Through the carefully selected research projects currently on the go at Tswalu Kalahari, the Tswalu Foundation continues to contribute in a meaningful way to the scientific and ecological management not only of this reserve but of communities both locally and internationally. The following selection of current projects provides insight into the depth of knowledge and experience informing conservation at Tswalu.






Student: Grace Warner


MSc ecology student Grace Warner’s project to better understand microclimate density and buffering capacity in the Kalahari, as a valuable resource for a changing climate, aims to help improve spatial conservation planning via the inclusion of microclimates. Grace is part of both the Wildlife Conservation Physiology and Herpetology labs at the University of the Witwatersrand, under the supervision of professors Andrea Fuller and Graham Alexander.

Arid areas in Africa, such as the Kalahari, are predicted to get hotter and drier in future decades. This prediction is of major concern for species that rely on the environmental temperature range, and access to hydration, to regulate their body temperatures. Yet, microclimates (small climatic differences formed within microhabitats, such as burrows or bird nests) are known to buffer species from extreme environmental conditions, with species often selecting specific microclimates as a way to regulate their body temperature and water loss. However, microclimates are not accounted for in course-resolution climate models, which are commonly used to predict species or ecosystem vulnerability to climate change. Hence, valuable areas of climatic refuge may be missed at such large scales, simply due to the lack of data available on microclimates.

This project aims to provide data on the density and distribution of microhabitats, and to identify which microhabitats might be most valuable to arid species in terms of accessibility and climatic buffering potential. The Kalahari is home to multiple species that may be vulnerable to climate change, with many of them acting as ecosystem engineers, creating and maintaining biotic microhabitats. By understanding the microclimatic thermal landscape, areas of land or species that are valuable to the maintenance of microhabitats will be able to be earmarked for conservation priority, and those that have minimized access to microhabitats may be able to be afforded increased conservation protection status.



Current research team: Jan Venter, Maartin Strauss, Herve Fritz

Student: Mike Vermeulen


An array of camera trap platforms, such as grids, are used as part of this long-term research project, which is funded by Foundational Biodiversity Information Program (FBIP). Camera trap platforms are used to monitor mammal biodiversity by providing effort-based foundational records of occurrence, with associated habitat and biological information. These platforms are deployed in areas of critical biodiversity, climate change vulnerability, high mammal biodiversity, and unsustainable-use vulnerability. The millions of photographs produced are processed through a citizen scientist platform called Zooniverse, in conjunction with artificial intelligence algorithms, facilitated by the University of Minnesota  to efficiently produce high quantities of quality data.

Snapshot Safari’s coverage includes ‘super sites’, which are sites with enhanced ability to measure and monitor biodiversity. The team is also currently expanding the platform’s detection capability by adding temperature sensors and acoustic recording devices. They will further expand detection at platforms by conducting bio-blitzes and collecting DNA from scats for meta-barcoding. An additional data processing hub has been started at the Centre for High-Performance Computing supercomputer where data can be managed and stored so that the project is run and managed within South Africa, building capacity in the biodiversity sector.

Snapshot Safari has established a highly effective baseline monitoring platform over the last three years with cutting edge technology, a large established citizen scientist and researcher network, as well as novel data processing capabilities. It is being developed further to produce a wider variety of biodiversity data which will be even better in serving the biodiversity sector in South Africa. Locally, the data improves checklists of species on reserves, provides a baseline for monitoring change in the environment over time, from various drivers, and increases our knowledge of the biology and behaviour of cryptic and crepuscular species. The data will feed directly into national priority programmes and projects, such as protected area planning, threatened species conservation, and for mitigating risks such as from poaching or over-exploitation.



Researcher: Dr Jean-Baptiste Ramond


Deserts and other areas that receive very little rainfall are the most dominant terrestrial biome, representing approximately 40 percent of the earth’s surface. Due to extreme environmental conditions, which include being nutrient poor, having a high incident of UV radiation, and extreme seasonal and daily temperature fluctuations, their indigenous macro-organisms generally have restricted distributions and diversities. As a result, their nutrient cycling and functioning are considered to be mainly driven by micro-organisms.

Global temperature increases in relation to climate change are expected to lead to the expansion of deserts globally, a process known as desertification. Additionally, climate change represents a real threat to these already water-stressed biomes as they will become even drier. At the macro-scale, namely higher plants and animals, the effect of climate change and higher temperatures is already visible At the micro-scale it is more difficult to assess. As a result, micro-organisms – and their activities – are often the forgotten actors of climate change and are ignored in models.

This is particularly surprising as environmental micro-organisms can be greenhouse gas producers or sources, for example CO2 is released by respiratory and organic matter (OM) decomposition processes, CH4 by OM decomposition, methanogens and synthrophs, and N2O by nitrifiers and denitrifiers, or consumers/sink (e.g., CO2 fixation by photosynthetic cyanobacteria, CH4 and N2O consumption by methylotrophs and denitrifiers, respectively. Therefore, the research I am performing at Tswalu aims at studying the impact of increasing temperatures – achieved with open-top warming chambers – on desert soil microbial diversity and function using state-of-the-art meta’omics’ (metagenomic and metabolomics, essentially).



Researchers: Dr Benjamin Schoville (University of Queensland) and Dr Jayne Wilkins (Griffith University), Australia


Benjamin Schoville and Jayne Wilkins are working on this long-term project at Tswalu to understand how the southern Kalahari’s unique landscapes were used by early humans. Stone artefacts can be seen on the surface all over Tswalu, some of which may be over one million years old. How did early human ancestors survive in a semi-arid environment? Through ongoing excavations on Tswalu and further east near Kuruman, they are beginning to piece together a record of past human behaviour.

Large stone tools, called hand axes, from the Earlier Stone Age (ESA) are found in many places on Tswalu. These are between 1.5-million and 500-thousand years old and were probably used by early human ancestors such as Homo erectus for butchery of large animals. There are also more recent stone tools from the Middle Stone Age (MSA) that are between 500,000 and 50,000 years old. During this time period, Homo sapiens emerges and evidence for symbolism and new innovations is seen. For instance, the earliest stone-tipped spears are from a site 70 kilometres southeast of Tswalu, near Kathu, and are 500,000 years old.

The team working on this project consists of South African and international researchers working together to understand the history of our species in the southern Kalahari. A variety of approaches are being employed to understand ancient environments. Some calcium-rich limestones, which form during wet periods, lock in isotopes that can be dated. Dr Robyn Pickering and her students at the University of Cape Town are dating these deposits to create a record of wet-dry phases in the region. The sediments excavated so far suggest periods much wetter than today – including large lakes that drew human ancestors to their shores. Dr Irene Esteban at the University of the Witwatersrand is using plant microfossils found in sediments to determine what past vegetation was available. Dr Luke Gliganic (University of Wollongong) and colleagues are dating the sites on Tswalu by determining when buried sand grains around artefacts were last exposed to sunlight through a technique called Optically Stimulated Luminescence.

The conservation narrative at Tswalu would be incomplete without the inclusion of humans and early human ancestors who have been hunting, collecting plants, and finding water here for more than one million years. Tswalu provides a rare opportunity to develop a more complete picture of the ‘Green Kalahari’ landscape on which the ancestors of all humans lived. Our project aims to understand the role the southern Kalahari played for our species’ origins, including the development of innovative technologies and adaptability to environmental change.



Student: Thilo Beck


Predators often have stabilizing effects on ecosystems as they regulate prey abundance. It is likely that snakes perform similarly essential key functions to sustain the integrity of the ecosystem. Thilo Beck’s study of the thermal ecology of Cape cobras using radio telemetry falls under the Kalahari Endangered Ecosystem Project (KEEP). This programme looks at the responses of Kalahari organisms to climate change. Thilo’s two supervisors are Graham Alexander (University of the Witwatersrand, Johannesburg) and Bryan Maritz (University of the Western Cape, Cape Town), both of whom are considered experts in the world of herpetology for their research on behavioural ecology in reptiles. Their current study at Tswalu researches the interactions between snakes, predominantly Cape cobras (Naja nivea) and Boomslang (Dispholidus typus), and Sociable weavers (Philetairus socius).

Since starting the research into Cape cobra behaviour three years ago, Thilo and his supervisors on the project have caught, measured and released 94 different Cape cobras on the reserve. Every single one of them has a miniature ID chip implanted in the body and their measurements (length, sex, location where found, and weight) form part of the database. In addition, about 35 of the snakes have been implanted with radio-transmitters and body temperature loggers with the assistance of a veterinarian. This allows Thilo to follow the snakes in the field and record their body temperature simultaneously.

Through this growing body of data, Thilo aims to understand the cobras’ ecology from a thermal perspective. As ectotherms, snakes generate very little body heat and rely on the environment’s temperature to a large extent. The most effective way for a snake to change its body temperature is through behavioural adjustments. So, if the snake wants to warm up, it moves into sunlight; if it gets too hot, it will move underground or into the shade. The temperature logger implants reveal these behavioural patterns. On a daily basis, the snakes are tracked by Thilo with the help of radio telemetry. He takes coordinates, observes their behaviour, and takes measurements of the environment and the surrounding temperatures.

His specific interest is in linking particular behaviours and activity periods to the snakes’ body temperature and the temperature of the environment. This allows him to classify Cape cobra activity remotely by looking at different patterns that emerge from their body temperature. These are referred to as body temperature profiles. Thilo’s goal is to understand the thermal requirements and needs of Cape cobras in the Kalahari to predict how they may cope with hotter and drier conditions in the face of climate change. Comprehending the challenges these snakes face in the Kalahari right now can also provide insight into potential threats many other reptiles may face with temperatures increasing worldwide.



PhD student: Paulo Henrique Pinheiro Ribeiro


Paulo Ribeiro is a PhD student in the Faculty of Animal, Plant and Environmental Sciences, at the University of the Witwatersrand. His research project on Mountain zebras is being supervised by Dr Francesca Parrini, Dr Jason P. Marshal.

Facing human development and the anthropogenic issues resulting from human expansion, biodiversity has been suffering several losses and most of them are irreversible. Most of these losses are reducing the necessary and available areas for species survival which can affect species even at a molecular level.

This project aims to evaluate how different characteristics, such as environmental changes, anthropogenic effect, and interspecific interactions cause spatial restrictions of a vulnerable herbivore, the mountain zebra (Equus zebra), and how these can affect the species in different scales such as species distribution, habitat use, and its genome. A multi-scale evaluation approach generates a better overview, allowing for the prioritization of sites needing more conservation efforts in a more efficient form. For a landscape overview, species distribution modelling has the best cost benefit, since most of the data come from online databases. Also, It is a reliable tool to have a greater overview of any aspect of the species distribution.

At a habitat, the scale is essential to understand the most refined factors that drive the species occurrence, therefore it is necessary to study them at their original locations. Lastly, genetic assessment is the most accurate method to determine hybridisation. Despite the fact, some species present hybrid characteristics in their phenotype, the only reliable method to confirm the gene exchange is through a genetic assessment.



Researcher: Alistair Green

The conservation and rehabilitation of the Kalahari ecosystem has been a major focus for the Tswalu Kalahari Reserve. Over the past 25 years, the reserve has implemented numerous research projects covering a broad range of species. Researcher, Alistair Green, from the University of South Africa, has partnered with the Tswalu Foundation to assess the historical and current ecological status of the reserve.

Tswalu provides habitat for many species of indigenous and endemic flora and fauna, many of which, including lions (Panthera leo), are documented on the IUCN red list of threatened species. As apex predators, lions are regarded as a keystone species and play a vital role in the ecosystem by suppressing the populations of smaller species. The future of lions in Africa is uncertain, as a result of large population decreases and range constrictions. This makes large well-managed reserves, like Tswalu, that can support viable populations of lions are increasingly important as a reservoir for global lion conservation. Currently, lions are limited to the Legkaba section of the reserve and the impact that they are having on the environment is unknown.

Alistair is also investigating the influence of lions through the densities and behavioural responses of the prey species. By comparing the two areas of the reserve, Korranaberg and Legkaba. Alistair aims to determine if there is any ecological parity between the areas. This is done through a combination of camera trapping, aerial counts, and herbivore drive transects. The information generated through this research is going to help inform management on different strategies and to identify whether there were specific knowledge gaps that merit further research.



Current research team: Dr Robert Thomson (FIAO, UCT), Dr Anthony Lowney (FIAO, UCT), Prof Michael Cramer (Biological Sciences, UCT), Dr Mariette Marais (ARC – Plant Protection Research Institute, Pretoria)

PhD students: Timothy Aikins Khan (UCT), Olufemi Olubodun (UCT).


This project examines the importance of Sociable Weaver (Philetairus socius) nests to Kalahari animal and plant communities. The team aims to understand how the ‘ecological engineer’ potential of these nests may have community-wide impacts, and how this impact may change across environmental gradients. Their objectives are to investigate the diversity of animals associated with the nests, the interactions between these species, and to gain insights into the life histories of associated species. The team also focuses on the Pygmy falcon (Polihierax semitorquatus) and investigates the costs and benefits of these falcons on the weaver colonies.

Facilitative interactions are predicted to increase in importance in stressful environments. In harsh environments, like the Kalahari, facilitation may become a crucial component of the adaptive responses of animal and plant communities. Ecological engineers – species that modify habitats and ameliorate abiotic stress for other species – are likely to be key species. Identifying and understanding the impact of ecological engineers is vital, especially in arid environments that are expected to become harsher with global climate change.

Pygmy falcons are the most ‘controversial’ user of the Sociable Weaver nest colonies. They never construct their own nests, depending entirely on chambers in the weaver nests for roosting and breeding: a unique obligate nesting association. These falcons also prey on weaver nestlings and even adults, suggesting a semi-parasitic relationship between the species. This project aims to describe the natural history and ecology of Pygmy falcons, and to characterise their interactions with Sociable weavers; do falcons provide benefits to weavers or are they vertebrate parasites? And how does their presence impact the ecological engineering role of weaver colonies.

The Kalahari has two iconic tree species, the Camelthorn (Vachellia erioloba) and the Shepherd’s tree (Boscia albitrunca). These trees frequently host Sociable weaver colonies. The team investigates the costs and benefits that these weavers have on their host trees. Sociable weavers forage in the landscape and bring plant and insect material back to their nest trees which is deposited as faeces. This nutrient input at weaver nests results in these sites being islands of fertility in the landscape. We study how this alters the soil chemistry, but also the impacts on plant communities and soil nematode communities.

This project is providing unique insights into the community ecology and between-species interactions in the Kalahari. Fascinating natural history stories have come to light, and brought attention to a unique system. The project aims to quantify the ecological engineering role of the Sociable weaver and determine the predicted role of their nests in a warming and increasingly arid Kalahari. Lastly, the outputs of this project will also contribute to available eco-tourism information that enhances the experience of visitors to landscapes within the distribution of the Sociable weaver.

Key co-supporters: DST-NRF Centra of Excellence grant; Tswalu Foundation; University of Cape Town launching grant, Suzuki South Africa.



Researchers: Susan Healy and Andy Young


When people visit Tswalu Kalahari Reserve they may wonder at the Dr Seuss-like structures built by White-browed sparrow-weavers (Plocepasser mahali). Not especially colourful or therefore noticeable, White-browed sparrow-weavers turn out to be quite interesting. Susan Healy, Andy Young and their research groups (from the universities of St Andrews and Exeter) are investigating the building behaviour of these birds, in which the dominant pair in a group are thought to cooperate to build structures. The first question they sought to answer was how these two birds cooperate to build a functional roost or nest. To answer this question the researchers have observed nest-building techniques and have measured more than 600 of the structures built by 40 families. If it was interesting to ask how two birds cooperated to build a functional structure, things became a lot more complicated when it became clear that all of the family members build. Even more surprisingly, the researchers have discovered that structures built by one family look different to those of its nearest neighbours, and some families have their own distinctive ‘architectural style’.

After accounting for a variety of plausible factors (e.g. environmental variation, genetic relatedness, social interactions) it looks as if the birds are doing something very surprising: it looks like the migrants conform to the architectural style of their new family. The researchers are now looking to determine whether conformity does explain weaver bird architectural styles: if it does, this would be the first time that conformity in building behaviour would have been seen in a bird.



PhD student: Makabudi Valery Phakoago


This study is observational on free-living aardvarks and ground pangolins at Tswalu Kalahari Reserve. It is focused on population densities, habitat preference, diet and activity patterns of aardvarks (Orycteropus afer) and ground pangolins (Smutsia temminckii) in the Kalahari. PhD candidate Valery Phakoago is under the supervision of Professor Andrea Fuller (Brain Function Research Group, School of Physiology, University of the Witwatersrand), co-supervised by Professor Shane Maloney (School of Anatomy, Physiology and Human Biology, University of Western Australia, Perth, Australia).

Whether southern African mammals will cope with progressively hotter and drier conditions associated with climate change is unknown. Aardvark, a keystone species that provides burrows as refuges to many other species, and Temminck’s ground pangolin, the most traded mammal in the world, are myrmecophagous mammals that specialize exclusively on a diet of ants and termites. Due to the elusiveness and nocturnal habits of pangolins, their actual population size and trends in the wild remain unquantified. Low survival rates in captivity, slow reproductive rates and low natural population densities of pangolins suggest that current illegal trade levels are unsustainable. Our previous work has indicated that aardvarks will be at risk in the face of warming and drying associated with climate change. Research in the Kalahari has shown that aardvark survival is highly dependent on one species of termite, the Northern Harvester termite (Hodotermes mossambicus; Weyer et al., 2020), while pangolins are more dependent on ants than on termites (W. Panaino, unpublished observations). Ant and termite availability decreases during droughts (Weyer et al., 2020), and is likely to decrease progressively with warming and drying in the Kalahari (V Phakoago, unpublished observations). Whether aardvark and pangolins will respond to climate change in a similar way is not known, given their differences in diet and ecological physiology.

The proposed study will thus monitor population fluctuations of both aardvark and pangolins, and correlate changes in populations with abiotic and biotic changes in the environment. In addition to population monitoring, the proposed research will complement our previous pangolin work by extending the investigation into the diet, activity patterns, habitat use, and dispersal of juvenile pangolins, for the first time. Obtaining accurate population densities will allow for better assessments of aardvark and pangolin status in the wild.

Understanding the ecology and population dynamics of myrmecophagous mammals in the Kalahari environment is crucial for improving our conservation efforts of the species through informed management practices. Ultimately, Valery hopes the impact of the research will make a contribution to the maintenance of biodiversity and ecotourism in South Africa.



Researcher: Reinier F Terblanche, PhD – Department of Conservation Ecology, University of Stellenbosch


The butterfly project at Tswalu Kalahari Reserve was initiated in July 2013 by the Tswalu Foundation. Initially the butterfly study at Tswalu focused on Brown-veined Whites but soon expanded into a butterfly biodiversity and landscape ecology project. The project is led by Reinier F Terblanche, PhD, from the Department of Conservation Ecology, at the University of Stellenbosch. To date, a checklist of 76 species of butterflies has been compiled. Furthermore, possible new butterfly taxa have been discovered, life histories of Acraea species have been found, new concepts of Brown-veined White butterfly biology in the field have been introduced, and new perspectives on a southern African butterfly migration have been presented.

Quantitative methods to count butterflies in the field, as discussed at a workshop on global monitoring of butterflies, have been applied and tested, interesting discoveries stemming from butterfly hilltopping surveys at Tswalu have been made, and detailed vegetation studies to inform landscape ecology of butterflies have been conducted. Reinier has also compiled an authentic list of host-plant species of butterflies of Tswalu Kalahari Reserve, including the shepherd’s tree.



Researcher: Dr Wendy Panaino


For her PhD studies at the University of the Witwatersrand, Wendy Panaino spent four years investigating the responses of ground pangolins (Smutsia temminckii) at Tswalu Kalahari to seasonal and yearly fluctuations in climatic conditions and food resources.

Ground pangolins are myrmecophagous (ant and termite-eating), burrowing mammals that occur only in eastern and southern Africa, including in the already hot and dry Kalahari region of South Africa. As a result of climate change, regions of Africa, including the Kalahari, are becoming hotter and drier. Such changes can impact mammals directly, primarily by increasing the heat load to which they are exposed, as well as indirectly, for example by impacting their food resources. Whether most mammals will be able to cope with such changes to their environment is unknown.

Pangolins are elusive and predominantly nocturnal animals, making it challenging to study them. Very little is therefore known about their ecology and physiology. With the support of Tswalu staff, the Tswalu Foundation, her supervisors professors Andrea Fuller and Francesca Parrini, as well as an experienced veterinary team, Wendy studied the responses of free-living pangolins equipped with miniature body temperature data loggers and VHF tracking transmitters. She also gathered long-term data on the food resources available to pangolins and investigated what the pangolins ate through behavioural observations and analyses of pangolin scats. By monitoring specific individual pangolins, Wendy has been able to gain unique insights into the lives of one of the world’s most secretive mammals.

Understanding the ecology and physiology of ground pangolins at Tswalu will not only provide insight into how these elusive Kalahari animals may cope in future, but will provide an analogue for how they might respond to climate change in other regions of Africa, where hotter and drier conditions are also becoming more common. The insights gained from the research will contribute to informed decision-making and management practices, ultimately improving the conservation efforts of a species already threatened by habitat loss and the illegal wildlife trade.



Ecologist: Tania Anderson


This monitoring programme, which Tania Anderson began in 2016, aims to document vegetation cover, structure, diversity and dominance through a fixed-point photographic record and via transect based sampling. Each year one of the five vegetation types at Tswalu Kalahari Reserve will be surveyed at 10 photo station sites, resulting in data for each vegetation type being collected on a five-year cycle.

In doing this research, Tania works in collaboration with masters’ students from the Plant Conservation Unit (PCU) at the University of Cape Town to augment the monitoring programme.  The vegetation type, the Olifantshoek Plains Thornveld, which is experiencing the most change due to bush encroachment, was the first to be surveyed in 2016. The importance of long-term monitoring should not be underestimated. In many cases, only after many years are trends in a population or ecosystem recorded, especially in a system like the Kalahari.



Researchers: Bryan Maritz, PhD; Graham Alexander, PhD


Despite the apparent importance of snakes as predators in ecosystems, hardly any research in Africa has examined the ecological links between snakes and their prey species in a quantitative framework. This project, started in 2017, focuses on the interaction between snakes, predominantly Cape cobras (Naja nivea) and Boomslang (Dispholidus typus), and a Kalahari ecosystem engineer, the Sociable weaver (Philetairus socius). Dr Bryan Maritz, from the Department of Biodiversity and Conservation Biology, University of the Western Cape, and Graham Alexander, Professor or Herpetology, University of the Witwatersrand, use radio-telemetry, mark-recapture, and genetic techniques to quantify the importance of Sociable weavers and their colonies to the snakes in terms of energy gain, spatial ecology, territoriality, reproductive biology, and interspecific competition. The work focuses particularly on issues related to interspecific competition between snake species.

The spatial ecology of the two snake species is of great interest. Specifically, the team is examining how spatial patterns of resource availability (including food, mates, oviposition sites, and thermal refugia) vary in space and time. Snakes are considered important indicator species, and thus imbalances in the system may be determined early through the study of these incredible animals.



Researchers: Dr Nico Avenant and Dr Duncan MacFadyen


Small mammals, specifically mice, shrews and sengis, are recognised as important bio-indicators. They are key components of terrestrial ecosystems, often contributing greater than 30 percent of the total mammal species constituent. With high densities of up to 300 animals per hectare, small mammals are a major component in the diet of carnivores, raptors and reptiles. This long-term project repeatedly investigates small mammal species’ richness, diversity, density, biomass, presence, or absence, of indicator species on a number of transects in a variety of habitats at Tswalu Kalahari. The work forms part of the extensive Kalahari Endangered Ecosystems Project (KEEP), a programme that aims to address the impact of climate change on the Kalahari ecosystem. Information from KEEP, as well as this specific part on the small mammal species and communities, is expected to make a significant contribution to species and ecosystem conservation at Tswalu and the larger Kalahari. Improved understanding of the ecosystem processes, coupled to environmental and habitat change, and the intricate food web of Kalahari organisms, will assist researchers to better predict future scenarios, and will be included in the biodiversity monitoring protocols and management plans of the reserve.