Doctoral Degrees (Zoology)

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Status of research on two parasitic zoonoses (Toxoplasmosis and toxocariasis) in Sub-Saharan Africa and their prevalence in selected rural communities of Kwazulu-Natal Province of South Africa using free-range chickens as a case study.
(2022) Omonijo, Adejumoke Oluwatosin.; Mukaratirwa, Samson.
Free-range chickens are among the popular livestock that are owned by most households in rural communities. They constitute a major source of food security, financial income, and are used in socio-cultural practices. However, due to their habit of scavenging for food they are exposed to parasitic agents thereby making them host for several disease pathogens such as Toxoplasma gondii and Toxocara spp. Toxoplasma gondii and Toxocara spp are the etiological agents of human toxoplasmosis and human toxocariasis respectively. Humans become directly infected via accidental ingestion of sporulated oocysts of T. gondii from felids and tachizoites/bradyzoites of T. gondii from raw/undercooked meat or embryonated eggs with second stage larva of Toxocara spp via contact with contaminated faeces of definitive hosts (dogs and cats), or indirectly via ingestion of contaminated water or consumption of raw or undercooked chickens. Following infection, the parasites migrate through the human body causing varying degree of diseases known as toxoplasmosis and toxocariosis respectively. Consumption of poultry meat viscera is an increasing dietary habit common in different communities worldwide and depending on socio-cultural preferences it can either be eaten raw, undercooked, or well cooked. However, the habit of eating raw/under cooked meat or viscera poses the risk of transmitting T. gondii and Toxocara spp from animals to humans. Limited information exist on the epidemiology of T. gondii and Toxocara spp in sub-Saharan Africa and let alone the role of free-range chickens in the transmission of these zoonotic parasites, hence, this study was designed to: ➢ review the status of research on these two parasitic zoonoses in sub-Saharan Africa. ➢ determine prevalence of the parasites in free-range chickens from selected rural communities in KwaZulu-Natal province through molecular approach. determine the level of awareness of the zoonotic transmission of these parasites when the viscera or meat of Free-range chicken are consumed raw or undercooked. A sytematic review and meta-analysis was conducted following the Preferred Reporting items for systematic Reviews and Meta-Analysis (PRISMA) guidelines on the epidemiology of T. gondii in animals and humans in southern Africa and epidemiology of Toxocara spp in canine, feline, and humans in sub-Saharan Africa respectively. The reviews showed that there is paucity of information on T. gondii and Toxocara spp in food animals including free-range chickens. Furthermore, to determine the prevalence of T. gondii and Toxocara spp in free-range chickens, free-range chickens were randomly purchased from selected rural communities namely, Gingindlovu (GI), Ozwathini (O), uMzinto (MZ), and Shonwgweni (SH) in KwaZulu-Natal (KZN). The chickens were euthanized according to ethical guidelines. The brain tissue of each chicken was divided into two equal halves. One half was examined for the presence of parasites while the remaining half was preserved in 70% alcohol for molecular analysis. To detect the presence of T. gondii, the preserved brain tissues were subjected to molecular analysis based on analysis of DNA sequences of the nuclear ribosomal internal transcribed spacer (ITS-1 and ITS-2) region using TOX4 and TOX5 primers. To detect the presence of Toxocara spp, various parts of chickens such as brain, heart, liver, spleen, kidney, duodenum, pectoral, thigh, and breast were digested using the acid/pepsin; 1:1 method and the larvae were recovered with 20-μm sieve. Three (3) larvae were recovered from the right pectoral from a chicken collected in GI; two (2) from the lungs of a chicken from MZ; three (3) each in the liver and left thigh of two separate chickens from SH. The recovered larvae were subjected to molecular analysis using Nem_18S primers. Toxoplasma gondii was not detected in the tissue samples which were subjected to molecular analysis, however, Toxocara canis was identified in Gingindlovu (n=1), uMzinto (n=1), and Shongweni (n=2). The identified T. canis showed 100% homology with Genbank isolates from China, the United Kingdom, and the United State of America. The occurrence of T. canis in free-range chickens from KZN province reveals the possibility of human toxocariasis transmission in the province. Moreover, we conducted a questionnaire survey to determine the knowledge and practices relating to consumption of free-range chicken viscera in selected rural communities of KwaZulu-Natal with respect to zoonotic transmission of T. gondii and Toxocara spp. There was low level of awareness of risk of zoonotic transmission of the parasites via ingestion of raw/undercooked free-range chicken meat/viscera and the majority of respondents consumed free-range chicken viscera. They preferred the viscera well cooked which reduces the risk of transmission of the the two parasites. The study contributes new knowledge on the prevalence of zoonotic parasites in free-range chickens as well as the level of knowledge and awareness on zoonosis transmission via consumption raw/undercooked free-range chicken viscera or meat.
Aspects of the ecology of invasive rose-ringed parakeets (Psittacula krameri) in eThekwini Metropolitan, KwaZulu-Natal Province, South Africa.
(2021) Shivambu, Tinyiko Cavin.; Downs, Colleen Thelma.
Globally, the rose-ringed parakeet Psittacula krameri (Scopoli, 1769) has been cited as one of the world’s worst gregarious invasive parrot species, having established breeding colonies successfully outside its native distribution range. The rapid expansion of its breeding population has been considered a major threat to the economy, agricultural production, biodiversity, human health and social life. To date, the rose-ringed parakeet’s population has been reported in ca. 35 countries and the pet trade is the main introduction pathway of this species across the globe. In South Africa, rose-ringed parakeets were introduced as pets in the 1900s. Their breeding population has successfully established in several cities, particularly in Johannesburg and eThekwini Metropole. Although their population seems to be expanding at an alarming rate, little is currently known about their population size, breeding status, and feeding biology. This includes public knowledge and perception towards them as invasive species. Moreover, impacts (environmental and socio-economic) and areas that are at risk of becoming invaded by rose-ringed parakeets and other selected invasive bird species are unknown. This study conducted monthly surveys in the greater Durban (eThekwini) Metropole, KwaZulu-Natal Province, South Africa, from August 2018 to December 2019, to determine the rose-ringed parakeet’s population size, feeding biology and breeding status. A questionnaire survey was developed to determine the public knowledge and perception of parakeets. The species distribution modelling and Generic Impact Scoring Scheme were also used to investigate areas that are likely to be invaded and potential impacts (environmental and socio-economic) associated with rose-ringed parakeets, and other selected introduced bird species. A total of five major roost sites with an overall mean monthly population size of 1,783 rose-ringed parakeets were located. Most of these roost sites were found around urban (public) parks and shopping centres. Seven bird species were found sharing communal roosting sites with rose-ringed parakeets, with the common myna Acridotheres tristis recorded the most. We identified 72 nests within 39 breeding sites, with the first breeding season accounting for 53 active nests and the second breeding season with 59 active nests. Rose-ringed parakeets used four tree species for nesting, with white milkwood Sideroxylon inerme being the most preferred tree species (71%). The recorded rose-ringed parakeet fledglings ranged between 1 – 3 per nest, and their numbers differed significantly between the seasons. A total of 63 feeding sites were identified, with most of them in the urban built land-use cover type. Rose-ringed parakeets were observed feeding on 31 fruiting/flowering trees and one insect species, with fleshy fruits (58%) and flowers (19%) primarily relied on. For our survey questionnaire, a total of 312 participants responded to the survey, with 92.5% being familiar with parakeets. A large population of rose-ringed parakeets were seen in shopping centres (38.5%), suburbia (26.3%), and golf courses (19.6%). Most survey respondents (58.3%) indicated that they provide feeding stations for these parakeets, and 57.7% did not consider them pests. In terms of invasion risk, the rose-ringed parakeets were found to have large areas in South Africa with high climatic suitability, and their impacts were both socio-economic and environmental. Agricultural production was the main impact through socio-economic, while competition and impact on other animals were the main environmental impacts. In general, this study showed continuous growth in the rose-ringed parakeets’ numbers in eThekwini Metropole, indicating that their population is breeding at an average rate. Our study also showed that rose-ringed parakeets feed on various food items, suggesting that they are generalist-opportunistic feeders. As a result, this plasticity in feeding behaviour may likely enhance competitive interactions with other species, contribute to seed dispersal, and increase damage to crops. Parakeets are not perceived as pests by most of the respondents in the eThekwini Municipality. This positive perception may have been exacerbated by the public’s poor knowledge regarding their impacts on biodiversity, economy, human social life, and health. Therefore, we recommend introducing environmental education, which involves the engagement with the community members and eThekwini Municipality. This may assist in making an informed decision regarding the control of this species in the area. Monitoring of rose-ringed parakeet’s population size, breeding status, feeding biology, and movement patterns should continue so that adequate information can be acquired on their biology. In conclusion, our results highlight the importance of studying rose-ringed parakeet’s ecology, which provides reliable data that can be considered in decision-making, management and eradication plans for parakeets in South Africa.
Assessing the risk of non-native small mammals in the South African pet trade.
(2021) Shivambu, Ndivhuwo.; Downs, Colleen Thelma.; Willows-Munro, Sandi.
Humans have introduced non-native small mammalian species for various purposes, including hunting, biological control, farming, fur markets, ornamental, and pet trade. The latter has been cited as one of the main invasion pathways for some small mammals through accidental escapes and intentional releases of pets. In addition, the pet trade has been cited as one of the major threats to biodiversity loss and human health through the spreading of zoonotic diseases. The trade of non-native pets is growing in South Africa, and this is of great concern as some of these species may become invasive should they escape or be released from captivity. There is also a lack of information regarding which non-native small mammalian species are sold in South Africa. As a result, two primary sources of trade (online and pet shops) were assessed to determine the extent of small mammal trade in South Africa. A list of the traded small mammalian species was compiled online and physical pet shops to determine which species pose an invasion risk and have potentially high impacts. Mitochondrial gene regions were used to assess the taxonomy and genetic diversity of 156 rodent specimens collected in the South African pet shops. We also determined if their genetic diversity follows a geographically correlated pattern. A total of seven websites and 122 pet stores in South Africa were recorded, with 24 non-native small mammalian species traded. Three provinces, Gauteng, Western Cape and KwaZulu-Natal, had the highest number of websites and pet shops selling these species. Overall, online trade had more species diversity when compared with pet shops. Rodents and primates dominated the trade; however, the European rabbit Oryctolagus cuniculus, guinea pig Cavia porcellus, Norwegian rat Rattus norvegicus and house mouse Mus musculus were the most available species in both online and pet shops. In terms of the potential impacts, traded small mammalian species were associated with both socio-economic and environmental impacts. Impacts on agricultural and animal production (livestock) prevailed for the socio-economic category, while the impacts on animals (predation) and competition were the main mechanisms in the environmental impacts. Of the species recorded, 14 had potential climatic suitability; however, species such as Guinea pig Cavia porcellus, sugar glider Petaurus breviceps, domesticated ferret Mustela putorius furo, M. musculus, O. cuniculus, European grey squirrel Sciurus carolinensis, and R. norvegicus are likely to become invasive given their popularity in the trade, large climatic suitability, and history of invasion through releases and accidental escapes. A total of 156 rodent samples were identified using molecular analyses, with 115 specimens identified as M. musculus, 35 as R. norvegicus and six as Southern multimammate mouse Mastomys coucha. Phylogenetic trees showed that the three species were monophyletic, and there was a genetic diversity within M. musculus and R. norvegicus. The specimens for M. musculus and R. norvegicus were more geographically diverse when compared with the specimens for M. coucha. As a result, this suggests that most of the provinces comply with the trade regulations as native species are prohibited from trade. The combined data recovered 19 unique haplotypes for M. musculus and eight haplotypes for R. norvegicus. However, the genetic diversity for M. musculus did not show a clear geographical pattern, while R. norvegicus showed a subtle geographic structure. Unique haplotypes in these species may be explained by the desire to breed rare varieties or introduce new strains from different pet trade sources. In conclusion, small mammalian species with high trade volume, suitable climate, potential environmental and socio-economic impacts are likely to become invasive and cause impacts in South Africa. In addition, M. musculus and R. norvegicus individuals may establish feral populations if released from captivity, given that their haplotypes were unique. Therefore, it is recommended to further monitor the pet trade (both online and physical pet shops), including surveillance, to determine if there are any escapes and releases from the trade.
Thermoregulatory capacity of arboreal small mammals in the tropics : insights from the past and implications for the future.
(2018) Welman, Shaun.; Lovegrove, Barry Gordon.
Species are expected to respond to global warming through range shifts that are either poleward or towards higher altitude such that they track the movement of their current thermal niches. This generalized view is fundamentally flawed because it marginalizes the role of key biological aspects in shaping ecosystems. For example, it disregards any potential influence that phenotypic flexibility may convey, the influence of habitat heterogeneity and the availability of microclimates as thermal refugia, differences between species dispersal ability, the importance of species interactions, and the influence of phenological mismatches. Given the limitations associated with the view that species will deal with global warming by continually migrating, as well as the rapid rate of warming, there is an urgent need to improve the understanding of how species potentially may respond. Thus, it is crucial that mechanistic approaches are adopted to generate a holistic perspective of the factors that govern species distributions and use this information to forecast responses to global warming. Physiological studies are vital because knowing the physiological tolerances of a species provides insight into their fundamental niche, and also provides a means of identifying species that face higher risks of experiencing more immediate effects due to global warming. Autecological knowledge would also serve to refine the species fundamental niche to more closely resemble their realized niche. In this regard, this thesis identifies arboreal mammals in the tropics as being vulnerable to hyperthermia due to global warming. The basis of this claim is related to the exposed lifestyle of many arboreal species, the biphasic effect of temperature on biological processes and the hypothesis that natural selection would have favoured the optimisation of bodily functions at or close to the species-specific body temperatures (Tb). Initially, there is a positive relationship between biological process and temperature as the rate of processes increase with temperature, up to a maximum point. Thereafter, hyperthermia ensues as further increases in temperature results in a rapid decline in the rate of said processes. Thus, it is plausible to expect that species with lower Tb risk deleterious effects at lower absolute Tbs relative to their higher Tb counterparts. Therefore, it is concerning that many small, tropical endotherms have low and thermolabile Tbs that, because of the small temperature differential between themselves and the ambient (Ta), compromises their capacity to passively off-load excess stored body heat. In addition, the high humidity of tropical environments would theoretically reduce their capacity to retard heat storage by off-loading body heat via evaporation. This reduced capacity to dissipate excess stored body heat, in combination with the exposed life-style of an arboreal species, suggests that small, tropical arboreal mammals are vulnerable to hyperthermia should even minor increases in Ta occur. The aim of this thesis was to assess the vulnerability of tropical, arboreal small mammals to hyperthermia due to global warming. This was achieved by determining and integrating the physiological susceptibility for heat stress in two species and relate that to the microclimate experienced within their habitats. Given the growing argument that adaptive heterothermy - the capacity for species to facultatively down-regulate metabolism and enter torpor or hibernation - may be employed at high Ta to cope better with hyperthermia, this thesis in addition investigated whether heterotherms use torpor at high Ta and identified the putative benefits of hyperthermic torpor. Furthermore, by considering the phylogenetic placement of the study species, this thesis also sought to provide insights into the evolution of endothermy in placental mammals. Flow-through respirometry was used to measure resting metabolic rate (RMR) and evaporative water loss (EWL) at a range of Ta in a heterothermic bat, the lesser dog-faced fruit bat (Cynopterus brachyotis), and a suspected heterothermic primate, the western tarsier (Cephalopachus bancanus). The animals were injected with temperature-sensitive passive integrated transponder tags to obtain concurrent Tb readings during respirometry measurements in freshly-caught individuals. In addition, Tb was measured in free-ranging tarsiers using custom designed temperature data-loggers. The Ta at capture sites were measured using commercially available data-loggers. The laboratory data show that, whereas tarsiers endeavoured to remain normothermic, lesser dog-faced fruit bats readily entered torpor at low temperatures. The free-ranging Tb data support the assertion that tarsiers may be incapable of adaptive heterothermy. The onset of heat storage in tarsiers occurred at approximately 30°C, once the thermal gradient (ΔT = Tb-Ta) approached 4°C, whereas the onset of heat storage in lesser dog-faced fruit bats occurred at approximately 31°C, which was only when ΔT approached 1°C. Given that both species have low normothermic resting Tbs (tarsiers: Tb ≈ 34.5°C; lesser dog-faced fruit bats: Tb ≈ 32.5°C), they seem physiologically susceptible to heat stress at moderately low Ta. Notably, though, lesser dog-faced fruit bats appeared to thermoconform at Ta above their thermoneutral zone suggesting that they may have entered torpor. Torpor seems to have allowed them to reduce heat storage. Field data suggest that lesser dog-faced fruit bats may have the option to exploit cool microclimates at their capture sites, but the data at the capture site of tarsiers suggest that they may not. However, even though the population of tarsiers studied may not have access to cool microclimates, the same may not be true for other populations of tarsiers. Thus, the empirical results support the argument that tropical, arboreal small mammals are physiologically susceptible to heat stress due to global warming, but they also suggest that thermal refugia are an important consideration as they may allow species to escape the predicted future high Ta and its related deleterious effects. This thesis also presents a meta-analysis on the thermoregulatory pattern of bats in general. The aim of this meta-analysis was to determine whether corroborating physiological support for the use of torpor at high Ta exists. A comprehensive literature search was conducted based on the availability of concurrent measures of Tb and RMR; a new dataset of thermoregulatory variables was generated for 29 species of bats (18 heterothermic spp. and 11 homeothermic spp.). The dataset was standardized, and phylogenetic relatedness was considered before any comparative analyses were performed. The results show that heterothermic bats maintain lower Tbs than homeothermic bats, yet they have similar upper limits of thermoneutrality (Tuc). In contrast to expectations, heterothermic bats had a lower rate of evaporative water loss at similar Ta, especially at Tuc. Crucially, in the case of heterothermic bats, Tuc exceeds Tb. The only manner in which heterothermic bats could achieve this, would be through a reduction in metabolic rate with the onset of heat storage at high Tas. Moreover, heterothermic species thermoconform even at comparatively moderate Ta, which presumably also minimizes heat storage and lowers evaporative water loss. Thus, these results support the hypothesis of torpor use at high Ta and suggest that heterotherms, in particular small, tropical, arboreal heterotherms, could benefit from a reduction in water use associated with evaporative cooling and tolerate higher Ta. Overall, the results presented in this thesis illustrate that even though small mammal species living in tropical regions may be physiologically susceptible to heat stress due to global warming, they could minimize their risk of lethal hyperthermia through behavioural mechanisms such as exploiting cooler microclimates; provided that suitable habitats are available. In addition, adaptive heterothermy may convey a physiological advantage that allows heterotherms to better cope with heat. As such, heterotherms may be resilient to the negative effects associated with global warming because they are able to employ torpor to conserve energy during periods of low resource availability, as well as to minimize heat storage and endure moderate hyperthermia to conserve water to use at more extreme Tas. Given the phylogenetic placement of tarsiers at the base of the Haplorrhini clade (Anthropoidea and Tarsiidae), the current lack of evidence for adaptive heterothermy in tarsiers, in combination with the lack of evidence in anthropoids, suggest that adaptive heterothermy in haplorrhine primates may have been lost at the Strepsirrhini-Haplorrhini split. The implication of the aforementioned idea is that many primates may not have the benefits associated with adaptive heterothermy to improve their future survivability as global warming continues. By adopting a mechanistic approach, this thesis highlighted the potential for species to respond to global warming using behavioural and physiological mechanisms that could allow them to persist in their current habitats until the end of the century at least. However, to improve the likelihood of arboreal tropical small mammals to persist in their current habitats for the foreseeable future, especially those mammals that are strictly homeothermic, conservation efforts must prioritise the preservation of areas that could serve as thermal refugia.
Ecology and conservation of the Cape vulture in the Eastern Cape Province, South Africa.
(2016) Pfeiffer, Morgan Briana.; Downs, Colleen Thelma.
Abstract available in PDF file.
Students' competence and understanding of scientific method in the life sciences at the University of KwaZulu-Natal.
(2015) Brown, Kelly Joanne.; Downs, Colleen Thelma.
This thesis focuses on describing the conceptions and misconceptions that undergraduate Life Science students hold regarding aspects of the scientific method at the University of KwaZulu-Natal (UKZN). This research is necessary in order that instruction strategies can be formulated and implemented to address these misconceptions, in response to a global call to redefine how science is taught at tertiary level. The University of KwaZulu-Natal is located over a number of campuses with courses and curricula material being taught across campuses by different faculty staff. The apparent role that faculty staffs’ epistemologies, instructional strategies and assessment tools may perform in influencing students’ conceptions of scientific method led us to concentrate on some of these areas. Life Science courses are taught by a variety of instructors with differences in their understanding, views and opinions regarding the process of science as well as their pedagogic approaches to teaching this process. We initially investigate the views of lecturers regarding hypotheses and experimental design in their personal research in the Schools of Agriculture, Earth and Environmental Sciences and Life Sciences at UKZN, and how these compare to what is taught at the introductory biology level. Interestingly, only 46.7% of the respondents conduct hypothesis-driven investigations and less than 7% use predictions in their personal research. There is also much variation in faculty members’ ideas regarding research hypotheses, alternative hypotheses and their use of sample size, repetition and randomization in their personal research. Critical analysis of faculty’s approach to undergraduate teaching of Life Sciences indicates an over-emphasis of content teaching rather than the development of scientific reasoning and critical thinking. Undergraduate courses need to engage Life Science students in the process of scientific inquiry where they are encouraged to think deeply about the process of science, and in particular experimental design. Successful Life Science courses train students to critically evaluate experimental design, statistical approaches and inferences in its entirety. Consequently, we tested first and second year Life Science undergraduates understanding of various aspects of experimental design using an open-ended questionnaire. We found that undergraduates performed poorly in 1) producing a completely randomized design of treatments 2) describing the benefits of limiting sources of variability and 3) describing the limitations to the scope of inference for a biologist. They only showed improvement from first to second year in their ability to correctly identify treatments from independent variables. These results add to the growing body of Life Science research that indicates that undergraduate curricula are not adequately producing well-rounded, critical thinking scientists. Next, we focus on assessments. Faculty staff have been challenged by science educators to change their approach to teaching in order to more accurately reflect the practice of biology. Meeting these challenges requires the critical analysis of current teaching practices and adjustment of courses and curricula through curriculum reform. Assessments play a vital role in providing evidence of effective instruction and learning. Student responses from two formative tests and one final summative examination for an undergraduate biology cohort (n = 416) at UKZN were analyzed both quantitatively and qualitatively to determine students understanding of aspects of the scientific method. Quantitative analyses revealed that the majority of first-year undergraduate students at the end of an introductory biology course were able to identify hypotheses and dependent and independent variables correctly. However, qualitative analyses indicated that sometimes students confuse hypotheses with predictions and are unable to identify independent variables correctly. Critical analyses of the assessments using the Blooming Biology Tool revealed that assessment design can considerably influence student results. It is essential that clear objectives and competencies are set at the outset and that there is a synergistic relationship between instruction and assessment. Assessment design requires careful consideration of content being covered as well as cognitive skills being tested throughout the course. In addition, we determine the types of conceptions that third year biology students’ hold regarding hypotheses, predictions, theories and aspects of experimental design. These conceptions were compared across two geographically separated campuses of the UKZN, namely the Pietermaritzburg (n = 28) and Westville (n = 50) campuses. They were also compared to descriptions located in prescribed textbooks and course manuals throughout their undergraduate biological studies. Results indicate that there is variability between and across campuses in students’ descriptions of research hypotheses, predictions and theories, repetition and randomization. These conceptions were sometimes partial conceptions while in other instances they were completely incorrect. Interestingly, many of the students’ responses lacked essential elements which could be found in the prescribed textbook and course manuals. The variability in student responses across campuses could be a result of differences in faculty instruction and therefore more research is required to test this. These results also indicate the necessity for courses to be designed with more consistency in concepts to be developed. Lastly, we focus on students’ competency in aspects of scientific inquiry revealed through a third year research project that is mentored by faculty staff members. This chapter is designed to describe students’ ability to effectively apply scientific inquiry at the undergraduate exit year. Biology 390 projects were analyzed from 2012 (n = 26 students), 2013 (n = 46 students) and 2014 (n = 34 students). Journal formatted project write-ups were examined for reference to aims, objectives, hypotheses and predictions. Students’ ability to appropriately apply experimental design was also assessed by documenting their use of replicates, sample size, randomization and controls. Conceptions of the broad nature of the scientific process and scientific inquiry were also noted by surveying project introductions, discussions and conclusions for evidence of students’ ability to link their research into the greater network of scientific knowledge. There was an overemphasis in the use of statistical hypotheses compared to scientific hypotheses by BIOL 390 students in their project write-ups. Many students used predictions inappropriately and a large majority of students failed to incorporate critical aspects such as randomization and controls into their experimental designs. Explicit didactic discussions by mentors with their students are necessary in order to improve these conceptions of the scientific process. It is suggested that mentors become familiar with both learning theories and common misconceptions associated with the nature of science and scientific inquiry so that they are able to apply these to their mentoring approaches of students conducting research projects. As a whole, this thesis finds a general lack of understanding of the basic premises of what entails “science” at all levels of undergraduate study within the Life Sciences at UKZN. This worrying trend reflects research from elsewhere, and suggests reform is needed to ensure that UKZN can produce critical higher-order thinking science graduates capable of correctly understanding the full intricacies of the variety of approaches to conducting scientific research. Suggestions for reform include the need for Faculty staff to engage up to date pedagogical research on how science should be taught, a recognition that a move away from knowledge transfer alone towards including skills transfer is needed, training for faculty staff in terms of mentoring skills for participatory research experiences for undergraduates that includes scientific process mentoring, and curriculum reform that recognizes the need to set clear measurable objectives and outcomes for undergraduate courses. Lastly, we also recommend analyzing assessment types used at UKZN in order to ensure that sufficient higher-order cognitive skills are assessed, rather than predominantly lower-order cognitive skills as is currently the case.
The sea turtles of South East Africa.
(1973) Hughes, George R.; Heydorn, A. E. F.
Abstract available in PDF file.
Intrinsic and extrinsic influences on African large herbivore assemblages and implications for their conservation.
(2014) Venter, Jan Adriaan.; Slotow, Robert Hugh.; Prins, Herbert Henri Theodore.
Understanding the intrinsic and extrinsic influences that affect large herbivore assemblages are important for protected area managers, especially if their current rate of population decline in Africa continues. I aimed to determine how large herbivore species in African grazing ecosystems, respond to intrinsic and extrinsic influences, and the implications of these influences for their conservation. Conservation planners struggle to reliably reconstruct grazer assemblages for ecological restoration into areas from which they were extirpated, because of the lack of historical distribution data for their regions. Large herbivore population trends in Mkambati Nature Reserve were investigated in order to determine how well grazing herbivores established since introduction, how the success of the introduction was influenced by facilitation and competition, and what the conservation implications are for the ecological restoration. Reconstructing species assemblages for ecological restoration, using biogeographic and biological information, could potentially provide the opportunity for a grazer assemblage which included beneficial facilitatory effects. A well-packed grazer assemblage in turn could potentially lead to an ecosystem which is able to maintain its grazer assemblage structure. I investigated the factors influencing forage patch use behaviour in Mkambati Nature Reserve. A limited set of traits yielded different patch use rules for different species. Patch use was influenced by anthropogenic impacts such as poaching and changed fire regimes. Environmental heterogeneity, species’ traits, water availability as well as anthropogenic influences, affected large herbivore behaviour. The dominant movement behaviour of large herbivores was Brownian motion, with one to four exponential distributions. When animals faced the trade-off between forage quality and quantity during the dry season, they moved further between forage areas and water sources in order to get to better forage. The number of movement scales, i.e. exponential step length distributions, increased in more heterogeneous areas, and home range size and fences had a significant affect on the number of movement scales. Finding suitable forage patches in a heterogeneous landscape, where patches change both spatially and temporally, poses challenges to large herbivores for maintaining energy budgets. I tested whether large herbivores used visual cues to gain a priori knowledge about potential higher value foraging patches at a habitat-patch scale. Large grazing herbivores did not use visual cues but rather adapted their movement behaviour to the heterogeneity of the specific landscape. In conclusion, I demonstrated that intrinsic factors, including individual species’ traits can influence the way large herbivores interact with their environment. These factors, in turn, determine how large herbivores react to extrinsic factors such as poaching, fire, artificial water holes and fences which are important to consider in the conservation management of protected areas.
The effects of sexual dimorphism on the movements and foraging ecology of the African elephant.
(2005) Shannon, Graeme.; Slotow, Robert Hugh.; Page, Bruce Richard.; Duffy, Kevin.
Large herbivores are key components of terrestrial biomes because of their relative abundance and pronounced influence on ecosystem functioning and habitat structure. To manage and conserve these species effectively, requires greater understanding of their distribution and use of resources at varying spatial and temporal scales. Sexual dimorphism is one aspect of large herbivore ecology likely to have a significant effect on resource use and community level interactions. Elephants present an ideal species to test the influence of sexual dimorphism due to their marked body size and pronounced behavioural differences. This study used location and behavioural data collected over an 8 year period in five different South African reserves, all of which had well documented elephant populations. The reserves were relatively small (<1000 km2) and had augmented water supplies so analyses were not influenced by surface water availability. Results indicated that male and female elephants resolve their available range at distinctly different scales. Both sexes were shown to expand their ranges with increasing forage quality, however males were the most flexible in their temporal and spatial response during periods of low resource availability. Females were more selective than males, targeting higher quality forage and being less destructive in their feeding approach. This may be due to females' higher mass specific energy requirements associated with their smaller body size and substantial reproductive investment. They were also constrained by the costs of group living compared to male elephants which range independently. Sexual segregation is a consequence of body size dimorphism and was investigated at both the habitat and plant scale to elucidate the mechanism driving the separation of the sexes. Whilst individual habitat preferences exist, these are not sufficient to segregate the sexes. At the plant scale, significant differences were shown with regard to foraging duration, tree size and plant parts eaten. Further investigation of sexual segregation involved testing the recently proposed activity budget hypothesis. Males and females have similar daily activity budgets and relatively high levels of behavioural synchrony, which is not sufficient to explain segregation. Instead, the marked sexual segregation appeared to be caused by social organisation, reproductive strategies and the divergent foraging behaviour of males and females at the plant scale. This research highlights the importance of considering male and female dimorphic herbivores as ecologically distinct species. For example, male elephants are likely to be driving the majority of destructive foraging bouts and this will often be in a heterogeneous manner, especially during periods of resource scarcity. Therefore, the effective management of elephants requires considering population structure, individual behaviour and population size.
An integrated approach to the management of common reedbuck on farmland in Natal.
(1983) Howard, Peter Charles.; Hanks, John.; Collinson, Roger.; Grimsdell, Jeremy.; Rowe-Rowe, David Treloar.
This study was motivated by the Natal Parks Board which has been receiving a growing number of complaints from farmers concerning reedbuck grazing of commercial crops. The reedbuck is an important conservation species, which has recently disappeared from 80 % of its previous range in South Africa, and has become extinct in the Cape Province and the Orange Free State. The study was intended to look objectively at the crop damage problem and conservation status of reedbuck on private land in Natal, and make recommendations for management. A postal questionnaire was used in assessing the species' present distribution in Natal, and an intensive study was undertaken in the Underberg district of the Natal highlands. The study area comprised approximately 10 500 ha of semi-intensive agricultural land, divided into 23 farm properties, and was considered representative of farmland throughout the highland and midland regions of the province, where nutritious food in the form of irrigated pasture grasses is available throughout the year. Four animal census techniques were critically evaluated, and reedbuck numbers assessed throughout the study area. The study area was divided into no-cull, low-cull and high-cull blocks, and population trend examined over two years in each. Population stability was demonstrated in all blocks. Post mortem examination of nearly 200 reedbuck showed that the animals were in excellent physiological condition throughout the year, and the population appeared to be at, or close to its genetic potential as regards productivity. A 20 % annual 'surplus' of animals appeared to be produced. Eighty four reedbock were marked, and resightings of some of these far from their place of capture confirmed that emigration of young animals is an important population regulatory process. A multiple regression analysis of reedbuck-habitat relations, based on observed reedbuck numbers on the 23 farm properties, demonstrated that population size appeared to be llinited by the availability of cover. An examination of social organisation and behaviour led to the belief that cover is limiting because it is a resource that is monopolised by dominant territorial males at the time when females are attracted to it to give birth. Within two months these females, nursing their newborn lambs, become oestrous again, and are mated by the territorial males. Because of the relatively low densities at which stability is achieved, crop damage only becomes a problem in exceptional circumstances. A best estimate of 0,2 t of pasture grass lost per reedbuck per winter was made.
Growth and reproduction in the fruit bat Epomophorus wahlbergi.
(1983) Sowler, Sandra Georgina.; Hanks, John.
This study was carried out on the Natal South Coast between 30° 12' S and 30° 19' S, where 1085 Epomophorous wahlbergii were caught by mist-netting, and a captive breeding colony was kept between June 1977 and February 1982. Age determination techniques were developed using three criteria; linear growth measurements to obtain the age of animals prior to the attainment of the growth asymptote, tooth eruption to determine the age of animals prior to the attainment of a full permanent dentition, and tooth wear in combination with birth-pulse timing to obtain the age of animals after the growth asymptote and full permanent dentition had been reached. Stevens asymptotic growth curve, performed on forearm length, eye-nose distance and zygomatic width, observations of tooth eruption in cage born bats and linear regression of tooth height data provided the basis for age predictions. Age structure of the population indicated that the greatest percentage of losses occurred between the 5-10 and 10-15 month age group in both sexes. A maximum ecological longevity of nine years is suggested. A killed sample of 81 males and one live caged male provided the basis for the male reproductive study. Puberty onset occurred at eight months and sexual maturity attainment at 13-17 months. Sperm was present throughout the year and no seasonal variations in testicular or gonadial parameters occurred. However, seasonality was shown in body mass, blood testosterone levels, epaulette hair length, calling and testes position. The unusual and constant presence of spermatocytes/spemlatids in the epididymis cauda was observed and meiotic abnormality suggested as an explanation. Epaulettes have an attractive function for females during the mating period, and calling probably acts as a means of year-round territory maintenance. Lek mating is considered possible and a seasonal change in behaviour during the mating season from male groups to individual callers may occur. Five hundred and fifty three captured and released females and a killed sample of 111 females provided the basis for the female reproductive investigation. Puberty commenced at 2,5 months and sexual maturity was attained at six months. The first proestrus onset took place at a mean age of 5,6 months and first conception at 6,2 months. The species exhibits a seasonally polyoestrous pattern with an extended season. Conceptions occur from May to December, the peak months being May, June and July. Births occur from October to June with the peak birth season in November and December. The majority of females undergo one pregnancy per year terminating in November/December with a small percentage terminating around April. Primordial, primary, secondary and early vesicular follicles were present in the ovary year round. The presence of intermediate and late vesicular follicles however followed a seasonal pattern covering April to November. Increased uterine epithelial height and endometrial gland numbers followed a bimodal pattern. Oestrus can occur in the absence of a male and conception peaks coincided with shortest daylength, lowest rainfall, temperature and humidity. Fruiting and rainfall are suggested as ultimate causes of breeding as the peak in lactation coincided with rainfall and fruiting maxima. A series of timetables showing variations in the timing of the annual reproductive cycle with one and two pregnancies is presented. A precaution against abortion and preparation for a postpartum pregnancy were used to explain the presence of intermediate and late vesicular follicles in the non-luteal ovary at the beginning and end of pregnancy. Ovaries and uterine horns showed a functional dextral dominance although anatomically left and right appear symmetrical. Alternation of ovarian function between left and right may occur in those animals undergoing two annual pregnancies. A localized endometrial reaction may occur but was not confirmed. No transovular migration takes place. The corpus luteum reached maximum size at the beginning of pregnancy and was absent at the end. E. wahlbergi was found not to fit into the usual pattern of autumn conceptions and spring births. The species showed a high fecundity rate for a monotocous species and the gestation period was long for its body size. Parturition, lactation, maternal care and juvenile behaviour were observed in the captive colony. A method for inducing birth, using Prostaglandin E(2) and Oxytocin was applied. Births took place during daylight hours. The labour posture was head down and delivery occurred after three hours of labour. Fetal presentation was head first and placental delivery was delayed until approximately two hours after birth. Placentophagia was observed. The infant is born dorsally furred, with eyes closed and large muzzle, weighing up to 20,3 % of the mother's postpartum mass. Mother/infant behaviour and juvenile behaviour up to flight initiation is described. Competent flight takes place at a mean age of 81,1 days. Milk is higher in carbohydrate content and lower in protein content than previously studied insectivorous bat milk. A correlation is suggested between head first delivery presentation, delay in placental delivery, appearance of the infant at birth and those species which carry their young in flight instead of leaving than behind in a nursery.
A review of the old world genera of Lauxaniidae (Diptera)
(1971) Stuckenberg, Brian Roy.; Bush, S. F.; Heeg, Jan.
This paper presents in key form a review of the Old World genera of Lauxaniidae. Thirteen new genera are erected, three genera are placed in synonymy, four subgenera are given generic status, and one genus is transferred from the Heleomyzidae. The development of lauxaniid generic classification is reviewed and a total of 126 recognised genera is obtained. An account is given of the regional distribution of Lauxaniidae; three main faunal aggregates are distinguished, namely the Neotropical, Holarctic and Old World tropical. The validity of certain characters for generic classification is discussed, and the suggestion is made that trigonometopine forms have evolved polyphyletically as adaptations for life in grass and comparable vegetation types. A division of the family into major groups of genera is considered, and a subfamily Homoneurinae is established. The validity of characters used to distinguish Cestrotus and Turriger is examined; a failure to find reliable characters results in the synonymy of the latter genus. Illustrated descriptions are given of the type-species of new genera.
Aspects of the biology and ecology of the estuarine fishes of the east coast of South Africa.
(1974) Wallace, John Henry.; Heydorn, A. E. F.
No abstract available.
Beyond DNA sequencing : integrative approaches to resolving selected higher and lower taxonomic problems in Afrotropical Chiroptera.
(2013) Richards, Leigh Rosanne.; Lamb, Jennifer Margaret.; Taylor, Peter John.; Schoeman, Marthinus Cornelius.; Goodman, Steven Michael.
Of the approximate 300 currently recognised bat species known from the Afrotropics, very few have been studied in sufficient detail to a) provide accurate species and distributional limits for extant taxa, b) identify possible cryptic species, and c) ascertain the closest sister lineage of numerous taxonomic groups. For those species where DNA-based phylogenies are available, the use of additional taxonomic markers and methods has provided further insights into the evolutionary history of certain extant chiropteran groups. This work comprises a series of systematic studies of African and Malagasy Chiroptera aimed at investigating sequence-based evolutionary hypotheses of higher and lower level taxa using comparative molecular cytogenetic and morphometric techniques. Efforts were directed at resolving taxonomic inconsistencies of chiropteran taxa from the African subregion and/or Madagascar, for which there is a general paucity of comprehensive and/or resolved phylogenies. Taxa belonging to the families Pteropodidae, Hipposideridae, Myzopodidae, and Molossidae were chosen for study because molecular-based have failed to provide consensus regarding evolutionary relationships amongst the above-mentioned taxonomic groups, or are in stark contrast to phylogenies based on morphological data. In addition, molecular cytogenetics and geometric morphometric approaches were used because they have had been applied in few evolutionary studies of Afrotropical bats. With the exception of a few karyotypic descriptions, scant data are available that details the chromosomal diversity and karyotypic evolution of bats from Madagascar in relation to their conspecifics or congenerics on other continents. To understand better the mechanisms that may have structured the karyotypes of extant Malagasy Chiroptera and the utility of chromosomal characters in retracing their evolutionary history, eight species from seven families were analysed using G- and C-banding and chromosome painting. Robertsonian (Rb) fusions and fissions were the dominant mode of genome restructuring amongst taxa and, for the most part, proved useful characters for investigations of phylogenomic relationships amongst families and genera. Chromosomal data generated from painting studies employing Myotis myotis (MMY) chromosomal probes, produced phylogenetically important characters that supported two conflicting hypotheses regarding the evolutionary affinities of the Myzopodidae, a family of bats endemic to Madagascar. The Rb fusion MMY 9+11 detected in Myzopodidae, also common to Phyllostomidae, could suggest a close association of Myzopoda aurita with the superfamily Noctilionoidea. However, the Rb fusion MMY 3+4 that is also present in vesper bats, suggests closer evolutionary ties between M. aurita and the Vespertilionoidea. A sex-autosome translocation, a cytogenetic character previously confined to phyllostomid and vespertilionid bats, was also detected in M. aurita casting further uncertainties on the evolutionary origins of this deep-branching species. This study highlighted the need for more refined cytogenetic investigations based on human-derived chromosomal paints and the application of highresolution bacterial artificial chromosomal (BACs) probes to map intrachromosomal breakpoints and/or subchromosomal rearrangements in the genome of Myzopoda. Heterochromatic polymorphisms and inversions appear to be important mechanisms of karyotypic evolution amongst pteropodid genera. Painting data revealed that at least five structural arrangements might be linked to the evolutionary divergence of pteropodine and rousettine fruit bats. A cryptic pericentric inversion was detected in the genome of Pteropus rufus corresponding to the homologue of MMY 4+19 (equivalent to HSA3+21); an ancestral syntenic character proposed for eutherian mammals. Proposed synapomorphies of the rousettine clade, as defined by molecular DNA studies, include the derived state of the MMY 4+19 homologue and the non-centric fusion of MMY 16/17+24 homologue. Integration of painting data on Hipposideros commersoni with published comparative maps of other hipposiderids enabled a brief revision of the postulated ancestral hipposiderid chromosomal complement. These data disputed previously proposed chromosomal synapomorphies of Hipposideridae and supported the basal position of H. commersoni within the genus. The inclusion of other hipposiderid genera, in particular Malagasy Paratriaenops and southern African Cloeotis, in chromosome painting studies may allow for further inferences regarding the evolutionary history of this diverse family. Morphometric approaches were employed to resolve uncertainties concerning species-level relationships within Afrotropical Otomops. Multivariate analyses delineated three well-supported morphological groups that corresponded to recently described genetic lineages and revealed several species-specific morphological traits for taxonomic diagnoses. Otomops from Djibouti, Ethiopia, Kenya, and Yemen constitute an undescribed morphologically and genetically cohesive group that requires a formal taxonomic description. Understanding the ecological and possible physiological adaptive value of morphological variation can provide valuable insights into the evolutionary history of this Afrotropical species complex. This work has provided further insights into the systematics of certain Afrotropical Chiroptera through the use of molecular cytogenetic and geometric morphometric techniques. Specifically, it has facilitated the interpretation of ancestral, independent and convergent chromosomal characters in the evolution of Afrotropical taxa belonging to the families Pteropodidae, Hipposideridae, and Myzopodidae, and has also elucidated lineage-specific morphological attributes in members of the genus Otomops thereby advancing our understanding of chiropteran diversity within the region.
Comparative studies on related free-living and pathogenic limax amoebae with particular reference to Naegleria.
(1977) Lastovica, Albert Joseph.; Meester, Jurgens Anthonie Jansen.
Over two hundred and forty strains of limax amoeba including eight potentially pathogenic strains of Naegleria and Acanthamoeba were isolated from a variety of habitats in South Africa. The amoeboid and flagellate stages of all Naegleria strains examined by light microscopy were found to be similar in morphology. Differences were noted in the excystment of Naegleria fowleri, Naegleria gruberi and other limax amoebae. Time-lapse microcinematography has been utilised to study cytokinesis and motility in the amoeboid and flagellate stages of Naegleria fowleri and Naegleria gruberi. A new phenomenon was observed in Naegleria where amoebae attempted cytokinesis after brief exposure to a temperature of 9°C. The amoeboid and flagellate stages of virulent and avirulent Naegleria were found to be similar in surface topology when examined under the scanning electron microscope. Differences were noted in the excystment patterns of various limax amoebae. No structure suggestive of a surface active lysosome was found in any of the cells examined. A comparative transmission electron microscope study of virulent and avirulent Naegleria and other limax amoebae has revealed striking similarities as well as sharply defined ultrastructural differences. Partioles suggestive of a virus were detected in several of the pathogenic Naegleria. Surface-active lysosomes were not found in any of the amoebae examined. Distinct feeding preferences were evident in Naegleria fowleri and Naegleria gruberi when they were tested on a variety of gram-negative and gram-positive bacteria. Differences were noted on the growth of these amoebae at various temperatures. Cell fractions of Pseudomonas aeruginosa affected excystment, encystment, cell division and the amoeba-to-flagellate transformation in Naegleria. Differences were observed in the transformation kinetics of Naegleria fowleri and Naegleria gruberi at 25ºC and 43º C. A variety of inhibitors affected motility and transformation in Naegleria. For the first time, La[3+]ion, a competitive inhibitor of Ca[2+]ion, was shown to inhibit amoeboid motion, transformation and flagellar beating in Naegleria. Electron microscope observation suggested that La[3+]ion acts on the plasmalemma. Material from two suspected cases of primary amoebic meningoencephalitis was examined and cultured but no limax amoebae were isolated. New criteria for the classification of virulent and avirulent Naeglerid. have been advanced.
Aspects of the biology of the red bishop Euplectes orix and other Euplectes species.
(1977) Craig, Adrian John Fergus Knott.; Maclean, Gordon Lindsay.
The breeding biology and the annual cycle of the Red Bishop Euplectes orix was studied over a two year period in Natal. Some comparative data were also gathered for the related species the Red-shouldered Widow E. axillaris and the Red-collared Widow E. ardens, and additional data from a ringer in Rhodesia have been analysed. The breeding season of these polygynous ploceids coincides with the summer rainy season, and the amount of breeding activity in the Red Bishop appeared to be correlated with the amount of rain during the previous year. Breeding success at the colony studied was low; predation was the major cause of nest failure. In all three species the entire population, including the juveniles, undergoes a complete moult at the end of the breeding season. There is some evidence that the birds may make local movements during the winter dry season. These species are sexually dimorphic, the males being larger than the females. The population sex ratio was Significantly biased in favour of males in the Red Bishop and the Red-shouldered Widow but not in the Red-collared Widow. However, about half the male birds are subadults which do not breed, so that there is an excess of females in the breeding population. Adult males undergo a partial moult at the start of the breeding season and acquire a distinctive nuptial plumage. This is shed again at the post-nuptial moult, and in eclipse plumage they resemble the females. There is a similar pattern of weight change in all three species, with peaks early in the breeding season and again during the moult. The lowest annual weights are recorded during the dry season. The mortality rate of the Red Bishop is not high for a small passerine. The findings of this study are compared with the available information on other members of the genus, and discussed in relation to the evolution of polygyny in the Euplectes species.
Systematics and bionomics of the scorpions of South West Africa (Arachnida, Scorpionida)
(1978) Lamoral, Bruno H.; Heeg, Jan.; Meester, Jurgens Anthonie Jansen.
All the taxa of scorpions previously described from South West Africa are revised and a monographic account presented with phylogenetic and biogeographic discussions and conclusions derived in terms of current concepts in systematic zoology which include cladistics and historical biogeography. South West Africa is treated as a subregion of the Afrotropical region and the limits of this subregion coincide broadly with the political borders. All the characters used are defined and illustrated. Many characters previously unstudied for the fauna are investigated. These include comparative studies of trichobothria distributions and detailed structures of the hemispermatophore. Disc electrophoresis of the haemolymph of a few species was carried out and the results discussed. Ecological factors are extensively described and discussed. The nature of the substratum, taken in its broadest possible definition, was found to be the most important single factor determining species distribution. 70 subgeneric taxa were revised, 45 of which are retained as valid, while 11 new species are described bringing the number of known species to 56. These are distributed among seven genera as follows: Buthotus, two species; Karasbergia, one species; Parabuthus, 14 species; Urop1ectes, 10 species; Hadogenes, three species; Lisposoma, two species; Opisthophthalmus, 24 species. Determination keys are provided for all levels of taxa occurring in South West Africa.
The mammals of the Transvaal.
(1978) Rautenbach, Ignatius Lourens.; Meester, Jurgens Anthonie Jansen.
The primary object of this study is to provide a checklist of the mammals occurring within the Transvaal. A general biological account of each species forms the bulk of this treatise, - discussing, in order of sequence, firstly the taxonomic status of each species as based on a study of available museum specimens. Thereafter the distribution of each species is discussed, and illustrated with a map of known distribution. Remarks are presented on the various environmental factors that may influence individual species ranges. Habitat preferences, habits, and food preferences are then discussed. Available data on breeding seasonality, as based on the monthly ratio of reproductively active and inactive females, are given. External measurements and masses of males and females are tabulated. Records of occurrence based on the number of museum specimens from each locality, and the institution where these specimens are housed, are finally listed for each species. The text is supplemented by a gazetteer, giving the latitudinal and longitudinal coordinates of all the collecting localities. This study is based on some 12 000 museum specimens, the greatest majority housed in the Transvaal Museum collections. During the field work phase of this project, 57 localities were sampled. This yielded the majority of the specimens and the greater part of the data on which this book is based. Information gained from a study of earlier collected material supplements these data files. Additional information such as sight records, field observations, and the published accounts of other scientists, have also been incorporated into the central data files and have been discussed in relation to my own findings. The results of selected studies comprise the discussion. The basic behavioural trends and mean mass of all the carnivore species of the Transvaal are employed to speculate on how interspecific competition is avoided. The distribution of all southern African mammals is employed to statistically evaluate the validity of the biotic zones previously empirically recognized for this subcontinent. The distribution patterns of Transvaal mammals are statistically analysed to subdivide the biotic zones overlying the Transvaal into community types of zoogeographical significance. Other zoogeographical phenomena are discussed in relation to regional species diversity. Reprints of papers arising from this study, and particularly the discussion, are bound in as appendices to this report.
Ecological and systematic relationships in Natal ranids (Rana Linn. sensu stricto and sensu Strongylopus Tschudi) with notes on a possible competitor, the leptodactylid Heleophryne natalensis Hewitt.
(1977) Channing, Alan Eric.; Van Dijk, D. E.
No abstract available.
Reproduction and population ecology of the blue wildebeest Connochaetes taurinus taurinus in Zululand.
(1977) Attwell, Charles Anthony Mallory.; Meester, Jurgens Anthonie Jansen.; Hanks, John.
A two-year study was made of the blue wildebeest Connochaetes taurinus taurinus in Zululand, Natal. Aspects investigated included age determination methods, growth and condition, reproductive physiology, habitat interactions, and population dynamics. Findings were related to suggested management of the species.

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