Thesis (PhD (Botany and Zoology))--University of Stellenbosch, 2008. / The Bathyergidae are subterranean rodents endemic to Africa south of the Sahara. They are characterised by divergent diploid numbers that range from 2n=40 in Fukomys mechowi to 2n=78 in F. damarensis. In spite of this variation there is limited understanding of the events that shaped the extant karyotypes and in an attempt to address this, and to shed light on the mode and tempo of chromosomal evolution in the African mole-rats, a detailed analysis of both the autosomal and sex chromosome components of the genome was undertaken. In addition to G- and Cbanding, Heterocephalus glaber (2n=60) flow-sorted painting probes were used to conduct cross-species chromosome painting among bathyergids. This allowed the detection of a balanced sex chromosome-autosome translocation in F. mechowi that involved a complex series of rearrangements requiring fractionation of four H. glaber autosomes and the subsequent translocation of segments to sex chromosomes and to the autosomal partners. The fixation of this rare rearrangement has probably been favoured by the presence of an intercalary heterochromatic block (IHB) that was detected at the boundary with the translocated autosomal segment. Male meiosis in Cryptomys, the Fukomys sister clade, was investigated by immunostaining of the SCP1 and SCP3 proteins involved in the formation of the synaptonemal complex. This allowed confirmation of a Y-autosome translocation that is shared by C. hottentotus subspecies. We discuss reduced recombination between Y and X2 that seems to be heterochromatin dependent in the C hottentotus lineage, and the implications this holds for the evolution of a meiotic sex chromosome chain such as has been observed in platypus. By extending cross-species chromosome painting to Bathyergus janetta, F. damarensis, F. darlingi and Heliophobius argenteocinereus, homologous chromosomal regions across a total of 11 species/subspecies and an outgroup were examined using cladistic and bioinformatics approaches. The results show that Bathyergus, Georychus and Cryptomys are karyotypically highly conserved in comparison to Heterocephalus, Heliophobius and Fukomys. Fukomys in particular is characterised by a large number of rearrangements that contrast sharply with the conservative Cryptomys. The occurrence and fixation of rearrangements in these species has probably been facilitated by vicariance in combination with life history traits that are particular to these mammals.

Dissertation (PhD)--University of Stellenbosch, 2004. / ENGLISH ABSTRACT: Historically, isopods of the suborder Phreatoicidea were thought to be represented in southern Africa by four species belonging to the endemic genus Mesamphisopus. This taxonomy was based on poor collections and the extent of variation among and within populations were poorly understood. In the present study, intensive sampling was undertaken to determine the diversity, distribution and biogeography of phreatoicidean isopods within South Africa. Analyses of allozyme data and mitochondrial DNA sequences (from the 12S rRNA and protein-coding COI genes) were used to examine differentiation among populations, extricate species boundaries (in combination with morphometric and morphological data) and to elucidate the evolutionary relationships among taxa. Additionally, conservation units were identified among the sampled populations and conservation threats highlighted. First, genetic and morphometric differentiation was examined among populations identified morphologically as M. capensis. Collection localities spanned two mountainous regions in the Western Cape and these were separated by a coastal plain remnant. Five morphometrically and genetically distinct species were identified. These taxa are also geographically partitioned in two regions, which were regarded as Evolutionarily Significant Units. Differentiation among populations of the two regions, and similar patterns in other taxa, was attributed to Cenozoic sea-level fluctuations. Second, populations, variably assigned to M. abbreviatus or M. depressus, were examined to determine whether they were conspecific. A large geographic area was sampled to account for intraspecific differentiation. Limited morphometric discrepancies were observed, with individual populations being either similar to the M. abbreviatus or the M. depressus syntypes. Genetic support for the recognition of a cryptic species complex among the sampled populations was equivocal. Substantial genetic differentiation and a lack of gene flow were observed among all populations. Clear patterns of isolation by distance were not detected, and genetic structure appeared to be unrelated to geography or drainage systems. The mosaic pattern of relatedness among populations was best explained by stochastic demographic processes, such as extinction-recolonization events or population bottlenecks.Thirdly, detailed taxonomic descriptions and illustrations of six new species, identified genetically and morphometrically among the populations included in the above analyses, were provided. These species were largely distinguished from each other, and the four original species, using a combination of setation, mouthpart, pleopod and uropod features. Lastly, phylogenetic relationships among all ten recognized Mesamphisopus species, and an additional unresolved group of populations, were examined. MtDNA data partitions and a recoded allele frequency matrix were analysed independently and in combination. Topologies indicated unrecognized species-diversity within an unresolved group of populations. Evolutionary relationships, the identification of six biogeographic centres, and the dating of divergences using a relaxed Bayesian clock suggested that differentiation and speciation within Mesamphisopus was largely allopatric or vicariant and driven by Mesozoic sea-level and climate change. Chance long distance dispersal events would, in turn, explain spurious phylogenetic relationships and distributions. This study contributes significantly to the understanding of the diversity and the conservation of the little-studied southern African freshwater invertebrates. Moreover, this study is the first to investigate genetic and morphometric differentiation, and phylogenetic relationships, below the generic level within the Phreatoicidea; thus establishing a methodological and theoretical framework for species delineation and the accurate determination of biodiversity within individual phreatoicidean genera. / AFRIKAANSE OPSOMMING: Isopoda van die suborder Phreatoicidea was histories in suidelike Afrika verteenwoordig deur vier spesies wat almal aan die endemiese genus Mesamphisopus behoort. Hierdie taksonomie is op ’n beperkte hoeveelheid versamelings gebaseer en die omvang van variasie tussen (en binne) bevolkings was swak verstaan. In die huidige studie is ekstensiewe versameling onderneem om die verspreiding, diversiteit asook biogeografie van dié Isopoda in Suid Afrika te bepaal. Analises van allosiem data en mitokondriale DNS volgorderbepalings (van die 12S rRNS en die proteïenkoderende COI geen) was gebruik om differensiasie tussen bevolkings te ondersoek, om (in kombinasie met morfometriese en morfologiese data) spesiesgrense te bepaal asook om die evolusionêre-verwantskappe tussen taksa te definieer. Benewens word bewaringseenhede binne die studie-bevolkings geïndentifiseer en moontlike bedreigings uitgelig. Eerstens is genetiese en morfometriese differensiasie tussen bevolkings, wat as M. capensis geïdentifiseer is, ondersoek. Versamelingslokaliteite was versprei oor twee bergagtige streke in die Weskaap wat geskei word deur ’n voormalige kusvlakte. Vyf morfometries- en geneties-afsonderlike spesies is geïdentifiseer. Dié taksa was geografies geskei tot die twee streke, wat elk as ’n Evolusionêre Beduidende Eenheid (ESU) gesien kan word. Differensiasie tussen populasies van die twee streke en vergelykbare patrone binne ander taksa word aan Cenosoïese seevlak veranderings toegeskryf. Tweedens is bevolkings wat as M. abbreviatus óf as M. depressus geïdentifiseer kan word ondersoek om te bepaal of hulle konspesifiek is. Bevolkings is oor ’n groot geografiese gebied versamel om intraspesifieke variasie in aanmerking te neem. Beperkte morfometriese verskille is waargeneem – enkel bevolkings was morfometries identies aan of die M. abbreviatus of die M. depressus sintipes. Genetiese getuienis vir die herkenning van ’n kriptiese spesieskompleks was dubbelsinnig. Bevolkings is gekenmerk deur merkbare genetiese differensiasie en die afwesigheid van geenvloei. Duidelike bewys van isolasie-metafstand was nie waargeneem nie en genetiese struktuur was nie verwant aan geografiese ligging of riviersisteme nie. Die mosaïese patroon van verwantskappe is moontlik teweeg gebring deur stogastiese demografiese prosesse soos uitsterwing en hervestiging of deur afnames in bevolkingsgrootte.Derdens is omvattende taksnomiese beskrywings en illustrasies van ses nuwe spesies wat deur bogenoemde analises geneties en morfometries uitgelig was, verskaf. Dié spesies is van mekaar, asook die ander vier spesies onderskeibaar deur ’n kombinasie van setasie-, monddeel-, pleiopoot- en uropooteienskappe. Laastens is die filogenetiese verwantskappe tussen al tien herkende Mesamphisopus-spesies en ’n groep bevolkings waarvan verhoudings onseker was, ondersoek. MtDNS datastelle en ’n hergekodeerde alleelfrekwensie matriks is afsonderlike en in kombinasie geanaliseer. Topologië het onherkende spesies-vlak diversiteit binne die bogenoemde groep bevolkings aangedui. Evolusionêre verwantskappe, die herkenning van ses biogeografiese gebiede, en die bepaling van tye van divergensie (d.m.v. ’n ontspanne Bayesiaanse molekulêre klok) het aangetoon dat spesiasie binne Mesamphisopus grootliks allopatries was en deur Mesosoïese seevlak- en klimaatsveranderings teweeg gebring is. Toevallige lang-aftstand verspreiding kon dan eienaardige filogenetiese verhoudings en verspreidings verklaar. Dié studie lewer ’n wesenlike bydrae tot die kennis van die diversiteit en tot die bewaring van die onbestudeerde Suid Afrikaanse varswater ongewerweldes. Daarenbowe, is hierdie studie die eerste om genetiese en morfometriese differensiasie benede die genusvlak binne die Phreatoicidea te ondersoek; sodoende word die metodologiese en teoretiese raamwerk vir die herkenning van spesies en die akkurate beskrywing van diversiteit binne afsonderlike genera van die Phreatoicidea geskep.

Dissertation (PhD)--University of Stellenbosch, 2006. / ENGLISH ABSTRACT: This multi-disciplinary study compiled taxonomic and biogeographical data to elucidate the extant diversity of lechwe antelopes (Kobus leche complex), and reconstruct their evolutionary history. Their diversification has been confined to wetlands across the south-central Africa plateaux. Lechwes are specialist grazers in water meadow floodplains; these stenotopic habitat requirements are invoked to explain why their evolution is atypical of terrestrial large mammals. Combined analyses of morphological (171 adult males), genetic (208 genotyped individuals) and palaeo-environmental datasets, revealed a recent (Middle Pleistocene) pulse of speciation in the K. leche complex. Multivariate morphometric analyses revealed the presence of five distinct groups that could be tied to the geography of the region. Furthermore, the genetic analyses supported the existence of at least four of these lineages, which show significant population separation at the level of the mtDNA control region. Most of the differences among populations were confined to frequency differences among populations and Bayesian analyses strongly suggest that the pattern obtained is the result of the retention of ancestral haplotypes with limited female geneflow among the extant populations. Evolution of the five lineages identified by the morphological and population genetic analyses were further investigated by making use of additional genetic data (mtDNA cyt b, SPTNB, SRY, Protamine 1, and b-Fibrinogen) and a subset of the samples. Topologies were largely unresolved due to the recent common ancestry of the lineages. Following the Evolutionary Species Concept, which was motivated by a philosophical review, five allopatric species could be recognized (anselli, kafuensis, leche, robertsi and smithemani). A model of drainage evolution compiled disparate facets of biological and geological evidence to detail interlinked histories of wetlands and their biota across the south-central Africa plateaux. This wetland archipelago is recognized as a distinct biogeographical unit in its own right - the Katanga-Chambeshi region. Evolutionary diversification of lechwes represents a dominant biogeographical signal reflecting how the aquatic biota have evolved in tandem with palaeo-drainage dynamics across this evolutionary theatre. Delimitation of key events in lechwe and drainage evolution was refined by archaeological dating of the Victoria Falls Formation, to decipher when the Zambezi river eroded the Batoka gorge. Demographic expansion in K. leche s.s (early Middle Pleistocene) corresponds to dessication of Palaeo-Lake Makakgadikgadi while more recent phylogeographic signals correspond to the tenure of Palaeo-Lake Bulozi. These speciation events in the Middle Pleistocene preceded peripatric speciation of K. kafuensis that accompanied the morphosis of the Kafue Flats (from palaeo-lake to floodplain), when the Kafue River attained its modern topology. The present study highlights that Lechwes represent a biota of evolutionary vibrant clades, rich in endemic species. As ecologically-dominant species in wetlands, lechwes deserve priority conservation attention, which is challenged to perpetuate evolutionary and ecological processes across an archipelago straddling five countries. / AFRIKAANSE OPSOMMING: Die multidisiplinêre studie bring saam taksonomiese en biogeografiese data om die evolusionêre geskiedenis en huidige diversitiet van basterwaterbokke (Kobus leche kompleks) te verklaar. Hulle diversifikasie is beperk to vleilande regoor die suid-sentraal Afrika plato. Basterwaterbokke is gespesialiseerde grasvreters in grasvloedvlaktes; hierdie stenotipiese habitatsvereiste word voorgehou om te verduidelik hoekom die evolusie van hierdie diere atipies is vir terrestriële groot soogdiere. Gekombineerde analise van morfologie (171 volwasse manlike diere), geneties (208 genotipes) en plaeo-omgewings datstelle toon aan dat daar ‘n onlangse (middel Pleistoseen) pols van spesiasie plaasgevind het in die K. lechwe kompleks. Multivariate morfometriese analyses het aangetoon dat vyf verskillende groepe diere bestaan wat ook sin gemaak het op grond van geografiese ligging. Verdermeer, die genetiese analise het die bestaan van ten minste vier van hierdie lyne geondersteun wat betekenisvolle bevolkings isolasie vertoon het op die vlak van die mtDNA kontrole gebied. Meeste van die verskille tussen bevolkings was beperk to frekwensieverkille tussen die bevolkings en Bayesian analise het sterk aanduidings getoon dat die patroon wat gekry is die gevolg was van die behoud van voorvaderlike haplotiepes met beperkte vroulike geenvloei tussen die huidige bevolkings. Evolusie van die vyf lyne wat deur die morfologie en bevolkingsgenetika studies geidentifiseer is was verder ondersoek deur gebruik te maak van addisionele genetiese data (mtDNA cytb, SPTBN, SRY, Protamien 1, en b-Fibrinogeen) en ‘n subset van die monsters. Topologieë was hoofsaaklik onopgelos as gevolg van die kort tyd tot die onlangse gemeenskaplike voorouer van lyne. Deur die Evolusionêre Spesies Konsep aan te hang, wat gemotiveer is deur ‘n filosofiese oorsig, is vyf allopatriese spesies herken (anselli, kafuensis, leche, robertsi and smithemani). ‘n Model wat dreinerings evolusie voorstel het verskeie fasette van biologiese en geologiese bewyse saamgvat om die verbindingsgeskiedenis van vleilande en hulle biota oor die suidsentraal Afrika plato te beskryf. Die vleiland argipelago word herken as ‘n onafhanklike biogeografiese eenheid in sy eie reg – die Katanga-Chambeshi streek. Evolusionêre diversifikasie van basterwaterbokke verteenwoordig ‘n dominante biogeografiese sein wat voortsel hoe die akwatiese biota ontwikkel het in tandem met die palaeo-dreinerings dinamika in hierdie evolusionêre konsert. Die afbakening van sleutelgebeure in basterwaterbok en dreinerigsevolusie is beter toegelig deur argeologiese datering wat gebasseer was op die vorming van die Victoria Valle om te bepaal waneer die Zambezi rivier die Batoka skeurgroef gevorm het. Demografiese uitbreiding binne K. leche s.s (gedurende die vroë Middel Pleistoseen) stem ooreen met die uitdroging van Palaeo-Meer Makakgadikgadi terwyl meer onlangse filogeografiese syne ooreenstem met die ontstaan van Palaeo-Meer Bulozi. Hierdie spesiasie gebeure in die Middel Pleistoseen het die peripatriese spesiasie van K. kafuensis voorafgegaan wat die morfose van die Kafue Vlaktes vergesel het (van palaeo-meer na vloedvlakte), toe die Kafue Rivier sy huidige vorm aangeneem het. Die huidige studie het uitgelig dat basterwaterbokke verteenwoordig ‘n biota van evolusionêre energieke eenhede, ryk aan endemiese spesies. As ‘n ekologiese dominante spesie in vleilande, moet basterwaterbokke as ‘n prioriteit gesien word in bewaring, waar dit dan die geleentheid sal hê om voort te bou op die evolusionêre en ekologiese prossese van die archipelago wat oor vyf lande strek.

Since becoming a pest in graminaceous crops in Africa, the African sugarcane stalkborer Eldana saccharina Walker has been the subject of much study. Its very cryptic habits have precluded more commonly available control measures being used against it. Biological control is regarded as a viable control option, but the apparent paucity of parasitoids in graminaceous crops leads to E. saccharina being regarded as lacking parasitoids, and thus not a good candidate for biological control in the classical sense. In contrast, this project argues that interactions in indigenous hosts of E. saccharina had been ignored, and that classical biocontrol principles and basic ecological theory could be applied by the discovery, collection and introduction of parasitoids from its indigenous habitat to its newly adapted habitat, sugarcane. The habitat offered by Cyperus papyrus L. was shown to be heterogenous both temporarily and spatially. Umbels, from young through mature to senescent, were available in the same proportion for colonisation throughout the year. Umbels with sexual reproductive stages (seeds) were present from early spring into late summer, and provided an additional component to the already heterogenous environment. Young umbels, in addition, developed from rhizomes in an environment regarded as sub-optimal for photosynthesis, until they reached the canopy. All stages of umbels were attacked by E. saccharina, but larvae were only found in rays of umbels and in the apex of the culm, which was the meristematic area for rays, both high nutrient areas. Young umbels were never found with borer pupae, only smaller larvae, indicating that E. saccharina development matched growth of young umbels until they reached canopy height. Also, the majority of borings found were occupied, indicating that infestation of young umbels was recent. All stages of E. saccharina development were found in mature umbels, which were also most abundant at anyone time. Numerous empty borings were found in addition to those occupied, indicative of past occupation by E. saccharina. Very few young larvae were found in old umbels, the majority of life stages found being pupae or empty pupal cases, and also many empty borings, showing that old umbels were not suitable for E. saccharina development. A guild of parasitoids which comprised Orgilus bifasciatus Turner, the most common parasitoid of small and smaller medium E. saccharina larvae, Goniozus indicus Ashmead the most common parasitoid of larger medium and large larvae, and an entomogenous fungus Seauveria bassiana (Sals.) Vuill. attacking all life stages of E. saccharina was found. Three uncommon parasitoids of smaller saccharina were also found, viz. Sassus sublevis (Granger), Iphiaulax sp. and Venturia sp. The former three natural enemies were instrumental in depressing a major outbreak within two months of it being observed and then maintaining the host population at a lower level in C. papyrus. G. indicus and B. bassiana were most effective during the summer and autumn months, and O. bifasciatus most effective during the winter months. This study supports the hypotheses that the apparent paucity of parasitoids and lack of biological control success thus far against E. saccharina in sugarcane has been because very little was known about its ecology and biology in its numerous indigenous host plants, and that studies of the latter factors coupled with ecological theory could enhance biological control programmes against this borer. As more indigenous host plants are investigated in the same way as has been done with C. papyrus, more will become known of natural enemies of E. saccharina. Parasitoid guilds could be selected, even from rare parasitoids in the more stable indigenous habitats, which would provide control in the unstable habitat of sugarcane. / Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 1994.

The three South African crane species, namely, the Wattled Crane (Bugeranus carunculatus), the Blue Crane (Anthropoides paradisea) and the Grey Crowned Crane (Balearica regulorum regulorum) are all threatened. South African legislation protects the cranes, however eggs and/or fledglings are sometimes illegally collected from the wild. These are then sold, often by registered breeders, who falsely claim them as the offspring of their captive breeding pair. DNA fingerprinting is one method to detect this crime. Fifteen RAPD primers were screened for polymorphism in the three species. Seven primers produced polymorphic profiles in the Blue Crane and eight each in the Grey Crowned Crane and Wattled Crane, with an average of 14.57, 12.38 and 5.88 scorable loci per primer, respectively. The Band Sharing Coefficient for unrelated individuals was found to be 0.665, 0.745 and 0.736 for the Blue, Grey Crowned and Wattled Crane respectively. Five microsatellite primers, originally developed for use in Whooping Cranes (Grus american), had previously been shown to be polymorphic in the Wattled Crane. This was also the case in this study with an average of 3.6 alleles per primer. Although all primers cross amplified, only a single primer each showed polymorphism in the Blue Crane (showing 6 alleles) and the Grey Crowned Crane (showing 5 alleles). The RAPDs were found to be irreproducible, show high numbers of novel bands and had parent: offspring BSC values that were not significantly higher than those of unrelated individuals. Statistics showed that, in the Blue Crane, the probability that misassigned parents would be detected was low whilst there was an almost certainty that true parents would be incorrectly excluded. The five microsatellite primers examined gave exclusionary powers of 0.869 and 0.641 where one or two parents were unknown in the Wattled Crane. The exclusionary powers for the Blue Crane and Grey Crowned Crane calculated at only one locus were much lower. It was concluded that RAPDs were totally inappropriate for parentage analyses, however, microsatellites are a suitable technique and recommendations are made that other microsatellites, developed for other species of crane, should be examined for their potential in this respect. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2004.

Animals in the Southern African sub-region are faced with unpredictable seasonal rainfall patterns and unpredictably low resource availability due to the influence of the El Nino Southern Oscillation System. This has led to conservative energetic traits in animals that offset the costs of maintaining homeostasis in the unpredictable environments they inhabit. One of these animals is the rock hyrax (Procavia capensis). Past research has looked at the thermoregulation of rock hyrax in the laboratory. Results indicated that rock hyrax had labile body temperatures that reached lethal levels at ambient temperatures above 39°C. Laboratory studies separate endogenous thermoregulation from behavioural thermoregulation and do not reflect the overall thermoregulatory potential of the rock hyrax in maintaining body temperatures. This study looked at the thermoregulation of rock hyrax in their natural environment. Body temperatures were measured in the field using Thermochron iButtons inserted into the intraperitonial cavity of the animals. Behavioural observations were also recorded on subgroups and individually marked animals. Rock hyraxes were exposed to large fluctuations in ambient temperatures and food availability during the course of this study. In winter, ambient temperatures ranged between 5-25°C and in summer between 18-42°C. Our results show that rock hyrax seasonally and daily altered both their physiological and behavioural thermoregulation to control body temperature efficiently. The physiological alterations observed in rock hyrax differed between winter and summer. During winter, when food availability was low, rock hyrax maintained body temperatures at a lowered level relative to summer. Body temperatures fluctuated to a greater extent during winter as a result of reduced body temperatures at night and increased body temperatures due to basking during the diurnal hours. During summer, rock hyrax displayed high body temperatures, which reached hyperthermic levels. This enabled rock hyrax to forage during midday hours since heat loads could be easily dissipated through passive conduction in the cooler rock crevices. Rock hyrax employed different behavioural patterns in winter and summer. It is proposed that rock hyraxes are unable to meet energetic demands on a low quality and patchy food resource under low ambient temperatures. Predation is also a cost to foraging and becomes increasingly important when rock hyraxes have to move large distances away from crevices to find food. The most frequent behaviour recorded in rock hyrax during winter was basking. Basking enabled rock hyrax to maintain body temperatures with very little thermoregulatory cost. Differences were also recorded in behavioural patterns in rock hyrax of different sizes. Juveniles, due to their small body size and high energetic demands foraged more frequently than adult rock hyrax. During summer, rock hyrax spent considerable time in the rock crevices. This was because ambient temperatures exceeded the upper limit of the thermoneutral zone of the rock hyrax throughout most of the day. Rock hyrax therefore escaped the excessive temperatures by utilizing the cooler rock crevices, which remained at temperatures within the rock hyraxes thermoneutral zone. The most frequent behaviour recorded in rock hyrax aboveground was foraging. Since forage was abundant around the rock crevices during summer, predation risk was less of a factor influencing foraging behaviour. Since basking is an essential component of the rock hyraxes thermal biology during winter we examined basking behaviour in more detail. Basking in the morning was not used to increase body temperatures from hypothermic levels as otherwise thought. Instead, it was used to maintain body temperatures at low ambient temperatures by altering posture, orientation to the sun and basking bout lengths. During the early morning, when heating rates were greatest, rock hyrax orientated their bodies exposing the greatest surface area to solar radiation. During midday, reduced basking bout lengths and the reduction of surface areas exposed to the sun reduced the heat loads during the hottest parts of the day. Rock hyrax appeared to utilize the warm rock surfaces during the late afternoon when the sun was setting to maintain body temperatures before entering the crevices for the night. The combination of physiological and behavioural thermoregulation therefore enables rock hyrax to maintain homeostasis with very little energetic costs in an environment that displays variability in both ambient temperatures and resource availability. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2003.

Metabolic rate (MR) and digestive duration are thermally dependant, and energy usage changes as body temperature (Tb) changes. Increased Tb during digestion causes a rapid increase in VO2 and a shorter postprandial metabolic response known as specific dynamic action (SDA). SDA is the additional energy expended above standard metabolic rate (SMR) to carry out functions associated with meal digestion and assimilation. SDA is affected by prey size, prey type and body mass (Mb). Liquid meals require less energy to digest and assimilate than intact prey items resulting in a lower metabolic scope and reduced postprandial metabolic response. Digestive efficiency and metabolism are also affected by the level of dietary specialization which can lead to increased digestive efficiency in terms of duration and energy used for digesting preferred prey items. Here, I investigated the effects of Mb, Tb and ontogeny on standard and digestive MR of two dietary specialists, Dasypeltis scabra and D. inornata. Dasypeltis scabra, found throughout South Africa, and D. inornata, endemic to the eastern parts of South Africa and western part of Swaziland, digest only the liquid contents of freshly laid bird eggs and should have a lower energy cost of digestion and assimilation than other snake species consuming intact prey containing bones, fur or chitinous carapace. To test the effect of changes in Tb on the metabolic response of Dasypeltis, pre- and postprandial metabolic responses of adult D. inornata and adult and neonate D. scabra were compared. SMR and SDA were quantified at five ambient temperatures 20, 25, 27, 30, 32°C using closed system respirometry. SMR was measured for 3 days twice a day at 08h00 and 20h00. Thereafter, snakes were fed a meal of chicken egg equivalent to 20% of Mb and oxygen uptake (VO2) was measured for an additional 5 days at 08h00 and 20h00, and then once a day at 08h00 for an additional 7 – 10 days. Increased Tb resulted in increases in metabolic response variables for all groups. Variation in Tb significantly affected SDA (kJ kg-1) of D. scabra adults and neonates and D. inornata adults. There were few significant interspecific and ontogenetic differences across all temperature trials. Within five days after meal consumption for all groups at 32°C, postprandial VO2 rates peaked at 3.16 - 3.73 times preprandial rates (scope), lower than most other snake species. The optimal digestion temperature appears to be around 32°C in terms of duration, but may be higher to optimize digestion. Across the range of temperatures (20 - 32°C) and masses (3.98 – 71.33g), the duration of significantly elevated VO2 was on average 1.5 - 2 days longer for D. scabra adults and neonates than D. inornata. Digestion duration ranged from 6.5 - 13.5 days for D. inornata and from 7.5 - 16.5 days for D. scabra adults and neonates. Digestive duration was longer for D. scabra than other snake species that consume meals of intact prey of similar size, at the same temperature. Dasypeltis species expended less total energy for digestion and used a smaller proportion of total energy consumed for digestion than other snake species at similar temperatures. Lower maintenance and digestive costs suggest that energy is conserved for allocation to other functions during periods of low prey availability. In addition, Dasypeltis species may rely on thermoregulation to capitalize on reduction in energy output and to increase energy savings between meals. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2009.

This thesis describes the behavioural ecology of South African fiscal shrikes through detailed field observations and experimental manipulations, and discusses these in the context of reproductive ecology, life history strategies, territoriality, and foraging theory. A population of fiscal shrikes was observed during the period October 1995-0ctober 1997 in a 336 Ha area of grazed bushveld near Pietermaritzburg, South Africa. Fiscal shrike reproduction coincided with the onset of the rainy season. Nests were placed in the centre or north-west regions of tree canopies and contained three or four eggs. Incubation and brooding were performed by females, and shading behaviour was observed in hot weather. Hatching and fledging success averaged 48%. High, exposed nests were less successful than other nests as they were prone to damage during inclement weather. There was a trend in life history strategies between equatorial and South African fiscal shrikes (an increase in clutch size, incubation and brooding durations, and territory size and a decrease in breeding season length), and between northern hemisphere Laniinae (increased intensity in the northern hemisphere), that could be explained by variability in precipitation and temperature, and clutch survival. Fiscal shrikes maintained individual or pair-held territories throughout the year using visual and vocal signalling. Territories averaged 2.2 Ha in area and almost all contained man-made structures. Territory size was inversely proportional to tall tree density, as trees were used for foraging. Fiscal shrikes resided in areas with few natural perch sites by utilising fence lines and overhead cables. When perch density was manipulated fiscal shrikes decreased and increased territory size accordingly. Fiscal shrikes were sit-and-wait foragers and primarily used perch-to-ground forays. The diet of breeding birds consisted of large invertebrates. Small items were consumed and larger items were cached or fed to offspring or females. Fiscal shrikes were central place foragers. Prey size increased in patches over 35 m from the nest. Perch height affected search area, which in turn affected foraging methods, search duration and subsequent movements. Perches may be the limiting resource for other sit-and-wait foragers and the manipulation of perch density could act as a conservation strategy for declining populations. / Thesis (M.Sc.)-University of Natal, Durban, 1998.

Populations of the humpback dolphin in Natal, South Africa, are subject to increasing pressures including capture in the shark nets and habitat degradation, and concern has been raised about the status of the population. A minimum of 95 humpback dolphins were caught in the shark nets during the period from 1980 to 1992. Capture and sighting records of the Natal Sharks Board revealed a relatively high occurrence of humpback dolphins at Richards Bay. Elsewhere, in southern Natal, the infrequent sightings and captures were attributed to a seasonal occurrence of dolphins, possibly due to temporary movements away from resident areas. Sighting rates reported by the Natal Sharks Board has decreased by 55%from 1984-86 to 1990-92 and may reflect a decrease in the population. In a photo-identification study, searches took place in ten search areas in Natal. The sighting rates in the different areas revealed a relatively high density of humpback dolphins occurring in north central Natal, from the Tugela River to the St. Lucia estuary (including Richards Bay). This distribution correlated significantly with the turbidity of the water and the width of the inshore continental shelf, and was inversely related to the density of bottlenose dolphins. Within the northern Tugela Bank region, higher densities of dolphins were found surrounding the five river mouths and estuaries. The Natal population was estimated to be between 161 to 166 animals (95% confidence limits 134 to 229). The annual mortality due to shark net captures approximates 4,5%of the population. Various evidence, including a high mortality rate and a decrease in the annual sighting per unit effort reported by the Natal Sharks Board suggest that the humpback dolphin population in Natal is vulnerable and may be decreasing in size. A proposal is made to reduce the capture rate by relocating shark nets away from the Richards Bay harbour. / Thesis (M.Sc.)-University of Natal, 1994.

The blue crane (Grus paradisea) is endemic to southern Africa and has the smallest geographical range of the 15 crane species occurring world-wide. Although this species is still found throughout most of its historic range, it has experienced a significant and rapid decline in numbers over the last 20 years. One factor causing this decline is the illegal removal of chicks from the wild. Permits are required to keep, trade in and breed cranes in captivity. However, birds must be captive bred in order to obtain a permit. Therefore, chicks taken illegally from the wild are fraudulently incorporated into an existing captive population under the pretence that they offspring of a legal captive pair. This study describes the development of a set of microsatellite markers to assist the identification of illegal trade in the blue crane. These markers can ultimately be used to verify the relationship between the offspring and its claimed parents by performing parentage analyses. Forty microsatellite loci were obtained from genomic libraries previously developed in two other crane species and tested for cross-species utility in the blue crane. In addition, 42 loci were developed for this study from a blue crane species-specific genomic microsatellite library, of which 19 were tested for polymorphism in this species. The microsatellite markers characterised here were also tested for their utility in two other crane species: wattled crane (G. carunculatus) and grey-crowned crane (Balearica regulorum). One locus, Gamu007, was found to be sex-linked and therefore excluded from the set of markers. A total of 28 polymorphic loci were tested for the suitability in parentage analysis in the blue crane. Of these, a set of 16 loci were determined to be as suitable for this purpose. These loci were shown to be inherited in a Mendelian fashion in a single blue crane family. In addition, statistical analysis of the loci were identified as exhibiting linkage equilibrium, this was supported by their distant association on a predicted Grus microsatellite map based on the chicken genome. The selected loci were also identified as having a low frequency of null alleles as well as a total first and second parent exclusion power of 0.9999 and 1.0000, respectively. These loci provide a valuable tool for parentage testing in blue crane, and may also be valuable in population genetic studies to assist conservation strategies. In addition, this set may be used to assist legal cases involving the illegal trade in blue cranes upon completion of additional microsatellite marker validation procedures. Twenty-seven loci were polymorphic in the wattled and grey-crowned crane. These could provide a valuable source of micro satellite loci in these species, and could potentially eliminate the need for the development of a species-specific microsatellite library. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2007.