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Item Lions in the Kgalagadi Transfrontier Park: Modelling the effect of human-caused mortality.(Blackwell Publishing Ltd., 2004-01-15) Van Vuuren, Jan H.; Herrmann, Eric; Funston, Paul J.An age-structured demographic matrix model is developed to determine the long-term viability of the Southern African Kgalagadi Transfrontier Park lion (Panthera leo) population that is subjected to persecution along the park boundaries. In doing so, maximum sustainable persecution rates are established, so that efficient conservation measures may be taken, if required, to ensure the continued survival of the species in the park. Sensitivity analyses indicate that adult female survival ability alone is the most important component of the model in terms of long-term population survival. Furthermore, these analyses show that the boundary prides of the park are able to increase their chances of survival and are able to sustain significantly higher human-caused mortality rates by inducing birth-sex ratio biases in favour of females. The model suggests that the persecution rate experienced by the study population over the period 1998–2001 cannot be sustained in the long term, provided that there is no immigration of adult females into the population from the park interior. To ensure the survival of existing park boundary prides, adult lionesses should, as far as possible, be afforded protection from persecution, so that park boundary populations do not merely serve as population sinks for lions from elsewhere or become extinct.Item Helicopter-based censusing of domestic dogs in Gauteng Province, South Africa.(South African Veterinary Association, 2000-09-01) Reilly, B.K.; Van der Vyver, F.Decision support in veterinary epidemiology often depends on density estimates of domestic animals. These estimates are usually based on ground surveys of various types. Ground surveys are difficult to undertake in the informal housing settlements that are frequently encountered in developing countries. In addition, they are time-consuming and expensive. In this study, field experience in enumerating wildlife from helicopters was used to count domestic animals in Gauteng Province, South Africa. Data for domestic dogs are analysed for precision and accuracy and the technique evaluated in terms of its value for decision support.Item The nature and extent of wildlife ranching in Gauteng province, South Africa.(Southern African Wildlife Management Association (SAWMA), 2003-10-01) Reilly, B.K.; Sutherland, E.A.; Harley, V.A survey of the nature and extent of wildlife ranching in the province of Gauteng was conducted during 2001. The survey was an empirical investigation of game-fenced properties. These included provincial nature reserves and privately owned wildlife ranches or nature reserves as well as game-fenced properties owned by the South African National Defence Force (SANDF), and mining companies in Gauteng. Questionnaires were completed for 89 properties. This represents more than 90% of game fenced properties larger than 50 ha in the province. The properties covered a total of 115 913 hectares. This is 6.8% of the province’s surface area. There is a concentration of wildlife ranches in the northern part of the province, which accounts for 70% of the game-fenced properties surveyed. Data were also collected on consumptive and non-consumptive wildlife utilization. Information on wildlife species and numbers are also presented. Wildlife ranching contributes to a limited extent to the economy of the province and, unlike most other provinces, it seems as if ecotourism rather than hunting is the primary revenue earner for the majority of Gauteng ranches. Of concern is the discrepancy between official perceptions and the facts on the ground concerning wildlife ranching in the province.Item Land-use and socio-spatial organization of female leopards in a semi-arid wooded savanna, Botswana.(Southern African Wildlife Management Association (SAWMA), 2009-10-13) Steyn, V.; Funston, P.J.Leopards (Panthera pardus) are the most widespread large felid, yet comparatively little is known about their fine-scale movement patterns and how these affect the risks they face. There has been much debate on the conservation status and management needs for leopards with much extrapolation from limited data. In order to gather more information on leopard movements in Botswana’s Northern Tuli Game Reserve, seven leopards were collared between February 2005 and August 2006. This allowed key aspects that affect demography, and thus resilience to anthropogenic effects, to be investigated. Generally, home ranges were typical for breeding females in woodland savanna (32.9 ± 7.3 km²) with substantial overlap (average 26.0%). Core areas though were independent and extremely small (1.9 ± 2.2 km²). These were used primarily for young cub rearing and were characterized by rugged terrain along riverbeds. This highly localized use places leopards at potential risk of snaring as snares tend to be concentrated along these landscape features. Furthermore, hunters can conceal blinds from which to shoot leopards more easily in these areas. Further risk to adult female survival came from excursions outside the reserve boundary during which livestock was predated. Three incidences of cannibalism by adult territorial males on adult females are also reported, suggesting significant intra-specific competition.Item Clinical demodicosis in African buffalo (Syncerus caffer) in the Kruger National Park.(Wildlife Disease Association, 2009-04-01) Wolhuter, Julie; Bengis, Roy G.; Reilly, Brian K.; Cross, Paul C.We investigated the relationship between prevalence and severity of clinical signs of Demodex cafferi infection in free-ranging African buffalo (Syncerus caffer) and other factors such as age, sex, pregnancy status, and concomitant infections with bovine tuberculosis (BTB), Rift Valley fever (RVF), and brucellosis (BA). Approximately half of 203 buffalo examined in this study had clinical signs of demodicosis (cutaneous nodules); younger age classes had the highest prevalence and severity of lesions (χ2=21.4, df=6, P=0.0015). Nodules were generally limited to the head and neck region, but in severe cases were present over the entire animal. We found no significant association between clinical severity of the Demodex infection and gender, pregnancy status, or infection with BTB, RVF, or BA.Item The plant communities of the Andover Game Reserve, South Africa.(AOSIS Publishing, 2008-05-21) Cronje, Heath P.; Panagos, Mike D.; Reilly, Brian K.Floristic characteristics of the Andover Game Reserve (AGR) were surveyed using an area-based survey technique and classified according to the data recorded from 88 relevés, using the PHYTOTAB-PC software package. Three plant communities, of which two each contain two variants, were described and mapped. The plant communities and their causative environmental factors were validated through detrended- and canonical correspondence multivariate analyses. The plant communities of the AGR were found to typify the floristics associated with the catenal sequences located in undulating areas on granite. Broad-leaved savanna is located at the crest and upper mid-slopes while fine-leaved savanna occurs along the foot slopes of the AGR. Seep lines, a characteristic occurrence along catenas, are found at the transitional zone between the upper broad- and lower fine-leaved savanna plant communities. This study forms the basis for the compilation of a revised ecological management plan for the Andover Game Reserve.Item Precision of helicopter-based total-area counts of large ungulates in bushveld(AOSIS, 2002-12-14) Reilly, B.K.Precision in helicopter total-area counts in bushveld for a range of common species are evaluated. Counts were conducted on properties ranging in size from 250 ha to 10 000 ha as part of experiments on precision and power. Counts were conducted in three vegetation types: mopane veld, sourish mixed bushveld and arid bushveld. Scant regard is given to precision as a factor in large herbivore monitoring, with more effort often devoted to accuracy. Coefficients of variation varied from 3.2 % to 70.9 %. Median values are generally acceptable for the establishment of trends for long-term monitoring but might be inadequate for annual population size monitoring and evaluation. A regression of all species and vegetation types by the standard error showed a significant correlation. Similar regressions were also developed for impala, kudu, warthog, and zebra. Regressions by vegetation type for mopane veld, sourish mixed bushveld, and northwest arid bushveld were also significant. However, the high correlation for some vegetation types might be an artifact of the small sample sizes.Item The phytosociology of the Villiers - Grootvlei area, South Africa: The plant communities of the Ea land type.(Elsevier, 1992-05-15) Breytenbach, P.J.J.; Myburgh, W.J.; Theron, G.K.; Bredenkamp, G.J.The vegetation of the Ea Land Type in the Villiers - Grootvlei area was classified by means of Braun-Blanquet procedures. A total of 77 releves in the land type were used. On the high-lying areas two major plant communities were encountered, one of which was divided into two sub-communities. On the low-lying areas five major plant communities were recorded, one of which was divided into five sub-communities and another into two sub-communities. A DECORANA ordination confirmed that the communities are related to specific environmental conditions.Item The phytosociology of the Villiers - Grootvlei area, South Africa: The plant communities of the Ba Land Type.(Elsevier, 1992-05-15) Breytenbach, P.J.J.; Myburgh, W.J.; Theron, G.K.; Bredenkamp, G.J.The vegetation of the Ba Land Type is classified by means of TWINSPAN and refined by the Braun-Blanquet method, in nine plant communities. One of the communities is divided into two SUb-communities. The plant communities were related to specific environmental conditions that were confirmed by the ordination (DECORANA) of the data.Item Differences in the dietary habits of verreaux’s eagles aquila verreauxii between peri-urban and rural populations.(Cambridge University Press (CUP), 2020-01-04) Padayachee, Kailen; Malan, Gerard; Lubcker, Nico; Woodborne, Stephan; Hall, GrantDifferences in the diets of urban and rural avian predators could indicate potential niche vulnerability in a particular habitat. This study compares the core-isotopic niche areas and diet disparity of a declining peri-urban Verreaux’s Eagle Aquila verreauxii population with a stable rural population in South Africa. In addition to stable isotope analyses, the diet of the peri-urban Verreaux’s Eagles was investigated using camera trap footage of prey delivered during the nesting season. Dominant prey consisted of species with a mixed diet of plants with a C3 and/or C4 photosynthetic pathway (browsers and grazers). Rock hyrax Procavia capensis contributed 60%of the total diet composition, scrub hare Lepus saxatilis 26% and Helmeted Guineafowl Numida meleagris 22%. The coreisotopic niche area for each population was calculated using bulk carbon (13C) and nitrogen (15N) stable isotope values chronological measured along the length of 18 feathers from 21 nests. The isotopic niche of the rural eagle population revealed that they consume prey from multiple trophic levels with a C3-plant-dominated prey base (browsers), likely including small carnivores. In contrast the isotopic niche of the peri-urban Verreaux’s Eagles correlated with the mixed mammalian and avian food-niche determined from camera trapping, confirming that the peri-urban population mainly hunted three abundant species that are all narrowly associated with modified human habitats. The decline in the Magaliesberg Verreaux’s Eagle population is, therefore, unlikely to be due to constraints in their dietary niche, as raptors benefit from the diversity and abundance of human-commensal prey associated with the peri-urban habitats.Item Fine-scale habitat requirements of the Heidelberg Opal butterfly (Chrysoritis aureus) in Gauteng and Mpumalanga, South Africa.(South African National Biodversity Institute (SANBI), 2017-09-11) Deysel, Rouxdene; Myburgh, Willem J.; Panagos, Mike D.Background: This study quantified the fine-scale habitat requirements of Chrysoritis aureus, at 11 known habitats in Gauteng and Mpumalanga, South Africa, in order to make habitat management recommendations for this endangered species. Objectives: The habitats were quantified in terms of plant species composition and structure with reference to their environmental characteristics. Method: A modified area-based phytosociological approach was used to collect floristic data along with environmental characteristics of habitats occurring on the Witwatersrand and Ventersdorp Geological Systems. Results: Species recorded were predominantly forbs and graminoids with a slightly higher number of plant species in the habitats of the Ventersdorp Geological System. Few dwarf shrubs and shrubs and very few trees were recorded. A higher number of plant species were recorded during the late growing season on both geological systems. The butterfly food plant Clutia pulchella var. pulchella L. (Euphorbiaceae) was recorded in all the habitats and was dominant in habitats in both geological systems. The occurrence of the food plant is essential for the survival of the butterfly at these habitats. Conclusion: Monitoring of the C. aureus butterfly populations and of the vegetation structure, species composition and growth forms to determine trends in the vegetation condition after planned fires; regular burning of the habitats in order to maintain suitable vegetation composition and structure; and the monitoring and eradication of alien invader plants are very important management activities to ensure the conservation of C. aureus.Item The phytosociology of the Villiers - Grootvlei area, South Africa: The plant communities of the Ib land type.(Elsevier, 2017-01-27) Breytenbach, P.J.J.; Myburgh, W.J.; Theron, G.K.; Bredenkamp, G.J.The vegetation of the Ib Land Type in the Villiers - Grootvlei area was classified by means of the Braun Blanquet method. A total of 41 releves in this land type were used. Six main plant communities were identified, with one of the communities divided into two sub-communities. The plant communities were related to specific environmental conditions that were confirmed by the ordination (DECORANA) of the data.Item Identifying potential protected areas in the Grassland Biome of South Africa.(Academy of Science of South Africa (Commercial Publishers), 2020-08-17) Prinsloo, Helen; Reilly, Brain; Myburgh, WillemSouth Africa is considered to be one of the most biologically diverse countries in the world. The conversion, degradation, and fragmentation of natural habitats have caused a loss of biodiversity in many areas. Grasslands have been widely recognised as important for both biodiversity and economic development. Many conservation efforts have in the past been theory driven, without actionable, feasible results. We hypothesised that correct implementation of the available data will indicate where conservation efforts should be focused to move closer to achieving targets for biodiversity conservation in the Grassland Biome in South Africa. We identified an area (near Heilbron and Petrus Steyn in the Free State) that is representative of the biodiversity in the region and is suitable for modern conservation efforts in the ‘real world’. This approach provides a practical look at conservation in the modern era and a feasible result for conservation efforts. Significance: • An area in the Free State Province was identified that has a high level of biodiversity representative of the Grassland Biome in South Africa. A subjective process was implemented to ensure that the area represents the factors that are considered important for conservation, land use and appropriate location in order to make the area a feasible target for conservation. The result therefore represents not only a theoretical finding that is based on data analysis, but also a practical approach to ensure that the findings can be implemented. This study is an effort to provide a baseline for a more modern approach to conservation, in which current land use, economic value and conservation value are all considered to achieve a sustainable result in terms of the conservation of biodiversity.Item Macro channel riparian vegetation of the Olifants River System in the Savanna Biome, Mpumalanga.(Aosis, 2004-12-18) Myburgh, W.J.; Bredenkamp, G.J.The vegetation associated with the macro channel of the Olifants River System was investigated to identify plant communities mappable at a spatial scale of 1:250 000. The results obtained by applying the PHYTOTAB PC classification and mapping program package revealed nine distinct plant communities associated with that section of the river system that flows through the Savanna Biome.Item The distribution and extent of declared weeds and invader plants in the macro channel of the Olifants river system, Mpumalanga.(AOSIS Publishing, 2005-06-30) Myburgh, W.J.; Bredenkamp, G.J.The vegetation associated with the macro channel of the Olifants River System was investigated to distinguish plant communities at a spatial scale of 1:250 000. The floristic data were analysed in terms of the sectional and longitudinal distribution and extent of declared weeds and invaders recorded during the survey. The results gained using the PHYTOTAB PC-classification and mapping program package revealed eight Grassland Biome and nine Savanna Biome plant communities from it's origin near the town of Breyten up to the border of the Kruger National Park. It was found that different invader species/weeds are associated with different biomes and habitats along the river system and that an alarming number of these species occur throughout the system.Item Pleistocene large reptile tracks and probable swim traces on South Africa’s Cape south coast.(Academy of Science of South Africa [Commercial Publisher], 2019-11-08) Helm, Charles W.; Cawthra, Hayley C.; Combrink, Xander; Helm, Carina J.Z.; Rust, Renée; Stear, Willo; Van den Heever, AlexThe Cape south coast of South Africa contains a wealth of Pleistocene vertebrate trace fossil sites in aeolianites and cemented foreshore deposits. Published studies have described mammal and avian tracksites identified along this coastline. We report here on a number of Pleistocene palaeosurfaces within the Garden Route National Park that exhibit tracks of large reptiles, including probable swim traces. The tracks were probably made by more than one species, and may include a crocodylian. There are no extant reptiles in this coastal region capable of making such tracks and traces, which probably represent an indication of a previously more extensive range for the Nile crocodile and a monitor lizard. These findings demonstrate the potential for ichnology to complement the traditional body fossil record. Two Middle Stone Age stone artifacts were found embedded in one palaeosurface containing multiple reptile trackways. These discoveries have implications for the understanding of Pleistocene palaeoenvironment and palaeoclimate - in an area which is important in the study of modern human origins. SIGNIFICANCE: • Large reptile Pleistocene fossil tracksites have recently been discovered on the Cape south coast of South Africa where there are no previous such records, and no reptiles of this size are currently found in the region. • These sites include the first reported probable reptile swim traces in Africa and one tracksite also contained two Middle Stone Age artifacts. • These discoveries have implications for Pleistocene environments and climate on the Cape south coast.Item The population status of the endangered endemic plant Aloe peglerae: Area of occupancy, population structure, and past population trends.(Elsevier, 2014-04-24) Phama, J.O.; Panagos, M.D.; Myburgh, W.J.; Pfab, M.F.Aloe peglerae Schönland is a rare succulent plant species, which is endemic to South Africa. The species is currently listed as Endangered and is threatened mainly by illegal collection. The aim of this study was to determine the population status of Aloe peglerae in the Magaliesberg Mountain Range, that is, whether the population is declining, stable or increasing. Key population parameters assessed for this study included plant density, population structure, area of occupancy, population size, and rate of past population decline. Nine subpopulations were surveyed in 2009 and 2010 using a distance sampling technique. Also, these data were compared to data collected in 1999 by the Gauteng Department of Agriculture, Conservation and Environment, so as to determine possible population trends. The results showed a decline of 43% in mean population density between 1999 and 2010, suggesting that the population of Aloe peglerae in the Magaliesberg is in a state of decline. The application of this technique to plant populations is relatively novel and key recommendations are provided to improve survey design.Item A comparison of three dry matter forage production methods used in South Africa.(Hans Publishers, 2014-04-11) Joubert, A. J.; Myburgh, W. J.A common method for determining forage production of rangelands is by clipping and weighing forage from quadrats with redetermined areas. This technique is however time consuming. Other techniques which require less time and labour include amongst others using the disk pasture meter or phytomass derived from the vegetation classification program PHYTOTAB, in conjunction with the Plant Number Scale, which is used to determine vegetation canopy cover. The phytomass determined using PHYTOTAB/Plant Number Scale and the disk pasture meter was compared to the phytomass obtained from the actual clipping and weighing of forage. Tests showed that there were indeed statistically significant differences between the mean phytomass values of the three techniques. Considerable variation was shown in the results of the disk pasture meter readings compared to the other two techniques. The phytomass values obtained using the disk pasture meter were significantly higher than the phytomass determined using both the PHYTOTAB/Plant Number Scale and the clipping and weighing techniques. Results further indicated a significant similarity in the phytomass determined using the PHYTOTAB/Plant Number Scale and the clipping and weighing technique. The results of this pilot study need further investigation.Item Macro-channel riparian vegetation of the Olifants river system in the Grassland biome, Mpumalanga.(Aosis, 2004-12-18) Myburgh, W.J.; Bredenkamp, G.J.The vegetation associated with the macro-channel of the Olifants River System was investigated to identify plant communities mappable at a spatial scale of 1:250 000. The results obtained by using the PHYTOTAB PC-classification and mapping program package, revealed eight distinct plant communities associated with the macro-channel of this river system that occurs within the Grassland Biome.Item Organochlorine pesticide bioaccumulation in wild Nile crocodile (Crocodylus niloticus) fat tissues: Environmental influences on changing residue levels and contaminant profiles.(Elsevier, 2020-09-27) Humphries, Marc S.; Myburgh, Jan G.; Campbell, Robert; Buah-Kwofie, Archibold; Combrink, XanderBiologically significant concentrations of organochlorine pesticides (OCPs) continue to be reported in wildlife populations and are of particular concern in species that occupy the highest trophic levels. Nile crocodiles (Crocodylus niloticus) are important apex predators occurring throughout much of tropical and subtropical sub-Saharan Africa, where they inhabit estuarine and freshwater habitats often impacted by contamination. In this study we examined pesticide residue accumulation in fat tissue from Nile crocodiles at Lake St Lucia, South Africa, where historically large quantities of OCPs have been used for agriculture and disease control. During 2019, we collected tail fat samples from wild (n = 21) and captive (n = 3) individuals to examine the influence of habitat, body size and sex on variations in bioaccumulation. The principal contaminant found was p,p′-DDE, a major persistent metabolite of DDT, which continues to be used in the region for combating malaria. Tissue p,p′-DDE concentrations in wild crocodiles (95–1200 ng g−1 ww) were significantly (p < 0.05) higher compared to captive individuals (23–68 ng g−1 ww) and strongly correlated (R2 > 0.70) to body length. Male (n = 14) and female (n = 7) wild crocodiles exhibited similar contaminant body burdens, however, total concentrations were substantially lower than those measured in the same population during 2016/2017. Marked differences in residue levels and profiles appear to reflect changes in food availability and dietary exposure associated with a shift in environmental conditions. These findings suggest that periods of environmental stress may be associated with enhanced toxicological risk in crocodiles. Additional work is needed to better understand contaminant accumulation and elimination mechanisms in crocodiles, and their potential effects on reproductive health.