Commercial sugarcane in South Africa is a monoculture, and therefore lacks vegetation diversity, which is instrumental in increasing associated faunal diversity. Diverse habitats tend to support more stable populations of herbivorous and predacious animals. It is hypothesised that lack of this diversity in sugarcane was partially responsible for the existence of Eldana saccharina infestation levels that are higher than is commercially acceptable. Amongst the available E. saccharina control strategies, is habitat management. This has been developed with the view of increasing and enhancing predator foraging activity. Through increasing arthropod predator abundance and activity, it is believed that E. saccharina control may be enhanced. In this study, habitat diversity was increased through intercropping beans within sugarcane. Arthropod populations were monitored throughout the sugarcane-growing period, to determine what effect this intercropping had on known potential arthropod predator populations of E. saccharina. The study site was divided into two plots: the intercrop (beans planted within sugarcane rows: sugarcane-bean intercrop) and sole sugarcane: control plot. At monthly intervals, epigeal arthropods were sampled with pitfall traps, while foliage associated arthropods were sampled with a suction trap. Predator activity at the base of the sugarcane stalk, where E. saccharina lays its eggs was monitored with sticky traps. Sampling took place in the sugarcane-bean intercrop and control plots as well as in the roadway bordering the study site. Epigeal predator habitat preference was assessed by randomly placing pitfall traps in the sugarcane rows, bean rows, interrows between sugarcane rows, interrows between sugarcane and bean rows and the roadway. Corresponding with monthly trapping, an E. saccharina infestation and damage survey was conducted. Environmental factors such as weather, light intensity, plant (beans and sugarcane) phenology and weed density were measured, and their effect on E. saccharina potential arthropod predators examined. At harvest, sugarcane stalks were sampled for sucrose yield analysis. Potential E. saccharina predators that were captured included species of the orders and/or families Acarina, Blattidae, Formicidae (Pheidole megacephala and Dorylus helvolus) and Araneida (Lycosidae, Oxyopidae, Thomisidae and Salticidae). P. megacephala and species of Acarina were the only predators caught with all three trapping techniques, thus indicating that they occurred both on the ground and foliage. D. helvolus and Acarina were the only predators caught in significantly higher numbers in the intercrop, suggesting that increased habitat management had positively affected their population sizes. D. helvolus were captured both on the ground and length of sugarcane stalk, while species of Acarina were captured on the ground, foliage and at the base of sugarcane stalk, indicating that they forage at the base of the stalk, where E. saccharina activity is concentrated. Specific ground habitats preferred by D. helvolus included the sugarcane rows and bean rows, while Acarina preferred the interrows between sugarcane and bean rows. Despite the generally low E. saccharina infestation levels during this study, significantly higher levels of infestation occurred in the intercrop when compared to sole sugarcane. As expected with high infestation, higher (although not statistically significant) damage occurred in the intercrop. Surprisingly, sucrose yield and sugarcane stalk mass were slightly higher in the intercrop. The implications of the observations made during this study are discussed in the context E. saccharina management. / Thesis (M.Sc.)-University of Durban-Westville, 1998.

Biodiversity changes, often resulting from climate change, land transformation, and the transportation of organisms across geographical barriers are among the most important human induced global changes. To optimize the spatial allocation of conservation efforts, and how to best protect indigenous species, requires an understanding of the principal determinants that structure ecological communities and ecosystems. We studied community-level interaction among a diverse assemblage of specialist and generalist browsers in an African savanna. Hluhluwe-iMfolozi Park (HiP), South Africa, hosts a complete assemblage of vertebrate species across all trophic levels and contains a diverse guild of large browsers. Using species abundance distributions (SADs) we graphically illustrate the diversity and abundance of woody species that comprise six structural habitat types within HiP. We calculated the Shannon-Wiener index and Pianka’s niche overlap to characterise the utilization of forage across habitat types among different browser groups. By using individual plant traits we investigated mechanisms of resource partitioning. We specifically investigated the effect of the temporal expansion of an exotic invasive plant (Chromolaena odorata) on the critically endangered black rhino using GIS and statistical analyses. We found that lower lying habitat types were important forage resources for browser species and individual plant traits that are highly correlated with digestibility strongly predicted browser preference. Black rhino used different strategic and metabolic mechanisms to successfully compete within the same forage height range of other, smaller, browsers. C. odorata has negatively impacted forage species utilization and has led to a spatial reorganization of the population of black rhino. This may partly explain the recent decline in the population. The principles within metapopulation management can be used to successfully conserve endangered species. High diversity of browse across three dimensions (diversity, abundance and maximum height) relative to area facilitates a high diversity and abundance of different browsing herbivores. Therefore the spatial configurations of resources ranging from topological attributes to the individual plant traits are essential to maintaining viable populations of many co-occurring species within conservation areas of limited extent. / Thesis (M.Sc.)-University of KwaZulu-Natal, 2009.

The Brown-headed Parrot (Poicephalus cryptoxanthus) is a poorly known species inhabiting open woodland in south-eastern Africa. This study elucidates critical aspects of the species ecology and although each of these categories impinge on one another, it concentrates on two broad biological aspects, diet and breeding biology, and vocalizations. The species has a generalist diet, switching from one suite of food species to another as and when those species become available, with no species critical for its survival. Analysis of dietary items throughout the year and comparison with handling times and availability reveals that at no time is the species under dietary constraint. Evidence from association indices and behavioural observation shows that the popular view that the Brown-headed Parrot forms pairs just before breeding is erroneous. Birds retain pair bonds and the bond is long-term, lasting at least throughout the year. Congregations are therefore of a classical fission/fusion type with the sub-units being the paired males and females. A mathematical model of the growth of captive chicks is presented, as a guideline to alert potential breeders of Brown-headed Parrots of malnutrition or disease. The species is a secondary cavity hole nester and whilst, the breeding biology of the species is summarised, the importance of large and old trees for breeding opportunities of the species is emphasised. This theme is continued by testing various adaptive hatching hypotheses as possible explanations of asynchronous hatching in the species. It is suggested that asynchronous hatching may be an adaptive strategy moderating against the number of suitable nesting cavities. The vocalization repertoire of the Brown-headed Parrot is described and seven separate vocalizations are recognized. None of these are associated with sexual situations, offering further evidence of a long-term pair bond. Evidence is offered that Brown-headed Parrot chicks can recognise their parents from individual vocal signatures supporting previous evidence from a number of species where chicks may mingle with unrelated chicks. Conversely, parents seem to be unable to recognise their chicks in the same way. It is concluded that this inability may be a result of strong one-way selection pressure, where the costs outweigh the benefits for parents with more than one chick or may be related to the experimental design. Individual recognition by voice implies individual voice differences and the adult double chip contact call is analysed using multivariate statistical techniques. The analysis separates individuals on the basis of frequency and temporal patterns and it is concluded that these parameters may allow individual voice differentiation. Finally, high frequency aspects of the double chip contact call are examined. These frequencies lie above the normally accepted upper threshold of avian hearing. From laboratory and field experiments, behavioural evidence is presented suggesting that the Brown-headed Parrot reacts to these frequencies and may use their degradation as a means of ranging distances to conspecifics. / Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 2002.

The behaviour, nesting, food resources and mating system of the African Jacana Actophilornis africanus were studied at Muzi Swamp, northern KwaZulu-Natal and at Darvill Sewerage Works, KwaZulu-Natal. African Jacanas show highly polyandrous behaviour associated with a marked reversed sexual size dimorphism. A high clutch loss was recorded because of predation and weather conditions. Contact behaviour was recorded, which is unusual in Charadriiformes. Vocalization and visual displays were distinctive and closely related to territorial and sexual behaviour. Unlike the Wattled Jacana Jacana jacana, the African Jacana practises male guarding behaviour. Rich food concentration in the African Jacana habitat was shown by field tests and this may be a reason for this species evolving in a floating environment. The presence of simultaneous polyandry in the African Jacana was analyzed mathematically and by computer modelling in order to determine possible advantages of polyandry. / Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 1997.

Aspects of olfactory, auditory, visual and tactile communication were investigated in five Elephantulus species (E. brachyrhynchus, E. edwardii, E. intuft, E. myurus, E. rupestris) and Macroscelides proboscideus, facilitating comparisons among species and genera. The purpose of this study was to determine whether species specific patterns of communication could be identified in the southern African elephant-shrews. Scent gland structure and location was investigated to determine whether species specific differences existed and to relate gland location to marking behaviour. Prominent scent glands were found in the oral angel, foot pads, anogenital region and tail of all elephant-shrew specIes. Marking behaviours such as sandbathing, digging and anal dragging correlated strongly with sent gland location, but no glandular size and/or structural differences were apparent among the different elephant-shrew species. Species specific differences in marking frequencies did exist among the six elephant-shrew taxa, but were unrelated to glandular development. Choice chamber preference tests indicated that Elephantulus species preferred conspecific odours, with males showing higher levels of discrimination than females . Audible vocalizations and footdrumrning were investigated and compared in the sex elephant shrew taxa. Distinct differences were present in the acoustic repertoires of the southern African elephant-shrew species. Footdrumming showed very clear species specific patterns, and footdrumming characteristics were compared with an existing morphological phenogram to derive a possible path of evolution for footdrumming. Visual and tactile communication were investigated by analysis of frequencies and sequences of behavioural acts. A comparison of male-female interactions of the different taxa showed differences in behavioural frequencies both between males and females of a species, and among the different species. Discriminant function analysis showed clear species specific patterns in the visual! tactile signalling systems of southern African elephant-shrews, and this was more clearly defined in males. Elephant-shrews showed higher levels of aggressive behaviour in interspecific encounters, indicating a possible role of aggression as a premating isolating mechanism between species. However, no differences in aggressive behaviour between allopatric and sympatric malefemale interactions could be discerned. Elephant-shrew males showed high frequencies of submissive behaviour in intraspecific encounters, which may be a strategy to reduce aggression in conspecific females. Species specific patterns of behaviour were found to exist in all three modes of communication investigated, and may all act to some extent as premating isolation mechanisms between species. However, many of these patterns are very subtle and it is suggested that a combination of all sensory modalities act together to form each species' signalling system. / Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 1996.

The causal and temporal aspects of blood tissue specification in the chick embryo were investigated in this study. The main focus was on the role of basic fibroblast growth factor (bFGF) in the determination of the erythropoietic tissue, particularly in context with its representation as a non-axial mesodermal derivative which arises in the posterior domain of the chick embryo. The initial strategy employed in this study was the use of agents that are known to block the activity of bFGF, and to determine their effects on erythropoiesis. Treatment of unincubated chick embryo explants with heparin, which binds specifically to the FGF family, was found to inhibit primitive streak formation and erythropoiesis, and also inhibited the formation of other mesodermal tissues. These initial findings suggested that one or more growth factors had become bound to the heparin, and that their activity is important for the specification of primitive streak formation and mesodermal patteming. The development of the erythropoietic tissue was assayed by a cytochemical test for haemoglobin using 0dianisidine; and by histological examination for blood islands and red blood cells in serial sections of the embryos after 48 hours incubation. Microscopic examination of the embryos at the stages of gastrulation on the first day of incubation revealed that heparin caused holes to appear in the ventral layer; and although a primitive streak did not form, a middle layer of mesenchymal cells were seen to accumulate between the ectodermal and ventral "endodermal" layers. It was significant that heparin's inhibitory effect on erythropoiesis could be reversed after the addition of a recombinant bovine bFGF to the heparin-treated embryos. However, the exogenous bFGF did not neutralize the inhibitory effect of heparin on the primitive streak and other mesodermal derivatives (Chapter Two). The inhibition of erythropoiesis by heparin was also reversed by the addition of a mesodermal-inducing factor extracted from a Xenopus embryonic cell line, namely XTC. The XTC mesodermal-inducing factor (MIF), which belongs to the transforming growth factor-B family and is a homologue of activin, could also reverse the inhibitory effect of heparin on primitive streak formation; but no recognizable axial mesodermal structures subsequently developed. Of consequence, was that both bFGF and XTC-MIF blocked heparin's effect on the ventral layer, preventing the gaps forming. Therefore, it is suggestive that the VI development of an intact ventral layer is important for the determination of the erythropoietic sequence (Chapter Three). By taking a more specific approach using antisera to bFGF (anti-FGF) and the bFGF receptor (anti-FGFR) on whole embryo explants, it was found that anti-FGP and anti-FGFR were able to inhibit erythropoiesis, but not primitive streak formation. However, these antisera caused defects in the posterior region of the embryonic axis. These embryos not only lacked posterior blood tissue, but heart and somites were missing; whereas the anterior head structures were well formed. These results therefore suggest that bFGF signalling is important for the development of the posterior body plan, which includes erythropoiesis (Chapter Four). Further evidence for the role of bFGF in the determination of the blood mesodermal tissue line was reached in an in vitro bioassay. In this part of the investigation, specific pieces of the blastoderm, namely pieces dissected from the posterior marginal zone (PMZ) and inner core of the central disc (lCD) were able to form haemoglobin under particular conditions. The PMZ components were found to have the capacity to form haemoglobin when dissected from blastoderms of stages X to xm when cultured in serum-free medium. This commitment to form haemoglobin could be blocked by treatment with anti-FGP at stages X and XI, but not at the later stages of xn and XIII. The ICD components were found to have a commitment to form haemoglobin only if this component was dissected from embryos at stage XIT and XITI, but not before. These results suggest that a determinative event for the haemoglobin differentiative pathway occurs between stages XI and XII. It was also found that the stage X central disc component could be induced to form haemoglobin if a stage xm hypoblast was added to it in tissue recombination sandwich cultures, or if bFGF (75 - 150 ng/ml) was added to the medium. These results lend further support that bFGF plays an important role in the determination of erythropoiesis; and furthermore, suggest that the hypoblastic tissue is the source of this induction (Chapter Four). Finally, immunocytochemical labelling with a polyclonal antibody to bFGF has revealed that bFGF increases significantly from stage XI in cells within the developing hypoblast layer and in the middle mesodermal layer. These cells are located predominantly in the posterior domain of the embryo. This polarized distribution of bFGF with the high value of bFGF concentration in the posterior area, is presumably responsible for inducing the overlying epiblast to form the posterior horseshoe-shaped region from which blood tissue is seen to arise. An immunocytochemical analysis of the distribution of the FGF receptor was vu assessed, as an indicator of the possible competence of the cells to respond to the bFGF signal. The bFGF receptor was found to be expressed at stage XII in cells that appeared to be in register with those immunoreactive to the bFGF ligand; therefore suggesting an autocrine function. It was interesting that at stage Xli an intense immunostaining with the anti-FGFR developed in the nuclei of cells within the epiblast layer (Chapter Five). In conclusion, this study has demonstrated that the initial determination of the erythropoietic cell lineage in the chick is at the time when the hypoblast is in the process of forming beneath the epiblast, Le. between stages XI and XII. Furthermore, it was found that an induction by an FGF-like signal from the hypoblast layer (or middle mesodermal cells that may be closely associated with the hypoblast) induces "competent" cells (Le. FGFR-positive cells) in the epiblast to form blood tissue in the posterior domain of the chick embryo. / Thesis (Ph.D.)-University of Natal, 1994.

The distribution, status, biology and ecology of four flufftail species were investigated in South Africa and Zimbabwe. The Redchested Flufftail is a successful and widely distributed species, occupying a wide range of dense vegetation, from seasonally wet grassland and sedges to permanently shallowly flooded reedbeds. It colonizes artificially created wetland patches and occupies very small patches of suitable habitat. Redchested Flufftails maintain a permanent pair bond and are permanently territorial and entirely sedentary. Their habitat is relatively stable but unpredictable catastrophic events such as burning may force temporary emigration in winter or spring. Displaced birds move a short distance, occupy often marginally suitable habitat and recolonize burned areas as soon as vegetation cover becomes adequate. Periodic burning improves habitat quality, and recommendations are formulated for the management of wetland habitats by burning. The size of the winter territory is larger than the minimum required for survival and provides an insurance against forced emigration, while immatures often share parental territories in winter. The Striped Flufftail's grassland habitats in Natal are decreasing and its numbers are declining. Striped Flufftails are sedentary in low-altitude grassland habitats, but in high-altitude sourveld the decrease in invertebrate food forces emigration in April-June, when the birds move to unknown wintering destinations (movements are possibly altitudinal). Return time to unburned vegetation is dependent upon invertebrate food availability. Return time to burned vegetation is governed by the development of suitable cover, which may occur too late in the breeding season to permit occupation. The species is well adapted to frequent burning of its habitats, which serves to maintain suitable fire-climax grassland, but is also adapted to post-fire-climax vegetation types. The Whitewinged Flufftail is rare but its occurrence was regularly noted during the summer at four sites in Natal and the Transvaal. Habitat preferences and movement patterns were clarified, as was the bird's ecological segregation from the Redchested Flufftail. No conclusive evidence was found for breeding in South Africa and it is suggested that lack of suitable breeding habitat (possibly as a result of its being occupied by breeding Redchested Flufftails) may account for this. Some aspects of the bird's behaviour and calling were investigated. In view of this bird's threatened status and the continuing destruction of its wetland habitats, further surveys are urgently required to clarify the bird's status and the full extent of suitable habitat in South Africa, while a captive breeding programme is recommended to study breeding behaviour. The Buffspotted Flufftail inhabits a wide variety of forested and bushed habitats, and in Natal is a successful colonist of exotic vegetation in gardens. Its breeding biology, territorial and aggressive behaviour, and feeding ecology, were investigated in detail. It has regular seasonal movements in Natal, probably both altitudinal and coastal, although birds may remain throughout the year in areas where conditions are suitable. Seasonal departures are correlated with decreasing invertebrate food availability, while return time is largely governed by food availability, although cover development in exotic vegetation delayed recolonization at one site. The pair bond and the territory are maintained throughout the breeding season, and possibly throughout the year under suitable conditions. Adult mortality is probably high and the species' breeding strategy emphasises fecundity, this being achieved by a large clutch size, a very restricted period of parental care and rapid re-nesting. Juvenile mortality is high. The plumage, behavioural and vocal development of the young were studied in detail. / Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 1994.

No abstract available. / Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 1981.

This work sets out to describe the socio-ecological niches of otonya irroratus, Rhabdomys pumilio and Praomys natalensis in the Natal midlands. This objective necessitated a broad-based approach in which aspects of the ecological niches, and the social behaviour and social organization of the three species were investigated in field (habitat and trapping) and laboratory (experimental and observational) studies, during the period January 1976-May 1978. To test the assumption that the commonly sympatric O. irroratus, R. pumilio and P. natalensis are primarily adapted to habitats which differ mainly in respect of water availability, an attempt was made to define their positions on a mesic/xeric continuum. The results suggest that in terms of the parameters measured (responses to water and cover availability, and to food and water deprivation), O. irroratus is more nearly mesically adapted than is R. pumilio, with P. natalensis positioned between the two extremes. However, in the case of P. natalensis it is apparently of overriding importance that this species is adapted to disturbed habitats. The mesic habitats preferred by O. irroratus are often of limited size, but resource availability within these areas is apparently high and stable. Extensive areas of suitable habitat are available to R. pumilio, but availability of resources is seasonally variable. The disturbed habitats preferred by P. natalensis arise unpredictably in nature and, depending on the rate of ecological succession, may be short-lived; hence availability of resources to this species is highly unpredictable. Social behaviour was studied by means of dyadic encounters in the laboratory. Communication in O. irroratus, R. pumilio and P. natalensis appears to be dominated by auditory, visual and olfactory signals respectively, although O. irroratus also has well developed visual signals in its communicatory repertoire. These differences are explained mainly in terms of patterns of diel activity and habitat preferences: R. pumilio is adapted to bright light, and its visual signals are subtle; O. irroratus is adapted to dim light, and its visual signals involve gross changes in posture, while the use of loud, low frequency vocalizations would allow conspecifics to know their precise location in relation to one another in dense vegetation; P. natalensis is nocturnal, and hence appears to emphasize olfactory (and possibly ultrasonic) communication, which would permit transfer of information in the dark. O. irroratus is overtly highly aggressive, but agonism is ritualized; ritualization of aggression has probably evolved to allow high densities of this species to exploit limited areas of prime habitat. R. pumilio is less overtly aggressive than O. irroratus, but aggression tends to be unritualized; direct aggression probably acts as a spacing mechanism, and is possible in view of the large areas of habitat available to this species. Agonism is poorly developed and ritualized in P. natalensis, permitting high sociability and group formation in this species, and maximum exploitation of locally abundant resources. Social organization was studied in the field (trapping studies) and by means of dyadic encounters in the laboratory. The social system of O. irroratus appears to include temporal territoriality, which would permit animals to live in close spatial association (in small areas of habitat) while seldom actually meeting. Hierarchical ranking occurs in male O. irroratus and R. pumilio, with competition in both most likely being for mating opportunities. Breeding females of these two species are intrasexually territorial, in the case of Q. irroratus thereby providing dispersing young with adequate space for establishment of a home-range in prime habitat, and in R. pumilio protecting the young against conspecific female aggression until dispersal. R. pumilio tends to aggregate in mesic refuge habitats in winter, which apparently reflects the seasonality of resource availability to this species in drier environments. P. natalensis is colonial, an adaptation facilitating maximum exploitation of temporarily abundant resources in transitory disturbed habitats. In response to intense courtship by the male, female R. pumilio appear to undergo reflex ovulation; this strategy would maximize the chances of fertilization occurring during occasional meetings between males and females. Courtship intensity is low in P. natalensis, and presumably because the colonial social system of this species ensures frequent association between potential mates, females appear to ovulate spontaneously. Sexual activity was not observed in O. irroratus. The life-history tactics of the three species are such that o. irroratus and P. natalensis respectively appear to be K- and r-selected, with R. pumilio falling between these two extremes on an r-K continuum. / Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 1982.

Chaerephon (Dobson, 1874), an Old World genus belonging to the family Molossidae, is part of the suborder Vespertilioniformes. Members of this genus are distributed across mainland Africa (sample sites; Tanzania, Yemen, Kenya, Botswana, South Africa and Swaziland), its offshore islands (Zanzibar, Pemba and Mozambique Island), Madagascar and the surrounding western Indian Ocean islands (Anjouan, Mayotte, Moheli, Grande Comore, Aldabra and La Reunion). A multifaceted approach was used to elucidate the phylogenetic and population genetic relationships at varying levels amongst these different taxa. Working at the subspecific level, I analysed the phylogenetics and phylogeography of Chaerephon leucogaster from Madagascar, based on mitochondrial cytochrome b and control region sequences. Cytochrome b genetic distances among C. leucogaster samples were low (maximum 0.35 %). Genetic distances between C. leucogaster and C. atsinanana ranged from 1.77 % to 2.62 %. Together, phylogenetic and distance analyses supported the classification of C. leucogaster as a separate species. D-loop data for C. leucogaster samples revealed significant but shallow phylogeographic structuring into three latitudinal groups (13º S, 15 - 17º S, 22 - 23º S) showing exclusive haplotypes which correlated with regions of suitable habitat defined by ecological niche modelling. Population genetic analysis of D-loop sequences indicated that populations from Madagascar have been expanding since 5 842 - 11 143 years BP. At the infra-generic level, I carried out analyses of sequences of the mitochondrial cytochrome b gene and control region, and the nuclear RAG2 region, to resolve the evolutionary history and taxonomy of the C. pumilus species complex from Africa and the western Indian Ocean islands. The nominate form comprised C. pumilus from Massawa, Eritrea, and this was genetically distinct from all other forms of Chaerephon. Our molecular evidence does not support that the syntype of C. limbatus and the holotypes of C. elphicki and C. langi and topotype of C. naivashae are specifically distinct from C. pumilus s.s. There is evidence of introgression of both C. pusillus and C. pumilus s.l. (south eastern Africa) mitochondrial haplotypes into C. leucogaster. The C. pumilus species complex has several attributes of a ring species, but appears to differ from this model in some important respects. It occurs on the African mainland and western Indian Ocean Islands, including Madagascar, ringing a potential barrier to gene flow, the Mozambique Channel. The taxa within the species complex form a ring in which the differentiated terminal forms, C. pusillus and C. leucogaster, occur in sympatry on Mayotte (Comoro Islands). Although there is evidence of isolation by distance around the ring, there is also a relatively high degree of genetic structure and limited gene flow. It appears that the island-based component species may have differentiated in allopatry, with some gene flow by over water dispersal, whereas the African mainland species may have differentiated through isolation by distance. A further study was aimed at re-examining the phylogeny of C. pumilus sensu lato from south eastern Africa based on a considerably larger sample set with a wider geographic range; I confirmed the previously-reported phylogenetic structure, and identified an additional strongly-supported control region clade. Discriminant Function Analysis based on four echolocation parameters could not discriminate between these clades. The hypothesised existence of cryptic species with distinct echolocation characteristics was not supported. Indices of diversity and neutrality, combined with a ragged multimodal mismatch distribution, are inconsistent with demographic expansion of a single C. pumilus south eastern African population and suggest that the control region lineages are stable populations at demographic equilibrium that were established during the late Pleistocene between 60 000 and 13 000 years ago. Further, more variable markers (microsatellites) were employed for finer-scale resolution of population genetic structure among the five genetic lineages of C. pumilus sensu lato found in the Durban area of KwaZulu-Natal, and to search for hybridization between these lineages. We recovered strong mitochondrial genetic structure, with 90% of the molecular variance occurring among four phylogenetically-defined groups, and a high significant Fst (0.897). Microsatellite data recovered three admixed populations with 3% of the nuclear variance occurring among populations, and global (Fst=0.037) and pairwise Fst values among populations were low and not significant. This is indicative of little genetic structure among the groups of C. pumilus s.l., which appear to comprise a single interbreeding population. Such high levels of mitochondrial genetic structure in the absence of significant nuclear structure are consistent with social isolation mechanisms such as female philopatry, and may reflect introgression of mitochondrial genes due to past hybridisation events with mitochondrially-distinct forms from outside the sampled area. / Thesis (Ph.D.)-University of KwaZulu-Natal, Durban, 2013.