A5089780156- Wildlife Ecology and Conservation
- Fish Ecology and Management Studies
- Viral Infections and Vectors
- Environmental DNA in Biodiversity Studies
- Mosquito-borne diseases and control
- Parasite Biology and Host Interactions
- Vector-Borne Animal Diseases
- Aquatic Ecosystems and Biodiversity
- Data Analysis with R
- Animal Disease Management and Epidemiology
- Aquatic Ecosystems and Phytoplankton Dynamics
- Genetic and phenotypic traits in livestock
- Species Distribution and Climate Change
- Bat Biology and Ecology Studies
- Toxic Organic Pollutants Impact
- Aquaculture Nutrition and Growth
- Malaria Research and Control
- Turtle Biology and Conservation
- HIV Research and Treatment
- Avian ecology and behavior
- Identification and Quantification in Food
- Wildlife-Road Interactions and Conservation
- Vector-borne infectious diseases
- Zoonotic diseases and public health
- Fish Biology and Ecology Studies
University of Pretoria
2014-2024
South African National Parks
2013-2022
Scientific Services
2013-2022
Onderstepoort Veterinary Academic Hospital
2012-2022
Krüger (Germany)
2013
Kruger (Canada)
2013
Abstract Background Fine-scale data on animal position are increasingly enabling us to understand the details of movement ecology and dead-reckoning, a technique integrating motion sensor-derived information heading speed, can be used reconstruct fine-scale paths at sub-second resolution, irrespective environment. On its own however, dead-reckoning process is prone cumulative errors, so that estimates quickly become uncoupled from true location. Periodic ground-truthing with aligned location...
Anopheles arabiensis Patton is primarily responsible for malaria transmission in South Africa after successful suppression of other major vector species using indoor spraying residual insecticides. Control An. current insecticide based approaches proving difficult owing to the development resistance, and variable feeding resting behaviours. The use sterile insect technique as an area-wide integrated pest management system supplement control was proposed currently under investigation. success...
Nile crocodile ( Crocodilus niloticus ) mass mortality events in the Olifants River between Letaba confluence South Africa and Lake Massingir Mozambique have been attributed to pansteatitis: a disease that affects fat depots of animals. The is also found sharptooth catfish Clarias gariepinus same area, cause pollution. Although Valley polluted, impact interventions such as dam construction on biodiversity receives little attention. We show onset pansteatitis epidemic crocodiles at...
Abstract Background Assessing adult mosquito populations is an important component of disease surveillance programs and ecosystem health assessments. Inference from trapping datasets involves comparing across space time, but comparisons based on different methods may be biased if traps have efficiencies or sample subsets the community. Methods We compared four widely-used for data collection in Kruger National Park (KNP), South Africa: Centers Disease Control miniature light trap (CDC),...
Abstract Humans alter the environment at unprecedented rates through habitat destruction, nutrient pollution and application of agrochemicals. This has recently been proposed to act as a potentially significant driver pathogen-carrying mosquito species (disease vectors) that pose health risk humans livestock. Here, we use unique set locations along large geographical gradient show landscapes disturbed by variety anthropogenic stressors are consistently associated with vector-dominated...
Reflecting their species richness and ecological diversification, insects play a central role in terrestrial ecosystems but difficulties species-level assignments have restricted large-scale analysis of community structure. Employing South Africa's largest national park as model system, we demonstrate that DNA barcoding can break this barrier. A year-long deployment Malaise traps at 25 sites Kruger National Park (KNP) generated 1000+ weekly collections containing about 800,000 specimens....
White rhinoceroses (Ceratotherium simum) anesthetized with etorphine combinations develop severe pathophysiologic changes, including hypoventilation, hypoxemia and metabolic acidosis. The aim of this study was to evaluate the addition butorphanol immobilizing mixture on cardiopulmonary effects in free-ranging white darted from helicopter. In control group (n=15), were etorphine, azaperone, detomidine, hyaluronidase administered intramuscularly. treatment (n=16), 10-20 mg added combination....
Large numbers of adult Nile crocodiles, Crocodylus niloticus (Laurenti), died from pansteatitis during autumn and winter 2008 in the lower Letaba Olifants River gorge Kruger National Park, South Africa. Consequently, health status fish these waters was investigated. The study presents pathological findings inhabiting rivers within boundaries Park. Changes typical steatitis were diagnosed many larger specimens sharptooth catfish, Clarias gariepinus (Burchell), caught gorge. These carried...
Based on previous necropsy results, Microcystis blooms in constructed water impoundments the Kruger National Park (KNP) have been identified as a cause of wildlife mortality. In response to mortality during 2007, samples, containing algal bloom material, were collected February 2007 and July from four dams (Nhlanganzwani, Mpanamana, Makhohlola, Sunset) southeastern part KNP follow-up investigation. The toxicity was determined using enzyme-linked immunosorbent assay (ELISA), protein...
Over the past decade, several clustered, multispecies, wildlife mortality events occurred in vicinity of two man-made earthen dams southern and south central regions Kruger National Park, South Africa. On field investigation, heavy cyanobacterial blooms were visible these impoundments analysis water samples showed dominance Microcystis spp. (probably aeruginosa). Macroscopic lesions seen at necropsy histopathological compatible with a diagnosis intoxication. Laboratory toxicity tests assays...
Annual mortality events in Nile crocodiles (Crocodylus niloticus) the Olifants River Gorge Kruger National Park, South Africa, were experienced between 2008 and 2012, during which at least 216 died. Live lethargic. Necropsy examination of 56 affected showed dark yellow-brown firm nodules both somatic fat abdominal body. In all 11 submitted for histology, degenerative, necrotic, inflammatory changes supported a diagnosis steatitis types. Crocodiles are apex predators this anthropogenically...
Trichinella zimbabwensis has been found naturally infecting crocodiles (Crocodylus niloticus) in Zimbabwe, Mozambique, Ethiopia and South Africa, as well monitor lizards (Varanus Zimbabwe. The reports on natural infections were mostly accidental rather than structured surveys involved very few animals. Previous surveillance studies Africa reported a 38.5% prevalence of T. among wild tested from the Mpumalanga province Kruger National Park (KNP). No have conducted to date geographical...
The objectives of the study were to determine species composition ticks infesting white and black rhinoceroses in southern Africa as well conservation status those tick that prefer rhinos hosts. Ticks collected opportunistically from had been immobilised for management purposes, 447 (Ceratotherium simum) 164 (Diceros bicornis) sampled South Africa, 61 Namibia, 18 12 Zimbabwe, 24 Zambia. Nineteen recovered, which two species, Amblyomma rhinocerotis Dermacentor rhinocerinus, A. was only...
The Kruger National Park (KNP) is a savanna ecosystem situated in the middle reaches of five large, dynamic and biologically diverse transboundary river systems. KNP has been at forefront applied ecosystems research for over 30 years. Meanwhile each its rivers unique set challenges from both flow water quality management perspective. These have often arisen anthropogenic changes catchments park. resultant give rise to an array effects that bear upon parks’ ability maintain viability aquatic...
Abstract Background Understanding what animals do in time and space is important for a range of ecological questions, however accurate estimates how use challenging. Within the animal-attached tags, radio telemetry (including Global Positioning System, ‘GPS’) typically used to verify an animal’s location periodically. Straight lines are drawn between these ‘Verified Positions’ (‘VPs’) so interpolation space-use limited by temporal spatial resolution system’s measurement. As such, parameters...
The combined use of global positioning system (GPS) technology and motion sensors within the discipline movement ecology has increased over recent years. This is particularly case for instrumented wildlife, with many studies now opting to record parameters at high (infra-second) sampling frequencies. However, detail which GPS loggers can elucidate fine-scale depends on precision accuracy fixes, being affected by signal reception. We hypothesized that animal behaviour was main factor...
Abstract Pansteatitis has been identified in wild populations of sharptooth catfish, C larias gariepinus ( B urchell), and N ile crocodiles, rocodylus niloticus L aurenti, inhabiting the same waters O lifants R iver Gorge K ruger ational P ark, S outh A frica. Mesenteric pectoral fat tissue was investigated microscopically by fatty acid analysis healthy pansteatitis‐affected catfish from both captive populations. Variation composition between mesenteric noted. Composition differed fish...
Bacteria are essential components of natural environments. They contribute to ecosystem functioning through roles as mutualists and pathogens for larger species, key food webs nutrient cycles. Bacterial communities respond environmental disturbances, the tracking these across space time may serve indicators health in areas conservation concern. Recent advances DNA sequencing samples allow rapid culture-free characterization bacterial communities. Here we conduct first metabarcoding survey...
Mosquito population dynamics are driven by large-scale (e.g. climatological) and small-scale ecological) factors. While these factors known to independently influence mosquito populations, it remains uncertain how drivers that simultaneously operate under natural conditions interact populations. We, therefore, developed a well-controlled outdoor experiment assess the interactive effects of two ecological drivers, predation nutrient availability, on life history traits multiple temperature...