Managing Variability: Herding Strategies in Communal Rangelands of Semiarid Namaqualand, South Africa

Herd mobility is a tool for managing environmental variability in African pastoral systems. This study examines the monthly mobility patterns of 24 herds over six years in the 20,000 ha communal area of Paulshoek, Namaqualand, and assesses the social, economic, and ecological factors affecting the livestock movement of individual herds and all herds combined. When the mobility pattern of all herds was considered, no seasonal or between-year differences in response to rainfall were evident. An analysis of individual herd mobility patterns showed that half of the herds were relatively sedentary over the study period while the other half were regularly mobile. Although herders used mobility to manage their herds in the unpredictable semiarid environment, their daily decisions were often made in response to their social, economic, or personal situations. There was no significant difference in livestock production between herding strategies, but sedentary herders had a greater localized impact on the rangeland than mobile herders. Our analysis suggests that non-environmental factors play a significant role in herd mobility and may consequently affect the efficiency of livestock production and environmental management.     

Changing Access to Labor,Pastures, and Knowledge: The Extensification of Grazing Management in Sudano-Sahelian West Africa

The broader ecological and social contexts within which livestock husbandry of Sudano-Sahelian West Africa operates have changed significantly over the past thirty years. This study concerns how: (1) these broader trends have affected the quantity and quality of labor investments into livestock herding; and (2) the ecological and animal nutritional implications of observed variation in labor investments into herding. The study was conducted in a 500 km² area of western Niger using a combination of qualitative interviews of herders and herd managers, household composition surveys, herd composition monitoring, grazing management monitoring and georeferenced vegetation and livestock grazing itinerary data. Statistical analyses were performed using a two-staged approach: (1) analysis of the factors affecting the allocation of labor to herding at the level of the managing household; and (2) analysis of the effect of herd characteristics, season, microgeography and herders’ social position on herders’ effort and the nutritional and ecological impacts of these efforts. The results of these analyses support the conclusion that the changing regional context of livestock husbandry leads to a reduction in labor (quantity and quality) investment or an “extensification” of herding with significant implications for livestock productivity and the environment.

Coping with Uncertainty and Variability: The Influence of Protected Areas on Pastoral Herding Strategies in East Africa

A large number of East African pastoralists reside around protected areas (PAs). Over the last few decades pastoralists have been affected by the loss of grazing lands and increasing climatic variability. Many pastoralists who reside around PAs have resorted to grazing inside PAs to counter environmental variability. However, there is little information on how PAs influence the herding strategies of pastoralists. This case study from southern Kenya employs a spatially and temporally explicit mixed-methods approach to understand and evaluate the herding strategies of pastoralists around a PA. The results find that pastoralists access PAs on a regular basis, regardless of seasonality or herd size. Movement into PAs was partly driven by the loss of grazing land to conservancies. PAs affected pastoral herding by presenting differential opportunity costs to disparate groups. However, households with large herd sizes utilized the most flexible strategies to counter environmental variability and uncertainty.     

An overview of environmental issues in Southern Africa

This paper provides an overview of some of the significant environmental problems in the Southern African region. The key problems highlighted are global warming and climate variability, loss of biodiversity, deforestation, desertification-land degradation, waste and littering, population growth, urbanization, pollution, poverty and health hazards. These problems present a challenge to governments and other players within and outside Southern Africa to seek for long-term solutions by addressing the root causes of these problems. The paper notes that although the environmental problems facing the Southern African region are being tackled at national, regional and international levels, there is more that can be done. At the national level, the different agencies and players, both within and outside government need to strengthen coordination and implementation of key interventions in different sectors in both rural and urban areas. At the African regional and international levels, there is a need to address geopolitical forces and issues that contribute to the underdevelopment of the African region. Among the major issues are poor terms of international trade, political instability, poverty, declining economic performance and international debt.     

Ecological gradients as a framework for analysis of land-use change in East Africa

This paper discusses the ecological gradient as an organizing framework to assist understanding the complex interactions between societal and ecological processes underlying land-use change in East Africa. Detailed case studies on the gradients of the slopes of Mt Kilimanjaro, Kenya show how land-use change is responsive to the dynamics of both local and external driving forces. The study has shown that the distinct ecological conditions at the extremities of gradients are associated with specific land uses which may be different within livelihood systems such as for wet and dry season grazing. Access to water for cultivation, domestic use, livestock and wildlife is critical in determining the nature and distribution of livelihood systems. Land-use systems interact across the different ecological zones of the gradients characterized by vigorous spatial, cultural and economic interactions. Sometime conflicts occur between or within land-use/livelihood systems. There is strong evidence that the areas of higher economic potential remain advantaged compared with areas lower on the gradient. The ecological characteristics have been found to influence human activities and distribution. Interactions between societies are important in terms of trade, social relations and access to resources.     

Florisbad and human population succession in Southern Africa.

The human cranium recovered at Florisbad in 1932 is compared with other Sub-Saharan African hominid remains from Broken Hill, the Omo and Klasies River Mouth. The Florisbad frontal is very broad, but despite this breadth and differences in zygomatic form, there is a definite resemblance to archaic Homo sapiens from Broken Hill. There is also some similarity to both Omo I and Omo II, while fragmentary remains from Klasies River are more lightly built and hence more modern in appearance. These impressions are strengthened by measurement and statistical analysis, which demonstrates that Florisbad and Broken Hill are distant from recent African populations. Even if Florisbad is less archaic than the earlier (Middle Pleistocene?) hominid, it is not noticeably Bushman-like. New dates suggestive of early Upper Pleistocene antiquity also place Florisbad securely in a lineage containing Broken Hill, and there is no evidence to support special ties with any one group of living Africans.     

Community Based Fisheries Management and Fisher Livelihoods: Bangladesh Case Studies

Poor fishers in Bangladesh have been disadvantaged by policies that favored powerful people leasing fishing rights. Community-based management was expected to improve fisher access, livelihoods, and the sustainability of fisheries. The impacts of community management in three floodplain waterbodies differed according to the environment and property rights. Where a set of fishers jointly held exclusive rights to a small enclosed lake they increased production by stocking fish and shared the returns. This strategy is productive but attracts competition for profits and fish consumption was unchanged. Access to capture fisheries in floodplain waterbodies enables the poor to catch diverse small fish for their consumption. Yet sustainability requires limits on fishing. Fish sanctuaries were respected, yet catches per day fell when more people from several villages increased fishing effort in a large wetland, while a tightly knit community restored the fishery in a smaller floodplain. Community organizations will need recognition of their long-term use rights to overcome future threats.

A survey of Echinococcus species in wild carnivores and livestock in East Africa

We examined 71 faecal samples of carnivores from Queen Elizabeth National Park (QENP), Uganda, for eggs of Echinococcus species. Thirty-nine faecal samples contained taeniid eggs. For species diagnosis, DNA was isolated from a total of 1984 individual taeniid eggs. To differentiate eggs of Echinococcus felidis from other taeniid taxa (including the closely related Echinococcus granulosus sensu stricto), a restriction fragment length polymorphism (RFLP)-PCR of the mitochondrial nad1 gene was developed. As the faecal samples were taken from the environment, the host species was determined for all samples, except for one, by RFLP-PCR of the cob gene. Seven hundred and ninety-one of the 1984 eggs yielded a suitable PCR product. E. felidis was present in 34 of 47 samples from lions, none of 18 samples from leopards, and one of five samples from spotted hyenas. No Echinococcus taxon other than E. felidis was found, but three samples from lions contained eggs of Taenia regis. Two hydatid cysts of warthog origin from QENP were available for this study; molecular examination showed that one belonged to E. felidis, the other to E. granulosus (G1 strain). As a comparison of methods demonstrated that molecular diagnostic tools used for previous surveys of Echinococcus isolates in eastern Africa are not suitable to discriminate between E. felidis and E. granulosus sensu stricto, we re-examined 412 hydatid cyst samples of human, sheep, cattle, camel and goat origin from Kenya. Previous results were confirmed, as E. granulosus sensu stricto and Echinococcus canadensis G6/7 strain, but no E. felidis was found among these samples. In conclusion, we provide evidence that E. felidis is a frequent parasite of lions in Uganda, and possibly also occurs in hyenas. Additionally, we show that warthogs interact as intermediate hosts for E. felidis. We did not find evidence that E. felidis is present in eastern Africa outside conservation areas.     

Community Resilience in Southern Appalachia: A Theoretical Framework and Three Case Studies

A fundamental assumption in nearly all research on social adaptation to environmental change is that there is a concomitant and inverse relationship between human communities’ dependence upon particular natural resources affected by environmental change and those communities or societies’ resilience to disturbances. However, recent theoretical and empirical developments suggest resilience is a dynamic social process determined, in part, by the ability of communities to act collectively and solve common problems. The interactional approach to community is utilized to develop a framework whereby various patterns of social interaction define the process of social resilience. Data come from multiple mixed methods case studies of forest dependent communities within Southern Appalachia. The findings reveal varied processes of social resilience can occur in communities with similar levels of resource dependence; a community’s composition of internal social ties and their cross-scale linkages to external agencies and organizations define these processes.     

The life and death of a street boy in East Africa: everyday violence in the time of AIDS

This article focuses on the life history of a single street boy in northwestern Tanzania, whom I name Juma. I suggest that Juma's experiences and the life trajectory of himself and of significant individuals around him (particularly his mother) were structured by everyday violence. I describe everyday violence in terms of a conjuncture between macrostructural forces in East Africa (including a history of failed development schemes and the contemporary political economy of neoliberalism) and the lived experience of individuals as they negotiate local, contextual factors (including land-tenure practices, the power dynamics between immediate and extended kin, life on the streets, and constructions of gender and sexuality). I suggest that AIDS and its many impacts on Juma's life course can only be understood in a broader context of everyday violence. From this basis, I draw several general conclusions regarding AIDS prevention and intervention strategies.     

A new species, Gazza squamiventralis, from the East Coast of Africa (Perciformes: Leiognathidae)

Gazza squamiventralis sp. nov. is described as the fifth species of the genus, based on the holotype and eight paratypes, 42–96 mm in standard length, collected along the east coast of Africa, from Kenya to Mozambique. The species is similar to other congeners in general appearance, differing clearly from them in having the ventrolateral surface of the body scaled anterior to a line from the pectoral fin base to the pelvic fin origin (vs naked) and a smooth supraorbital ridge (vs finely serrated). Additionally, the species differs from G. dentex, G. rhombea, and G. achlamys in having the dorsolateral surface of the body scaled anterior to a vertical through the tip of the posterior branch of the supratemporal canal (vs corresponding region naked), and from G. minuta in having the first dorsal fin pterygiophore narrowly expanded anteriorly, with a concave margin (vs broadly expanded, with a convex or linear margin), and a short antrorse extension of the first anal fin pterygiophore (vs long). A key to the five species of the genus Gazza is provided. Received: May 30, 2000 / Revised: September 16, 2000 / Accepted: January 16, 2001     

Developing wetland inventories in southern Africa: A review

The status of wetland inventory effort and availability of maps and other data sources is reviewed for the ten countries of southern Africa: Angola, Bostwana, Lesotho, Malawi, Mozambique, Namibia, South Africa, Swaziland, Zambia and Zimbabwe. The aims and strategies for inventory are discussed and the main survey methods compared. Prior to commissioning new inventory work careful collation of existing maps and imagery is recommended together with targeting of strategic inventory at Province level, reserving high resolution effort only for certain important sites.     

Stability in a multi-species assemblage of large herbivores in East Africa: an alternative interpretation

Summary Prins and Douglas-Hamilton (1990) analyzed data based on nine census counts of large herbivore species in Lake Manyara National Park, northern Tanzania, over the period 1959–1984. Their major conclusion was that even if individual species-showed large fluctuations in numbers, the different species compensated the fluctuations of the other species in a way resulting in a constancy of total herbivore biomass, constancy of plant biomass consumption, and overall stability of the system under natural conditions. The authors believed that they had found a support for this view by calculating the stability index based on correlations between numbers of large herbivores. In this paper I show that Prins and Douglas-Hamilton's calculation of the stability index was not justified. Grazing and browsing pressure by large herbivores in Lake Manyara National Park seems to be remarkably constant. However, available information does not allow any rigorous conclusions about the stability of this community. We need more data from other systems dominated by large herbivores to be able to make comparisons and to be able to say which systems are more stable and in what sense.     

Social Learning and the Maintenance of Cultural Variation: An Evolutionary Model and Data from East Africa

Human societies maintain between-group variation despite mixing of people and ideas. In order for variation to remain, migrants or their children must preferentially adopt local norms, customs, and beliefs. Yet the details of how cultural variation is maintained, despite mixing, remain unknown. This article addresses this problem by using a simple model of the evolution of cultural learning to interpret the results of a study of cultural variation in a small region of East Africa. I argue that the manner in which migrants of two diverse regions adapt to local beliefs and behavior depends on the costs and accuracy of learning in each domain. Observational studies are never definitive tests of any hypothesis, but these results suggest that conclusions about the significance of cultural learning for understanding individual attitudes and behavior depend strongly upon the domain of investigation.     

A critique of the chronometric evidence for hominid fossils: I. Africa and the Near East 500-50 ka

The chronometric dating evidence for all hominid fossils from Africa and the Near East that have previously been dated to 500-50 ka is critically assessed using the concept of chronometric hygiene, and these dates are revised using Bayesian statistical analyses where possible. Sixteen relevant hominid sites lacking chronometric evidence are briefly discussed. Chronometric evidence from 37 sites is assessed in detail. The dates for many hominid fossils are poorly constrained, with a number dated by comparisons of faunal assemblages-a method that does not have good chronological resolution for much of the last million years. For sites with stratigraphic sequences of dates, it is generally possible to refine the dating, but in some cases, the revised chronology is less precise than previous chronologies. Fossils over 200 ka in age tend to be poorly dated, but for the last 200 kyr, dating is better due to the availability of electron-spin-resonance and thermoluminescence dating. Consideration of the chronologies favored by the proponents of the out-of-Africa and multiregional hypotheses of human evolution shows their selectivity. The chronological assessment of the fossils here is compatible with either hypothesis. If evolutionary schemes that do not rely on the morphology of the hominid fossils to decide the sequence of fossils are to be built, then further dating is required, alongside full publication of existing dates.     

Developing A Regional Ecological Risk Assessment: A Case Study of a Tasmanian Agricultural Catchment

A regional ecological risk assessment was conducted for the Mountain River catchment in Tasmania, Australia. The Relative Risk Model was used in conjunction with geographic information systems interpretations. Stakeholder values were used to develop assessment endpoints, and regional stressors and habitats were identified. The risk hypotheses expressed in the conceptual model were that agriculture and land clearing for rural residential are producing multiple stressors that have potential for contamination of local waterbodies, eutrophication, changes in hydrology, reduction in the habitat of native flora and fauna, reductions in populations of beneficial insects in agricultural production systems, increased weed competition in pastures, and loss of aesthetic value in residential areas. In the risk analysis the catchment was divided into risk regions based on topography and land use. Stressors were ranked on likelihood of occurrence, while habitats were ranked on percentage land area. Risk characterization showed risks to the maintenance of productive primary industries were highest across all risk regions, followed by maintenance of a good residential environment and maintenance of fish populations. Sensitivity analysis was conducted to show the variability in risk outcomes stemming from uncertainty about stressors and habitats. Outcomes from this assessment provide a basis for planning regional environmental monitoring programs.     

Burning the Seasonal Mosaic: Preventative Burning Strategies in the Wooded Savanna of Southern Mali

Data are presented indicating a seasonal mosaic pattern of burning in the savanna of southern Mali. A seasonal mosaic is a landscape that is annually re-created by people, and which contains patches of unburned, early burned, and recently burned vegetation. A survey of over 100 farmers and in-depth interviews demonstrates that rural inhabitants of southern Mali begin an annual burning regime early in the dry season in order to fragment the landscape, with the goal of preventing later fires that can damage natural resources. The process of gradually burning off the driest vegetation creates a seasonal mosaic of habitat patches that increases the potential of the landscape for a variety of dry season land uses, including hunting, gathering of savanna products, and grazing. An analysis of a series of Landsat images shows that the practice of mosaic burning is widespread in the wooded savanna, in which burning usually begins early and large fires are rare. On the basis of recent developments in ecological theory and empirical evidence from similar burning regimes in parts of Australia, it is suggested that seasonal mosaic burning in Mali not only prevents damaging late-season fires but increases biodiversity. It is concluded that discourse on African savanna burning overemphasizes the ecologically detrimental aspects of fire, while neglecting the beneficial ones resulting in misguided policies that pose a threat to human livelihoods and savanna ecosystems.     

A Multilevel Analysis of the Impact of Land Use on Interannual Land-Cover Change in East Africa

Abstract The aim of this study was to characterize the short-term land-cover change processes that were detected in Eastern Africa, based on a set of change metrics that allow for the quantification of interannual changes in vegetation productivity, changes in vegetation phenology and a combination of both. We tested to what extent land use, fire activity and livestock grazing modified the vegetation response to short-term rainfall variability in East Africa and how this is reflected in change metrics derived from MODerate Imaging Spectrometer (MODIS) time series of remote sensing data. We used a hierarchical approach to disentangle the contribution of human activities and climate variability to the patterns of short-term vegetation change in East Africa at different levels of organization. Our results clearly show that land use significantly influences the vegetation response to rainfall variability as measured by time series of MODIS data. Areas with different types of land use react in a different way to interannual climate variability, leading to different values of the change indices depending on the land use type. The impact of land use is more reflected in interannual variability of vegetation productivity and overall change in the vegetation, whereas changes in phenology are mainly driven by climate variability and affect most vegetation types in similar ways. Our multilevel approach led to improved models and clearly demonstrated that climate influence plays at a different scale than land use, fire and herbivore grazing. It helped us to understand dynamics within and between biomes in the study area and investigate the relative importance of different factors influencing short-term variability in change indices at different scales.     

Integrated Human and Ecological Risk Assessment: A Case Study of Tributyltin and Triphenyltin Compounds

Tributyltin and triphenyltin (TBT and TPT) are biocides that have been used to prevent fouling of boats, preserve wood, kill molluscs, and other uses. Due to observed effects on oysters and snails, their use in boat paints has been banned in many nations. However, use on ships and some uses other than as antifouling paints continue. These uses, the relative persistence of these compounds, their tendency to bioaccumulate, and their toxicity cause lingering concerns about risks to humans and non-human organisms. This paper outlines an integrated assessment of TBT and TPT. Based on prior human health and ecological assessments, it suggests that an integrated assessment that recognized common pathways of transport, fate and exposure, and common modes of action would be more efficient and complete than additional independent assessments. The presentation of risks in an integrated manner could also lead to better decisions by defining the various benefits of any management action.