A5005749266- Wildlife Ecology and Conservation
- Animal Behavior and Welfare Studies
- Rangeland Management and Livestock Ecology
- Ecology and Vegetation Dynamics Studies
- Human-Animal Interaction Studies
- Rangeland and Wildlife Management
- Effects of Environmental Stressors on Livestock
- Genetic and phenotypic traits in livestock
- Animal Ecology and Behavior Studies
- Geographies of human-animal interactions
- Plant Taxonomy and Phylogenetics
- Ruminant Nutrition and Digestive Physiology
- Ecology and biodiversity studies
- Wildlife-Road Interactions and Conservation
- Economic and Environmental Valuation
- Animal Disease Management and Epidemiology
- Ecosystem dynamics and resilience
- Conservation, Biodiversity, and Resource Management
- Plant Reproductive Biology
- Meat and Animal Product Quality
- Plant and animal studies
- Agriculture and Rural Development Research
- Reproductive Physiology in Livestock
University of Pretoria
2015-2020
African Wildlife Foundation
2018
Wageningen University & Research
2009-2015
1. Understanding and accurately predicting the spatial patterns of habitat use by organisms is important for ecological research, biodiversity conservation ecosystem management. However, this understanding complicated effects scale, because scale analysis affects quantification species–environment relationships. 2. We therefore assessed influence environmental context (i.e. characteristics landscape surrounding a site), varied over large range scales ambit radii around focal sites), on...
Predation risk from lions (Panthera leo) has been linked to habitat characteristics and availability traits of prey. We separated the effects vegetation density presence drinking water by analyzing locations lion kills in relation rivers with dense vegetation, which offer good stalking opportunities, artificial points low density. The spatial distribution was studied at Klaserie Private Nature Reserve, South Africa. distance between 215 nearest source analyzed using generalized linear...
1. Elucidation of the mechanism determining spatial scale patch selection by herbivores has been complicated way in which resource availability at a specific is measured and vigilance behaviour themselves. To reduce these complications, we studied an animal with negligible predation risk, African elephant. 2. We introduce concept nutrient load as product size, number patches local concentration. Nutrient provides novel spatially explicit expression total available nutrients herbivore can...
Elephant and impala as intermediate feeders, having a mixed diet of grass browse, respond to seasonal fluctuations forage quality by changing their composition. We tested the hypotheses that (1) decrease in is accompanied change from more monocots wet season dicots dry pronounced faster than elephant; (2) mopane (Colophospermum mopane), most abundant dicot species, important species elephant woodland, whereas feed relatively less on due high condensed tannin concentration; (3) nutrient-rich...
Abstract Eco‐tourism and human–wildlife interaction can lead to increases in stress, vigilance aggression many species, however, studies investigating wildlife viewing are scarce. We present the first study impact of tourism on African elephant, Loxodonta africana, behaviour. Over 15 months, we studied effect monthly tourist pressure (tourist numbers) occurrence stress‐related, conspecific‐directed aggressive behaviour 26 individually identified elephants up three vehicles direction travel...
Abstract ContextWildlife tourism has been shown to increase stress in a variety of species and can negatively affect survival, reproduction, welfare, behaviour individuals. In African elephants, Loxodonta africana, increased physiological linked use refugia, rapid movement through corridors, heightened aggression towards humans. However, we are unaware any studies assessing the impact pressure (tourist numbers) on elephants. AimsWe used faecal glucocorticoid metabolite (fGCM) concentrations...
Multiple factors determine diet selection of herbivores. However, in many studies single nutrients is studied or optimization models are developed using only one currency. In this paper, we use linear programming to explain by African elephant based on plant availability and nutrient deterrent content over time. Our results indicate that at our study area maximized intake phosphorus throughout the year, possibly response deficiency region. After adjusting model incorporate effects...
Abstract We investigated whether mass and morphological spatial patterns in plants possibly induced the development of enlarged soft mouth parts especially megaherbivores. used power functions geometric principles to explore allometric relationships both foraging characteristics mammalian herbivores South African savannah, covering a body size range more than three orders magnitude. Our results show that, although intradental volume scaled slightly less one mass, actual bite volume, as...
Background: Faecal hormone metabolite measurement is a widely used tool for monitoring reproductive function and response to stressors in wildlife. Despite many advantages of this technique, the delay between defaecation, sample collection processing may influence steroid concentrations, as faecal bacterial enzymes can alter composition post-defaecation.Objectives: This study investigated changes glucocorticoid (fGCM), androgen (fAM) progestagen (fPM) concentrations faeces male female...
Abstract Conservation biologists can use hormone measurements to assess animals’ welfare, reproductive state, susceptibility stressors, as well energy expenditure. Quantifying concentrations from faecal samples is particularly advantageous be collected without disturbing behaviour. In order for an endocrine marker useful wildlife managers, we need understand how extrinsic and intrinsic factors affect in free-ranging animal populations. Thyroid hormones are linked basal metabolic rate...
Abstract With an increase in poaching of elephants Loxodonta africana across Africa, it is vital to know exactly how many remain and where they occur, ensure that protection management are planned appropriately. From a nationwide survey we provide current population distribution data for South Africa. We consider the viability elephant populations country, as well some techniques implemented effective these controlling numbers. According our surveys there were 28,168 Africa December 2015,...
Background: Faecal hormone metabolite measurement is a widely used tool for monitoring reproductive function and response to stressors in wildlife. Despite many advantages of this technique, the delay between defaecation, sample collection processing may influence steroid concentrations, as faecal bacterial enzymes can alter composition post-defaecation.Objectives: This study investigated changes glucocorticoid (fGCM), androgen (fAM) progestagen (fPM) concentrations faeces male female...
The scale of resource heterogeneity may influence how resources are locally partitioned between co-existing large and small organisms such as trees grasses in savannas. Scale-related plant responses may, turn, herbivore use the vegetation. To examine these scale-dependent bi-trophic interactions, we varied fertilizer [(nitrogen (N)/phosphorus (P)/potassium (K)] applications to patches create different scales nutrient patchiness (patch size 2 × m, 10 or whole-plot 50 m) a field experiment...
There is increasing evidence of compromised welfare for elephants managed in captivity. Should such facilities eventually close, more will need to be rehabilitated and reintegrated into the wild. The goal reintegration would restore any physical or psychological aspects elephant that may have been captivity, followed by introduction a free-roaming system where they can interact with other elephants. However, achieve this goal, methods implemented assessed ensure remains priority. objective...
South Africa has many fenced reserves harbouring small to medium sized populations of African elephant (Loxodonta africana), most which have been translocated. Elephants on may be exposed various management interventions and practices (translocation, hunting, darting, high tourism impact, contraception programs, disruption due infrastructure maintenance, etc.). These factors impact the welfare elephants. Poor serious consequences such as increased inter- intra-species aggression that could...
Management interventions are necessary to control elephant numbers within fenced wildlife reserves in South Africa. Use of non-lethal methods is increasing, but information about their suitability and effects not widely available. Three such currently available: immunocontraception with porcine zona pellucida vaccine, vasectomy gonadotropin-releasing hormone vaccine. Here we consolidate what know these methods, using published sources material shared at a workshop held Africa 2016, order...