie. Nietemin, tussen-spesies kompetisie is nie ‘n belangrike bron vir spesialisasie, divergensie of gemeenskapsorganisasie nie. Gemeenskapsorganisasie is klaarblyklik slegs ‘n gevolg van die spesiasie proses.

Afin d'accroître leur survie et leur succès reproducteur, les espèces proies tentent de maximiser leur apport énergétique tout en évitant la prédation, induisant un compromis entre acquisition des ressources alimentaires et détection des prédateurs. Cependant, les ajustements comportementaux des herbivores impliqués dans ce compromis peuvent être influencés par de nombreux paramètres environnementaux, sociaux et individuels et varier entre individus d'une population. Ce travail de thèse a pour objectif de mieux comprendre comment les herbivores proies ajustent leur compromis entre vigilance et approvisionnement en fonction du risque de prédation, du contexte social et de la disponibilité des ressources ; ainsi que d'étudier si ces ajustements varient entre individus. Basées sur l'étude de femelles kangourous gris de l'Est (Macropus giganteus) et de femelles impala (Aepyceros melampus), j'ai tout d'abord observé que bien que de nombreux facteurs influençaient la vigilance et l'approvisionnement à court terme, ces comportements étaient principalement influencés par la variation de la ressource à long terme. Ensuite, j'ai démontré que les variations de contextes écologiques et sociaux tels que le risque de prédation, la ressource alimentaire et la compétition induisaient des réponses comportementales différentes au regard de ce compromis, ainsi que sur la fonction et le coût de la vigilance. Enfin, j'ai observé l'existence de variations entre individus, plus ou moins exprimées dans différentes conditions. Il apparaît que les animaux régulent leur activité de vigilance afin de maximiser l'acquisition de ressources, ou d'informations sociales, tout en assurant leur sécurité / Prey species foraging under a risk of predation have to trade between food acquisition and safety from predation in order to increase their fitness. This trade-off is commonly investigated by studying the trade-off between foraging and vigilance activities. However, vigilance and foraging can be affected by numerous environmental, social, and individual parameters which can also vary seasonally and differ between individuals from the same population. In this context, the overall objective of my PhD was to better understand how herbivorous prey animals manage the feeding/vigilance trade-off at a fine scale, considering the wide range of variables that may affect it, individual variation, and the different functions of vigilance, using female eastern grey kangaroos (Macropus giganteus) and impalas (Aepyceros melampus) as models. I observed that despite the many factors that shape vigilance and feeding rates over short time scales, these behaviours were mainly driven by variation in food resources over longer temporal scales. I also highlighted that predator and social contexts induced different behavioural responses in relation to this trade-off, and that decisions of prey to adjust their vigilance in terms of function and cost were driven by predation risk, food availability, and competition but varied between seasons. Finally, I observed that between-individual variation occurs for this trade-off but that this variation is context dependant. This thesis shows that prey animals constantly adapt their behaviour and strategies according to the situation they experience, in order to balance the acquisition of food and social information with staying safe

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