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Climatic and edaphic conditions at eragrostis lehmanniana nees sites in Arizona, USA and the cape province, RSA and potential seeding sites in Southern Africa
Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa • Authors: JerryR. Cox --- U.S. Department of Agriculture, USA J.L. Stroehlein --- Soil and Water Department, USA J.H. Fourie --- , Republic of South AfricaClimatic and edaphic conditions at Eragrostis lehmanniana Nees sites in southeastern Arizona, USA were compared with those in the Cape Province, RSA to determine a range of conditions under which the species might be expected to establish and persist in... -
Quantified range condition assessment of open Camelthorn savanna along a degradation gradient
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: I Zimmermanno FP Graz MH Berry NNT Imasiku ND Muroua MM Sibalatani CS SikopoMeasurements were taken at 20 different sites in a relatively homogenous area of open Camelthorn savanna in eastern Namibia. Ordination of grass species composition did not provide a good degradation gradient, due to domination by different species of annual grasses... -
Cattle diet selection during the hot-dry season in a semi-arid region of Namibia
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: MLJ Katjiua D WardThe northern Kalahari Desert is dominated by Terminalia sericea savanna woodland and a sparse herbaceous layer. Range ecologists regard T. sericea as a major encroaching species and that such encroachment represents a cost to cattle production. In contrast, pastoralists regard... -
Perspective article: Simulation models for semi‐arid rangelands of southern Africa
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: T. Wiegand --- Department of Ecological Modelling, Germany F. Jeltsch --- Department of Ecological Modelling, Germany S. Bauer --- Department of Ecological Modelling, Germany K. Kellner --- Department of Plant‐ and Soil Sciences, South AfricaIn semi‐arid regions, the effects of grazing or sparing management on natural communities of long‐lived plants generally take decades to become evident. Event‐driven dynamic behaviour, unpredictable and low rainfall, and complicated interactions between species make it difficult to gather sufficient... -
Modeling woody vegetation resources using Landsat TM imagery in northern Namibia
Item type: Journal Article • Journal: The Southern African Forestry Journal • Authors: Alex Verlinden Risto LaamanenIn 1995 a forest inventory covering northern Namibia was initiated, based on stratified systematic field sampling of plots with a radius of up to 30 m. In these plots detailed tree parameters were measured. Due to security problems the most... -
Seasonal nutrient fluctuation in selected plant species in the Kalahari
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: FH Stapelberg MW van Rooyen J du P BothmaSeasonal changes in crude protein, phosphorus and calcium contents of five common plant species in the south-western Kalahari were investigated. Three species that are browsed by springbok (Acacia erioloba, Grewia flava and Rhigozum trichotomum) and two grass species (Schmidtia kalahariensis... -
A test of five mechanisms of species coexistence between rodents in a southern African savanna
Item type: Journal Article • Journal: African Zoology • Authors: M.R. Perrin --- School of Biological and Conservation Sciences, University of KwaZulu-Natal, South Africa B.P. Kotler --- Blaustein Institute for Desert Research, Mitrani Department of Desert Ecology, IsraelThe operation of five different mechanisms of species coexistence in a community of rodents was examined in a semi-arid Kalahari savanna in southern Africa. The two most common species were Tatera leucogaster (bushveld gerbil) and Rhabdomys pumilio (striped mouse). The... -
Possible optimal foraging for Brants’s whistling rats by caracals in the Kgalagadi Transfrontier Park
Item type: Journal Article • Journal: African Zoology • Authors: H. I. A. S. Melville --- Centre for Wildlife Management, University of Pretoria, South Africa J. du P. Bothma --- Centre for Wildlife Management, University of Pretoria, South AfricaOptimal foraging in caracals has never been substantiated. However, several authors have found that these predators select foraging paths to minimize distances between areas of high prey availability. The foraging pattern used by a predator relative to a common prey... -
Activity patterns in southern Kalahari leopards
Item type: Journal Article • Journal: African Zoology • Authors: J. du P. Bothma --- University of Pretoria, South Africa M. D. Bothma --- Geowolf Environmental, South AfricaPreliminary results based on two satellite-tracked adult leopards in the arid, open savanna of the southern Kalahari indicated that most movement occurred at night, with some movement in the daytime to seek shade. -
Mammal and bird road mortalities on the Upington to Twee Rivieren main road in the southern Kalahari, South Africa
Item type: Journal Article • Journal: African Zoology • Authors: K. L. Bullock --- Department of Nature Conservation, South Africa G. Malan --- Department of Nature Conservation, South Africa M. D. Pretorius --- Department of Nature Conservation, South AfricaRoad ecology is becoming an increasingly important aspect of conservation biology. Carcasses lying on the road often confront visitors travelling to the Kgalagadi Transfrontier Park between Upington and the Twee Rivieren Rest Camp. This study investigated the species killed, the... -
Can behaviour buffer the impacts of climate change on an arid-zone bird?
Item type: Journal Article • Journal: Ostrich: Journal of African Ornithology • Authors: Susan J Cunningham --- Percy FitzPatrick Institute of African Ornithology, DST–NRF Centre of Excellence, South Africa Rowan O Martin --- Percy FitzPatrick Institute of African Ornithology, DST–NRF Centre of Excellence, South Africa Philip AR Hockey --- Percy FitzPatrick Institute of African Ornithology, DST–NRF Centre of Excellence, South AfricaBehavioural thermoregulation, particularly the use of cool microclimates, is one method by which organisms could avoid the worst effects of climate warming. However, retreat into cool microsites, e.g. shady vegetation or burrows, may carry important lost-opportunity costs. These could include... -
Elevated temperatures drive fine-scale patterns of habitat use in a savanna bird community
Item type: Journal Article • Journal: Ostrich: Journal of African Ornithology • Authors: Rowan O Martin --- Percy FitzPatrick Institute of African Ornithology, DST–NRF Centre of Excellence, South Africa Susan J Cunningham --- Percy FitzPatrick Institute of African Ornithology, DST–NRF Centre of Excellence, South Africa Philip AR Hockey --- ,Many animals use thermally buffered microhabitats, e.g. patches of shade within trees, to avoid temperature extremes. These ‘thermal refugia’ may mediate the impact of climate change on animals. Predicting how species and communities will respond to rising temperatures therefore requires... -
Ons is Boesmans: commentary on the naming of Bushmen in the southern Kalahari
Item type: Journal Article • Journal: Anthropology Southern Africa • Authors: William F. Ellis --- Centre for Humanities Research, South AfricaThis paper examines academic debates about the nomenclature of the San in light of recent ethnographic data. Academic debates centre around two aspects: the apparent complicity of the term “bushman” in construing the San as lower on the hierarchy of... -
Estimation of the lion (Panthera leo) population in the southwestern Kgalagadi Transfrontier Park using a capture–recapture survey
Item type: Journal Article • Journal: African Zoology • Authors: J.G. Castley --- Conservation Services, South African National Parks, South Africa M.H. Knight --- Conservation Services, South African National Parks, South Africa M.G.L. Mills --- Conservation Services, South African National Parks, Endangered Wildlife Trust, and Mammal Research Institute, University of Pretoria, South Africa C. Thouless --- Department of Wildlife and National Parks, BotswanaA previous estimate of the lion (Panthera leo) population in the southwestern Kgalagadi Transfrontier Park (KTP) was made over 20 years ago. This together with increased fears regarding the viability of the population as a result of recent killings of... -
Differences in resting metabolic rates of two southern African tortoises: Psammobates oculiferus and Geochelone pardalis
Item type: Journal Article • Journal: The Journal of the Herpetological Association of Africa • Authors: Michael Scantlebury --- University of Pretoria, South Africa Peter Minting --- Ayrshire Rivers Trust, UKEnergy metabolism varies considerably between different groups of endotherms, yet there is little or no reported variation among extant groups of reptiles. We measured lower resting metabolic rates (RMRs) in Kalahari tent tortoises (Psammobates oculiferus) than in sympatric Leopard tortoises... -
Huddling in the heat? Rarely seen thermoregulatory behaviours as Southern Pied Babblers Turdoides bicolor compete for cool microsites
Item type: Journal Article • Journal: Ostrich: Journal of African Ornithology • Authors: Amanda R Bourne --- University of Cape Town, South Africa Camilla Soravia --- The University of Western Australia, AustraliaHuddling is an important thermoregulatory behaviour used by many group-living endotherms to conserve energy during cold weather or periods of food scarcity. It is not typically considered a strategy for keeping cool during hot weather, largely because endotherms produce body... -
Highly variable breeding phenology in an arid region colonial cooperative breeder, the Sociable Weaver Philetairus socius
Item type: Journal Article • Journal: Ostrich: Journal of African Ornithology • Authors: Pietro B D’Amelio --- Université Paris-Saclay and Centre National de la Recherche Scientifique (CNRS), Institut des Neurosciences Paris-Saclay, France Nicolas J Silva --- , France Liliana R Silva --- University of Porto, Portugal André C Ferreira --- University of Zurich, Switzerland Franck Theron --- University of Porto, Portugal Claire Doutrelant --- , France Rita Covas --- University of Porto, PortugalDescribing breeding phenology (the timings of reproductive events) is central for studying individual fitness and population dynamics. While fundamental differences in breeding strategies between different biomes (e.g. tropics and temperate regions) have long been identified, detailed descriptions based on long-term...