Northern South Africa Research Articles

Crustal structure of the Bushveld complex, South Africa from 1D shear wave velocity models: Evidence for complex-wide crustal modification

Thirty-nine 1D shear wave velocity profiles, obtained by jointly inverting receiver functions and Rayleigh wave group velocities, are used to investigate the crustal structure of the Bushveld Complex in northern South Africa. Data from teleseismic earthquakes recorded on broadband seismic stations between 1997 and 1999 and 2015–2020 were used to compute P-wave receiver functions. Rayleigh wave group velocities between 5 and 30 s period were obtained from an ambient noise tomography and combined with group velocities between 30 and 60 s period from a published continental-scale surface wave tomography model. Moho depths of 45–47.5 km are found under the center of the complex compared to 40 km thick crust, on average, surrounding the complex, indicating ∼5–7 of crustal thickening. The bottom ∼10 km or more of the lower crust across much of the Bushveld Complex has a Vs ≥ 4.0 km/s, consistent with a mafic composition, whereas in most areas around the margins of the complex the thickness of the mafic lower crust is much less than 10 km. In the upper crust higher velocity structure (Vs > 3.6 km/s) above 15 km depth underlain by lower velocity structure is seen in many locations, suggesting the presence of mafic/ultramafic layering. These results favor the continuous-sheet model for the structure of the Bushveld Complex because the ensemble of 1D models is characterized by three diagnostic features consistent with that model: (1) thicker crust under the center of the complex than away from the complex; (2) a greater thickness of high-velocity (i.e., mafic) layering in the lower crust under the complex compared to away from the complex; (3) high-velocity (i.e., mafic/ultramafic) layering in the upper crust beneath much of the complex. The lack of upper crustal mafic/ultramafic layering beneath some parts of the complex is consistent with the post-emplacement tectonic and magmatic history of the complex.

Botryosphaeriaceae partially overlap on asymptomatic and symptomatic tissues of Anacardiaceae in agroecosystems and conservation areas in northern South Africa.

Members of the Botryosphaeriaceae are well-known endophytes and stress-related pathogens. We recently characterised the diversity of Botryosphaeriaceae in healthy tissues of three tree species in the Anacardiaceae, namely Sclerocarya birrea, Mangifera indica and Lannea schweinfurthii. Here we ask how that diversity compares with the Botryosphaeriaceae diversity associated with dieback on those tree species. Samples were collected from agroecosystems (Tshikundamalema and Tshipise in Limpopo) and conservation areas (Nwanedi and the Mapungubwe National Park in Limpopo and the Kruger National Park in Mpumalanga) ecosystems. Species were characterised using multigene sequence data and morphological data. Diplodia allocellula, Dothiorella brevicollis, Do. viticola, Lasiodiplodia crassispora, L. mahajangana and Neofusicoccum parvum occurred on both asymptomatic and symptomatic samples. Dothiorella dulcispinea, L. gonubiensis and L. exigua, as well as a previously unknown species described here as Oblongocollomyces ednahkunjekuae sp. nov, only occurred in asymptomatic branches. An interesting aspect of the biology of O. ednahkunjekuaeae is that it appears to be adapted to higher temperatures, with an optimum growth at 30 °C, and faster growth at 35 °C than at 25 °C. Lasiodiplodia pseudotheobromae only occurred in symptomatic branches. Neofusicoccum parvum was notably absent from conservation areas, and in agroecosystem it was most common on M. indica. Only L. crassispora and L. mahajangana overlapped on all three tree species and were the dominant species associated with dieback. These results show that not all Botryosphaeriaceae occurring asymptomatically in an area contribute equally to disease development on a related group of hosts, and that environmental disturbance plays a significant role in the distribution of N. parvum. Citation: Slippers B, Ramabulana E, Coetzee MPA (2024). Botryosphaeriaceae partially overlap on asymptomatic and symptomatic tissues of Anacardiaceae in agroecosystems and conservation areas in northern South Africa. Fungal Systematics and Evolution 13: 131-142. doi: 10.3114/fuse.2024.13.07.

Poor transferability of richness models: Predicting plot-scale plant diversity in the Waterberg, South Africa

Modelling measures of biodiversity for understudied taxa or regions is one method to address taxonomic and geographic biases in biodiversity data. However, modelling biodiversity metrics, such as species richness, to unsampled areas is only useful if predictions are reliable. As a result, testing the transferability of richness models is necessary for assessing the potential for models to predict to unsampled areas. Here we test the transferability of plant richness models between two reserves to examine if the richness-environment relationship from one reserve can accurately estimate richness patterns in the other reserve, using the vascular plant species richness of the Waterberg region (savanna biome; northern South Africa) as a model system. Six richness response variables (total species, grass species, herb species, woody species, genus, and family richness) and a set of 16 predictor variables were analysed with three modelling approaches and two statistical techniques to build: (1) models comprising all available predictor variables, (2) models using a subset of predictor variables chosen based on model performance, and (3) models using a subset of predictor variables that reduce the difference in the environmental conditions between the two reserves. The models’ performance in the training area varied considerably, but soil variables were consistently the most important predictors of plant richness. However, the transferability of all the models was consistently poor across all modelling approaches and both techniques, possibly reflecting the degree to which each reserve contains novel environments absent from the other reserve (despite being separated by only c. 60 km and sharing vegetation types). Due to the poor performance of these richness models, they are currently not useful for predicting richness to other areas in the vicinity of the reserves or in the broader region. However, in areas, like the Waterberg region, that have high plant diversity and are poorly sampled, there may be value in continued development of richness models to address biodiversity gaps, thereby providing better data to inform conservation decisions.

A Perspective of the Epidemiology of Rabies in South Africa, 1998-2019.

Despite the implementation of various control strategies aimed at eliminating canine-mediated rabies, the disease is still endemic in up to 150 countries across the world. Rabies remains endemic to South Africa, with various reservoir species (both wildlife species and domestic dogs) capable of maintaining rabies infection, and the epidemiology of the disease is yet to be adequately defined. As such, this study used surveillance data collected between 1998 and 2019 from the two diagnostic laboratories in the country for a statistical space-time analysis to determine regions where significant disease clusters could occur. In addition, the robustness of surveillance activities across the country was evaluated through the mathematical evaluation and visualization of testing rates based on the average number of samples tested per species group. In our study, various significant disease clusters were detected for domestic animals, wildlife and livestock. The significant disease clusters for domestic animals and livestock were primarily restricted to eastern South Africa, while the significant disease clusters in wildlife species were detected across northern and western South Africa. Furthermore, the testing rates identified districts from various provinces where surveillance activities could be considered inadequate, consequently influencing the geographical range of the observed clusters. These results could be used to direct intervention campaigns towards high-risk areas, while also allocating the required resources to improve surveillance in the surrounding areas where surveillance was deemed inadequate.

Patterns of Animal Rabies Prevalence in Northern South Africa between 1998 and 2022.

Rabies is endemic in South Africa and rabies cycles are maintained in both domestic and wildlife species. The significant number of canine rabies cases reported by the World Organization for Animal Health Reference Laboratory for Rabies at Onderstepoort suggests the need for increased research and mass dog vaccinations on specific targeted foci in the country. This study aimed to investigate the spatiotemporal distribution of animal rabies cases from 1998 to 2017 in northern South Africa and environmental factors associated with highly enzootic municipalities. A descriptive analysis was used to investigate temporal patterns. The Getis-Ord Gi statistical tool was used to exhibit low and high clusters. Logistic regression was used to examine the association between the predictor variables and highly enzootic municipalities. A total of 9580 specimens were submitted for rabies diagnosis between 1998 and 2022. The highest positive case rates were from companion animals (1733 cases, 59.71%), followed by livestock (635 cases, 21.88%) and wildlife (621 cases, 21.39%). Rabies cases were reported throughout the year, with the majority occurring in the mid-dry season. Hot spots were frequently in the northern and eastern parts of Limpopo and Mpumalanga. Thicket bush and grassland were associated with rabies between 1998 and 2002. However, between 2008 and 2012, cultivated commercial crops and waterbodies were associated with rabies occurrence. In the last period, plantations and woodlands were associated with animal rabies. Of the total number of municipalities, five consistently and repeatedly had the highest rabies prevalence rates. These findings suggest that authorities should prioritize resources for those municipalities for rabies elimination and management.

Patterns of Grewia (Malvaceae) diversity across geographical scales in Africa and Madagascar.

Quantifying spatial species richness is useful to describe biodiversity patterns across broad geographical areas, especially in large, poorly known plant groups. We explore patterns and predictors of species richness across Africa in one such group, the palaeotropical genus Grewia L. (Malvaceae). Grewia species richness was quantified by extracting herbarium records from GBIF and Tropicos and creating geographical grids at varying spatial scales. We assessed predictors of species richness using spatial regression models with 30 environmental variables. We explored species co-occurrence in Madagascar at finer resolutions using Schoener's index and compared species range sizes and International Union for Conservation of Nature status among ecoregions. Lastly, we derived a trait matrix for a subset of species found in Madagascar to characterize morphological diversity across space. Grewia species occur in 50 countries in Africa, with the highest number of species in Madagascar (93, with 80 species endemic). Species richness is highest in Madagascar, with ≤23 Grewia species in a grid cell, followed by coastal Tanzania/Kenya (≤13 species) and northern South Africa and central Angola (11 species each). Across Africa, higher species richness was predicted by variables related to aridity. In Madagascar, a greater range in environmental variables best predicted species richness, consistent with geographical grid cells of highest species richness occurring near biome/ecoregion transitions. In Madagascar, we also observe increasing dissimilarity in species composition with increasing geographical distance. The spatial patterns and underlying environmental predictors that we uncover in Grewia represent an important step in our understanding of plant distribution and diversity patterns across Africa. Madagascar boasts nearly twice the Grewia species richness of the second most species-rich country in Africa, which might be explained by complex topography and environmental conditions across small spatial scales.

Genomic Analysis of Sindbis Virus Reveals Uncharacterized Diversity within the Australasian Region, and Support for Revised SINV Taxonomy.

Sindbis virus (SINV) is a widely dispersed mosquito-borne alphavirus. Reports of Sindbis disease are largely restricted to northern Europe and South Africa. SINV is frequently sampled in Australian mosquito-based arbovirus surveillance programs, but human disease has rarely been reported. Molecular epidemiological studies have characterized six SINV genotypes (G1-G6) based on E2 gene phylogenies, mostly comprising viruses derived from the African-European zoogeographical region and with limited representation of Australasian SINV. In this study, we conducted whole genome sequencing of 66 SINV isolates sampled between 1960 and 2014 from countries of the Australasian region: Australia, Malaysia, and Papua New Guinea. G2 viruses were the most frequently and widely sampled, with three distinct sub-lineages defined. No new G6 SINV were identified, confirming geographic restriction of these viruses to south-western Australia. Comparison with global SINV characterized large-scale nucleotide and amino acid sequence divergence between African-European G1 viruses and viruses that circulate in Australasia (G2 and G3) of up to 26.83% and 14.55%, respectively, divergence that is sufficient for G2/G3 species demarcation. We propose G2 and G3 are collectively a single distinct alphavirus species that we name Argyle virus, supported by the inapparent or mild disease phenotype and the higher evolutionary rate compared with G1. Similarly, we propose G6, with 24.7% and 12.61% nucleotide and amino acid sequence divergence, is a distinct alphavirus species that we name Thomson's Lake virus.

Molecular epidemiology of SARS-CoV-2 in Northern South Africa: wastewater surveillance from January 2021 to May 2022.

Wastewater-based genomic surveillance of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) provides a comprehensive approach to characterize evolutionary patterns and distribution of viral types in a population. This study documents the molecular epidemiology of SARS-CoV-2, in Northern South Africa, from January 2021 to May 2022. A total of 487 wastewater samples were collected from the influent of eight wastewater treatment facilities and tested for SARS-CoV-2 RNA using quantitative reverse transcriptase polymerase chain reaction (qRT-PCR). SARS-CoV-2 positive samples with genome copies/mL ≥1,500 were subjected to allele-specific genotyping (ASG) targeting the Spike protein; 75 SARS-CoV-2 positive samples were subjected to whole genome sequencing (WGS) on the ATOPlex platform. Variants of concern (VoC) and lineages were assigned using the Nextclade and PangoLIN Software. Concordance for VoC between ASG and WGS analyses was determined. Sequence relationship was determined by phylogenetic analysis. Seventy-five percent (365/487) of the influent samples were positive for SARS-CoV-2 RNA. Delta and Omicron VoC were more predominant at a prevalence of 45 and 32%, respectively, and they were detected as early as January and February 2021, while Beta VoC was least detected at a prevalence of 5%. A total of 11/60 (18%) sequences were assigned lineages and clades only, but not a specific VoC name. Phylogenetic analysis was used to investigate the relationship of these sequences to other study sequences, and further characterize them. Concordance in variant assignment between ASG and WGS was seen in 51.2% of the study sequences. There was more intra-variant diversity among Beta VoC sequences; mutation E484K was absent. Three previously undescribed mutations (A361S, V327I, D427Y) were seen in Delta VoC. The detection of Delta and Omicron VoCs in study sites earlier in the outbreak than has been reported in other regions of South Africa highlights the importance of population-based approaches over individual sample-based approaches in genomic surveillance. Inclusion of non-Spike protein targets could improve the specificity of ASG, since all VoCs share similar Spike protein mutations. Finally, continuous molecular epidemiology with the application of sensitive technologies such as next generation sequencing (NGS) is necessary for the documentation of mutations whose implications when further investigated could enhance diagnostics, and vaccine development efforts.

Living and dying in the shadow of coal: Relocating social death and its contestations in Lephalale

Marapong, “place of bones”, is situated in the shadow of the coal-fired Matimba Power Station and Grootegeluk coal mine in Lephalale, northern South Africa. Marapong was named after the bones of a local woman, Salaminah Moloantoa, which were found during the development of Grootegeluk in 1973. That same year her bones were buried on Naawontkomen farm where she had lived. Thirty-four years later with the construction of coal-fired Medupi Power Station, Moloantoa’s bones became the site of industrial construction again in this current iteration of extractivism. Working from two provocations that emerged during fieldwork – we are dead here and the mines turn our lives upside down – I relocate social death and its relation to different kinds of violence that constitute racial capitalism in this city of coal. In so doing, I engage with literature on Afropessimism, the black radical tradition, and land and ancestral struggles and argue for reconceptualising social death as grounded in place and time rather than a totalising ontological condition. Such a rereading emphasises relationality and the processes of contestation over land, life, and death, that open up futures beyond that of bones becoming coal for fossil fuel development.

A Retrospective Geospatial Simulation Study of Helicopter Emergency Medical Services’ Potential Time Benefit Over Ground Ambulance Transport in Northern South Africa

ObjectiveOne of the most important benefits of helicopter emergency medical services (HEMS) is a time benefit, either through expedited access to the casualty or a reduction in the transport time to definitive care. However, HEMS utilization does not come without risk to the public and crew or at an insignificant cost. Cost is an essential consideration for health policy decisions, especially in low- to middle-income countries, such as South Africa. The aim of this study was to determine whether there is a time benefit of HEMS dispatch in South Africa compared with simulated driving time. A secondary aim was to determine the distance from the incident site to the hospital at which a time benefit can be guaranteed. MethodsA retrospective study was undertaken by comparing the prehospital times of patients who underwent HEMS transportation with simulated ground emergency medical services (GEMS) transportation times. Handwritten patient records of actual flights were reviewed and analyzed. The actual flight times recorded were used to calculate the helicopter transport time, activation to scene time, scene time, and scene to hospital time. Times were assigned based on a nonsimultaneous dispatch model, as is used in South Africa. For each helicopter mission, Google Maps (Google Inc, Mountain View, CA) was used to simulate the fastest ground route from the same location of the incident to the same receiving hospital corrected for typical traffic trends. The actual HEMS and simulated GEMS times were compared using the paired t-test. Linear regression analysis was performed to determine a minimum driving distance at which HEMS provides a time benefit. ResultsA total of 118 HEMS transports were analyzed, the majority of which were trauma related (n = 115, 97%). HEMS transport resulted in a mean time deficit of −15 minutes (95% confidence interval, −18 to −11; P < .05) compared with simulated GEMS drive times. After regression, HEMS transport provides a time benefit at a driving distance greater than 119 km. ConclusionThe current study demonstrated that there was rarely a time benefit for actual primary emergency responses when HEMS was used compared with simulated driving time of GEMS transport. Using a nonsimultaneous dispatch model, a time benefit only occurs when the driving distance from the incident site to the hospital is greater than 119 km. There is an urgent need to critically evaluate HEMS utilization in the South African context.

Just an energy transition? A gendered analysis of energy transition in Northern Cape, South Africa

abstract The world faces a climate crisis due to the extraction and burning of fossil fuels which has supported industrialisation and capitalist expansion. One of the solutions to the climate crisis is to reduce carbon emissions by transitioning from a fossil fuel-based energy system to one based on renewable sources, such as solar or wind energy. The just energy transition promises to address unemployment and poverty while reducing the carbon intensive nature of the energy system. However, this energy transition is complex and holds uncertainty and risk for many people, particularly communities and workers who depend on the coal value chain. This article adopts a feminist political economy lens to explore the relationship between the development of renewable energy and gendered labour. This approach highlights the importance of the economy, the household and the state in the process of social reproduction. By analysing the impact of the development of solar power plants on the communities and workers in three towns in the Northern Cape, South Africa, and focusing on the three components of social reproduction, I find that the energy transition in its current form will not deliver justice for the poor and working classes or promote gender equality.

Peace Settlements and Political Transformation in Divided Societies: Rethinking Northern Ireland and South Africa, written by Adrian Guelke

Peace Settlements and Political Transformation in Divided Societies: Rethinking Northern Ireland and South Africa, written by Adrian Guelke

Reconstructing the geological provenance and long-distance movement of rectangular, fishtail, and croisette copper ingots in Iron Age Zambia and Zimbabwe.

The southern third of Africa is unusually rich in copper ore deposits. These were exploited by precolonial populations to manufacture wound-wire bangles, other forms of jewelry, and large copper ingots that were used as stores of copper or as forms of prestige. Rectangular, fishtail, and croisette ingots dating between the 5th and 20th centuries CE have been found in many locations in the Democratic Republic of the Congo (DRC), Zambia, and Zimbabwe, with isolated finds in Malawi and Mozambique. Molds for casting these ingots have been found mostly in the Central African Copperbelt, but also around the Magondi Belt copper deposits in northern Zimbabwe. For years, scholars have debated whether these ingots were exclusively made in the Copperbelt or if the molds found in Zimbabwe indicate that local copies were produced from Magondi Belt copper ore (Garlake 1970; Bisson 1976). Before the recent application of lead isotopic and chemical methods to provenance copper in central and southern Africa, there was no way to discern between these hypotheses. Rademakers et al. (2019) and Stephens et al. (2020) showed that copper artifacts from southern DRC (mostly from Upemba) and from northwestern Botswana (Tsodilo Hills) match the lead isotope ratios of ores from the Copperbelt. Building upon these previous studies, we present here the first results from a copper provenance project across the southern third of Africa, from the Copperbelt to northern South Africa. We apply lead isotopic analysis (LIA) and chemical analyses to establish the provenance of 29 croisette ingots recovered in Zimbabwe, 2 fishtail and 1 rectangular ingot recovered from sites in Zambia, and an "X" shaped ingot smelted in an experiment in Zambia in the 1970's. Our chemistry and lead isotopic results indicate that 16 of these objects were smelted with copper from the Copperbelt, 16 objects source more specifically to the Kipushi deposit within this geological district, and only one HXR ingot sources to the Magondi Belt in Zimbabwe. Taken together, we clearly illustrate that croisette ingots were traveling significant distances to reach their eventual sites of deposition, and that there was also local production of these objects in Zimbabwe.

Call repertoire of Ptychadena uzungwensis (Anura: Ptychadenidae) to complement molecular and morphological identification of the species from the Soutpansberg, South Africa.

ABSTRACT The identity of adults and tadpoles of Ptychadena uzungwensis from the Soutpansberg range in northern South Africa was confirmed using a combination of morphological characters and molecular analysis. Detailed vocalisation analysis was made and used to complement existing species identification methods. This study confirms the presence of P. uzungwensis in South Africa. Sound recordings obtained by way of directional manual recordings were used to analyse call structure and call type while Passive Acoustic Monitoring with Song Meter® technology were used to survey circadian call patterns. Following confirmation of species identity, the detailed vocalisation analysis indicated a much more diverse repertoire than previously known. Three call types were observed with Type A consisting of two or three compressed notes; Type B consisting of a multi-note vocalisation, containing multiple pulses and notes produced in rapid succession; and Type C being a multi-note vocalisation consisting of rapidly released, randomly-spaced single notes. Detailed descriptions of call repertoires, including patterns and call types are useful for species identification and for use in comparison studies.

Shell disc beads and the development of class-based society at the K2-Mapungubwe settlement complex (South Africa)

The K2-Mapungubwe settlement complex is widely regarded as the centre for the development of class-based society out of earlier ranked communities between c. AD 900 and AD 1300 in northern South Africa, southern Zimbabwe, and eastern Botswana. Beads made from ostrich eggs, the shells of Achatinidae snails, and freshwater bivalves formed an important part of the K2-Mapungubwe economy. Although thousands of shell beads have been excavated at the K2-Mapungubwe complex, this assemblage has never been analysed or even quantified in any meaningful manner. As such, only rough estimates of the distribution, use, and meaning of shell beads at these important sites were done. This article represents the first focussed research effort on this assemblage. The results demonstrate distinct spatial and chronological changes in the shell bead assemblage. Achatina beads are more common earlier in earlier phases, but after AD 1220, ostrich eggshell beads dominate. This could indicate access to new sources of raw materials. Our analysis took into account the spatial and social contexts of beads. This indicated that shell bead assemblage from the higher-status royal living areas remained morphologically constant over time, with a clear preference for smaller-sized beads. In contrast, beads from the lower-status areas could be grouped into distinct clusters of larger and smaller beads. The grouping of smaller bead on lower-status areas closely resembles elite assemblages. Smaller beads however become proportionally rarer outside elite areas over time. This may reflect changes in elite control and preferential access to shell beads. These results demonstrate how the use and manufacture of shell beads intersected with the socio-political changes that characterise the period. It also highlights the need for careful consideration of shell beads as a significant component of the political economy in the southern African Iron Age.

Archaeometallurgical Explorations of Bloomery Iron Smelting at Mutoti 2, an Early Iron Age Site in Venda, Northern South Africa

When established, bloomery iron smelting profoundly transformed farming communities that settled in Africa south of the Sahara. Sustained research in the Lowveld region of northern South Africa identified multifarious evidence of metal working dating to the Early Iron Age (Common Era 200-900). Not surprisingly, the region is celebrated in oral traditions, myths, legends, and other reservoirs of local knowledge for its highly skilled metallurgists who reduced exceptionally rich magnetite (Fe3O4) and hematite (Fe2O3) ores at locales such as Tshimbupfe, Tshirululuni, Vuu, Thomo, and Thengwe. However, the technology of iron smelting and how the smelted iron (Fe) transformed producer and user communities in the region is a subject that, until recently, attracted limited archaeometallurgical work. We present the results of archaeometallurgical analyses of iron production remains from Mutoti 2 using complementary macroscopic (physical examination), microstructural (Optical Microscopy), and compositional techniques (WD-XRF). The results show that the technology of iron smelting fitted within the bloomery method. However, the quantities of iron production remains at the site suggest a scale and organization of production geared for needs beyond single villages. This embedded first-millennium CE iron production into the socio-economic, political, and environmental transformations that shaped the political economy of farming communities of the time.

A review of the conservation status of Black Stork Ciconia nigra in South Africa, Lesotho, and Eswatini

Summary Across South Africa, Lesotho, and Eswatini, long-term citizen science atlas data have suggested concerning declines in the population of Black Stork Ciconia nigra. Unlike the Asian and European populations, the southern African Black Stork population is described as resident and is listed as “Vulnerable” in South Africa, Lesotho, and Eswatini. Here we report on surveys of historical nesting locations across northern South Africa, finding evidence for nest site abandonment and limited evidence of recent breeding. We undertook detailed species distribution modelling within a maximum entropy framework, using occurrence records from the BirdLasser mobile app. We cross-validated the models against information in the Southern African Bird Atlas Project (SABAP2) database, highlighting Lesotho as an important potential breeding area. Additionally, we used SABAP2 to assess population trends by investigating interannual patterns in reporting rate. Comparing current reporting rates with those from SABAP1 (1987–1992), we found that there has been a dramatic decrease. We noted that a large proportion of the population occurs outside the breeding range during the breeding season, suggesting a considerable non-breeding population, especially in the extensive wildlife refuge of the Kruger National Park. The slow declines observed might be indicative of a population which is not losing many adults but is failing to recruit significant numbers of juveniles due to limited breeding. Using densities derived from transect surveys, we used predictive models to derive estimates of breeding range carrying capacity and a population estimate, which suggested declines to numbers around 600 for this subregion. Minimising disturbance at breeding sites of this cliff-nesting species and improving water quality at key population strongholds are pathways to improving the status of the species in the subregion.

Spatial genetic patterns in African wild dogs reveal signs of effective dispersal across southern Africa

Across much of Africa, decades of civil war, land reforms, and persecution by humans have decimated wildlife populations. African wild dogs (Lycaon pictus) have declined dramatically during the past decades, but have shown recent natural recolonisation of some areas. In Angola, they were rediscovered after almost five decades when no surveys were being conducted, and they have recolonised areas in southern Zimbabwe and northern South Africa. Wild dogs were also reintroduced to Mozambique, where only few individuals remained. Against this backdrop, understanding genetic structure and effective dispersal between fragmented populations is essential to ensure the best conservation approaches for the long-term survival of the species. Our study investigated population genetic diversity, differentiation and gene flow of wild dogs across southern Africa, to include areas where they have recently been rediscovered, reestablished or reintroduced. Our results point to four weakly differentiated genetic clusters, representing the lowveld of Zimbabwe/Limpopo, Kruger NP, Angola/KAZA-TFCA, and the managed metapopulation, counterbalanced by moderate levels of effective dispersal on a southern African scale. Our results suggest that if the human footprint and impact can be significantly minimized, natural dispersal of wild dogs could lead to the demographic recovery of the species in southern Africa.

Maize producers' vulnerability to climate change: Evidence from Makhuduthamaga Local Municipality, South Africa.

Climate change is predicted to impact agricultural production and affect food security in poor communities of developing countries due to the likely negative impacts on rainfall characteristics. South Africa is one of the largest producers of maize crops in the Southern African Development Community (SADC) region. The majority of crop production is rainfed with precipitation received during the summer growing season. This study evaluated the impact of climate change on maize yields using trend and multiple regression analysis in northern South Africa. Exposure and vulnerability of maize farmers to the impacts of climate change were also evaluated. Rainfall characteristics showed variability of 20.35% with rain days standard deviation of 10.25 days and coefficient of variation of 18.57%. The results revealed a weak relationship between annual rainfall and rainy days, and annual rainfall and maize yields, both showed an r² and p-values of less than 0.5 and 0.005, respectively. The study found that variations in rainfall did not significantly influence variation in maize yields. Despite a clear fluctuation in yields, the results demonstrate a rising trend that can be attributed to agricultural practices such as the use of fertilisers and planting drought resistant cultivars as opposed to climate variables. The study further found that maize producers were proactively adapting to climate change, thus, reducing their vulnerability to its impacts.

Aloe immaculata and A. affinis (Asphodelaceae subfam. Alooideae), two endemics from northern and eastern South Africa, are different maculate aloe species

We show that Aloe immaculata and A. affinis (Asphodelaceae subfam. Alooideae) are two different species. Aloe immaculata, a Limpopo province, South Africa, endemic, is therefore reinstated and treated as distinct from A. affinis, an endemic of the eastern, mainly Drakensberg escarpment in Mpumalanga, South Africa, and southeastern Limpopo, and northwestern Eswatini. Vegetatively, the two species mainly differ in terms of leaf colour (dull green to brownish green in the case of A. immaculata and brighter green in the case of A. affinis). Reproductively, the species differ in inflorescence structure (subcapitate to conical and round-topped racemes in the case of A. immaculata and cylindric-acuminate ones in the case of A. affinis) and flower size and colour (pale flesh pink and 28–33 mm long in A. immaculata and scarlet red and 40–45 mm long in A. affinis). The two species are compared and illustrated, and descriptions for both species and a combined distribution map are provided.