A5086454918- Wildlife Ecology and Conservation
- Ecology and biodiversity studies
- Rangeland Management and Livestock Ecology
- Ecology and Vegetation Dynamics Studies
- Rangeland and Wildlife Management
- Animal Ecology and Behavior Studies
- Species Distribution and Climate Change
- Genetic and phenotypic traits in livestock
- Animal Behavior and Welfare Studies
- Archaeology and Natural History
- Human-Animal Interaction Studies
- Avian ecology and behavior
- Zoonotic diseases and public health
- Bat Biology and Ecology Studies
- Animal Disease Management and Epidemiology
- Fish Ecology and Management Studies
- Primate Behavior and Ecology
- Genetic diversity and population structure
- Plant Ecology and Soil Science
- Ruminant Nutrition and Digestive Physiology
- Pleistocene-Era Hominins and Archaeology
- Wildlife-Road Interactions and Conservation
- Soil and Water Nutrient Dynamics
- Amphibian and Reptile Biology
- Land Use and Ecosystem Services
University of the Witwatersrand
2014-2024
Council of Science Editors
2012
University of Arizona
2004-2009
California Department of Fish and Wildlife
2009
Arizona Game and Fish Department
2009
Cermaq (Canada)
2006
University of Alaska Fairbanks
2006
We studied habitat use by desert mule deer (Odocoileus hemionus eremicus) in the Sonoran Desert to understand relative importance of vegetation, terrain characteristics, human disturbances, and water sources determining their distribution. located 44 radiocollared female weekly over 5 years. In spring, when was most scarce, were areas with lower elevations, shallower slopes, greater normalized difference vegetation index (NDVI) rates, compared random locations. Use developments (i.e.,...
Abstract While African leopard populations are considered to be continuous as demonstrated by their high genetic variation, the southernmost population exists in Eastern and Western Cape, South Africa, where anthropogenic activities may affecting this population's structure. Little is known about elusive, last free‐roaming top predator region study first report on structuring using nuclear DNA . By analyzing 14 microsatellite markers from 40 tissue samples, we aimed understand populations'...
Inaccurate estimates of animal populations may lead to flawed management interventions, therefore, it is essential understand the status and population trend a species in order plan its efficiently. Aerial surveys are considered useful method for estimating size large conspicuous animals inhabiting areas, but raw count data from aerial usually underestimate sizes due imperfect detection. The use N-mixture models with provides tool estimate while taking detection probability into account. As...
Gray wolf (Canis lupus) predation is density dependent if the proportion of prey killed by wolves increases wit h density. The functional response 1 component that has important effect on whether density-dependent occurs, and consequently have potential to regulate a low-density equilibrium. Because alone may determine regulatory, researchers been attempting accurately describe for wolves. We used simulated datasets based typical variances found in wolf-moose (Alces alces) data evaluate...
We used long-term El Nino southern oscillation (ENSO), rainfall, and deer harvest records to investigate effects of ENSO rainfall on mule (Odocoileus hemionus) population trends in the Sonoran Desert, southeastern California, USA. found significant relationships between index (R 2 = 0.38, P≤0.001), annual 0.25, P ≤ 0.001). also that (i.e., an abundance) any year was related accumulations >5 years before hunting season 0.34), whereas change rate change) most immediately prior 0.15)....
Different ungulate species that co-occur over evolutionary time have been hypothesized to develop mechanisms limit the degree which they directly compete for same limited resources (i.e. resource partitioning). In situations where an exotic has recently introduced a system, partitioning not likely developed; this appears be situation between feral ass Equus asinus and indigenous mountain sheep Ovis canadensis in Sonoran Desert of southeastern California, USA. We analysed data from aerial...
Abstract The factors that affect resource selection by a foraging herbivore can vary according to the resources or conditions associated with particular levels of organization in environment, and scales over which perceives responds those conditions. To investigate role forage this hierarchical process, we studied mixed‐feeding large herbivore, impala ( Aepyceros melampus ). We focussed on three spatial scales: plant species, feeding station patch. In paired sites where were not observed,...
Nutritional ecology forms the interface between environmental variability and large herbivore behaviour, life history characteristics, population dynamics. Forage conditions in arid semi‐arid regions are driven by unpredictable spatial temporal patterns rainfall. Diet selection herbivores should be directed towards overcoming most pressing nutritional limitation (i.e. energy, protein [nitrogen, N], moisture) within constraints imposed forage conditions. We investigated influence of...
We investigated associations between rainfall and body condition of desert mule deer (Odocoileus hemionus eremicus) in the Sonoran Desert, California, using two indices based on fat: a categorical score subcutaneous fat visibility bones under skin free-ranging animals via remote photography, percent marrow long-bones harvested males. There were positive correlations proportion good (r = 0.60, P 0.064) fair 0.70, 0.017). Proportion poor was negatively correlated with −0.72, 0.020). evidence...
Carnivores that exhibit fission–fusion social organization can adapt group sizes to prevailing and ecological conditions. This study focuses on of African lions (Panthera leo) in the Okavango Delta, a seasonally flooded wetland. We used generalized estimating equations linear mixed models estimate effects flooding, as well prey availability intraspecific competition lions. During years high flood, total lion pride reproductive rates declined. Prides showed extensive overlap annual home...
Continued persistence of black rhinoceros (Diceros bicornis) will likely depend on the cooperation many reserves and application metapopulation models to manage across reserves. The suitability any reserve, however, depends factors that promote constrain occupancy. Constraining factors, particularly human disturbance, are concern in small because constraints have potentially greater effects, relative reserve size, than large We investigated landscape use by rhinos at Zululand Rhino Reserve....
We studied use of habitats and diets mule deer (Odocoileus hemionus) feral asses (Equus asinus) by comparing vegetation (i.e., normalized-difference-vegetation index, normalized-difference-vegetation-index rate), elevation, slope, distances to water-catchments, roads, rivers canals, washes used each species. Distribution was similar with respect catchments, canals in winter, index distance catchments spring, summer, slope autumn. Diets (from microhistological analysis feces) revealed...
The physiological condition of animals connects resources in the environment to demographic responses through reproduction, survival and abundance, it provides critical information for conservation management wildlife populations. We used archived data (early-wet season 1987, late-wet early-dry 1988) from culls impala (Aepyceros melampus) compare how kidney fat index (KFI, short-term body condition) carcass mass (long-term index) varied seasonally. For females, KFI increased across seasons,...
We used microhistological analysis of fecal pellets to identify plant species in diets desert mule deer (Odocoileus hemionus eremicus) southeastern California and investigate seasonal changes use forage classes. identified 34 taxa plants, 7 which have not been reported previously the deer. Browse were abundant during all seasons, but lowest spring, when forb most commonly observed. Use succulents generally was low, with highest occurring autumn (3 24%). Grasses composed ≤1% diet seasons. Our...
The addition of wildlife water developments (i.e., catchments) to arid areas may concentrate foraging by desert ungulates and decrease forage availability near catchments. We looked for gradients in biomass use mule deer (Odocoileus hemionus) bighorn sheep (Ovis canadensis) along dry riparian streams measured pellet group density transects following vegetation edges washes catchments control with >3 km away. Ungulate use, as reflected density, was greatest place years. There some evidence a...
We evaluated the relative importance of intrinsic (density-dependent) and extrinsic (density-independent) sources resource variability in dynamics bighorn sheep ( Ovis canadensis Shaw, 1804) populations southwestern USA. tested hypothesis that experiencing greater variation forage availability are less likely to be at equilibrium density with supplies, thus, would demonstrate weaker evidence intraspecific competition. used regression relate population growth rate rainfall (forage conditions)...
Our understanding of large‐scale climatic phenomena and dynamics large herbivore populations comes principally from research in northern regions with temperate, seasonal climate animal communities relatively low species diversity. To assess the generality that perspective, we investigated effects El Niño–Southern Oscillation (ENSO) on population African buffalo Syncerus caffer inhabiting a semi‐arid savanna variable rainfall. We used linear nonlinear‐threshold models to investigate...
Adult survival is a primary determinant of abundance and dynamics large herbivore populations. For species that are inconspicuous, however, accurate estimation depends on accommodating low detection probability. with individually recognizable markings, photographic capture–recapture (CR) provides an approach to estimate population parameters while accounting for imperfect detection. I investigated the use CR cryptic herbivore, nyala, in region Hluhluwe–iMfolozi Park, South Africa. conducted...