Biological Sciences

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Aligning elephant conservation with societal aspirations.
(2022) Van de Water, Antoinette.; Slotow, Robert Hugh.
Protection of biodiversity and social development often seem at odds in the world of today. The aim of this thesis is to show that it does not need to be that way. Most global social compacts focus on either economic development, or biodiversity conservation. Few prioritise the needs, values and rights of local people living in or near conservationsensitive areas. If biodiversity and human well-being goals are to be realised simultaneously, we must find ways to increase land use for conservation purposes, while respecting the values and needs of local people and future generations. In an effort to contribute to this aim, this thesis explores and analyses how elephants are valued and perceived by a wide range of stakeholders; it investigates why narrow conservation approaches fail; and it uses the research outcomes to develop an alternative roadmap for conservation, one that realises beneficial outcomes for elephants, people and the environment. Through literature review, participatory workshops, questionnaires, interviews and reports provided by reserves and provincial government, I developed: (1) the TUSKER framework to reconcile integrity of nature with human well-being, (2) the pluralist elephant valuation system to incorporate all values of elephants that I have been able to uncover and provide insight into trade-offs associated with conservation decisions, (3) a theory of change for human-elephant coexistence and building common ground, and (4) a One Well-being framework to holistically assess and rank the consequences of elephant management interventions at different scales of animal, human and environmental well-being. The frameworks can be used in strategies that promote animal well-being and range expansion, while simultaneously empowering local communities and enhancing local economies. They may be employed by policymakers and managers to work towards ‘living-in-harmony’ conservation schemes, in which elephants and other iconic species do not represent a threat to humans but a chance for development and joy. Through ‘Living in harmony’, ‘convivial conservation’, and the incorporation of African philosophy Ubuntu (a philosophy that recognises moral values such as justice, dignity and rights), we will move towards a more ethical, just, and sustainable world.
Alleviating delayed field curing-induced deterioration in rice seeds by cathodic water invigoration: a comparison of seed and seedling responses in two upland rice species and their interspecific hybrid.
(2021) Bam, Raphael Kwame.; Varghese, Boby.; Naidoo, Sershen.; Pammenter, Norman William.
Rice constitutes the major source of the world’s food supply. A number of varieties are grown in many parts of the world, all which produce orthodox seeds that are usually stored between growing seasons. As in other crop species, storage-induced loss of seed quality (viability and vigour) is inevitable but considerable research effort has been invested in optimising seed bank storage protocols for rice to ensure acceptably high levels of seed germinability and seedling emergence. However, poor post-harvest practices such as delayed field curing before threshing in developing countries in the humid tropics, such as Ghana, result in curing-induced seed deterioration in the field prior to ex situ storage. Given that many rice growing regions are likely to experience significant levels of climate change, seed processing and storage induced declines in rice seed quality could exacerbate the crop losses incurred by rice farmers in these regions in the future. This motivated the present study which was designed around three aims: 1) to investigate how environmental conditions and the duration of field curing influenced seed macro-structural integrity, susceptibility to microbial infection, and seed germinability and vigour; 2) to identify macro-structural and ultrastructural indicators/ biomarkers of field curing and associated storage-induced stress/ damage; 3) to assess whether the invigoration of field-cured seeds with cathodic water (CW), an established antioxidant-based seed invigoration medium, and deionized water (DW) can alleviate the deteriorative effects of delayed field curing on rice seed cellular integrity, germination and subsequent seedling growth and biomass. The specific objectives of this comparative study, which involved an Asian (Oryza sativa L.) and African (Oryza glaberrima Steud) upland rice species and their interspecific hybrid (O. sativa × O. glaberrima), were as follows: a) to compare the impacts of delayed field curing in wet and dry environments on seed physical, physiological and pathological quality; b) to identify potential ultrastructural biomarkers of seed sensitivity to delayed field curing-induced stress/ damage in embryonic root meristematic cells using transmission electron microscopy (TEM); c) to assess whether CW invigoration alleviates cellular stress/ damage induced by delayed field curing using selected ultrastructural biomarkers of seed sensitivity to such curing-induced stress/ damage; and d) to assess whether invigoration with CW and DW improves seed germinability and emergence, and subsequent plant growth in field cured seeds, relative to non-invigorated (NI) dry seeds.
Applied carnivore management in a data deficient world: leopard Panthera Pardus as a case study.
(2016) Ross, Tyzack Pitman.; Slotow, Robert Hugh.; Hunter, Luke Thomas.
Large carnivores are vital to biodiversity at a global scale, through their role as keystone species, but also present significant challenges for conservation and management due to the lack of basic information on carnivore abundance and distribution, particularly at regional and sub-continental scales. Consequently, large-scale carnivore management decisions are seldom supported by science-based evidence. In this thesis, I use leopards Panthera pardus as a model large carnivore, in Limpopo Province, South Africa, to investigate and address some of the fundamental components that underpin wildlife management and conservation in a landscape dominated by people. Furthermore, I develop practical and scientifically justified methods to facilitate accurate and efficient management of the species at a scale that is meaningful to leopard conservation. I begin by developing a model approach to leopard management, particularly in the context of trophy hunting, using data that are currently available to management authorities, and provide management recommendations to improve leopard population persistence. Next, I focus on the game ranching industry—the primary driver responsible for lethal leopard control—and assess the relationship between game ranchers and free-ranging wildlife. I then explore the evolution of game ranching practices to better understand the concomitant change in game rancher tolerance of free-ranging wildlife, and integrate this mechanistic understanding into the challenges facing conservation policy making more generally. Given the challenges faced by leopards across Limpopo (e.g., high levels of trophy hunting, statesanctioned population control, and illegal killing), I then set out to investigate leopard resource use and landscape connectivity across Limpopo to better understand leopard space use in the region. I present an efficient method of integrating connectivity within wildlife management, and in doing so, identify key conservation priorities. Lastly, given that so little is known about how species respond to hunting, I present a simulation study focused on assessing biological sustainability of leopard hunting. I demonstrate that the sustainable hunting of leopards remains a challenging objective given the high degree of additive anthropogenic mortality (i.e., illegal killing and state-sanctioned problem animal control) and challenges associated with accurately aging leopards in the field. The findings presented in this thesis provide valuable information and novel guidance that could benefit the management and conservation of leopards across the region, and further afield.
Aspects of the ecology of spotted hyena (Crocuta crocuta) in relation to prey availability, land use changes and conflict with humans in western Zimbabwe.
(2018) Mhlanga, Mlamuleli.; Downs, Colleen Thelma.; Ramesh, Tharmalingam.
Patch selection by carnivores is affected by various factors including availability of prey and denning areas, extent of vegetation cover, competition from sympatric large carnivores and anthropogenic habitat change among other variables. Understanding the influence of such factors is fundamental in the management of the carnivores. The study investigated spotted (i) hyena occupancy and (ii) co-occurrence with mesocarnivores in Zambezi National Park, Matetsi Safari (hunting) Area and Dimbangombe Ranch (mixed livestock and wildlife) in western Zimbabwe during the dry and wet seasons of 2014 and 2015 using camera traps. First, habitat characteristics, potential major prey and possible disturbance factors were modelled using the occupancy modelling approach to quantify habitat occupancy of the spotted hyena. It was found that the spotted hyena mean site occupancy was high (ψ = 0.617, SE = 0.147 and ψ = 0.502, SE = 0.107 for wet and dry seasons respectively). Furthermore, spotted hyena habitat occupancy increased in clayey soil and grasslands in the national park and hunting area, a behaviour attributed to denning preferences and possibly prey movement. Management priorities should focus on improving habitats for wild prey outside protected areas while preserving clayey areas for enhanced productivity of the spotted hyena inside protected areas. Secondly, it was predicted that mesocarnivores would avoid habitats occupied by the spotted hyena resulting in seasonal variation in temporal overlap between the spotted hyena and mesocarnivores. The study found that the detection probability of the mesocarnivores varied in the presence of the spotted hyena as a function of the detection of the leopard, presence of rocky and mixed vegetation habitats and road network. The high temporal coefficients of overlap for all pairs of species implied high chances of co-detection at the same sites. It was recommended that land management and top predator introductions should consider how optimal use of the habitat by small carnivores is affected. In addition, the study (iii) determined spotted hyena prey selection by comparing differences in frequency of occurrence of prey remains in their scats from a hunting area (117 scats) and a national park (137 scats). Small, medium and large-sized mammalian prey contributed 19.8 %, 41.9 % and 19.8 % to the diet of the spotted hyena in the safari area, compared with 34.3 %, 24.0 % and 35.9 % in the national park, inclusive of domestic stock (10.3 % in the safari area; 12.0 % in the national park). The difference in diet composition of the spotted hyena between the two land-uses was attributed to the ability of the species to shift between prey species in relation to the availability. Furthermore, a questionnaire survey was done (iv) to assess the attitudes and perceptions towards the spotted hyena of people (n = 353 households) in communities living at various distance categories within 0 - 20 km from the protected area boundary. It was found that livelihood source and extent of livestock loss had an influence on perceptions about the spotted hyena. The study recommended development of a modified incentive driven model that will encourage human-wildlife coexistence. Bushmeat harvesting is thought to affect prey distribution for the carnivores and a questionnaire survey was done on 355 households (v) to determine the factors driving bushmeat activities in the area in relation to conservation efforts. Bushmeat availability was highly influenced by scarcity of protein sources and season (dry). The dry season peak in bushmeat availability was attributed to increased demand that coincided with a period of low protein availability in the villages. The hunting zone (distance from protected area boundary) was the most influential predictor of how communities viewed illegal bushmeat harvesting in relation to conservation efforts. Mitigating illegal activities would likely be effective when started in settlements that are inside wildlife zones. Insights on community perceptions towards conservation may help in managing edge effects around PAs.
Aspects of the molecular systematics, taxonomy and population genetics of Otomops (Chiroptera: Molossidae) in Africa and Madagascar.
(2015) Ralph, Taryn Marietta Cecilia.; Lamb, Jennifer Margaret.; Taylor, Peter John.; Goodman, Steven Michael.
Abstract available in the print copy.
Assemblages of surface-active arthropods in pristine and disturbed savannah.
(2022) Mavasa, Risuna Wain.; Tsvuura, Zivanai.; Yekwayo, Inam.; Mwabvu, Tarombera.
Savannahs are structurally complex ecosystems rich in biodiversity, and the conversion of savannahs into human-modified landscapes poses a significant risk to organisms with limited dispersal abilities. Surface-active arthropods have limited dispersal abilities and are sensitive to changes in their environment; as a result, they are restricted to specific habitats with the resources that they need. Surface-active arthropods are essential in ecosystem processes, such as playing a direct or indirect role in water infiltration into the soil and its storage, decomposition of plant and animal matter, nutrient cycling, humification and biological pest control. Many landscapes of natural vegetation in South Africa have been transformed into croplands, residential and commercial areas. In Mpumalanga province, croplands (including fruit plantations) dominate the landscape where savannah vegetation occurred previously. This study investigated the influences of disturbance (transformed savannah vs pristine savannah) and season on the diversity of four groups of surface-active arthropods (ants, beetles, millipedes and spiders) in the savannah biome in Mpumalanga province. The objectives of the study were to determine 1) whether flightless arthropod assemblages differ between disturbed and pristine savannah, and 2) whether functional guilds of flightless arthropod assemblages differ between summer and winter. Field sampling using pitfall traps was done to collect the surface-active arthropods in pristine and disturbed savannah during summer and winter. All samples were sorted into morphospecies and identified into family or genus where possible and then assigned into functional guilds. Functional guilds were allocated based on the feeding habits of the surface-active arthropods, resulting in three distinct functional guilds (detritivores, herbivores and carnivores) being identified. Surface-active arthropods with diverse feeding habits were lumped to form a fourth functional guild, the “diverse functional guild”. I found significant differences in the species composition of ants, beetles and spiders between disturbed and pristine savannahs. The species richness and abundance of ants was significantly greater in the disturbed than pristine savannah, while beetles and spiders had similar species richness and abundance between the two habitat types. The number of unique species of the surface-active arthropods in the disturbed savannah were two times more than those in the pristine savannah. The species richness and composition of all functional guilds of the surface-active arthropods differed between summer and winter, with greater species richness in summer than in winter. Herbivorous and carnivorous arthropods had significantly higher abundance in summer than in winter, while the abundance of detritivores and the “diverse functional guild” was similar between the two seasons. This study shows that different vegetation types support different compositions of surface-active arthropods and that there may be a positive relationship between vegetation structure and the assemblages of surface-active arthropods in the savannah. Furthermore, the study highlights a potentially positive relationship between the assemblages of herbivorous and carnivorous arthropods. I recommend that it may be essential to consider both disturbed and pristine habitat types in the conservation of surface-active arthropods, especially in South Africa where most of the land is outside of formal conservation areas. This assertion is supported by the greater number of unique species of surface-active arthropods found in the disturbed than in the pristine savannah. My study provides relevant baseline information because little is known about the assemblages of surface-active arthropods in savannah landscapes dominated by croplands. Furthermore, my study gives some insight on how the assemblages of surface-active arthropods may respond to disturbance in the savannah.
Assessment of roadkills in Hluhluwe-Imfolozi Park, KwaZulu-Natal, South Africa.
(2017) Mkhohlwa, Muzi Nicholas.; Downs, Colleen Thelma.
Anthropogenic land-use activities are considered to be the main contributor to current worldwide changes in natural ecosystems. South Africa is one of the countries that has been severely affected by changing land-use. The changes in land-use in South Africa are driven primarily by the need to provide food, water, and shelter to a growing human population and for economic growth. However, consequences of such actions impact biodiversity negatively with effects that lead to habitat fragmentation, loss of wildlife habitats, wildlife mortalities and species declines. One factor that contributes negatively is the increased number of roads and associated traffic. This study was conducted in Hluhluwe-Imfolozi Park (HIP), KwaZulu-Natal, South Africa, to assess roadkills on roads of the park. We conducted monthly roadkill surveys on three main roads (R618 corridor road traversing the HIP, paved road from Memorial Gate to Hilltop Resort, and an unpaved road from Memorial Gate to Isivivaneni Lookout) within HIP for a year. Furthermore, we assessed the public’s level of awareness about roadkills using questionnaire surveys. Relatively few roadkills were reported in our study when compared with other studies. The taxa that were reported as roadkills included mammals, birds, reptiles and amphibians. The R618 corridor road traversing the HIP had the highest number of roadkills, followed by the paved road then the unpaved road within park. Factors that contributed to reported roadkills were season, type of road, amount of game in the vicinity, and the distance to roadside vegetation from the road. In addition, the public showed limited awareness about roadkills occurring in HIP, but were aware of how they were expected to drive within protected area road networks. Mitigation measures such as mowing, signage, enforcement of harsh laws and introduction of fines were recommended as means that would help in the reduction of roadkills in HIP.
Behavioural responses of rodents to the scent and taste of compounds associated with sugar and protein degradation : implications for the evolution of chemical signals in rodent-pollinated flowers.
(2015) Records, Darryn.; Johnson, Steven Dene.; Nicolson, Susan W.
Volatile compounds in nectar may influence the behavioural responses of animal flower visitors, and thus have fitness consequences for both animal and plant mutualists. Rodents may use certain volatiles associated with sugar fermentation or protein degradation as a cue to locate food. Plants pollinated by rodents may thus emit these volatiles to enhance their attractiveness to rodents. However the presence of certain compounds in nectar may also indicate reward degradation, reducing its attractiveness to potential pollinators. The effects of these compounds on small mammal flower visitors are largely unknown and the consequences of nectar degradation by microorganisms for small mammal flower visitors need investigation. The present study examines the responses of a known rodent pollinator, the Namaqualand rock mouse Micaelamys namaquensis, an occasional floral visitor, the four-striped field mouse Rhabdomys pumilio, and a closely-related congener, the mesic four-striped field mouse Rhabdomys dilectus towards four compounds - ethanol, ethyl acetate, acetic acid and dimethyl disulphide - that are associated with the degradation of sugars and proteins. The study aimed to: (i) Identify if fermentation and protein degradation volatiles act as behavioural cues for small mammals, and have the potential to assist in the finding of food resources; and (ii) to determine the responses of rodents to the taste of volatiles in nectar. In chapter 1, I investigated whether fermentation and protein degradation volatiles elicit a behavioural response in small mammals, using a traditional Y-maze choice apparatus. Rodent species differed in their responses to the four volatiles tested. Ethanol emerged as an attractant for all of the species, with the strongest response seen at the 0.3 % ethanol concentration, while only R. dilectus responded positively to dimethyl disulphide. Acetic acid and ethyl acetate were generally not attractive. In chapter 2, the palatability of fermentation and protein degradation compounds at varying concentrations in experimental nectars was tested. A paired choice test analysis was used to determine if animals altered their choice with the addition of volatiles to sucrose solutions (0.73 and 1.46 M). Rodents showed a dose-dependent response towards the volatile concentrations presented to them. Both M. namaquensis and R. pumilio preferred medium (0.3 %) concentrations of ethanol in high sugar concentration diets, but found this compound distasteful in lower sugar concentration diets. Acetic acid and ethyl acetate were generally not preferred by any species at either sugar concentration. Dimethyl disulphide was preferred by all species when present in greater sugar concentrations (1.46 M) and at low volatile concentrations (0.003 %). These results suggest that rodents do alter their choice of nectar in relation to the tested compounds. I conclude that certain compounds associated with sugar fermentation or protein degradation have the potential to act as behavioural cues in rodent pollination and that further studies to reveal the effect of nectar degradation by microorganisms are needed to help in understanding plant-pollinator interactions.
Cathodic water invigoration of deteriorated orthodox seeds – implications on subsequent plant growth.
(2020) Fatokun, Kayode.; Beckett, Pichard Peter.; Varghese, Boby.; Pammenter, Norman William.
Orthodox seeds deteriorate even when kept under the best of conditions leading to loss of germination, poor seedling growth. In this study, a novel approach via the use of cathodic water, an electrolysed form of calcium magnesium solution, was used to invigorate fresh and controlled deteriorated seeds of wild (Bolusanthus speciosus (Bolus) Harms, Combretum erythrophyllum (Burch.) Sond., Erythrina caffra Thumb.) and agricultural (Pisum sativum L., Cucurbita pepo L.) species. Other treatment solutions investigated alongside cathodic water were un-electrolysed calcium-magnesium solution and deionized water. Fresh seeds of the test species were controlled deteriorated to 50% germination (P50) at 40°C and 100% relative humidity. Thereafter, the seeds were invigorated with the treatment solutions. Fresh and un-primed controlled deteriorated seeds served as the control. In addition, to study the mechanism of invigoration, the effects of priming on the membrane stability index (MSI), amylase activities, lipid peroxidation products malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE) were investigated. The effects of priming on the reactive oxygen species (ROS) scavenging enzymes superoxide dismutase, and catalase and DNA (concentration and purity). All priming treatments improved germination, emergence, growth parameters and subsequent seedling photosynthesis relative to the unprimed seeds. In general, cathodic water was most effective at invigorating seeds in the all test species. Also, controlled deteriorated seeds benefitted more than the fresh seeds treatments. Analyses of the lipid peroxidation products and antioxidant enzyme activities in invigorated seeds provided support for the hypothesis that the effectiveness of cathodic water in the invigoration of debilitated orthodox seeds derive from its ability to act as a potent antioxidant. This study, which is a novel approach at bringing the concept of electrochemistry into germplasm conservation via the use of cathodic water, has also confirmed the efficacy of cathodic water in invigorating debilitated seeds. This is especially critical for seeds containing traits that may be under the threat of being lost due to various reasons. The current study reinforces the strong potential of cathodic water in the recovery of aged germplasm and improved yield of orthodox seeded species.
The challenges and opportunities in conserving wide-ranging cross-border species : a case study of the Greater Mapungubwe Transfrontier Conservation Area elephant population.
(2015) Selier, Sarah-Anne Jeanetta.; Slotow, Robert Hugh.; Page, Bruce Richard.; Di Minin, Enrico.
Transfrontier conservation areas potentially play a key role in conserving biodiversity and promoting socioeconomic development. However, socio-political factors often affect their effectiveness in achieving biodiversity conservation and sustainable development objectives. Following a transdisciplinary approach, I assessed the challenges and opportunities in conserving and managing the African elephant (Loxodonta africana) population within the Greater Mapungubwe Transfrontier Conservation Area (GMTFCA) in Botswana, South Africa and Zimbabwe, southern Africa. The results showed that the current rate of offtake of bull elephant in the GMTFCA is unsustainable. At current rates of hunting, in fact, trophy bulls were predicted to disappear from the population in less than 10 years. Elephant densities were higher in South Africa and Botswana where the gross domestic product is higher. In addition, elephant densities were higher at sites where the proportion of agricultural land around them was the lowest and where vegetation productivity was the highest. Trophy hunting, as well as other localised human activities, also affected the distribution of elephant within sites, forcing them to trade-off between disturbance avoidance and the availability of food and water. While at the international level, a significant body of law and policy relevant to elephant conservation exists, I found that there was little cooperation among Botswana, South Africa and Zimbabwe, and a lack of implementation of these provisions on a national and trilateral level. Overall, this study confirmed that poverty was an important factor affecting elephant abundance at the country level, but highlighted that, at the site level, anthropogenic disturbance played a crucial role. A revision of the current hunting quotas within each country and the establishment of a single multi-jurisdictional (cross-border) management authority regulating the hunting of elephant is needed. Further, to reduce the impact of increasing human populations and agricultural expansion, the development of coordinated legislation and policies to improve land use planning, and the development of conservation corridors to link current protected areas, is needed. The issues regarding the management of this elephant population illustrate the significant challenges involved in achieving a comprehensive, consistent and effective implementation of a transboundary population approach. Southern African countries make an important contribution to elephant conservation and could soon become the last stronghold of elephant conservation in sub-Saharan Africa. Therefore, immediate actions are needed to reduce pressures from human activities in order to enhance the long-term persistence of the species.
Chemokines and haematological profile in Sprague-Dawley rats infected with trichinella Zimbabwensis and Plasmodium berghei ANKA.
(2017) Mdleleni, Yanga.; Mukaratirwa, Samson.; Murambiwa, Pretty.
Trichinellosis is an important re-emerging parasitic zoonosis caused by nematode species of the genus Trichinella and Plasmodium falciparum malaria is among the leading causes of mortality and morbidity in sub-Saharan Africa (SSA). Co-infection of the two diseases in rural communities is likely to be a common phenomenon although no reports have been made up to date. There is paucity of information on the consequence of co-infection regarding the clinical outcome of these diseases, especially malaria. Helminths, such as tissue-dwelling Trichinella spp larvae induce Th2 immune responses, while malaria induce Th1 immune responses as a survival strategy. On the other hand, chemokines are chemotactic cytokines produced by the host macrophages in order to elicit a protective immune response. Immuno-pathogenesis during co-infection remain obscure. It is against this background that this study aimed to determine host chemokine and haematological responses in male Sprague-Dawley rats during co-infection with Trichinella zimbabwensis and Plasmodium berghei. A 42 day follow up study was carried out, where 168 male Sprague-Dawley rats (90-150g) were randomly divided into four separate groups, control (n=42); malaria infected (n=42); Trichinella infected (n=42) and co-infected group (n=42). On day 0, male Sprague-Dawley rats were orally infected with 3 T. zimbabwensis muscle larvae per gram body weight. Followed at day 28 post-Trichinella infection with malaria induction using 105 P. berghei parasitized RBCs for the mono-infected group. While 42 male Sprague-Dawley rats were co-infected with T. zimbabwensis and P. berghei on day 0 and P. berghei infection occurred on day 28pi. Experimental animals were sacrificed on day 0,7,14,21,28,35 and 42 pi. Where whole blood and sera were collected. Plasmodium berghei percentage parastaemia, T. zimbabwensis adult worm count and muscle larvae load, haematological parameters and serum levels of IP-10, RANTES and EOTAXIN were determined. Co-infection with P. berghei and T. zimbabwensis showed elevated P. berghei percentage parastaemia, as well as upregulation of RANTES and EOTAXIN as a Th2 immune response, while IP-10 was downregulated as an effective immune response to parasitic infections. Mono-infection with P. berghei caused an upregulation of IP-10 as a Th1 immune response.
Comparative studies of the ultrastructure of Entamoeba histolytica and Entamoeba coli.
Proctor, Eileen Margarita.; Elsdon-Dew, R.
No abstract available.
Concurrent spatiotemporal ecology of African lions and spotted hyenas and the potential for inter- and intraspecific interactions in semi-arid and wetland ecosystems.
(2022) Barker, Nancy Ann.; Slotow, Robert Hugh.
Intraguild interactions among apex predators can potentially influence carnivore population densities and distribution, which may have profound effects on trophic processes within ecosystems. Coexisting carnivores are able to mitigate such interactions through behavioural mechanisms that promote spatiotemporal separation. Despite increasing research which highlights the occurrence and prevalence of competitive interactions between African lions (Panthera leo) and spotted hyenas (Crocuta crocuta), studies that incorporate the effects of such interactions on lion and hyena space use patterns are limited. Interactions among sympatric carnivores reveal how predators utilize spatial and temporal partitioning strategies within jointly used areas, and elucidate the spatiotemporal patterns enabling species coexistence between them. Thus, an understanding of how inter- and intragroup interactions drives the movement responses of apex predators has important implications for the structure and function of large carnivore communities, and their conservation. We used remote tracking data to investigate aspects of the ecology and behaviour of lions and spotted hyenas, with an emphasis on the spatiotemporal patterns among coexisting populations. Both lions and spotted hyenas mediated the potential for interference competition through subtle differences in temporal activity, fine-scale habitat use differentiation, and localized reactive-avoidance behaviours. Recursivity to, and duration of time at, locales of high competitor probabilities, were similar among female lions and both sexes of hyenas, but different for male lions. Our findings of lion space-use patterns across arid and mesic environments indicated the seasonal influences of competitive interactions with competitors (spotted hyenas), in that lions selected for, and chose to move through areas with a lower probability of competitors during the dry season. Dyadic interactions among lions and spotted hyenas illuminates how hyenas effectively reduced their potential of interactions with lions by utilizing spatiotemporal partitioning strategies and local reactive avoidance behaviours within shared space use areas. Quantifying the types of movement behaviour between competitors highlights the type of interaction occurring in a dyad and enhances our understanding of the potential effects of interspecific interactions among large carnivore space-use patterns within an apex predator system. Both lions and spotted hyenas exploit different behavioural strategies resulting in fine-scale spatiotemporal segregation among shared space-use areas enabling the two species to co-exist, and show adaptability across heterogeneous and homogeneous environments. Such findings are essential in understanding the behavioural choices made by members of a guild that subsequently affects population dynamics and community structure of multi-species food networks.
The curious case of the Satyrium neglectum complex: a taxonomic, ecological, and phylogenetic study.
(2021) Rule, Matthew James.; Van der Niet, Timotheus.; Johnson, Steven Dene.
Classical herbarium taxonomy uses a combination of morphological features from pressed specimens and distribution information as data in species delimitation. Whilst morphology is critical to species delimitation, additional information on phylogenetic relationships and fieldbased studies of ecology can inform taxonomic decisions. Satyrium neglectum Schltr. is a highly variable taxon currently comprising two subspecies, ssp. neglectum (Schltr.) A.V. Hall and ssp. woodii (Schltr.) A.V. Hall both of which are widely distributed in subtropical southern and eastern Africa. Variation in morphology and differences in apparent pollination systems, both between the subspecies, and within ssp. neglectum suggests the presence of two taxa within the current concept of the latter. This information, as well the exclusive reliance on herbariumbased taxonomy in the most recent species revision, formed the background to this re-evaluation of the systematics of the complex. A combination of detailed morphometrics and molecular phylogenetics demonstrated that the current concept of S. neglectum ssp. neglectum is inaccurate. A principal components analysis using traits measured from herbarium records from across the range, and ethanol-preserved flowers from South Africa, confirmed the presence of two morphologically distinct clusters within ssp. neglectum. Representatives from these two forms are separated along an elevation gradient. Bayesian inference using a combination of plastid and nuclear DNA sequence data revealed incongruent topologies. The nuclear topology is not consistent with current taxonomic boundaries, and revealed a separation between the high-elevation form and the low-elevation form of S. neglectum ssp. neglectum as well as ssp. woodii. The plastid data set also confirmed the separation of the high-altitude form of ssp. neglectum, but otherwise the topology reflects geography, as southern African accessions are separate from eastern African accessions. Floral scent was investigated in combination with published and novel pollinator observations in the Satyrium neglectum species complex. Floral scent composition and emission rates are mostly representative of associated pollination syndromes in previously published pollination work, with the exception of the high-elevation form. Published observations of ssp. woodii indicate that the species is pollinated by amethyst and the greater-double-coloured sunbirds, and the scent composition and emission rate is largely reflective of this. In addition, published observations showed a system of butterfly pollination in the low-elevation form of ssp. neglectum and long-proboscid fly pollination in the high-elevation form. However, new night time observations revealed additional pollination by settling moths in the high elevation form. These observations make sense in the context of the scent profile, which is dominated by compounds typically associated with moth pollination, such as phenylethyl alcohol and eugenol. In addition, two settling moths showed electroantennographic responses to the two dominant compounds in the scent bouquet of the high-elevation form. The compounds that dominate the scent of the butterfly-pollinated low elevation form are hexan-1-ol, octan-1-ol and benzyl alcohol, while previously published work on ssp. woodii showed that it is virtually unscented, and has emission rates that are markedly lower than other taxa pollinated by insects. Based on the morphological, phylogenetic and scent chemistry analyses, a case was made for the high-altitude form to be considered a separate taxonomic entity. This is formally described under the new name Satyrium basutorum. The analyses suggest that ssp. neglectum and ssp. woodii should be retained as subspecies, but a further investigation is required to identify the status of the eastern African synonyms Satyrium sceptrum and S. neglectum var. brevicalcar.
Cytokine and haemtological profiles in sprague-dawley rats experimentally infected with trichnella zimbabwensis and plasmodium berghei Anka.
(2017) Umo, Ekuyikeno Silas.; Mukaratirwa, Samson.; Murambiwa, Pretty.
Abstract available in PDF file.
Decadal changes in rocky shore communities in KwaZulu-Natal and survey methods for future monitoring.
(2020) Mvula, Philile Emelda.; Macdonald, Angus Hector Harold.; Pfaff, Maya Catherine.
Intertidal rocky shores form part of the sea during high tides and part of the land during low tides. They are therefore subjected to diverse anthropogenic pressures, including climate change, pollution, coastal erosion and harvesting. Due to their accessibility, rocky shores are among the most heavily exploited marine ecosystems. The rocky shores of the East and the South coasts of South Africa have been exploited for thousands of years. With growing coastal populations, they require management practices that ensure their ecological integrity and function. Rocky shore community structure along the KwaZulu-Natal (KZN) coast has been well studied between the years 1996 and 2000 when surveys were conducted at 39 sites. A monitoring Programme has since been established by Ezemvelo KwaZulu-Natal Wildlife in partnership with the Department of Environmental Affairs, Forestry and Fisheries (DEAFF) to inform the management of these heavily impacted ecosystems. This study aimed to contribute to the monitoring Programme in two ways: Firstly, by characterising and evaluating changes in rocky shore communities that have occurred since 2000, which was done by resurveying historical sites and comparing community structure and diversity between decades. Secondly, by comparing and evaluating different rocky shore sampling methods to identify the most suitable sampling protocol for a long-term monitoring programme of KZN rocky shores. This required statistical analyses of parallel surveys conducted using different methods. Significant changes in the community structure were observed with increased species richness and evenness. A decline in the abundance of harvested mussels was also noted, coupled with an increase in coralline algae and the arrival of two species of alien barnacles. Even though more long-term studies will be required to determine the status of the intertidal communities under anthropogenically induced change, the current study can be used to initiate better managementpractices in order to maintain species diversity and distribution.
Development and utilization of a river system model to integrate human and ecological water requirements in a southeastern United States river basin.
(2016) Leitman, Steven.; Kiker, Gregory Alan.
Abstract available in PDF file.
Diet preference of common mynas (Sturnus tristis) in urban areas of Pietermaritzburg and Durban, KwaZulu-Natal.
(2017) Gumede, Silindile Thobeka.; Downs, Colleen Thelma.
Urbanization is one of the anthropogenic land use changes with a negative impact on biodiversity generally. However, some species are persisting well in urban areas and are termed urban exploiters. One of these species is the common myna (Sturnus tristis). It is also considered amongst the 100 worst alien invasive birds globally. As relatively little is known about the factors that affect common mynas invasive ability and urban persistence, aspects of their diet were investigated. Consequently, the main aims of this project were to investigate the macronutrient preference, sugar type and concentration preference, and assimilation efficiency of captive common mynas in the laboratory from July 2016 to March 2017. In addition, patterns of occurrence of common mynas in urban areas of Pietermaritzburg and Durban, KwaZulu-Natal, South Africa, and the influence of supplementary feeding and anthropogenic foods on their diet were investigated using questionnaires. Common mynas (n = 10) macronutrient preference was investigated in the laboratory where they were offered pairwise choices of three different diets (high in lipids diet, high in soluble carbohydrates (including sucrose) diet, and high in protein diet). Common mynas significantly preferred the high in lipids diet compared with either the high in protein diet or the high in carbohydrate diets. Common mynas (n = 7) were offered pairwise choices of three nectars (glucose, fructose and sucrose) to investigate their sugar type and concentration preference. Birds showed a significant preference for diluted glucose when given a choice of nectars. The sugar content of their excreta showed that they were unable to digest and absorb sucrose in nectar. Responses from the questionnaires showed that common mynas were found in the two study cities and were abundant year around. Results also showed that they were feeding mostly on anthropogenic foods compared with natural foods. Anthropogenic supplementary feeding has likely influenced the occurrence of common mynas because they follow food resources (human food waste) in urban areas and therefore successfully persist through lean periods. Further research is needed to help understand the ecology and behaviour of common mynas in order to get insights on how to monitor and control them in urban areas, in particular in South Africa where their range is expanding. Common mynas behaviour is currently poorly documented in South Africa. Since these are alien invasive birds with negative impacts in other countries, more research, especially on their behaviour, is required to prevent their negative impacts occurring in South Africa.
DNA barcoding of KwaZulu-Natal afromontane forest parmelia (parmeliaceae) species: a molecular approach to accurate specimen identification and sensitivity to climate change.
(2018) Ndhlovu, Nqobile Truelove.; Willows-Munro, Sandi.; Beckett, Richard Peter.
Accurate species identification is challenging, especially in groups with subtle taxonomically diagnostic characters such as lichens. Molecular-based techniques have shown to be a valuable tool for accurate specimen identification in fungi, in particular the use of DNA barcoding has become popular. Specifically, the internal transcriber spacer (ITS) region has been shown to successfully discriminate a broad range of fungal species. In this study, the utility of the ITS DNA barcode for use as a species diagnostic tool in the cosmopolitan lichen-forming fungus, Parmelia (Parmeliaceae) was investigated. Sixty-eight ITS sequences were generated from specimens collected from five sites around the province of KwaZulu-Natal and analysed. Phylogenetic analysis indicated that unlike European Parmelia species that form strong monophyletic clades, what appeared to be morphologically very similar Parmelia species in KwaZulu-Natal are paraphyletic or polyphyletic. No barcode gap was detected between the intra and interspecific distances. This suggests that the taxonomy of Parmelia lichens in South Africa needs to be thoroughly revised. The molecular data presented in this study provides evidence of previously hidden species-level diversity in Parmelia and as such contributes to the knowledge and understanding of the biodiversity of lichenized fungi in South Africa. The thermotolerance of Parmelia collected from different sites along an altitudinal gradient around Kwa-Zulu Natal was invesigated Chlorophyll fluorescence was used to assess the performance of lichen photobionts following stress, while ion leakage that of the mycobiont. For heat tolerance, results suggested that tolerance was correlated with the climatic conditions in which the lichens grow. Material from the coastal site of Hawaan were more heat tolerant than that from the three Midlands sites. Counter to our expectations, the coastal collections were more cold tolerant than those from the other sites. However, the genus clearly contains genetic variation with respect to stress tolerance, suggesting that it may have the potential to adapt to climate change.
Ecology and conservation of the African golden cat Caracal aurata.
(2015) Bahaa-el-din, Laila.; Slotow, Robert Hugh.; Macdonald, David Whyte.; Hunter, Luke Thomas B.

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