Catalogue Search | MBRL
Are you sure you want to remove the book from the shelf?
{{itemTitle}}
147
result(s) for
"Kalahari Desert."
Sort by:
The Kalahari Desert
This colorful book describes the geological makeup and history of the Kalahari Desert in Africa.
Book
Life Histories of the Dobe !Kung
Life Histories of the Dobe !Kung re-examines an important anthropological data set for the Dobe !Kung, the well-known \"Bushmen\" of the Kalahari Desert, collected by Nancy Howell and colleagues. Using life history analysis, Howell reinterprets this rich material to address the question of how these hunter-gatherers maintain their notably good health from childhood through old age in the Kalahari's harsh environment. She divides the population into life history stages that correlate with estimated chronological ages and demonstrates how and why they survive, even thrive, on a modest allotment of calories. She describes how surplus food is produced and distributed, and she considers both the motives for the generous sharing she has observed among the Dobe !Kung and some evolutionary implications of that behavior.
eBook
Green lands for white men : desert dystopias and the environmental origins of apartheid
\"A compelling and timely history, Green Lands for White Men explores how white farmers in southern Africa grappled with arid environments and climate change as they sought to consolidate white dominance over the Black majority. In the early twentieth century, white southern Africans engaged in bitter disputes over the reality of climate change and its consequences. Many whites argued that rainfall was declining and that if they did not do something about it, the subcontinent would become a desert and white civilization in the region would collapse. The believers in climate apocalypse found their savior in Ernest Schwarz, a geology professor who promised that diverting rivers into the Kalahari would restore southern Africa's once-rainy climate, creating newly greened lands for the settlement of millions of whites and securing the future of a \"white man's country\" in Africa. Green Lands for White Men uses the story of this popular (though fortunately unrealized) attempt to engineer southern Africa's climate and racial order to examine the agrarian roots of apartheid in the mid-twentieth century. We live in a time of growing climate catastrophe, public mistrust of scientific experts, and emboldened white nationalism. In this book we witness this on another continent and in another century and see how these apparently unrelated factors came together to reinforce a worldview that proved highly resistant to argumentation and challenge by scientists\"-- Provided by publisher.
BOOK
Adaptive thermoregulation during summer in two populations of an arid-zone passerine
Heterothermy plays an important role in lowering the costs of thermoregulation in endotherms by reducing water and energy requirements. We tested predictions that birds in arid habitats should express fine-scale variation in their thermoregulatory patterns as a function of prevailing climatic conditions. We assessed the effects of air temperature (Tair) and water vapor pressure deficit (D) on body temperature (Tb) in free-living white-browed sparrow-weavers (Plocepasser mahali) during summer in two arid habitats in the Kalahari Desert, South Africa, using data from a dry period at a hot, desert site (n = 7), and a dry (n = 4) and a wet period (n = 5) at a milder, semi-desert site. The desert birds maintained a significantly (p < 0.001) higher set-point Tb (41.5 ± 0.2 °C) than semi-desert birds (40.2 ± 0.2 °C). During the warmest part of day (12:00 - 18:00 hours), Tb increased significantly during periods of high Tair and/or high humidity, and mean and maximum Tb were up to 1.4 and 2.3 °C, respectively, above normal levels. However, as Tair increased, birds at the desert site maintained Tb at or below set-point levels for a greater proportion of the time than birds at the semi-desert site. Birds at the desert site also expressed a greater magnitude of daily heterothermy (mean Heterothermy Index, HI = 2.4 ± 0.3 °C) than birds at the semi-desert site: the latter population showed a greater magnitude of heterothermy during a dry period (HI = 2.1 ± 0.3 °C) than during a wet period (HI = 1.6 ± 0.2 °C). Birds continued foraging throughout the warmest part of the day, despite the fact that heat dissipation (% time spent panting and wing-spreading) increased significantly with increasing Tair. Our findings reveal that populations can vary in their thermoregulatory responses in both space and time, and suggest that small changes in Tair can have significant effects on thermoregulation in free-ranging desert birds, even when Tair < Tb. These data have important implications for assessing vulnerability of species to climate change, suggesting that sensitivity should be assessed at the population, rather than species level.
Journal Article
The costs of keeping cool : behavioural trade-offs between foraging and thermoregulation are associated with significant mass losses in an arid-zone bird
Avian responses to high environmental temperatures include retreating to cooler microsites and/or increasing rates of evaporative heat dissipation via panting, both of which may affect foraging success. We hypothesized that behavioural trade-offs constrain the maintenance of avian body condition in hot environments, and tested predictions arising from this hypothesis for male Southern Yellow-billed Hornbills (Tockus leucomelas) breeding in the Kalahari Desert. Operative temperatures experienced by the hornbills varied by up to 13 °C among four microsite categories used by foraging males. Lower prey capture rates while panting and reductions associated with the occupancy of off-ground microsites, resulted in sharp declines in foraging efficiency during hot weather. Consequently, male body mass (M
b) gain between sunrise and sunset decreased with increasing daily maximum air temperature (T
max), from ~ 5% when T
max < 25 °C to zero when T
max = 38.4 °C. Overnight M
b loss averaged ~ 4.5% irrespective of T
max, creating a situation where nett 24-h M
b loss approached 5% on extremely hot days. These findings support the notion that temperature is a major determinant of body condition for arid-zone birds. Moreover, the strong temperature dependence of foraging success and body condition among male hornbills provisioning nests raises the possibility that male behavioural trade-offs translate into equally strong effects of hot weather on female condition and nest success. Our results also reveal how rapid anthropogenic climate change is likely to substantially decrease the probability of arid-zone birds like hornbills being able to successfully provision nests while maintaining their own condition.
Journal Article
High temperatures are associated with substantial reductions in breeding success and offspring quality in an arid-zone bird
During hot weather, terrestrial animals often seek shaded thermal refugia. However, this can result in missed foraging opportunities, loss of body condition and impaired parental care. We investigated whether such costs could compromise breeding success in a widespread southern African bird: the Southern Yellow-Billed Hornbill Tockus leucomelas. We predicted that hornbills might be especially vulnerable to temperature-dependant reductions in parents’foraging capacity due to extreme asymmetry in sex-specific roles during breeding: females are confined within the nest cavity for most of the nesting period and the burden of provisioning falls solely on the male during this time. We followed 50 hornbill nesting attempts in the Kalahari Desert between 2012 and 2015, collecting data on provisioning rates, adult and nestling body mass, fledging success and size of fledglings. Mean daily maximum air temperatures (Tmax) during nesting attempts ranged from 33.2 to 39.1 °C. The likelihood of successful fledging fell below 50% at mean Tmax > 35.1 °C; a threshold now regularly exceeded at our study site due to recent climate warming. Additionally, offspring fledging following the hottest nesting attempts were > 50% lighter than those fledging following the coolest. Sublethal costs of keeping cool including loss of body condition, production of poor-quality offspring and breeding failure are likely to become issues of serious conservation concern as climate change progresses; even for currently widespread species. Missed-opportunity costs associated with behavioral thermoregulation and direct sublethal costs of temperature exposure should not be overlooked as a potential threat to populations, especially in environments that are already hot.
Journal Article
Innovative Homo sapiens behaviours 105,000 years ago in a wetter Kalahari
The archaeological record of Africa provides the earliest evidence for the emergence of the complex symbolic and technological behaviours that characterize
Homo sapiens
1
–
7
. The coastal setting of many archaeological sites of the Late Pleistocene epoch, and the abundant shellfish remains recovered from them, has led to a dominant narrative in which modern human origins in southern Africa are intrinsically tied to the coast and marine resources
8
–
12
, and behavioural innovations in the interior lag behind. However, stratified Late Pleistocene sites with good preservation and robust chronologies are rare in the interior of southern Africa, and the coastal hypothesis therefore remains untested. Here we show that early human innovations that are similar to those dated to around 105 thousand years ago (ka) in coastal southern Africa existed at around the same time among humans who lived over 600 km inland. We report evidence for the intentional collection of non-utilitarian objects (calcite crystals) and ostrich eggshell from excavations of a stratified rockshelter deposit in the southern Kalahari Basin, which we date by optically stimulated luminescence to around 105 ka. Uranium–thorium dating of relict tufa deposits indicates sporadic periods of substantial volumes of fresh, flowing water; the oldest of these episodes is dated to between 110 and 100 ka and is coeval with the archaeological deposit. Our results suggest that behavioural innovations among humans in the interior of southern Africa did not lag behind those of populations near the coast, and that these innovations may have developed within a wet savannah environment. Models that tie the emergence of behavioural innovations to the exploitation of coastal resources by our species may therefore require revision.
Human populations in the southern Africa interior were collecting non-utilitarian objects at around 105,000 years ago, suggesting that the development of this innovative behaviour did not depend on exploiting coastal resources.
Journal Article
Post-2000 greening of Kalahari Desert and southern African grasslands reduces food and economic insecurity in Africa
The Kalahari high-pressure system that forms the Kalahari and Namib Deserts of Southern Africa is maintained by the sinking motion of the Hadley circulation. Despite projected desertification under the climate change, beginning in the early 21st century the Kalahari Desert and grasslands of South Africa, Lesotho–Drakensberg highland and Eswatini has experienced a trend of greening/Savannisation. Here, we find that the disparity is likely due to strong multidecadal variability. A positive phase of the Atlantic multidecadal oscillation during this period has intensified the Hadley circulation and widened the Kalahari anticyclone, thereby facilitating moisture transport from the warm Angola–Benguela front to southern African landmasses. The advected moisture brought wetness at its periphery, which satisfied the water demand for cropland expansion (∼10%–15%) in southern Africa. A water-food-economy nexus is increasing Africa’s crop yields by approximately 25%, reducing food and economic insecurity through a nearly fourfold increase in agricultural exports and contributing approximately 26% to the continent’s total agricultural output. However, in the opposite phase of multidecadal variability, the superposition of greenhouse warming would exacerbate the drying trend that will amplify aridity.
Journal Article
13,000 years of sociocultural plant use in the Atacama Desert of northern Chile
Throughout Earth’s most extreme environments, such as the Kalahari Desert or the Arctic, hunter–gatherers found ingenious ways to obtain proteins and sugars provided by plants for dietary requirements. In the hyperarid Atacama Desert, wild plant resources are scarce and unevenly distributed due to limited water availability. This study brings together all available archaeobotanical evidence gathered in the Atacama Desert from the Late Pleistocene (ca. 13,000 cal bp) until the Inka epoch (ca. 450 cal bp) to help us comprehend when these populations acquired and managed useful plants from the coastal zone, Intermediate Depression, High Andes, as well as tropical and subtropical ecosystems. Widespread introduction of farming crops, water control techniques and cultivation of diverse plants by 3,000 cal bp ended not only a chronic food shortage, but also led to the establishment of a set of staple foods for the Atacama Desert dwellers, a legacy that remains visible today. By contrasting these trends with major sociocultural changes, together with palaeodemographic and climatic fluctuations, we note that humans adapted to, and transformed this hyperarid landscape and oscillating climate, with plants being a key factor in their success. This long-term process, which we term the “Green Revolution”, coincided with an exponential increase in the number of social groups inhabiting the Atacama Desert during the Late Holocene.
Journal Article
Participatory Indicator Development: What Can Ecologists and Local Communities Learn from Each Other
Given the growing popularity of indicators among policy-makers to measure progress toward conservation and sustainability goals, there is an urgent need to develop indicators that can be used accurately by both specialists and nonspecialists, drawing from the knowledge possessed by each group. This paper uses a case study from the Kalahari, Botswana to show how participatory and ecological methods can be combined to develop robust indicators that are accessible to a range of users to monitor and enhance the sustainability of land management. First, potential environmental sustainability indicators were elicited from pastoralists in three study sites. This knowledge was then evaluated by pastoralists, before being tested empirically using ecological and soil-based techniques. Despite the wealth of local knowledge about indicators, this knowledge was thinly spread. The knowledge was more holistic than published indicator lists for monitoring rangelands, encompassing vegetation, soil, livestock, wild animal, and socioeconomic indicators. Pastoralist preferences for vegetation and livestock indicators match recent shifts in ecological theory suggesting that livestock populations reach equilibrium with key forage resources in semiarid environments. Although most indicators suggested by pastoralists were validated through empirical work (e.g., decreased grass cover and soil organic matter content, and increased abundance of Acacia mellifera and thatching grass), they were not always sufficiently accurate or reliable for objective degradation assessment, showing that local knowledge cannot be accepted unquestioningly. We suggest that, by combining participatory and ecological approaches, it is possible to derive more accurate and relevant indicators than either approach could achieve alone.
Journal Article