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Our Research

Using Telemetry to Track Pygmy Falcons

The Dedeben Research Centre recently had Jess Lund from the University of Cape Town for a visit. Jess is looking at whether pygmy falcons go into a state of hypothermic torpor on winter nights (temperatures can plummet to well below zero!) in the Kalahari as part of her BSc Honours. Her research will attempt to determine what torpor (or the lack thereof) in pygmy falcons can tell us about the incidence of torpor relative to bird physiology, habitat and phylogenetic position is. It may even reveal whether there are thermoregulatory benefits to living in a group colony as well as if there are any differences in physiology related to group size.

 

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Meso-predators: Ecological effects in the absence of apex-predators in a Kalahari System

I am currently looking at the possible effects that take place in a Kalahari ecosystem when large predators have been excluded. It’s well documented in various systems globally that the presence or absence of large carnivores can have a dramatic and sometimes lasting impact on the environment. Tswalu presents a neat case-study as the reserve has two sections – one containing lions and the other without, while the whole suite of naturally occurring game are found on both. My study aims to look at small animal assemblages (notably small mammals and birds) and try determine if there are any distinct differences between the two sections. This research will lead to a greater understanding of the impacts of large predators on the Kalahari ecosystem.

 

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Snake Ecology

Despite the apparent importance of snakes as predators in ecosystems, hardly any African research has examined the ecological links between snakes and their prey species in a quantitative framework. This project will focus on the interaction between snakes, predominantly Cape Cobras (Naja nivea) and Boomslang (Dispholidus typus), and a Kalahari ecosystem engineer, the Sociable Weaver (Philetairus socius). Our work will 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, interspecific competition. My work will focus particularly on issues related to interspecific competition between snake species.Work will focus on the spatial ecology of the two snake species. Specifically, I will examine how spatial patterns of resource availability (including food, mates, oviposition sites, and thermal refugia) vary in space and time.

 

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Effects of Light Pollution on Foraging Behaviour of Rodents

Simone Ackerman, MSc | moosthui@zoology.up.ac.za
University of Pretoria, Department of Zoology and Entomology
Duration: 2017 - Present

This master’s thesis is focused on investigating the effects of light pollution on rodents. Light pollution is increasingly being recognised as a contributing factor to global change, many claiming that it may help explain phenomena that thus far lack an explanation. The project focusses on both the physiological effects that light pollution may have on rodents in South Africa, as well as the behavioural impacts. It targets the foraging behaviour of rodents on Tswalu Kalahari Reserve under various light conditions in order to understand how different levels of light pollution may affect the feeding ecology of rodents. The project makes use of artificial feeding trays and portable street lights to investigate the patch foraging behaviour and giving up density of rodents.

 

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Feeding Ecology, Habitat Utilisation and Population Responses of Ungulates in Arid Systems

Mika Vermeulen, MSc | s212200046@live.nmmu.ac.za
Nelson Mandela Metropolitan University
Duration: 2016 - Present

My study focusses on the feeding ecology, habitat utilisation and population responses of ungulates in arid systems. The study sites for my project are Tswalu Kalahari Reserve and the Karoo National Park. Ungulate dung samples were collected on numerous field trips to both study sites. These samples are being analysed to characterise seasonal forage selection. I will also be exploring the relationships between various variables to both ungulate habitat utilisation and population growth rates.

 

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A Systematic Study of the Jumping Spiders
(Araneae: Salticidae) of South Africa

Mokgadi Asnath Modiba, PhD | mokgadi.modiba@ul.ac.za
University of Limpopo
Duration: 2016

Salticidae (jumping spiders) is the largest family amongst spider families but their phylogenetic relationships are mostly unknown and only speculated about. The aim of this study is to perform a morphological taxonomic revision of the Afrotropical species of the genus Pseudicius, where re-descriptions will be done by examining specimens collected from field trips, those deposited in National Collection of Arachnida at the ARC-Plant Protection Research Institute in Pretoria and museum collections (National Museum of Bloemfontein, MRAC and the Natal Museum) using a stereo and light microscope, their genitalia were dissected and illustrations will be drawn to show how each species differs from others and it is the first comprehensive systematic study of South African salticids.

This study intends to estimate the phylogenetic relationships of species of Pseudicius and members of the family Salticidae using four genes (COI, 16S-ND1 and 28S) and as many specimens representing as many genera and sub-families as possible to attempt to clarify the classification of some genera into subfamilies. Salticids collected and preserved during field trips from different localities were used for DNA extractions and gene fragments amplified and sequenced. As such most provinces are represented in the material under study. I intend to investigate the phylogenetic relationships of species of Pseudicius and members of the family Salticidae.

 

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Effects of Size‐selective Predation on Population Dynamics of in Modern and Fossil Ecosystems

Jacqueline Codron, Postdoc | jacquicodron@gmail.com
National Museum, Bloemfontein, SA, Centre of Excellence in Palaeosciences
Duration: 2016 - Present

This project investigates the effects of size‐dependent predation on dynamics and sustainability of prey populations. The focus is on how different patterns of size selectivity differentially affect prey populations with different life history strategies. The research will resolve patterns of size selection across three predator classes: opportunist, optimal and selective feeders, in contemporary ecosystems. The data collected at Tswalu, combined with collected records of temporal changes in prey population size structures, will be used to develop and test ecological models of size-dependent predator-prey interactions.

 

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Long Term Vegetation Monitoring Programme

Tania Anderson, Ecologist | spothil@gmail.com
Independent
Duration: 2016 - Present

The monitoring programme 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 will be surveyed at 10 photo station sites, resulting in data for each vegetation type being collected on a 5-year cycle. This project involves collaborative research with master’s students from the Plant Conservation Unit (PCU) at UCT 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.

 

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Comparison of the Reproductive Performance of Female White rhinoceroses in Captive and Wild Populations

Martin van Rooyen, MSc | martincvanrooyen@gmail.com
University of Pretoria, Mammal Research Institute
Department of Zoology and Entomology
Duration: 2016

I aim to identify the challenges faced by captive and semi-captive breeding programs of southern white rhinoceros (Ceratotherium simum simum). Healthy captive populations may prove critical in maintaining genetic diversity of the species, and act as a ‘safety net’ should conservations efforts fail in the wild. However, captive populations of this species are not sustainable due to poor reproductive performance of females born and raised in captivity. This project’s objectives are to compare the reproductive performance of females in captive conditions to those in the wild, as well as consider the possible role of phytoestrogen activity in the diet of captive animals. I will also try to understand what drives the demand for rhinoceros horn, and identify how the value of rhinoceros products have changed over the last three and a half millennia Improved understanding of these processes will facilitate the development of strategies directed at reducing the demand for rhinoceros horn and provide insight into future trade scenarios.

 

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Long-term Vegetation Monitoring using Remote Sensing Techniques in Tswalu Kalahari Reserve

Wataru Tokura, MSc | turaturawako@hotmail.co.jp
University of Cape Town; Plant Conservation Unit, Percy FitzPatrick Institute of African Ornithology
Duration: 2016

To sustainably manage a nature reserve, we need to monitor the condition of the vegetation, as plants provide food and habitat structures for the wildlife. This is particularly important in the Kalahari, where the land is sensitive to overgrazing, and restoration is notoriously difficult. Vegetation monitoring sounds quite straightforward, but was not that easy in the vast and variable landscape of Tswalu. For my MSc, I worked with Prof. Timm Hoffman, Sam Jack (Plant Conservation Unit, University of Cape Town) and Tania Anderson (Plant Ecologist) to evaluate variations and long-term changes in vegetation productivity in relation to potential drivers using remote sensing techniques. We found an erratic rainfall pattern strongly regulates plant productivity in Tswalu, while fire and herbivory exhibit localised and relatively isolated effects.

 

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Competition for Cavity Nest Sites in Kalahari Woodlands: The Birds and The Bees

Mark Stanback, PhD | mastanback@davidson.edu
Davidson College, Department of Biology, North Carolina, USA
Duration: 2016

Even though the semi-arid woodlands of southern Africa are characterized by trees of relatively small stature, a surprising variety of bird species breed in cavities in these trees. Moreover, many of these cavity-nesting birds are of substantial size, and thus require relatively large nest cavities. Even in the Kalahari, hornbills, rollers, hoopoes, owlets, and starlings use tree holes for breeding. It is unclear, however, how these species share this resource – and which are more threatened by the loss of older trees targeted by the charcoal industry. Last year, with my Tswalu collaborators, I installed nest boxes in groups of one, two, and three. By documenting how species segregate spatially, we should be able to assess their relative dominance.

 

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Brown Hyena Density on Tswalu Kalahari Reserve

Ingrid Wiesel, PhD | Ingrid.wiesel@strandwolf.org
University of Cape Town, Animal Demography Unit
Duration: 2015 - Present

The Brown Hyena Research Project’s objectives are the research of the brown hyena in its natural habitat to ensure their long-term conservation and survival, and to create solutions for their conservation. The international red data list status of the brown hyaena has remained unchanged since 2008, predominately because of the paucity of data. A major focus of our work lies in the review of the brown hyena’s conservation status through research. Our aim is to determine the current and potential future global distribution of the brown hyena by identifying key environmental, ecological and socio-economic drivers, reviewing brown hyenas' space use drivers and discussing feasible population size modelling techniques combining GPS telemetry, camera trapping, genetic data and citizen science data. Our main study areas are located in Namibia, but we have been collaborating with Tswalu Kalahari Reserve since 2014.

 

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Pangolin Ecology on Tswalu Kalahari Reserve

Wendy Panaino, MSc, PhD | wpanaino@gmail.com
University of the Witwatersrand, Brain Function Research Group and Centre for African Ecology
Duration: 2015 - Present

The ground pangolin (Smutsia temminckii) is a primarily nocturnal mammal that is covered in hard, brown scales and is one of four pangolin species that occur in Africa. It is the only pangolin species that occurs in South Africa. Very little is known about pangolin physiology and ecology. Tswalu is situated on the south-western edge of the ground pangolin's distribution range, an area that is predicted to get hotter and drier with climate change. The objective of my research is to investigate how pangolins might cope with these predicted changes in climate. Hotter and drier conditions will likely affect the availability of the ants and termites on which pangolins prey. I’m investigating the body temperature and activity patterns of free-living ground pangolins in response to climatic conditions and prey availability.

 

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The Origin of Altruism - What can mole-rats teach us?

Markus Zöettl | mz338@cam.ac.uk
Cambridge University, UK
Duration: 2015 - Present

The Allee effect is an inverse density dependence of individual fitness which is mostly a population wide phenomenon but can act at a group level. In highly social species such as cooperative breeders it is likely that groups falling below a critical size face a higher risk of extinction. This idea gave rise to the central argument of the group augmentation hypothesis (GAH) which suggests that animals in stable social groups can increase their fitness through costly cooperative behaviour because enlarged group size provides fitness benefits shared by all group members. Evidence of correlations between group size and individual fitness are often regarded as support for the GAH. However, the relationship between group productivity and group size could arise through differences in habitat quality. It remains unclear whether large groups hold the best territories because of their competitive advantage over small groups (as predicted by GAH), or if their group size is a consequence of high recruitment due to favourable ecological circumstances. The aim of this study is to better understand how group structure and habitat quality affect Damaraland Mole-Rats.

 

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Scorpions of Tswalu Kalahari Reserve

Jonathan Leeming | Info@JonathanLeeming.com
Independent
Duration: 2015

An ongoing survey to sample the scorpion fauna of Tswalu Kalahari was undertaken. Scorpions are active during different times of the year so this survey is spread out throughout the year. Historically speaking, the area has been poorly sampled and favourable for the discovery of new species. Using scorpion habitat preferences I could predict which scorpions are more likely to come into contact with the staff based on the location of staff accommodation or where they work. Using periods of scorpion activity and weather patterns I could also indicate when scorpions would be more likely to interact with people and medically important stings where more likely to occur. With southern Africa’s most venomous scorpion occurring on the reserve, it is important to educate the employees and their families regarding scorpion related issues. Talks, posters, publications and activities allow the employees and their family’s insight into working and living in areas where scorpions abound.

 

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Coordination and Collaboration in Group Hunting Species on Tswalu Kalahari Reserve

Natalia Borrego, PhD, postdoc | mz338@cam.ac.uk
University of KwaZulu-Natal, College of Biological Science, Pietermaritzburg
Duration: 2015 - Present

I am broadly interested in the evolutionary mechanisms driving complex cognition and sociality. My dissertation focused on the hypothesized link between social complexity and cognitive complexity (the Social Intelligence Hypothesis). To examine the evolutionary links among social, ecological, and cognitive complexity, I use African carnivores as a comparative framework to experimentally test cognition in socially diverse taxa. Through my current work as a postdoc, I am exploring the evolutionary pressures that have led to coordination and collaboration in group hunting species, specifically lions and wild dogs. Additionally, I am continuing my research with captive carnivores and experimentally comparing cognition associated with solving social and ecological problems, i.e., innovation, impulsivity, social learning, and memory.

 

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Anti-predator behaviour on Tswalu Kalahari Reserve

Meredith S. Palmer, PhD | www.lionresearch.org
University of Minnesota, Department of Ecology, Evolution, and Behavior, Minneapolis
Duration: 2015 - present

My graduate research is focused on predator-prey interactions; specifically, how predators change prey behaviour in ways that could potentially impact coexistence and ecosystem functioning. I am currently interested in how predators that use different hunting techniques (stalking/ambush vs. coursing/endurance) evoke different anti-predator behaviours. In Serengeti Park, Tanzania, using a long-term camera trap grid to investigate how variation in predation risk across space and time - the so-called "landscape of fear" - affects ungulate distribution and activity patterns. In South Africa, I am conducting new experiments to study prey responses to simulated predator encounters. No previous study has yet employed a rigorous, repeatable experimental design to parse out which aspects of predator, prey, or environment evoke particular responses and to determine whether responses reflect a broader pattern of ungulate antipredator behaviour. For these experiments, I am using life-sized, moving, photo-realistic models to examine the types and intensities of evasive behaviours elicited during simulated predator encounters.

 

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Understanding the Responses of Kalahari Aardvarks to Environmental Change

Nora Weyer, PhD | weyer.nora@gmail.com
University of the Witwatersrand, Johannesburg, Brain Function Research Group
Duration: 2013 - Present

The highly secretive aardvark is one of Africa’s charismatic large mammals, usually spending most of the day in burrows and emerging at night to feed on termites and ants. Its burrows are co-used by many animal species, making the aardvark an important ecosystem engineer. Climate change is expected to result in a hotter and drier climate over Africa, and may threaten the local survival of aardvarks in the Kalahari. As temperatures rise, a demise of aardvarks will result in fewer burrows, which are becoming increasingly important thermal shelters. It is vital to understand the responses of keystone species such as the aardvark to current environmental challenges if we wish to forecast their survival in the face of climate change. To this end, for several years I have recorded body temperature, activity patterns, body condition, burrow locations, diet, and prey availability for wild aardvarks at Tswalu.

 

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Butterflies of Tswalu Kalahari Reserve

Reinier Terblanche, PhD | reinierf.terblanche@gmail.com
University of Stellenbosch, Department of Conservation Ecology
Duration: 2013 - Present

The butterfly project by at Tswalu Kalahari Reserve was initiated in July 2013 by Tswalu Foundation. Initially the butterfly study at Tswalu Kalahari Reserve focused on Brown-veined White but soon expanded into a butterfly biodiversity and landscape ecology project. So far, a checklist of 76 species of has been compiled, possible new butterfly taxa were discovered, life-histories of Acraea species were found, new concepts of Brown-veined White butterfly biology in the field were introduced, new perspectives on a southern African butterfly migration were presented, quantitative methods to count butterflies in the field such as discussed at a workshop on global monitoring of butterflies were applied and tested, interesting discoveries stemming from butterfly hilltopping surveys at Tswalu were made, detailed vegetation studies to inform landscape ecology of butterflies were conducted and an authentic list of host-plant species of butterflies of Tswalu Kalahari Reserve was compiled.

 

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Can behaviour buffer the impacts of climate change on an arid-zone bird?


Suzan J Cunningham, PhD | Susie.j.c@gmail.com
University of Cape Town, Percy FitzPatrick Institute of African Ornithology
Duration: 2012 - 2014

We used Ivlev’s electivity index to assess preference of breeding males for perch types with different thermal properties. We found that Southern Fiscals preferred to hunt from high, sunny perches at all times, except on hot afternoons (air temperature 35 °C), when they switched their preference to high, shaded perches. Black-bulb thermometers indicated shaded perches were always cooler than sunny perches, especially on hot afternoons. Therefore, Southern Fiscals could reduce thermoregulatory costs by switching foraging locations. However, Southern Fiscal foraging success rates were highest when hunting from sunny perches, and were reduced by 50% when hunting from shaded perches. Our data suggest that Southern Fiscals were making a trade-off on hot afternoons, compromising foraging intake in return for thermal benefits.

 

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Sociable Weaver Nests as Ecological Engineers &
The Life History of Associate Species

Dr Robert Thomson, PhD | robert.thomson@uct.ac.za
University of Cape Town, Percy FitzPatrick Institute of African Ornithology
Duration: 2011 - Present

We examine the importance of Sociable Weaver Philetairus socius nests to Kalahari animal and plant communities. The objectives are to investigate the diversity of animals associated with the nests, the interactions between species, and to gain insights into the life histories of associated species. We also aim to understand how the ‘ecological engineer’ aspect of these nests, have community-wide impacts on structure and function, and how this impact may change across environmental gradients. Evidence of the importance of facilitation in communities has accumulated, and challenges the emphasis on negative interactions in ecology. Facilitative interactions are predicted to increase in importance in stressful environments and may be a crucial component of the adaptive responses of communities under stress. Ecological engineers, species that modify habitats and ameliorate abiotic stress for other species, are a key research focus. Identifying and understanding the impact of ecological engineers is vital, especially in arid environments that are expected to become harsher with global climate change.

 

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Manipulating Colony Composition in Free Ranging Damaraland Mole-rats: The Effects of Cross-fostering and Removal of Breeding Individuals

Hannah Thomas | hgthomas@zoology.up.ac.za
University of Pretoria, Department of Zoology and Entomology
Duration: 2013-2015

Reduced and sporadic rainfall patterns in the arid regions increases energy demands on burrowing and searching for widely dispersed food resources in the form of bulbs, corms and tubers.One of the major selection pressures for natal philopatry may have been the high demands on energetic costs to a solitary mole-rat in digging foraging burrows and ultimately locating food resources. Group size, used as an indirect measure of cooperative breeding, correlates strongly with those factors that indicate habitat aridity, namely geophyte density and rainfall pattern. The work involved monitoring the recruitment and plasticity of both breeding and non-breeding mole-rats of both sexes in colonies at pre and post dispersal events within selected colonies from a marked population over two successive years, cross fostering juveniles of a particular sex into host Damaraland mole-rat colonies and following through to maturity remove either the breeding male or breeding female in 12 colonies. In addition, 12 colonies will serve as controls and will not have cross fostering done to the colony, but breeders of either sex will be removed at the same time as those of the experimental groups.

 

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Convergence of Gut Microbiomes in Ant-eating Mammals

Frédéric Delsuc, PhD | Frederic.Delsuc@umontpellier.fr
Université de Montpellier, Institut des Sciences de l’Evolution, CNRS, Montpellier, France
Duration: 2013 - 2014

The current paradigm for explaining the adaptation to a strictly myrmecophagous diet in mammals postulates that these species probably rely on endosymbiotic bacteria enabling them to digest the chitin contained in ants and termites exoskeletons. This hypothesis has never been formally tested however. The field sessions conducted at Tswalu allowed getting access to fresh scat samples from African ant-eating species: aardvark (Orycteropus afer), aardwolf (Proteles cristata), ground pangolin (Manis temminckii) and bat-eared fox (Otocyon megalotis). The main objectives of this project are the characterization of the taxonomic composition and functional gene content of the gut microbiome in ant-eating mammals in order to evaluate the respective roles played by the host genome and its associated microbiome in the adaptation to the myrmecophagous diet.

 

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Weaver Nests as a Resource to the Kalahari Animal Community


Anthony Lowney, PhD | anthonym.lowney@gmail.com
University of Cape Town, Percy FitzPatrick Institute of African Ornithology
Duration: 2011 - Present

My project investigates the importance of Sociable Weaver nests to the animal community of the Kalahari. The main aim is to understand the diversity of the animal communities associated with these nests, and how interactions between these associated species are facilitated. My project is still in its infancy, but integrates research by Dr Robert Thomson that was initiated in 2011. This project will also visit sites across the full range of sociable weaver distribution, south-east to north-west in the Kalahari and Namib deserts (central South Africa to northern Namibia). These sites will incorporate a precipitation (harshness) gradient; data of species use of nests across this gradient will be collected.

 

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Life History of the African Pygmy Falcon: Dispersal, Habitat Selection and Breeding Strategies


Dr Diana Bolopo, candidate PhD | bolo_po@yahoo.es
University of Cape Town, Percy FitzPatrick Institute of African Ornithology
Duration: 2011–present

African pygmy falcons Polihierax semitorquatus are obligate users of the sociable weaver nests, they utilise one or more chambers of the weaver’s colonies to roost and breed. I am interested in how the two species live together, being the weavers occasional preys of the falcons. My main aim is to characterize this relationship evaluating benefits and costs for each species in order to find out whether it is mutualistic, parasitic or fluctuating depending on environmental conditions. I am also interested in the natural history of the falcons specially breeding system, diet and territoriality.

 

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The Lacewings of Tswalu Kalahari Reserve
(Insecta: Neuroptera)

Mervyn W Mansell, PhD | mansel@mweb.co.za
University of Pretoria, Department of Zoology and Entomology
Duration: 2010 - Present

The primary objective of this study is to compile a faunal inventory of Tswalu Neuroptera to obtain baseline data for a study of the biology of these insects, and to compare the diversity with that of another well-studied area, the Kalahari Gemsbok National Park to provide an objective assessment of the influence of the more varied biotopes at Tswalu. This will enable our team to determine which species are protected within the Tswalu Kalahari Reserve and add to our assessment of their conservation status within southern Africa.

Specimens collected at Tswalu will be utilized for more detailed research and analysis, including molecular phylogeny on lacewings.

Data will also be provided to the Animal Demography Unit at the University of Cape Town as part of the Lacewing Map project for distribution modelling as well as the South African Biodiversity Information Facility (SANBI) for the South African tree of Life project (SATOL). A further order, Diptera, is also being surveyed during this project, thereby adding an extra dimension to the study. Co-workers on the project are Clarke H. Scholtz, Catherine L. Sole & Jonathan B. Ball, all from the University of Pretoria.

 

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Herpetofauna Biodiversity Survey on Tswalu Kalahari Reserve


Luke Verburgt, M.Sc.
University of Pretoria, Department of Zoology and Entomology
Duration: 2010-2011

Reptiles are generally small, secretive and active for only a few hours a day. In dry climates such as the Karoo and Kalahari the reptile community biomass makes up a very large proportion of the total fauna biomass. This project aimed to determine the species richness and abundance of reptiles at Tswalu Kalahari Reserve. A reptile and amphibian species composition list for the reserve was established, important for the management of the reptile community to identify species “hotspots” and breeding “hotspots”. Species hotspots are defined as a relatively localized area with a large species diversity and high biomass, many species of which are endemics. These areas are of primary concern for the conservation of biodiversity. Furthermore, breeding hotspots were identified and were incorporated into a conservation management plan to ensure the continued survival of certain species.

 

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Cooperation & Conflict in Kalahari Sparrow Weavers


A.J. Young, PhD | A.J.Young@exeter.ac.uk
University of Exeter
Duration: 2008 - Present

In many animal societies, including our own, individuals engage in so-called cooperative behaviour - helping others at a cost to themselves. Darwin himself recognised that such cooperative behaviour posed a fundamental problem for his theory of evolution by natural selection: as natural selection is expected to favour selfish behaviour, how has such seemingly altruistic cooperative behaviour evolved? As evolutionary biologists, my research group and I are interested in cracking this problem through long-term field studies of cooperative animals, including white-browed sparrow weavers and Damaraland mole-rats at Tswalu Kalahari Reserve. In both sparrow weaver and mole-rat societies, subordinate individuals routinely forego reproduction themselves and help to rear the offspring of dominants. We are therefore investigating the evolution of this cooperative helping behaviour, why some individuals are much more cooperative than others, and the impact that cooperation has on the way that these animals age. For example, do parents that are assisted by more helpers enjoy lower workloads and age more gracefully as a result?

 

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Adaptive Resource Use in a Re-Introduced Black Rhinoceros Population

Joanne Shaw, PhD │ jshaw@wwf.org.za
University of the Witwatersrand, Johannesburg, Centre for African Ecology
Duration: 2005-2007

The aim of biological management for black rhinoceros (Diceros bicornis) conservation is to maximise meta-population growth rates to aid species recovery. This research investigated how adaptive resource use in response to seasonal variation in resource availability could affect maximum productive habitat capacity for this critically endangered species. Analysis was based on a population of rhinos which had shown excellent annual growth rates and low inter-calving intervals since re-introduction to Tswalu Kalahari Reserve in the Northern Cape of South Africa in 1995. Acacia haematoxylon, a semi-evergreen species, was identified as the key resource forming the majority of diet contents during the late dry season. Use of this species resulted in a low level of seasonal variation in dietary contents of energy and protein. During the data collection period, energy and protein gains of individual female rhinos were estimated to exceed maximum requirements for reproduction throughout the seasonal cycle.

 

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Damaraland Mole-rat Ecology

Andy Young, PhD | A.J.Young@exeter.ac.uk
University of Exeter
Duration: 2008 - Present

In cooperative animal societies, such as those of the ants and bees, only dominant group members breed and a host of non-breeding workers help to rear their offspring. Darwin recognized that the altruism of these workers posed a problem for his theory of natural selection, which was thought to favour only selfish behaviours. As a result, biologists have been fascinated for generations by the challenge of understanding how these bizarre societies have evolved in so many animal groups (e.g. African wild dogs, fairy wrens, cichlid fish, leafcutter ants, meerkats and Damaraland mole-rats).

The African mole-rats show the full range of social complexity from solitary species to species with complex cooperative societies (where sterile workers help to rear the queen’s young). Comparing all of these species revealed that only the two cooperative species lived in very dry regions (naked mole-rats and Damaraland mole-rats). This led to the idea that cooperative societies may have evolved in these species, because only by living in large cooperative groups are they able to find enough food in such a challenging environment.

The primary goals of the research were as follows:
1. How do Damaraland mole-rats benefit from group living?
2. Do workers really help to rear the queen’s offspring?
3. How do the workers prepare for the challenge of dispersing to found new colonies?

 

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