A taphonomic study of seal remains from archaeological sites on the Western Cape coast

Bibliography: leaves 238-259.A method of interpreting the seal body part representation from archaeological sites is presented and applied to three Holocene archaeological assemblages from the west coast of South Africa. The approach that is developed integrates several different methods that have previously been applied to terrestrial species, but that, with few exceptions, have not be.en employed in the analysis of seal remains. Most of the existing taphonomic indices cannot be applied to seals because of their unique physiology. Appropriate field observations and laboratory measurements are used to construct taphonomic indices that can be widely applied to seal bone assemblages. These include: a hardness index that mediates bone destruction through mechanical attrition, a utility index that mediates differential transport of body elements, and two indices that mediate the impact of carnivore ravaging - the carcass consumption sequence, and the carnivore destructive template. A new approach that caters for the simultaneous application of several taphonomic indices to an assemblage, where previously they have been applied individually or in pairs, is developed. In addition to the taphonomic indices, a method of determining ontogenic age is presented, and the potential limits of seal storage are explored

New AMS dates for the Middle Iron Age in the Mapungubwe landscape

Research in the Limpopo Valley has documented over 500 Middle Iron Age sites (AD 900–1320) relevant to the origins of Mapungubwe – the capital of the first indigenous state in southern Africa. Fifteen new accelerator mass spectrometry (AMS) dates from 11 of these archaeological sites establish the boundaries of the ceramic facies that form the culture-history framework for such diverse topics as land use, ethnic stratification, population dynamics and rainfall fluctuations. Mapungubwe was abandoned at about AD 1320.Significance: Because Mapungubwe developed relatively recently (circa AD 1200), it can clarify the origins of older states. Environmental factors such as droughts, along with agriculture and trade, played a role in the abandonment of Mapungubwe

Synergy between climate and human land-use maintained open vegetation in southwest Madagascar over the last millennium

Madagascar experienced environmental change during the Late-Holocene, and the relative importance of climatic and anthropogenic drivers is still the subject of an ongoing debate. Using palaeoecological records from the southwest region at Lake Longiza, we provide additional records to elucidate the complex history of the island and to identify the changes that occurred in the tropical dry forest during the Late-Holocene. The data showed vegetation changes associated with climate variability until AD 900 as reflected by the variation in grass, dry-adapted taxa, deciduous trees, and isotope records. An increasing effect of human activities was recorded, indicated by increased coprophilous spore concentration, as a result of a shift from foraging to pastoralism leading to further opening of the ecosystem from AD 980. At the same time, the regional palaeoclimate record showed drier conditions from around AD 1000, which could have accentuated the changes in vegetation structure. More open vegetation was likely maintained by increased use of fire and herbivory around the area, as indicated by the multiple peaks in the charcoal and spore records. Since AD 1900, the pollen record from the southwest region showed that the ecosystem became increasingly open with an increased abundance of grass, pioneer taxa, and reduced diversity, which was linked to a simultaneous effect of climate and agropastoralism activities. Our study suggests that the dry conditions around AD 950 initiated the replacement of forest-dominant vegetation with grass-dominant communities over the last millennium, depicted as an open ecosystem at present. Subsequent changes in subsistence activities would have further maintained an open-structured ecosystem.university of cape town https://doi.org/10.13039/501100007112The University Research Committee accredited (URC)southern african science service centre for climate change and adaptive land management https://doi.org/10.13039/501100011013neurosciences research foundation https://doi.org/10.13039/100007431African Origins PlatformPeer Reviewe

Modelling water temperature in the lower Olifants River and the implications for climate change

Freshwater systems in southern Africa are under threat of climate change, not only from altered flow regimes as rainfall patterns change, but also from biologically significant increases in water temperature. Statistical models can predict water temperatures from air temperatures, and air temperatures may rise by up to 7 °C by 2100. Statistical water temperature models require less data input than physical models, which is particularly useful in data deficient regions. We validated a statistical water temperature model in the lower Olifants River, South Africa, and verified its spatial applicability in the upper Klaserie River. Monthly and daily temporal scale calibrations and validations were conducted. The results show that simulated water temperatures in all cases closely mimicked those of the observed data for both temporal resolutions and across sites (NSE>0.75 for the Olifants River and NSE>0.8 for the Klaserie). Overall, the model performed better at a monthly than a daily scale, while generally underestimating from the observed (indicated by negative percentage bias values). The statistical models can be used to predict water temperature variance using air temperature and this use can have implications for future climate projections and the effects climate change will have on aquatic species. Significance:• Statistical modelling can be used to simulate water temperature variance from observed air temperature, which has implications for future projections and climate change scenarios.• While there are many other factors affecting water temperature, air temperature accounts for up to 95% of water temperature variance.• The model used can successfully simulate water temperature variance for different rivers

Past environmental proxies from the Middle Stone Age at Sibudu, Kwazulu-Natal, South Africa

Middle Stone Age technological and behavioural developments in southern Africa are central to understanding the emergence of modern humans, and elucidating the role of environmental change in this trajectory is dependent on emerging palaeoclimatic reconstructions. Climate proxies from Middle Stone Age sites are often poorly preserved, coarsely resolved or subject to anthropogenic selection and are not considered in favour of global environmental proxies despite the fact that the modern climate regimes at the relevant archaeological sites differ profoundly. Sibudu has a well-preserved Middle Stone Age sequence that has yielded abundant palaeoclimate proxy data. Isotopic analysis of charcoal, charcoal anatomy and species representation, macro- and micro-faunal remains, sediment texture, mineralogy and magnetic susceptibility, pollen and macrobotanical remains provide evidence for the environmental succession specific to this site. The isotopic data suggest that archaeological charcoal was not significantly post-depositionally altered. During the Howiesons Poort (65–62 ka) the local environment was thickly forested, moist and more humid than during the 58 ka occupations. The environment changes during the post-Howiesons Poort occupation (~58 ka) into the late MSA occupation (~48 ka); conditions became drier and colder than present with vegetation shifting to open savanna grassland or woodlands.Les évolutions technologiques et comportementales du Middle Stone Age dans le sud de l’Afrique sont essentielles pour comprendre l’émergence de l’Homme moderne, et la compréhension du rôle des changements environnementaux dans cette trajectoire dépend des reconstitutions paléo-climatiques émergentes. Les données indirectes liées au climat du MSA sont souvent mal conservées, de résolution grossière ou soumis à une sélection d’origine anthropique et sont abandonnées au profit des données indirectes liées aux conditions environnementales globales, en dépit du fait que les régimes climatiques modernes sur les sites archéologiques étudiés diffèrent profondément. Sibudu a une séquence bien conservée du Middle Stone Age qui a fournit d’abondantes données paléoclimatiques indirectes. L’analyse isotopique de charbons de bois, l’anatomie du charbon de bois et la représentation des espèces, des restes de faunes macroscopiques et microscopiques, la texture des sédiments, la minéralogie et la susceptibilité magnétique, le pollen et les restes macrobotaniques fournissent des indices de l’évolution de l’environnement spécifique à ce site. Au cours de la période Howiesons Poort (65–62 ka), l’environnement local est couvert de forêts épaisses et humide, plus humide encore lors des occupations de 58 ka. L’environnement change au cours de l’occupation post-Howiesons Poort (~ 58 ka) jusqu’a la fin de l’occupation MSA (~ 48 ka) : il devient plus sec et plus froid qu’à présent et la végétation se mue en grande savane herbeuse ou boisée.Palaeo-Anthropological Scientific Trust (PAST), the National Research Foundation (NRF), the Council for Scientific and Industrial Research (CSIR) and the University of the Witwatersrand.http://www.african-archaeology.dehb201

Radiocarbon investigation of a superlative grandidier baobab, the big reniala of Isosa

The article discloses the accelerator mass spectrometry (AMS) radiocarbon dating results of the Big Reniala of Isosa, which is a massive Grandidier baobab (Adansonia grandidieri Baill.) of Madagascar. The investigation of this baobab shows that it consists of 5 perfectly fused stems and exhibits a cluster structure. The calculated wood volume of the tree is 540 m 3 , which makes the Big Reniala of Isosa the largest individual of all Adansonia species and also the biggest known angiosperm in terms of volume. Several samples were collected from the outer part of the stems. The oldest dated sample had a radiocarbon date of 934 ± 24 BP, which corresponds to a calibrated age of 845 ± 25 years. This value indicates an age of 1000 ± 100 years for the big Reniala of Isosa

A 1000-year carbon isotope rainfall proxy record from South African baobab trees (Adansonia digitata L.)

A proxy rainfall record for northeastern South Africa based on carbon isotope analysis of four baobab ( Adansonia digitata L.) trees shows centennial and decadal scale variability over the last 1,000 years. The record is in good agreement with a 200-year tree ring record from Zimbabwe, and it indicates the existence of a rainfall dipole between the summer and winter rainfall areas of South Africa. The wettest period was c. AD 1075 in the Medieval Warm Period, and the driest periods were c. AD 1635, c. AD 1695 and c. AD1805 during the Little Ice Age. Decadal-scale variability suggests that the rainfall forcing mechanisms are a complex interaction between proximal and distal factors. Periods of higher rainfall are significantly associated with lower sea-surface temperatures in the Agulhas Current core region and a negative Dipole Moment Index in the Indian Ocean. The correlation between rainfall and the El Niño/Southern Oscillation Index is non-static. Wetter conditions are associated with predominantly El Niño conditions over most of the record, but since about AD 1970 this relationship inverted and wet conditions are currently associated with la Nina conditions. The effect of both proximal and distal oceanic influences are insufficient to explain the rainfall regime shift between the Medieval Warm Period and the Little Ice Age, and the evidence suggests that this was the result of a northward shift of the subtropical westerlies rather than a southward shift of the Intertropical Convergence Zone

Final radiocarbon investigation of Platland tree, the biggest African baobab

Author Posting. © Studia Chemia, 2017. This article is posted here by permission of Studia Chemia for personal use, not for redistribution. The definitive version was published in Studia Universitatis Babes-Bolyai, Seria Chemia 62, no. 2, Tom 2 (2017): 347-354, doi:10.24193/subbchem.2017.2.27.The article discloses the main results of our new investigation of Platland tree, a.k.a. Sunland baobab, the largest known African baobab. Our recent research was motivated by the three successive splits of 2016 and 2017, which determined the collapse and demise of the stems that have built the main unit of the tree. According to our new findings concerning the architecture of large and old baobabs, we established that Platland tree has a double closed-ring shaped structure and consists of two units/rings that close two separate false cavities. The larger unit was composed of five fused stems, out of which four toppled and died, while the fifth stem is already broken. The smaller unit, which is still standing, consists of three fused stems. We also determined that the larger unit had an age of 800 yr, while the smaller unit is 1100 yr old.The research was funded by the Romanian Ministry of Scientific Research CNCS-UEFISCDI under grant PN-II-ID-PCE-2013-76

Nutritional significance of a winter-flowering succulent for opportunistic avian nectarivores

The winter-flowering succulent Aloe marlothii provides nectar for many opportunistic avian nectarivores in southern African savannas. We assessed the importance of A. marlothii nectar sugar for opportunistic nectarivores by analysing temporal changes in stable carbon isotope ratios (d13C) in the tissues of birds in Suikerbosrand Nature Reserve, South Africa. The blood of the 11 most common non-granivorous opportunistic nectarivores at our site was enriched in 13C by 3.4 ± 1.5& during the flowering period of A. marlothii, reflecting the enriched crassulacean acid metabolism (CAM) isotopic signature of nectar ()12.6 ± 0.5&). This relatively small contribution of A. marlothii nectar to assimilated carbon in whole blood contrasted with that of exhaled CO2 in African Red-eyed Bulbuls Pycnonotus nigricans and Cape White-eyes Zosterops capensis. In both these species, the d13C of breath samples was significantly enriched compared with blood and feathers, and closely resembled that of the nectar, revealing combustion of ingested nectar rather than assimilation. Although our analysis was complicated by the presence of C4 grasses, whose d13C values are similar to those of CAM photosynthesizers, when considered with previously published feeding observations our data reveal that opportunistic nectarivores feeding on A. marlothii nectar obtain a relatively small fraction of their assimilated carbon, but most of their metabolized carbon, from this seasonally available carbohydrate food resource. Because the d13C values of insects associated with C3 plants also became enriched during the flowering season, some insect-eating opportunistic nectarivores may have assimilated A. marlothii carbon indirectly from insects. This study highlights the importance of understanding isotopic routing when assessing the nutritional significance of specific dietary items to consumer communities.The National Research Foundation of South Africahttp://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1474-919X/ab201

Subterranean sympatry : an investigation into diet using stable isotope analysis

In the Western Cape three species of mole-rat occur in sympatry, however, little is known about differences in their dietary preferences. Dietary composition of the three species; the common mole-rat (Cryptomys hottentotus hottentotus), the Cape mole-rat (Georychus capensis) and the Cape dune mole-rat (Bathyergus suillus) were examined using stable isotope analysis. Blood, fur and claw samples were collected from 70 mole-rats, in addition to several potential food items, to assess food selection of the three species under natural conditions. Overall there was a significant difference in the isotopic composition (d13C and d15N) between all three species and significant differences in their diet composition. There were also significant differences between tissues in all three species suggesting temporal variation in diet. The small size and colonial lifestyle of C. h. hottentotus allows it to feed almost 100% on bulbs, while the solitary and larger species G. capensis and B. suillus fed to a greater extent on other resources such as grasses and clover. B. suillus, the largest of the species, had the most generalized diet. However, overall all species relied most heavily upon geophytes and consumed the same species suggesting competition for resources could exist. We also showed a high level of individual variation in diet choices. This was most pronounced in B. suillus and G. capensis and less so in C. h. hottentotus. We demonstrate that stable isotope analysis can successfully be applied to examine dietary patterns in subterranean mammals and provide insights into foraging patterns and dietary variation at both the inter and intra population level.G. Robb was funded by a University of Pretoria Post-doctoral fellowship. N. Bennett and fieldwork costs were funded through the Department of Science and Technology and National Research Foundation SARChI Chair of Mammal Behavioural Ecology and Physiology.http://www.plosone.orgab201