Theses and Dissertations

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The phenological study of Securidaca longepedunculata, in the Nylsvley Nature Reserve, Limpopo Province, South Africa
(2023-10-05) Mukhithi, Aluwani Godfrey; Ligavha-Mbelengwa, M. H.; Magwede, K.
Phenological observations were conducted through analysis of phenological phases and stages of 200 sampled S. longepedunculata plant individuals in the sandy soil areas of Nylsvley Nature Reserve, Limpopo Province, South Africa. Phenological stages comprised of onset, peak development and decline; while phenological phase is time spent by those stages for example leaf yellowing (Ruml and Vulic, 2005). Phenological phases patterns were analysed by focussing on vegetative and reproductive phenophases. Vegetative phenophase considered the presence of budding and developmental stages of leaves until they are shed. Reproductive phenophase considered the presence of flowering and developmental stages of fruits until they are shed. Phenological data was mainly collected through direct ground based observation. The results showed that budding, leaf greening and flowering were observed from mid spring in September in response to upcoming summer which is warmer and rainy. Ripe seeds and leaf yellowing were predominantly visible in autumn and winter respectively, as they are in their annual maturity stage. Leaf and seed shedding were observed at their peak development from late winter in June to early spring in August, probably due to the effect of windy conditions on site. Changes in the phenology of S. longepedunculata plant individuals caused by environmental changes resulted in changes at the community level. This shows that thorough phenological pattern monitoring is essential in order to forecast plant species behaviour. Also, it is necessary to provide knowledge on proper management of the reserve and protection of the plant species.
Thermal biology of the two-spotted stink bug, Bathycoelia distincta (Hemiptera: Pentatomidae) a major pest of macadamia
(2023-10-05) Muluvhahothe, Mulalo Meriam; Foord, S. H.; Joubert, E.
The physiological functions of insects are mainly dictated by temperature because they rely on the external environment to regulate their body temperatures. This temperature dependence drives their performance, with profound implications on abundance and distribution. Daily environmental temperature fluctuations may outpace an insect’s thermal tolerance capacity, which requires physiological plastic mechanisms to survive. In the context of global warming, insects may be vulnerable to temperature variations, and may ultimately determine their population dynamics. The two-spotted stink bug, Bathycoelia distincta (Distant) (Hemiptera: Pentatomidae) is an important pest of macadamia in South Africa. It causes damage by direct feeding on the kernel and comprises more than 80 % of the shield bugs in the orchards. Increased crop losses due to stink bug damage threaten macadamia nut production. Modern pest management practices require an understanding of the biology of pests and ecology. An important question to pose is, how does an organism's thermal plastic traits affect its ecological population dynamics? First, this study aimed to quantify the effects of temperature on biological parameters of B. distincta life stages, such as the development rate, development duration, survival, adult longevity, pre-oviposition period, oviposition period, and life table parameters, to determine its thermal requirements and population growth at constant temperatures ranging from 19 to 29 °C. In addition, the effect of diet (macadamia nut and sweetcorn) on development, survival, and sex ratio was investigated at 25 °C (Chapter 2). Second, to quantify the phenotypic plasticity of B. distincta life stages. Two thermal tolerance indices were explored: rapid hardening (rapid heat hardening: RHH and cold hardening: RCH) and acclimation (critical thermal maximum: CTmax and minimum: CTmin). RHH and RCH were determined by exposing B. distincta life stages to extreme temperatures of 41 and -8 °C, respectively. Acclimation effects on CTmax and CTmin were quantified by exposing B. distincta life stages to 48 h at 20, 25, and 30 °C. Temperature was ramped up and down at a rate of 0.2 min-1 to score survival at high (CTmax) and low (CTmin) critical temperature points (Chapter 3). Thirdly, the development rate was monitored (on the host plant) at temperatures ranging from 18 to 40 °C to acquire the total heat required to complete development (degree-days) and thermal requirements of each life stage of B. distincta. iv Lastly, the physiological traits, degree-days, and thermal requirements were used to predict seasonal generation turn-over, heat and cold thermal stress, thermal safety margin (TSM), and relative fitness in macadamia orchards along an elevational gradient (705 - 1493 m a.s.l.) to determine the effects of climatic zones (Cwa climate zone: Monsoon-influenced humid subtropical climate, Cwb: Subtropical highland climate or Monsoon-influenced temperate oceanic climate, and Bsh: Hot semi-arid steppe climate) (Chapter 4). B. distincta developed at a wide range of temperatures on sweetcorn (18 to 29 °C) and macadamia nut (18 to 35 °C). The survival rate was high (51 to 100 %) between temperatures with a monotonic increase of population growth from 19 to 29 °C. The total number of heat units required to complete development was 783 DD. All life stages of B. distincta displayed thermal plasticity, but instar 2 was the most plastic stage except in response to cold acclimation. Response to extremes varied more at low extreme temperatures compared to high extremes. As expected, the number of generations decreased with increasing elevations from the Cwa (Arbor: 2.4 generations) to the Cwb climate zone (Highfield: 1.1 generations). None of the life stages experienced thermal stress. TSM and relative fitness were highest at the Cwb climate zone of the highest elevation. These findings suggest that B. distincta will potentially cause more damage in response to global warming because of its estimated population growth rate at elevated temperatures. Although relative fitness was highest in the Cwb climate zone, damage could be expected in the Cwa zone due to increased number of generations. This study can also help identify macadamia orchards in climate zones vulnerable to climate-related consequences such as outbreaks. Climatic data combined with the DD model can be used to predict the phenology of B. distincta and timing of chemical applications. The impacts of global warming on crop losses due to insect pests are evident worldwide, and this study has shown that macadamia orchards in certain climatic zones (e.g., Cwa climate zone) could be at risk of increased abundance of B. distincta. Thus, integrated pest management strategies should be of priority to macadamia farmers for effective management of B. distincta. Given that South Africa is the largest producer of macadamia globally and its major pest is thermal plastic, linking the physiological traits of B. distincta life stages to climatic conditions of all macadamia growing regions in South Africa will help understand its distribution limits.
An inventory, nutritional analysis and biological evaluation of underutilized indigenous vegetables used to manage non-communicable diseases in Thulamela local municipality, Vhembe District Municipality, South Africa
(2022-11-10) Phaswane, Mukhethwa Concila; Masevhe, N. A.; Amoo, S. O.
Non-communicable diseases have emerged as a serious public health concern around the world, with a high death rate. The study aim was to document and evaluate the biological activities of underutilized indigenous vegetables used by local people in Thulamela Local Municipality to manage non-communicable diseases. An open structured interview was used to conduct an ethnobotanical survey, and 25 underutilized indigenous vegetables belonging to 13 families were documented. Cucurbitaceae was the dominant family, constituting 21% of the documented species, followed by Urticaceae with 13% of the species. Six of the documented species, which are Citrullus colocynthis, Cleome gynandra, Cucumis africanus, Oxygonum dregeanum, Pouzolzia mixta, and Sonchus oleraceus, were selected and evaluated using standard laboratory procedures for quantifying nutritional, phytochemical constituents, antioxidant, and anti-diabetic activities. The above-mentioned six vegetables contained a considerable amount of important nutrients. Cucumis africanus has the highest levels of ascorbic acid, Ca, Fe, and Mg. In comparison to other vegetables studied, Citrullus colocynthis had the highest levels of total phenolics, total flavonoids, and condensed tannins. The free radical-scavenging activity of all the plant extracts was moderate compared to the positive control (ascorbic acid). On the other hand, dichloromethane and acetone extracts exhibited high antioxidant activity in the beta-carotene-linoleic acid antioxidant system. Most dichloromethane, acetone and distilled water extracts showed low alpha-glucosidase inhibition compared to the positive control (acarbose). However, the dichloromethane extract of Citrullus colocynthis and acetone extract of Cucumis africanus exhibited significantly high alpha-glucosidase inhibitory activity than acarbose. According to the information gathered, people in Thulamela Local Municipality rely on indigenous vegetables for medicine to treat non-communicable diseases. The quantified nutritional and phytochemical contents and the antioxidant and alpha-glucosidase inhibitory activities exhibited by the selected underutilized indigenous vegetables confirm their traditional uses as food and medicine to manage diabetes and other non-communicable diseases. To obtain precise data that can be used to verify these findings, in vivo methods should be used.
Genomic mechanisms underpinning phenotypic diversity in the spiral-horned antelopes (Genus: Tragelaphus)
(2022-11-10) Rambuda, Thabelo; Moodley, Yoshan; Rakotoarivelo, Andrinajoro
The world is old, full of diversity, and the history of all organisms that once lived on Earth is recorded in the DNA of its descendants. The genomes of living organisms contain ancestral information that, if analyzed, reveals the underlying mechanisms to explain an organism’s evolutionary history. Therefore, it is crucial to study the whole genomes of highly diverse and specialized groups of organisms that could help our understanding of the speciation process. The continent of Africa is home to phenotypically diverse spiral-horned antelopes (genus Tragelaphus) which have gone through a recent adaptive radiation. Previous studies on Tragelaphus have argued that they comprise either nine or ten species based on mtDNA and nuclear DNA respectively/chromosomal number difference. With the same mentioned molecular data, there is discordance in their previously reconstructed species tree, placing species in different clades with different markers. At the mtDNA level, the nyala (T. angasi) is sister to the bushbuck (T. scriptus) making the mtDNA diversity polyphyletic within the bushbuck complex. The two bushbuck species and other phenotypically similar non-sister Tragelaphus lineages lead to the suggestion by scientists that some phenotypes evolved through convergent evolution. In this study, one whole genome of each Tragelaphus lineage was sampled with the aim to analyze the genome-wide relationship of these species by reconstructing their phylogenetic species tree. The study also aims to assess the genome-wide levels of diversity and to assess whether there has been gene flow between species which could have led to phylogenetic discordance among traditional markers. The relationship was analyzed with non-model based PCA and biological model-based IBS and maximum likelihood. All the methods used for structure analysis revealed the same genomic structure and confirmed other studies showing that morphologically similar Tragelaphus species were not most closely related at the genome level. The reconstructed genome-wide species tree was used for the assessment of introgression between species. Most of the observed gene flow was ancestral, the alleles of which are randomly kept in some lineages and passed from generation to generation but lost in others. Therefore, I propose that some phenotypic similarities between unrelated species could be due to high ancestral gene flow between these non-sister lineages. To confirm this would require further investigation using more samples for each species.
Ethnoecological investigation of Spirostachys africana Sond. population at Ha-Matsa Village, Limpopo Province, South Africa
(2022-11-24) Phalanndwa, Mashudu Victor; Tshisikhawe, M. P.; Magwede, K.
Availability of natural resources for the generations to come depends on the current state of harvesting as well as use patterns. Such anthropogenic activities impact on the species survival and functioning of ecosystems. Harvesting of plant species that exudates gum, resins and/or latex like Spirostachys africana Sond. dates as far back as the Middle Stone Age (MSA) period. The demand for ethnobotanical use of plant material particularly tree is continuously increasing particularly in developing countries. This leads to unsustainable and uncontrolled extraction of plant material, involving excessive debarking, felling of the entire trees, root harvesting, and other activities that are currently threatening plant species and indigenous forests. These unfavourable practices mostly lead to most species being threatened. This study investigated ethnobotanical use of S. africana by the Vhavenda at Ha-Matsa village in Vhembe district, Limpopo province, South Africa. This was achieved through interviewing informants using a semi-structure questionnaire. The study further investigated population structure of S. africana and how harvesting is affecting the population of this species. The ethnobotanical data collected showed that various parts of S. africana (mainly branches, bark and stem) are harvested for various uses by Vhavenda of Ha-Matsa village. The study further revealed that the S. africana population at Ha-Matsa village is mainly represented by high number of sub-adults and that this population is failing to recruit seedlings. Lack of seedlings was ascribed to high percentage of crown harvesting and other anthropogenic activities such as manmade fires observed in this study. Furthermore, the basal stem diameter exhibited a bell-shaped distribution curve suggesting that the S. africana population at Ha-Matsa village is unstable.
The effects of root severance in savanna trees in Nylsvley Nature Reserve, Limpopo Province, South Africa
(2022-11-10) Mulaudzi, Thilivhali Adelaide; Ligavha-Mbelengwa, M. H.; Tshisikhawe, M. P.
Root severance has effect on Terminalia sericea and Burkea africana. Burkea africana is a deciduous tree belonging to the family Fabaceae (Caesalpinioideae) while Terminalia sericea is a deciduous tree of the family Combretaceae. Savanna trees respond to root severance in different ways including producing root suckers. Root suckering take place commonly following disturbance events such as fire, and root severance. The root suckers originate from primordia which are formed from meristematic cells in the cork cambium of the roots during secondary growth. The suckering of roots allows individuals spreading from the original establishment site, thereby promoting new sites colonization. Root suckering is affected by light, soil temperature, soil aeration, growth regulators, hormones, and root carbohydrates reserve. The study site was located subjectively in an area dominated by the species under study. Twenty juvenile and adult trees of the two species were selected where one lateral root was cut. The data collected in each selected species are basal stem diameter of trees, tree crown, and tree height; direction of root cut; number of root suckers produced; root sucker diameter and height of the trees. The result shows that root severance by producing root suckers as observed in Burkea africana and Terminalia sericea. More distal root suckers were produced than proximal root suckers. The health of the plant is not affected by either severing root or development of root suckers. The growth or vigour of root suckers depends on the parent root system, where they are initiated, micro environmental conditions such as soil temperature and herbivory. Juvenile plants produced more root suckers compared to adult plants of Burkea africana. Burkea africana responded quickly but Terminalia sericea needs more time to develop root suckers. Therefore, the knowledge of root sucker and root severance of the two species (i.e. Terminalia sericea and Burkea africana) in this study may contribute to the conservation and management recommendation of the population of the species.
Genomic diversity and structure among South and East Asian human populations
(2022-11-10) Ngoveni, Maria Dunisani; Moodley, Yoshan; Rakotoarivelo, Andrinajoro
Genetic variability is a complex concept that is affected by many factors. Studying the genetic variability within the human population provides a better understanding of how populations evolve. The genetic variability within modern humans resulted from different conditions experienced in different routes used by out of Africa migrations to other parts of the world. These events included mating with other human species (Neanderthals and Denisovans) and the development of cultural practices as they arrived in other parts of the world. Asia is more diverse in terms of physical geography, cultures, and languages, which makes it an interesting region to study human population genetic diversity and population structure. From animal studies, colonization of islands is often associated with loss of genetic diversity resulting in isolation. Although humans can easily move around, various aspects could result in isolation between populations. To test the concept of low genetic variability in island populations, I used 1000 genomes project variant calls datasets (autosomal, X-chromosome, Y-chromosome, and mitochondrial data), which include 983 individuals from ten Asian populations. I estimated the genetic diversity from autosomal dataset of South and East Asian populations to compare the genetic affinities between mainland and island populations. Reduced levels of genetic diversity were observed in Japan suggesting a possible genetic bottleneck during the initial colonization of the island. Despite the diverse cultural practices and South Asia being colonized early the populations are not more internally structured nor more genetically diverse compared to East Asia. Most East Asian populations had higher heterozygosity compared to South Asian populations. It is clear from the results that physical geography plays a crucial role in shaping the genetic diversity between populations. Significant levels of gene flow were observed between populations that are at close geographical distance compared to populations at distant proximity.
The value of Mopane worms: quantifying ecosystem services in terms of nutrient cycling in semi-arid regions of Limpopo
(2022-07-15) Netshanzhe, Mutali Winnie; Swanepoel, L.; Swanepoel, C.; Foord, S.
Mopane worms are the late-instar stage caterpillars of the mopane moth, Imbrasia belina/ Gonimbrasia belina, found in southern Africa virtually following their hosts' trees, Colophospermum mopane, Terminalia seriscea, and Sclerocarya birrea, among others. The caterpillars are harvested for consumption and sale, thus crucial for rural livelihoods. Due to their importance to the livelihood of people and the rise in the human population, coupled with poverty, there is growing concern about harvest rates which might pose a risk to their sustainability. It is thus essential that research focused on aspects related to sustainable harvest rates is done alongside research focusing on the general species ecology. This study has two parts; firstly, the study aimed to do a systematic review to determine the current state of knowledge and research on mopane caterpillars in southern Africa. Secondly, the study aimed to assess the contribution of mopane caterpillars’ frass to nutrient cycling by determining the nitrogen mineralization rates of frass compared to that of mopane leaves. We used search engines such as African Journals Online (AJOL), Google Scholar, and Web of Knowledge. The online databases were searched using the following keywords, 'mopane worms', 'mopane caterpillar', 'Imbrasia belina', 'Imbrasia belina caterpillars', and 'Gonimbrasia belina'. All the publications were compiled and evaluated based on title, keywords, and abstract to select only studies focusing directly on mopane caterpillars. Only peer-reviewed publications were included and did not include grey literature, such as reports, presentations, dissertations, or book chapters. A total of 104 publications were found that fit the assessment criteria. The temporal distribution showed that studies on mopane caterpillars began in the 1960s, and there was a steady increase from 1991 onwards. The spatial distribution of publications closely followed the mopane caterpillars distribution in southern Africa. Two main themes emerged from the papers: resource use and ecology. Most papers (79 papers; 76%) focused on resource use, while only 25 papers (24%) focused on the species' ecology. Furthermore, spatially there was a lack of studies in many countries where mopane caterpillars occur, highlighting the spatial bias in studies. The review highlighted that research on mopane caterpillars is biased to resource use, with little attention toward the ecological role the species play in the ecosystem. We conducted an incubation experiment to measure mineralization rates between mopane caterpillars’ frass and mopane leaves. The results showed that frass had high mineralizable N due to the high NH4⁺ and NO3⁻ concentration compared to the whole and fine (ground) leaves. Overall, frass released more inorganic N than leaves; thus, it seems that mopane caterpillars’ frass has high mineralization potential and is essential in aiding nutrient cycling in the ecosystem. From this, we recommend more field and lab studies to establish the mineralization potential of mopane caterpillar frass and the rate at which the frass release nutrients. We also recommend more studies that will focus on consumption of leaves and the release of frass by mopane caterpillars to determine the biomass consumed and consequently returned to the ecosystem by mopane caterpillars.
The potential of bats as bioindicators for areas currently transformed by opencast mining within the Vhembe Biosphere Reserve, Limpopo Province, South Africa.
(2022-07-15) Cory-Toussaint, Dawn; Taylor, Peter J.; Barnhoorn, Irene E. J.
Bats are the second most diverse order of mammals and provide crucial ecosystem services from insect control (including significant crop pest species), to pollination of plants and seed dispersal. Bats are known to be sensitive to alterations in their environment. Globally, bat populations and communities are under pressure due to anthropogenic activities that alter their natural habitats creating unfavourable habitats for some bat species and favourable conditions for others. Anthropogenic activities, impose a multitude of impacts on bats such as artificial lighting throughout nocturnal periods and excessive noise during both diurnal and nocturnal periods. These alterations of habitats affect bat roosting and emergence behaviour, disrupt commuting routes to foraging grounds and alter interspecific competition. Additionally, bats are exposed to and suffer physiological issues relating to contaminants such as heavy metals and trace elements of which their liberation is exacerbated by human activities. African bat conservation is already under considerable pressure from the development occurring throughout the continent. A looming development of significant concern is the proposed African Mining Vision to develop mining and transport networks throughout sub-Saharan Africa. The fate of bat conservation in Africa is dependent on bat taxonomy (with new species regularly described), an understanding of African bat ecology and the responses of bat species to changes in their environment. Research covering these aspects are greatly needed in order to propose environmental mitigation and remediation strategies. Bats have the potential as bioindicators to provide information concerning ecosystem health pre-, during and post- large scale developments such as mining. My study focused on how a bat community in northern Limpopo Province was impacted by the de Beers Venetia opencast diamond mining operation. I investigated which bat species have the potential to be bioindicators based on the impact of habitat degradation (Chapter 2). The impact of artificial light and anthropogenic noise was explored (Chapter 3) and the use of bat fur and blood as biomarkers of bat exposure to heavy metals and trace elements (Chapter 4). Bats have the potential to be good bioindicators as they are easy to monitor in areas like mines that are often a challenge to access and or have high safety risks due to heavy machinery movement and human exposure to possible environmental contaminants. By using passive acoustic recording techniques, the composition and activity of the bat community was determined on the Venetia diamond mine and over the natural areas neighbouring the mine. Six bat detectors were deployed for a full summer and winter season to determine what factors (both anthropogenic and natural) influenced total bat activity as well as species richness and diversity. The effect of habitat type (natural habitats Musina Mopane Bushveld and Limpopo Ridge Bushveld vs altered landscapes of the wastewater dam and opencast pit), season, minimum temperature (Tmin) and moon phase were investigated. Habitat type and season were shown by the best-fit models to be the main factors affecting bat activity, which was lower during winter and consistently lower over the heavily disturbed opencast mining pit. It was evident from the passive acoustic recordings of echolocation calls that the Venetia diamond mine was an important resource for numerous bat species, particularly at the wastewater dam, boasting ~18 out of 22 species/species groups. The wastewater dam provided a sought after resource for foraging and possibly drinking by bats. The infrastructure of the mine was also observed to be used by molossid bats as roosting opportunities. Based on the clear-cut response of three species/species groups to habitat type, Laephotis capensis/Pipistrellus (Vansonia) rueppellii, Afronycteris nana and Pipistrellus rusticus/Neoromicia anchietae were proposed as bioindicators on the Venetia diamond mine. All three species/species groups could be environmental indicators which means that they respond to physical changes in the environment, in this case, changes in preferred habitat. Laephotis. capensis/P. rueppellii generally avoided the mining footprint and were abundant in the natural areas whereas A. nana and P. rusticus/N. anchietae were prolific over the wastewater dam, particularly during winter. The response of A. nana and P. rusticus/N. anchietae may be a reflection of changes in insect species composition over the wastewater dam in relation to potential changes in water quality and as such, have also been suggested as ecological indicators as they may be reflecting the change in another taxon or group (invertebrates). Further research in this regard is required. Bat species were characterised as exploiters and adapters to resources provided by the mine such as new artificial roosting opportunities in infrastructure and resource creation, particularly artificial water sources that would otherwise be scarce for bats in the semi-arid environment. Examples of these exploiter and adapter species were Chaerephon pumilus/Mops condylurus that exploited resources provided by the mine from roosting in buildings to using the wastewater dam, and P. hesperidus as an adapter that used the wastewater dam as an important resource particularly during winter and was only recorded in natural areas during summer but is not known to roost in the infrastructure of the mine. Even though the mining activities provided resources, bats were exposed to continuous anthropogenic noise and artificial light during their night-time foraging period. To investigate the impacts of anthropogenic noise and artificial lighting, a transect was installed on the Venetia diamond mine using six SM4BAT acoustic recorders (bat detectors) (Wildlife acoustics, Inc.) to passively record bat species and their associated activity. The transect began in a brightly lit area near some workshops and a conveyor belt system and extended past the well-lit and noisy processing plant, into an open-air laydown storage area and terminated in natural vegetation. Surprisingly, according to mixed-effects models, in general, anthropogenic noise did not have a significant impact on bat activity or species richness. Artificial light only negatively impacted foraging activity and there was little evidence of bats foraging under the floodlights near the workshop and processing plant. Artificial light may possibly impact total bat activity and searching/commuting behaviour. In support of the data concerning the lowest bat activity and species richness over the habitat devoid pit of the mine, the percentage of natural vegetation cover was the most important factor influencing all bat activity and species richness. With significant bat activity recorded over the mine wastewater dam, there is potential for bats to be exposed to high concentrations of contaminants, particularly heavy metals and trace elements that would otherwise be naturally occurring at lower concentrations in the environment. Therefore, I investigated the potential bioaccumulation of elements in molossid bats from the mining footprint and in a control area adjacent to the mine. There is great interest in using bats as bioindicators of environmental contaminants and with a focus on non-lethal and less invasive methodologies, the fur and blood of several Tadarida aegyptiaca and C. pumilus/M. condylurus was tested for 23 elements. Fur is a good indicator of exposure to elements over an extended period and blood provides insight into more recent exposure. Fifteen of the 22 elements (barium excluded as it was predominantly below detection limits), were higher in the fur that in the blood samples. Concentrations of boron (B), potassium (K), rubidium (Rb) and cadmium (Cd) in fur and zinc (Zn), and mercury (Hg) in blood were significantly higher in samples from the opencast diamond mine compared with the control site. Manganese (Mn) was higher in the blood of bats from the control site than from the mine. Although weak, the only significant correlations between fur and blood element concentrations were found for Hg and strontium (Sb). Comparative data with other bat species is scant in the literature and there are currently no toxicological thresholds for elements in bats, thus the low concentrations of most elements, except aluminium (Al), iron (Fe) and Zn, may reflect background values. These data are the first presented to compare blood and fur elemental concentrations of South African bats the implications of which are currently unknown. 3 These data presented in my thesis has great potential to add to the environmental monitoring of the Venetia diamond mine by providing insight into trends in the bat population (including species richness) that utilise the mine associated (drinking and foraging areas over the waste water dams, and roosting opportunities in mine infrastructure). These data can be used as a baseline to monitor the current and future environmental impacts of the mine as production continues and, can be used to monitor and assist rehabilitation efforts soon to be underway.
Evolutionary Genomics of the Trans-Atlantic Slave Trade
(2022-07-15) Ndou, Maanda; Rakotoarivelo, Andrinajoro; Moodley, Yoshan
The Trans-Atlantic Slave Trade is a remarkable large-scale migration in the human history. On several occasions between the 16th and 19th century, millions of African men, women, and children were purchased from African traders and some abducted for slavery by the Europeans, for forced labour in the European colonies established in the American continent. The barbarous nature of the slavery left significant genetic modifications in the ancestry of modern-day descendants of former slaves (African Americans in United States and in Barbados). This research uses differently inherited high coverage Whole Genome Sequences (WGS) from autosomal, X, Y, and low coverage mitochondrial chromosomes collectively to present a detailed genetic point of view of the African Americans, their genetic relations to Africans and their interactions with America’s other residents: Europeans and Native Americans. The results show that African slaves were abducted from West Africa (dominantly from Nigerian populations). Gene flow patterns were observed among former African slaves, their European slave masters, and Native American populations, resulting in genetic diversity among modern-day African Americans that is greater than any other population currently inhabiting the Americas and even higher than their source populations in Africa. The gene flow pattern was unidirectional from Europeans to African Americans and Native Americans, but bidirectional between the African Americans and Native Americans.
Seasonal use and mortalities of mammals along the Phalaborwa – Hoedspruit railway line in Balule Nature Reserve, South Africa.
(2022-07-15) Thela, Siboniso Khulekane; Swanepoel, L. H.; Bhardway, M.; Collison-Jonker, W. J.
Railways are essential transportation corridors that facilitate the movement of goods and people with important environmental and economic benefits. Despite these benefits, railways and trains can negatively affect wildlife through mortalities, barrier effects, disturbances, and habitat loss. There is growing evidence that human activity negatively affects the spatial distribution of wildlife in relation to the distance from the infrastructure and wildlife also adjust their spatiotemporal activity to avoid or minimize encounters of human activity. Moreover, wildlife mortalities due to collision with trains are a major conservation concern which can jeopardize the persistence of wildlife populations as wildlife-train collisions are non-specific with regard the species, age and sex of the animal affected. In this study, I assessed the activity patterns of six medium-large sized mammals (≥ 10 kg) and monitored the mortalities of wildlife from four different taxonomic groups on the landscape bisected by the railway line in Balule Nature Reserve. Impala and giraffe occurrences on the railway line is mostly diurnal. Meanwhile, lion occurrence on the railway line is mostly nocturnal. Four of my focal species moderately overlapped with train activity, with no seasonal differences in their degree of activity overlap. African buffalo and elephant activity decreased with increasing distance from the railway line. Giraffe, impala, and lions are less active around the railway line in the wet season than the dry season. Spotted hyaena are more active around the railway in both open grassland and woodland compared to mixed shrubland habitat intersecting the railway. I recorded a total of 99 rail-kills from a total of 450 km surveyed over a 90-day period. Of these rail-kills, mammals were recorded more often (29.29%), followed by birds (26.26%), reptiles (26.26%) and amphibians (18.18%). There was no significant difference in the frequency of mortalities on the railway line between seasons (U = 286.5, n = 49, p = 0.421). The rail mortalities of diurnal did not differ significantly from nocturnal species (x² = 0.55, df = 1, p = 0.458). However, there were significantly more mortalities of diurnal species than nocturnal species on the railway line during the dry season (p < 0.05). Most encountered deaths on the railway line occurred in a mixed shrubland section but there was no significant association in the frequency of rail mortalities and rail-side habitat type (H = 0.84, df = 2, p = 0.657).
Frass from black soldier flies as a valuable fertilizer and biopesticide for crops
(2022-07-15) Kubayi, Consol; Foord, S. H.; Madala, N. E.; Swanepoel, C. M.
Recently, insect farming has gained recognition globally. This is particularly true for the black soldier fly, Hermetia illucens. However, the byproduct of insect feeding, a combination of food residue and frass left by the insects after harvesting, has not been given much attention and even fewer studies focus on the use of frass as a bio-fertilizer. In sub-Saharan Africa, human populations are expected to double by 2050, expensive fertilizers and increased food prices will exacerbate conditions further. This study is divided into three data chapters. Firstly, we conducted a systematic review of published literature on BSF (black soldier fly) larvae frass. In this review we collected literature from across the world, and we compared the research done in Africa with that of the rest of the world. The results show that more studies have been done in developed countries (82 %) as compared to developing countries (18 %). Topics explored around BSF frass included waste disposal, organic fertilizer, bioconversion, chemical composition, and economics. The results from all these studies show that frass can be used as a complementary organic fertilizer or independently. However, none of the papers have explored all the benefits of frass and the impact of different waste streams on frass quality. A better understanding of pH and electrical conductivity (EC) impact on frass as fertilizer are required. Secondly, the data chapter presents the results from a greenhouse pot trial where we assessed the effectiveness of frass as a potential biofertilizer to improve plant growth. Frass was compared to commercial fertilizer and a control in a greenhouse at the University of Venda. Amaranthus hybridus was used in the pot trial, and growth parameters that were measured included number of leaves, plant height, dry biomass, and chlorophyll. The results indicated that dry biomass is highest in the NPK (Nitrogen, Phosphorus, and Potassium) treatment, with the control treatment being the lowest. Frass application at the lowest level did not significantly differ from the control, however, the biomass increased with in response to increased BSFL (black soldier fly larvae) frass addition and commercial fertilizer. The addition of 20g of frass improved all the parameters, and they performed similarly with commercial fertilizers. Frass maturity was performed through phytotoxicity test, and further evaluated the efficiency of frass tea as a biopesticide for crop pests through foliar spray technique. The results further revealed that frass used in the study was not matured enough iii as the relative root growth rate was below 50 %, hence it was phytotoxic. Less leaf damage was observed in brewed frass tea compared to boiled frass tea as it was utilized as a foliar spray. Lastly, ultra-high-performance liquid chromatography- quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS) and some chemometric software including XC-MS and R-Software were utilized to characterize different metabolites found in Amaranthus hybridus. A total of 30 metabolites have been identified including derivatives of coumaric acid, caffeic acid, ferulic acid, and flavonoids. These metabolites serve different functions in plants including plant defence against pests and cardiovascular diseases in humans. Different frass treatment levels affected the distribution of metabolites. In conclusion, frass remains a promising option to substitute inorganic fertilizers, thus reducing global warming challenges and alleviating poverty in developing countries.
An investigation of the genetic integrity of Oreochromis species and incurring in Nandoni and Albasini Dams using the control region of mitochondrial DNA
(2020-02) Mboweni, Vusi Besil; Moodley, Y.; Barnhoorn, I. E. J.
The genus Oreochromis represents a radiation of mouth-breeding Tilapiine fish inhabiting lakes and rivers throughout Africa. Due to incomplete reproductive isolation, most of the 31 species within this radiation can interbreed giving rise to fertile F1 hybrids. Oreochromis mossambicus is endemic to southern Africa but is now coming under threat throughout much of the sub-region because of the introduction of invasive Oreochromis species, which typically inhibit other parts of Africa. Due to their exceptional growth rates, invasive species were brought to South Africa for the aquaculture industry, and it is feared that they may have hybridized with or displaced O. mossambicus. This study aims to determine, using genetics, the extent of invasion of non-native Oreochromis species into Nandoni and Albasini dams of the upper Levubu in Limpopo South Africa. It is suspected that O. niloticus entered the River after the creation of Albasini Dam, which is upstream of Nandoni Dam. Therefore, it is predicted that typically O. niloticus mtDNA haplotypes will be observable in Nandoni, but that their frequency should be much lower upstream in Albasini Dam. I collected 141 samples from both dams, amplified and sequenced the control region of mitochondrial DNA. I then reconstructed networks and phylogenies with our samples combined with the downloaded samples from which I was able to determine the magnitude of Oreochromis invasion into the upper Levubu. Surprisingly, not one of the sequenced samples possessed a haplotype that clustered with O. mossambicus reference samples. However, I was able to identify two invasive species within the upper Levubu: O. andersonii in both Albasini and Nandoni dams and O. niloticus in Nandoni Dam. Oreochromis andersonii has high genetic diversity and with evidence of demographic expansion based on results from its mismatch distribution and Bayesian skyline plot. These results provide insights into the events that led to the invasion of foreign Oreochromis species to the Levubu system. A genetic signal for a demographic xi expansion might have been caused by O. andersonii haplotypes being in the system before the “big flood” in the year 2000, with a re-introduction into Nandoni after the flood from a different source. This could explain why some haplotypes of O. andersonii are present in both dams and some are only present in Nandoni Dam. Oreochromis niloticus on the other hand, has low genetic diversity in Nandoni Dam compared to downloaded samples, and was probably introduced only once, and may have undergone a demographic bottleneck. From these results, it is clear that O. mossambicus has been all but replaced by non-native Oreochromis in the upper Levubu. Hybridization or total replacement of O. mossambicus may have also occurred in another river system across its native range. O. mossambicus is better adapted to poorer eutrophic conditions and, most importantly it is well adapted to high salinity. Therefore, a strategy conserving genetically diverse O. mossambicus population in the lower reach of the river system, where there is higher salinity, like the lower Changane river, could be most appropriate for this species. The estuarine swamps could then become a refuge for O. mossambicus within its native range.
An inventory of woody and herbaceous invasive alien plants in Thohoyandou Botanical Garden, Limpopo Province, South Africa
(2021-10-07) Neluonde, Mboneni; Ligavha-Mbelengwa, M. H.; Tshisikhawe, M. P.
Species migration out of their local range into new zones by people has brought about the rise of biological invasions. Exotic or non-native species need to conquer various boundaries to establish, naturalize, produce localized self-supporting populations, and in the end spread naturally before they are considered as invasive. These invasive alien species are currently perceived as key drivers of human’s instigated global change as they have negative impacts on biodiversity, ecosystem services and human prosperity which makes the investigations on invasive species imperative to direct approach plan and management important. This study was motivated by the need to control invasive alien plants in protected areas and this inventory of invasive alien plants (IAP) marks the first step in creating baseline data for managing invasive alien plants in the garden. Protected areas are threatened by the impacts of invasive alien plants that invade them and Thohoyandou Botanical Garden is no exception. Invasive alien plants are the second greatest threat to biodiversity worldwide and estimates suggest that invasive alien species cost the country over R 6.5 billion per year. The study aimed to document the woody and herbaceous invasive alien plant species in Thohoyandou Botanical Garden in the Vhembe District. Three belts of 100 m x 500 m were constructed and within them quadrats of 10 m x 10 m were randomly constructed. All the invasive alien plant species were identified and grouped as per their growth forms. Their impacts on the adjacent native species were investigated and their health status identified using a sliding scale of 1 – 5, where 5 is healthy and 1 is unhealthy. All the data were stored in Microsoft Excel and later analyzed using One-way analysis of variance(ANOVA) was also used to compare mean frequency count and mean height between invasive and native species. Data was analysed through the Microsoft Excel programme. This study has shown that invasive species have the potential to reduce native species at a rate of 2.92 species per every 40 invasive species, on average. Thus, for every 40 invasive species that are found in any chosen area within Thohoyandou Botanical Garden, an average of 3 native species will be lost as a result. These results have a very strong implication in that they can guide management and control strategies aimed at ensuring that the impact of invasive species on the growth and survival of native is kept to minimal levels.
The rate of recolonization by native plant species after the eradication of invasive alien plant species in Limpopo Province, South Africa
(2020-11-25) Mbedzi, Melford; Tshisikhawe, M. P.; Sinthumule, N. I.; Rahlao, S.
Invasive alien plant species found in riparian zones are known to compete with native plant species for water, space, sunlight, and other natural resources by lowering the structural diversity of native vegetation, thereby altering the functioning of plant communities. This may impact on the number and variety of organisms that a certain vegetation type may support. The aim of the study was to investigate the rate of recolonization by native plant species after the eradication of the in situ alien invasive plant species. This was done by measuring the rate of recolonization by native species after the removal of alien invasive species (Chapters 3 and 4), and by identifying factors to consider for recolonization to occur (Chapter 5). By measuring and identifying the above, it was possible to develop an adaptive management plan (Chapter 6) for the study area, which would assist local and provincial conservation agencies in conserving native species that should improve ecosystem dinamics. The study was carried out in the Waterberg and Makhado district municipalities, Limpopo Province, on farms that are highly infested with alien invasive plant species. Seventy-two permanent plots of 10 m2 each were constructed along three transects. The alien tree species in the plots were eradicated during March 2016 via mechanical clearing, and the area periodically monitored over a period of 34 months. The choice for the dimensions of quadrats depended on the size and distribution of the alien invasive trees, which grow in an aggregated form (such as Acacia decurrens and Populus alba) and have small canopies, except for Lantana camara in some cases. The species present (native and invasive alien plant in the quadrats were identified and recorded during March 2016 before removal of the invasive alien plant species. This was done to establish the rate at which the species (native or alien) were germinating. Results from this study indicate that in the case of Acacia decurrens and Lantana camara, recolonization of native species would be possible in the near future with continued monitoring and management, as some native grass and herb species were emerging on the study site. Populus alba proved troublesome due to its ability to reproduce vegetatively through root suckering, which enabled it to subsequently re-occupy the study area in larger numbers than before due less competition from other native and alien species. Therefore, it would require more time to eradicate this species than the other two. It is conclyuded that, the recolonization by native plants is possible, though it needs more monitoring. It is recommended that there needs to be an adaptive management plan that would assist in providing more affective results in ecosystem recovery and conserve the native plant species.
The Survival of Acacia decurrens , Acacia melanoxylon and Populus alba in Vaalwater, Waterberg Biosphere Reserve, Limpopo Province, South Africa
(2021-06-23) Matukana, V.; Ligavha - Mbelengwa,M. H.; Tshisikhawe, M. P.
Invasive alien plants use survival strategies to outcompete native plants. Invasive alien plants occurring next to water bodies consume lot of water and are difficult to control and remove within their area of existence. Government uses public funds to control and remove invasive alien plants and use different methods to control them. Mechanical control can only be used for specific plants, not for all invasive alien plants existing in field. Only three species of invasive alien plants were sampled in this study, namely; Acacia decurrens, Acacia melanoxylon and Populus alba. Two sites were sampled, one away from the water body and the other site next to the river. Twenty quadrats were sampled per site and trees were controlled through mechanical method of digging the roots and cutting at the ankle and knee height size within the quadrats. Over 18 months monitoring was conducted to check the response of these plants. The results show that, out of twenty quadrats sampled per site, the response of sprouts next to the water body was very successful. All stumps cut at knee level next to the river had sprouts and root suckering was observed more on trees that were closer to the river, especially on Populus alba and Acacia decurrens. This study emphasizes the need to consider the impact of survival strategies of invasive alien plants when controlling them.
The effects of experimental drought, grazing, and seasonality on ant and spider diversity in an arid region of South Africa
(2020-04) Ratshibvumo, Tshikambu; Foord, S. H.; Munyai, T. C.
Coupled with irreversible shifts, climate-driven disturbance of ecosystems will probably be the largest impact of climate change on humans. With higher rainfall variability and more intense events, separated by extended dry periods, semi-arid rangelands will be severely altered. Adding to these climatic events, livestock grazing is one of the most common land use practices globally, which will increase as human populations grow. The magnitude of these synergies between drought and grazing could also vary with season. Our understanding of faunal response to the interaction of both drought and grazing is limited. This study investigated the response of ants and spiders, two dominant components of epigeal invertebrate assemblages, to a long-term drought and grazing experiment. The experiment consisted of four 40 x 40 m blocks, each with nine 10 x 10 m plots. Drought was simulated using rainout shelters, whilst grazing was manipulated by excluding livestock from the plots using ~ 1 m high fence around the plots. Ants and spiders were collected seasonally in a blocked and two-way crossed experiment using a total of 96 pitfall traps. Both ant and spider size were assessed using community weighted mean. Grazing treatment had the bigger impact on ants than drought, as they got smaller, functionally less diverse and less active with grazing. The interaction between grazing and drought encouraged the increase in activity of large ants. There was an interesting interaction between grazing and drought, plots with grazing had smaller ants than plots without grazing, but only in plots for which there had been drought. This could be attributed to antlion abundance and how they interact with grazing on the specific plots. Assemblage level analysis confirmed the importance of size in structuring these communities, with larger species of ants associated with open and dry habitats. In contrast, spiders were more responsive to drought than grazing treatments. The spider response to the treatments was in conjunction with seasonality, with spider richness decreasing with cold, dry season (winter) and hot, dry season (spring) respectively. Spiders also became less active during the dry seasons. Interestingly, smaller spider species were more active during cold, dry season, and larger species were more active during the hot, dry season where there is no grazing. At assembly level, grazing and no drought interaction encouraged mobile species that were more of active hunters, as open habitats are ideal hunting ground. Our findings clearly suggest that both long-term drought and grazing have an impact on ants and spiders. How these taxa respond to long-term effects on drought and livestock grazing in semi-arid rangelands in the face of climate change is likely to shed light also on how other invertebrates are likely to be affected, and what it could mean for the ecosystem as whole. Further studying is needed to uncover other underlying changes, how that affects and shapes the semi-arid rangeland ecosystems in the long-term.
Does observational methods affect the observed impacts of exotic plants on flower visitors in around Macadamia orchards
(2020-02-20) Ramotjiki, Mancha Lorraine; Foord, S. H.; Schoeman, C. S.
Pollination of flowering plants is mostly facilitated by insects. However, there is a global decline in the pollination services caused by invasive alien plants (IAPs), excessive use of pesticides, habitat loss, and fragmentation. IAPs affect native plants pollinators and integrate into their network interactions. Habitat loss leads to small remnant patches surrounded by a matrix of mainly agricultural activities, these remnant patches support native vegetation and provide forage to pollinators within and outside the flowering period of agricultural crops. However, these patches are also vulnerable to invasion by IAP’s. Macadamia nuts are one of the fastest growing markets in South Africa. Macadamia nut trees (Macadamia integrifolia) are mostly pollinated by wild and managed honey bees (Apis mellifera), but studies have shown that large densities not only impact negatively on pollination services but affect pollinator communities as a whole. Here we study plant flower visitation by potential pollinators in a remnant patch, invaded by exotic plants, adjacent to a macadamia orchard in a heavily transformed, commercial agricultural landscape. The impact of IAPs on flower visitor community composition (abundance and species richness) was assessed using two field methods of observation methods (camera trap and visual observation). Relative to visual observation, camera traps recorded smaller species and those that tend to avoid humans, while rarer species were more prevalent in visual observation. Therefore, camera traps observed more species at a sampling point, but less species overall. Observational methods are explained by the largest amounts of conditional variation. IAPs and native plants were visited by a larger and diverse set of flower visitors than macadamia although macadamia flower densities were twice as high and covered a much larger extent. IAPs were more generalist in the flower visitors they attracted. Native plants were more specialized in the flower visitors they attract with GLMM suggesting although not significantly were associated with more species richness. These plants were also associated with overall visitation of species. More visitation of Apis mellifera were on IAP’s and native plants which contrast with macadamia with less than 10%. However, this small amount account for 65% of all macadamia flower visitations, the remainder was largely (33%) made up by Eristalis tenax. Dominant flower visitors seemed to avoid A. mellifera by partitioning their activity in time or iii specializing on certain plant species. The importance of IAP’s in providing forage to A. mellifera before macadamia flowering periods are noted. However, this probably has negatively impacted on other potential native pollinators of macadamias (e.g. Eristalis tenax). The removal of IAPs around mass flowering native plants such as Gymnanthemum myrianthum, should support and facilitate the second most common flower visitor of macadamia, E. tenax and flower visitors in general.
Insectivorous bat diversity in relation to proximity and type of water source at two sites in the Limpopo Valley, South Africa
(2019-11-25) Nelufule, Murunwa; Taylor. Peter John; Parker, Daniel; Weier, Sina
Water availability plays an important role in the habitat requirements of bats. Previous studies have shown that water bodies (both natural and artificial) are used by bats and other animals for drinking water and foraging. I collected my data in the semi-arid landscape of the Venetia Nature Reserve (VNR) and the Mapungubwe National Park (MNP) which is bordered by the Limpopo River. I sampled bats acoustically for 25 nights in total at VNR and MNP, and in three austral seasons (autumn, winter and summer). A total of 21030 bat echolocation calls were recorded, and 23 different species were identified. These species represented the families Vespertilionidae, Molossidae, Emballanuridae, Miniopteridae and Rhinolophidae. Mops condylurus, Chaerephon pumilus, Rhinolophus smithersi were the most commonly recorded species at MNP, while Neoromicia capensis and Mops condylurus were the most commonly recorded species at VNR. Rarefaction analysis showed no significant differences in the estimated richness/diversity between MNP and VNR. However, VNR sites near artificial water bodies had a higher species richness and diversity compared to sites 500-750 m away. No such trend was evident at MNP, likely because all sampling sites were not more than two kilometers away from riparian habitats along the Limpopo river. These results show both the importance of riparian habitats (contributing to higher diversity and activity associated with proximity to the Limpopo River) and how important artificial water bodies are for bats in semi-arid habitats. My results illustrate that MNP has higher overall bat activity compared with VNR, probably because of its proximity to the Limpopo river. Sampling season and moon phases were also important predictors of bat activity and species richness in this study; there was more activity in autumn than in summer and winter, while winter had the lowest activity. VNR and MNP are protected areas where future research about the biology, morphology and behaviour of bats which are biological indicators should take place in order to improve the understanding of challenges faced such as climate change.
Distribution, population status and conservation of the samango monkey (Cercopithecus albogularis schwarzi) in the Limpopo Province, South Africa
(2020-02) Linden, Birthe; Taylor, Peter J.; Dalton, Desire L.
A general introduction about the need for studying forest dwelling primate populations in fragmented landscapes and more specifically in the Soutpansberg is given in Chapter 1. Forests affected by fragmentation are at risk of losing primate populations over the long term. In addition, although the impact of fragmentation on primate populations has been studied in many places in Africa, Asia and South America there is no consensus of how the different primate species react to forest disturbance and fragmentation. This study aims to investigate the impacts of natural and anthropogenic forest fragmentation on the Soutpansberg samango monkey population including their distribution, genetics, and phylogeography, identifying threats and mitigation measures. To date, no detailed population level research has been undertaken on samango monkey populations in the far north of their South African distribution. By collecting a diverse data set, in addition to existing ecological data, this study generates conservation and management recommendations suited specifically to the study area and the study species and provides baseline data for future monitoring. Chapter 2 details how through creating an accurate forest distribution map and collecting samango monkey distribution records through surveys we were able to investigate how both natural and anthropogenic forest fragmentation influences the distribution of samango monkeys in the Soutpansberg. We explored forest patch occupancy and connectivity, determined the degree and nature of matrix utilisation and identified possible threats to forests and samango monkeys between the contrasting landscapes of the eastern and western Soutpansberg. Here we found that samango monkeys largely occupied forest patches <100 ha in size and that the Soutpansberg has very few forest patches > 100 ha available. We showed that samango monkeys used all components of the surrounding matrix and that lone or bachelor group males used the matrix more extensively than groups. We found that paved roads pose a major threat, however not a barrier, to samango monkey populations when navigating the matrix. Forest connectivity was found to be influenced by the distance between patches and possible corridors or stepping stones of isolated forest patches connecting them. Patterns found in this chapter contrasted between the eastern and western landscapes requiring different adaptive strategies from the samango monkeys and different conservation approaches from practitioners. In this chapter we conclude that samango monkeys, having evolved in fragmented landscapes, are comparatively tolerant and adaptable to a human- transformed matrix. In Chapter 3 we focused on the effects that natural and anthropogenic habitat fragmentation in the Soutpansberg has on the genetic diversity and structure of the samango monkey population in the mountain range. Here we used microsatellite and mitochondrial DNA data from faecal and tissue samples collected from four local samango monkey populations across the Soutpansberg. We also included samples from an outlying population on the escarpment south of the mountain, the most likely historical migration route into the Soutpansberg. Our analyses showed that the Soutpansberg population is divided across the mountain and that genetic diversity within the Soutpansberg decreases with increasing distance to the escarpment population and from east to west. We found a lack of contemporary gene flow suggesting that the Soutpansberg population is completely isolated from the closest source population in the escarpment and that populations within the mountain range are isolated from each other. Based on our results we suggest that extensive anthropogenic changes to the landscape in the eastern Soutpansberg and distance between high canopy forest patches in the western Soutpansberg appear to have reduced the ability of samango monkeys to disperse between sampling areas. Overall, we found that natural and anthropogenic fragmentation and geographical distance are potential drivers for the observed population genetic differentiation and that the matrix surrounding forests and its suitability for samango utilisation plays a role at the local scale. In this chapter we conclude that the degree of samango monkey population subdivision and the apparent lack of contemporary migration between populations raises concerns about the long-term viability of populations across the mountain range. Having identified road fatalities as the main direct anthropogenic threat samango monkeys are exposed to when utilizing the matrix, we further investigated this issue in more detail in Chapter 4. Here we aimed to get a better understanding of where roadkills most likely occur and how to mitigate these through using suitable canopy overpasses. As road fatalities threaten primate populations globally, we used the samango monkey (Cercopithecus albogularis) as a model species to test the suitability of two different canopy bridge designs through field experimentation and behavioural data collection for arboreal guenon roadkill mitigation. Analysis of actual roadkill data collected in the study area provided insights into the nature of high-risk localities. We showed that canopy overpasses are a viable intervention for mitigating arboreal guenon road fatalities, reducing the probability that monkeys will cross a road on the ground. Samango monkeys clearly preferred a pole bridge over a rope ladder design and canopy bridges were preferred to trees and the ground when the tree canopy was open. Pole bridges were also used by other non-guenon primates and non-primate species. We showed that although samango road kills were not predictable in time (no seasonality), adult female and immature fatalities were predictable in space, restricted to bisected riparian zones and roads close to intact forests. We further found that adult male road fatalities can be expected in seemingly unsuitable habitat areas. This chapter highlights the importance of the correct interpretation of spatial, temporal and demographic data on road fatalities and how experimental research prior to installing crossing structures could increase mitigation impact. In Chapter 5 we investigate the regional phylogeography of samango monkeys, providing a deeper understanding into their evolutionary history in repeatedly fragmented forest habitat due to paleoclimatic fluctuations. Here we used mtDNA and microsatellite data obtained from tissue samples from a coastal population (Vamizi Island) in Mozambique and compared this to existing data from South Africa. The additional analysis of Mozambique animals allowed us to further test the number and timing of radiation events of Cercopithecus monkeys in southern Africa. In this chapter we propose the occurrence of a single, north-south radiation event during the midPleistocene along the Afromontane forest belt and that after the Last Glacial Maximum, samango populations re-radiated into (re)established coastal forests on a more local scale. Taking the findings from all chapters together we provide overall conclusions and conservation and management recommendations in Chapter 6. Here we also include interview data to give insights into public perceptions of samango monkeys and possible human-primate conflicts as we consider this an important aspect of conservation planning. In this final chapter we conclude that although samango monkeys appear comparatively adaptable to changes in the matrix surrounding their forest habitat, direct threats and forest patch isolation by distance may pose risks to populations in future. We advocate that conservation and management strategies aimed at the longterm persistence of the samango monkey populations and their forest habitat across the Soutpansberg should be formulated separately for the eastern and western parts of the mountain range as differing landscape variables pose different threats to forest and samango monkeys, thus requiring separate conservation and management approaches. We further recommend explicit mention of distinct management requirements for maternal groups and lone or bachelor group males to achieve a holistic conservation approach for samango monkey populations on the landscape scale. Findings of our study are not only relevant for samango monkey populations in the Soutpansberg but also for populations elsewhere in South Africa and southern Africa generally where forests and samango monkeys share the same paleohistory and current anthropogenic threats.

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