The rapid expansion of informal settlements places significant pressure on social-ecological systems, contributing to climate vulnerability and encroachment into public spaces. Nature-based solutions are increasingly recognised as effective interventions for enhancing urban resilience by regulating ecosystem functions, sustaining ecosystem service provision, attenuating climate-related hazards, and strengthening adaptive capacity. Yet, empirical evidence from informal settlements remains scarce, despite these settlements accommodating approximately 59% of the urban population in Sub-Saharan Africa. Scholarship on urban green infrastructure in informal settlements often emphasises limited benefits while ignoring disbenefits and environmental hazards. This systematic review synthesises current knowledge on nature-based solutions in informal settlements in sub-Saharan Africa, with a focus on the spatial and temporal evolution of studies, including biases in leadership, funding, and publication outlets, as well as the types of nature-based solutions implemented, their ecosystem services and disservices, barriers, and actors involved. A comprehensive review of peer-reviewed and grey literature was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Of the 1,632 studies initially identified, 54 met the inclusion criteria. Our review shows significant knowledge gaps in nature-based solutions remain in informal settlements, slums, and peri-urban areas across sub-Saharan Africa, with most research conducted in South Africa, followed by Ghana, Kenya and Tanzania. This review identifies 38 types of nature-based solutions, with trees being the most cited (48.1%), followed by open green spaces (38.9%), gardens (29.6%), public and private parks (27.7%), wetlands and rivers (24.1% each), highlighting their potential to deliver multiple ecosystem services and support livelihoods. Effectiveness is constrained by outdated policies, weak institutional capacity, insecure land tenure, and limited community participation. Implementation is largely state- and partnership-driven, with limited community and academic engagement. Governments have led greening and restoration initiatives, although budget allocations often prioritise formal urban areas. Future research should therefore incorporate multilingual literature to provide a more balanced, comprehensive, and inclusive understanding of nature-based applications across Sub-Saharan Africa. Additionally, greater use of quantitative methods is needed to assess ecosystem service supply and demand, generating evidence to support urban planners and policymakers in the design, management, and implementation of effective NbS strategies for informal and peri-urban settlements.
Recent conservation efforts have resulted in the growth of protected and conserved areas as a land use across African drylands. However, land use and land cover change (LULCC) associated with habitat fragmentation continues to be a substantive driver of biodiversity loss in multiple-use landscapes. This study highlights the significance of perspectives from diverse stakeholders in understanding LULCC in a southern African dryland where the coverage of protected and conserved areas is increasing. The study models future land cover change scenarios and assesses their alignment with the Sustainable Development Goals (SDG) Agenda 2030 and the African Union (AU) Agenda 2063. Three scenarios representing business-as-usual conditions, conservation and livestock production, and agricultural and livestock production are outlined. Under business-as-usual conditions, protected areas are conserved and built-up areas expand. However, land degradation occurs where people are concentrated around key resource areas. In a scenario focused on conservation and livestock production, conservation initiatives are strengthened, but expansion of shrublands occurs in livestock-dominated areas that are not well managed. In a scenario focused on agricultural and livestock production, farms grow but their expansion within protected areas causes human-wildlife conflicts. Desirable near and far futures — characterised by environmental integrity, human-wildlife coexistence, and an equitable, thriving wildlife-based economy — are seen as attainable through coordinated land-based activities and the implementation of community-based conservation legislation. Outputs from this study demonstrate the value of a stakeholder-led approach in tackling conservation challenges and in planning for a sustainable future for an arid region heavily reliant on land-based livelihoods.
The genus Alphavirus harbors arboviruses of great concern, such as the Chikungunya virus and the equine encephalitis viruses. Transmission of pathogenic alphaviruses by mosquitoes could be influenced by insect-specific alphaviruses such as Eilat virus (EILV). However, insect-specific alphaviruses are rarely found in wild mosquitoes and only a few have been described in the literature. Here, we report the detection of EILV in a Culex univittatus mosquito from the north-eastern Namibian Zambezi region. Full genome analysis of MP458-NA-2018 showed 94.5% nucleotide identity to an EILV isolate from Israel. MP458-NA-2018 grouped with EILV in phylogenetic analysis and was placed within the clade of insect-specific alphaviruses. The virus was isolated in mosquito cells and shown to be restricted to insects as hosts by the inability to infect different vertebrate cell lines and a complete block of virus replication at 34°C. We further showed that infection of cells with EILV MP458-NA-2018 reduced production of infectious particles of Sindbis virus by 2000-fold over the entire course of infection, whereas reduction rates of Bagaza and Middleburg virus were approximately 3-10-fold and dependent on time after infection. While production of infectious particles of cells superinfected with the Chikungunya virus were approximately 30-fold reduced and more pronounced at a lower multiplicity of infection of 0.01, EILV seemed to enhance production of West Nile virus infectious particles by >5-fold when superinfected at a multiplicitiy of infection of 0.1. In summary, EILV from the Namibian Zambezi region influences in vitro replication of endemic flavi- and alphaviruses.
BACKGROUND:The distribution of resources can affect animal range sizes, which in turn may alter infectious disease dynamics in heterogenous environments. The risk of pathogen exposure or the spatial extent of outbreaks may vary with host range size. This study examined the range sizes of herbivorous anthrax host species in two ecosystems and relationships between spatial movement behavior and patterns of disease outbreaks for a multi-host environmentally transmitted pathogen.METHODS:We examined range sizes for seven host species and the spatial extent of anthrax outbreaks in Etosha National Park, Namibia and Kruger National Park, South Africa, where the main host species and outbreak sizes differ. We evaluated host range sizes using the local convex hull method at different temporal scales, within-individual temporal range overlap, and relationships between ranging behavior and species contributions to anthrax cases in each park. We estimated the spatial extent of annual anthrax mortalities and evaluated whether the extent was correlated with case numbers of a given host species.RESULTS:Range size differences among species were not linearly related to anthrax case numbers. In Kruger the main host species had small range sizes and high range overlap, which may heighten exposure when outbreaks occur within their ranges. However, different patterns were observed in Etosha, where the main host species had large range sizes and relatively little overlap. The spatial extent of anthrax mortalities was similar between parks but less variable in Etosha than Kruger. In Kruger outbreaks varied from small local clusters to large areas and the spatial extent correlated with case numbers and species affected. Secondary host species contributed relatively few cases to outbreaks; however, for these species with large range sizes, case numbers positively correlated with outbreak extent.CONCLUSIONS:Our results provide new information on the spatiotemporal structuring of ranging movements of anthrax host species in two ecosystems. The results linking anthrax dynamics to host space use are correlative, yet suggest that, though partial and proximate, host range size and overlap may be contributing factors in outbreak characteristics for environmentally transmitted pathogens.
The scale of climate migration across the Global South is expected to increase during this century. By 2050, millions of Africans are likely to consider, or be pushed into, migration because of climate hazards contributing to agricultural disruption, water and food scarcity, desertification, flooding, drought, coastal erosion, and heat waves. However, the migration-climate nexus is complex, as is the question of whether migration can be considered a climate change adaptation strategy across both the rural and urban space. Combining data from household surveys, key informant interviews, and secondary sources related to regional disaster, demographic, resource, and economic trends between 1990 and 2020 from north central and central dryland Namibia, we investigate (i) human migration flows and the influence of climate hazards on these flows and (ii) the benefits and dis-benefits of migration in supporting climate change adaptation, from the perspective of migrants (personal factors and intervening obstacles), areas of origin, and areas of destination. Our analysis suggests an increase in climate-related push factors that could be driving rural out-migration from the north central region to peri-urban settlements in the central region of the country. While push factors play a role in rural-urban migration, there are also several pull factors (many of which have been long-term drivers of urban migration) such as perceived higher wages, diversity of livelihoods, water, health and energy provisioning, remittances, better education opportunities, and the exchange of non-marketed products. Migration to peri-urban settlements can reduce some risks (e.g. loss of crops and income due to climate extremes) but amplify others (e.g. heat stress and insecure land tenure). Adaptation at both ends of the rural–urban continuum is supported by deeply embedded linkages in a model of circular rural–urban-rural migration and interdependencies. Results empirically inform current and future policy debates around climate mobilities in Namibia, with wider implications across Africa. Graphical abstract
Proclaimed in 1907, Etosha National Park in northern Namibia is an iconic dryland system with a rich history of wildlife conservation and research. A recent research symposium on wildlife conservation in the Greater Etosha Landscape (GEL) highlighted increased concern of how intensification of global change will affect wildlife conservation based on participant responses to a questionnaire. The GEL includes Etosha and surrounding areas, the latter divided by a veterinary fence into large, private farms to the south and communal areas of residential and farming land to the north. Here, we leverage our knowledge of this ecosystem to provide insight into the broader challenges facing wildlife conservation in this vulnerable dryland environment. We first look backward, summarizing the history of wildlife conservation and research trends in the GEL based on a literature review, providing a broad-scale understanding of the socioecological processes that drive dryland system dynamics. We then look forward, focusing on eight key areas of challenge and opportunity for this ecosystem: climate change, water availability and quality, vegetation and fire management, adaptability of wildlife populations, disease risk, human-wildlife conflict, wildlife crime, and human dimensions of wildlife conservation. Using this model system, we summarize key lessons and identify critical threats highlighting future research needs to support wildlife management. Research in the GEL has followed a trajectory seen elsewhere reflecting an increase in complexity and integration across biological scales over time. Yet, despite these trends, a gap exists between the scope of recent research efforts and the needs of wildlife conservation to adapt to climate and land-use changes. Given the complex nature of climate change, in addition to locally existing system stressors, a framework of forward-thinking adaptive management to address these challenges, supported by integrative and multidisciplinary research could be beneficial. One critical area for growth is to better integrate research and wildlife management across land-use types. Such efforts have the potential to support wildlife conservation efforts and human development goals, while building resilience against the impacts of climate change. While our conclusions reflect the specifics of the GEL ecosystem, they have direct relevance for other African dryland systems impacted by global change.
Translocation of wildlife species from one area to another is a conservation tool that contributes to the restoration of depleted populations, augments declining populations, or establishes of new populations. This paper documents one of the first studies examining in detail stakeholders' perceptions of the factors influencing the outcomes of translocations of wildlife into a community conservation area, using the case of eland (Taurotragus oryx) translocations into the Nyae Nyae Conservancy in Namibia. The translocations took place between 2000 and 2005 as part of the national community-based natural resource management programme and were monitored through annual waterpoint counts. These data on perceptions were collected through a household survey and focused group discussions involving community members and leaders and key informant interviews with external stakeholders. Community members' perceptions could not confirm that the translocated eland decreased or increased, however, reflected that eland individuals moved away from the release site soon after translocation to more distant locations further away from human settlements. The outcomes of the translocations were perceived to be most strongly associated with anthropogenic factors compared to habitat or environmental factors. However, stakeholders exhibited divergent perceptions regarding which of the anthropogenic factors was of most importance, particularly with respect to the roles of the different types of hunting, and to a lesser degree, the role of traditional burning of landscapes on translocation outcomes. The paper illustrates the complexities associated with translocations of wildlife into community conservation areas compared to state protected areas, given the strong influence of human disturbances on translocation success. It highlights the importance of understanding the social factors influencing how and why translocated individuals may adapt well or poorly to their new environment. Building this understanding is essential to improving the outcomes of similar translocations in the future.
Environmental factors are common forces driving infectious disease dynamics. We compared interannual and seasonal patterns of anthrax infections in two multihost systems in southern Africa: Etosha National Park, Namibia, and Kruger National Park, South Africa. Using several decades of mortality data from each system, we assessed possible transmission mechanisms behind anthrax dynamics, examining (1) within- and between-species temporal case correlations and (2) associations between anthrax mortalities and environmental factors, specifically rainfall and the Normalized Difference Vegetation Index (NDVI), with empirical dynamic modeling. Anthrax cases in Kruger had wide interannual variation in case numbers, and large outbreaks seemed to follow a roughly decadal cycle. In contrast, outbreaks in Etosha were smaller in magnitude and occurred annually. In Etosha, the host species commonly affected remained consistent over several decades, although plains zebra (Equus quagga) became relatively more dominant. In Kruger, turnover of the main host species occurred after the 1990s, where the previously dominant host species, greater kudu (Tragelaphus strepsiceros), was replaced by impala (Aepyceros melampus). In both parks, anthrax infections showed two seasonal peaks, with each species having only one peak in a year. Zebra, springbok (Antidorcas marsupialis), wildebeest (Connochaetes taurinus), and impala cases peaked in wet seasons, while elephant (Loxodonta africana), kudu, and buffalo (Syncerus caffer) cases peaked in dry seasons. For common host species shared between the two parks, anthrax mortalities peaked in the same season in both systems. Among host species with cases peaking in the same season, anthrax mortalities were mostly synchronized, which implies similar transmission mechanisms or shared sources of exposure. Between seasons, outbreaks in one species may contribute to more cases in another species in the following season. Higher vegetation greenness was associated with more zebra and springbok anthrax mortalities in Etosha but fewer elephant cases in Kruger. These results suggest that host behavioral responses to changing environmental conditions may affect anthrax transmission risk, with differences in transmission mechanisms leading to multihost biseasonal outbreaks. This study reveals the dynamics and potential environmental drivers of anthrax in two savanna systems, providing a better understanding of factors driving biseasonal dynamics and outbreak variation among locations.
The genus Orbivirus includes a variety of pathogenic viruses that are transmitted by biting midges, mosquitoes and ticks. Some of the economically most relevant orbiviruses are endemic to Namibia, like the livestock-pathogenic Bluetongue and African horse sickness viruses. Here, we assessed the diversity of orbiviruses circulating in the Zambezi region of north-eastern Namibia. A total of 10 250 biting midges and 10 206 mosquitoes were collected and screened for orbivirus infections. We identified Palyam virus (PALV) in a pool of biting midges (Culicoides sp.) sampled in the Wuparo Conservancy and three strains of Corriparta virus (CORV) in Culex sp. mosquitoes sampled in Mudumu National Park and the Mashi Conservancy. This is, to our knowledge, the first detection of PALV and CORV in Namibia. Both viruses infect vertebrates but only PALV has been reported to cause disease. PALV can cause foetal malformations and abortions in ruminants. Furthermore, a novel orbivirus, related to Kammavanpettai virus from India and Umatilla virus from North America, was discovered in biting midges (Culicoides sp.) originating from Mudumu National Park and tentatively named Mudumu virus (MUMUV). Complete genomes of PALV, CORV and MUMUV were sequenced and genetically characterized. The Namibian CORV strain showed 24.3 % nucleotide divergence in its subcore shell gene to CORV strains from Australia, indicating that African CORV variants vary widely from their Australian relatives. CORV was isolated in cell culture and replicated to high titres in mosquito and duck cells. No growth was found in rodent and primate cells. The data presented here show that diverse orbiviruses are endemic to the Zambezi region. Further studies are needed to assess their effects on wildlife and livestock.
Flaviviruses include a great diversity of mosquito-borne arboviruses with epidemic potential and high global disease burden. Several flaviviruses are circulating in southern Africa affecting humans and livestock, among them West Nile virus (WNV) and Wesselsbron virus. Despite their high relevance, no arbovirus surveillance study has been conducted for more than 35 years in Namibia. In this study we assessed the diversity of flaviviruses circulating in mosquitoes in the densely populated, semi-tropical Zambezi region of north-eastern Namibia. In total, 10,206 mosquitoes were sampled in Bwabwata and Mudumu national parks and Mashi and Wuparo conservancies and screened for flavivirus infections. A high infection rate with insect-specific flaviviruses was found with 241 strains of two previously known and seven putative novel insect-specific flaviviruses. In addition, we identified ten strains of WNV in the main vector Cx. univittatus sampled in the Mashi conservancy. Surprisingly, the strains fell into two different clades of lineage 2, 2b and 2d. Further, three strains of Bagaza Virus (BAGV) were found in Cx. univittatus mosquitoes originating from Mudumu national park. Assessment of BAGV growth in different cell lines showed high replication rates in mosquito and duck cells and about 100,000fold lower replication in human, primate and rodent cells. We demonstrate a wide genetic diversity of flaviviruses is circulating in mosquitoes in the Zambezi region. Importantly, WNV and BAGV can cause outbreaks including severe disease and mortality in humans and birds, respectively. Future studies should focus on WNV and BAGV geographic distribution, as well as on their potential health impacts in and the associated social and economic implications for southern Africa.
When a transmission hotspot for an environmentally persistent pathogen establishes in otherwise high-quality habitat, the disease may exert a strong impact on a host population. However, fluctuating environmental conditions lead to heterogeneity in habitat quality and animal habitat preference, which may interrupt the overlap between selected and risky habitats. We evaluated spatio-temporal patterns in anthrax mortalities in a plains zebra ( Equus quagga ) population in Etosha National Park, Namibia, incorporating remote-sensing and host telemetry data. A higher proportion of anthrax mortalities of herbivores was detected in open habitats than in other habitat types. Resource selection functions showed that the zebra population shifted habitat selection in response to changes in rainfall and vegetation productivity. Average to high rainfall years supported larger anthrax outbreaks, with animals congregating in preferred open habitats, while a severe drought forced animals into otherwise less preferred habitats, leading to few anthrax mortalities. Thus, the timing of anthrax outbreaks was congruent with preference for open plains habitats and a corresponding increase in pathogen exposure. Given shifts in habitat preference, the overlap in high-quality habitat and high-risk habitat is intermittent, reducing the adverse consequences for the population.
Southern African cities face several challenges including management of rapid urbanization, rising populations, expanding informal settlements; adequate water and other service provision, and a host of governance challenges. Climate change and variability add a compounding effect to this complex, multi stressor context. Addressing the complexity requires an understanding of urban ecosystems functioning and interactions amongst the built and natural environment (climate) and human systems. In this paper we argue that learning is essential for cities to be resilient to current and future challenges. We profile the Future Resilience for African CiTies And Lands (FRACTAL) project which contributed towards climate resilient development by providing relevant climate information for decision-making at the city regional scale in southern Africa. Following FRACTAL's city-to-city learning approach of sharing good practices, knowledge and experiences framed around transdisciplinary research, the study cities of Harare, Lusaka, Windhoek and Durban conducted city learning exchange visits between 2017 and 2018. We used a mixed methods approach to collect and analyze historical climate and hydrological data and current socio-economic and development data among the cities. A qualitative, in-depth, case study comparative analysis was used to identify similarities and differences as well as lessons drawn from the learning process during the city exchanges and these were complimented by desktop studies. Results showed water scarcity, large informal settlements, reliance on external water and energy sources, inadequate protection of ecologically sensitive resources and service provision as some of the common complications in the cities. Several lessons and transferable practices learnt from the cities included effective water conservation and waste management and the use of public-private partnerships in Windhoek, community engagements in Durban and Lusaka while lessons on decisive leadership in dealing with informal settlements emanated from Harare's limited informal settlements. Lastly, Durban's Adaptation Charter and integrated climate planning provided lessons for biodiversity protection and mainstreaming climate change at city governance level. While we recognize that cities are context-specific we consider these good practices as being broadly transferable to other southern African cities. We conclude that social, experiential and structured learning can be an innovative way of multi-stakeholder engagement and a useful approach to increase city resilience planning across southern Africa and cities that face similar developmental challenges.
Ungulates are famous for large-scale movements in response to local and regional changes in plant productivity. However, it is poorly understood how non-migratory ungulates respond towards shortages in plant availability. In the arid Kunene Region of Namibia, we studied the variation of home ranges and habitat use of gemsbok during a period of severe drought that led to a critical food shortage. We then related the spatiotemporal behaviour of gemsbok to relative plant greenness and local plant productivity, using local Normalized Differenced Vegetation Indices (NDVI) as a proxy, and to satellite images to assess habitat types and topography. Core home range sizes of gemsbok did not vary with decreasing local NDVI values, while total home-ranges increased with decreasing NDVI values. Gemsbok responded to resource fluctuations by using a combination of habitats differing in plant productivity, topography and vegetation cover. Gemsbok increased the number of habitats used when NDVI values decreased. Individuals remained non-migratory even during the period of peak drought. Non-migratory gemsboks are capable of exploiting local resources efficiently by adjusting their habitat use, when facing declining resources and unpredictable food shortages. Our study provides important information on the habitat use of gemsbok for the sustainable management of populations in arid environments.
The emergence of the communal conservancies in Namibia contributed to community-based conservation approach outside protected areas. This study was conducted to establish the status of biodiversity conservation of the Nyae Nyae Conservancy by analysing the mammal species composition and diversity changes for 13 years. The long-term wildlife count data were obtained from the conservancy in Tsumkwe, Otjozondjupa region. A total of 20 mammal species, comprising of ungulates and predators, were recorded from 2001 through 2013. The overall trend of the mammal species population sizes was positive, though not statistically significant (r = 0.477; t10 = 1.574; P = 0.145). In addition to the stable species composition over the years, the mammal species diversity in Nyae Nyae conservancy was high (Simpson Index of Diversity, SID = 0.81). However, a significant decline in the diversity of mammal species (SID = 0.72) was detected in 2013 evident from the low species count data. This low diversity may be attributable to many factors including but not limited to the effects of severe drought which may have led to the emigration of some species, reduction in the abundance of some species due to deaths from drought and low reproductive output. Hence Nyae Nyae Conservancy, though an open unfenced system, serves as a good example in which a community-based natural management program outside protected areas contributes not only to the conservation of natural resources including wildlife but also utilisation of these resources for the benefit of local community members.
Species with highly restricted ranges are disproportionately at risk of extinction, particularly where habitat loss occurs as a result of mining. Postmining restoration of rare species populations is considered as an appropriate response to counter such threats, but requires a careful, evidence‐based, and information‐driven approach. The economically important diamond mining at Sendelingsdrif in the southern Namib Desert occurs in the highly diverse Succulent Karoo Biome and threatens a significant part of the population of the narrow endemic succulent plant species Juttadinteria albata. To decrease the inherent risks of restoring such a rare species, we studied the habitat features of premining J. albata populations and experimentally tested whether some features could assist future reintroductions in postmining substrates. Plots where J. albata occurred were mostly south‐ to west‐facing and had among others higher rock cover and steeper slopes than plots where J. albata plants were absent. A revegetation experiment, with J. albata cuttings that were established on postmining substrate mounds, revealed that plants on steeper slopes, facing south to west, grew faster than plants on other slopes and aspects. Slope and aspect are therefore important habitat properties to recreate when restoring J. albata populations. These, and other preferred habitat properties such as higher levels of organic C, should now be tested in larger‐scale field trials. Validation of habitat requirements of J. albata through the revegetation experiment has decreased the risks at least partially and provides additional empirical evidence of the importance of establishing reference conditions to enhance ecological restoration.
The aim of the paper is to present a story about the 2015 to early 2017Windhoek drought in the context of climate change while using the narrative approach. The story that is presented here is derived from the engagement of participants in a transdisciplinary, co-productive workshop, theWindhoek Learning Lab 1 (March 2017), as part of the FRACTAL Research Programme. The results show that the story starts with the 'complication' where the drought had reached crisis levels where the water demand increasingly exceeded the supply in the face of the drought. The City ofWindhoek (CoW) was unable to address the problem, particularly the recharging of the Windhoek aquifer due to lack of funding. Phase 2 then shows four reactions to the drought: water conservation by water demand management; a Water Saving campaign; the Windhoek Managed Aquifer Recharge Scheme; and, the setting up of the Cabinet Technical Committee of Supply Security. The resolution of the story, Phase 4, is when the national government instructs NamWater to provide the funds for CoW to complete the recharging of the aquifer, which supplied water to the city at the last minute at the end of 2016. The final situation of the story is that ongoing collaborative work by CoW with FRACTAL on the city's burning issues is planned to integrate climate change into future decision making for the longer term. The main actors in the story are the Ministry of Agriculture and NamWater as hero and villain, and CoW a hero, with the victims of the story, the residents of informal settlements. The main learnings from this story are that the lack of decentralization of power and resources serve to exacerbate water crises at the local level and hamper climate adaptation, despite a proactive and innovative local municipality. The paper also shows that the narrative approach provides the thread of the story to simplify a very complex set of arrangements and contradictions.
Anthrax in herbivorous wildlife and livestock is generally assumed to be transmitted via ingestion or inhalation of Bacillus anthracis spores. Although recent studies have highlighted the importance of the ingestion route for anthrax transmission, little is known about the inhalational route in natural systems. Dust bathing could aerosolize soilborne pathogens such as B. anthracis, exposing dust-bathing individuals to inhalational infections. We investigated the potential role of dust bathing in the transmission of inhalational anthrax to herbivorous wildlife in Etosha National Park, Namibia, an area with endemic seasonal anthrax outbreaks. We 1) cultured soils from dust-bathing sites for the presence and concentration of B. anthracis spores, 2) monitored anthrax carcass sites, the locations with the highest B. anthracis concentrations, for evidence of dust bathing, including a site where a zebra died of anthrax on a large dust bath, and 3) characterized the ecology and seasonality of dust bathing in plains zebra (Equus quagga), blue wildebeest (Connochaetes taurinus), and African savanna elephant (Loxodonta africana) using a combination of motion-sensing camera traps and direct observations. Only two out of 83 dust-bath soils were positive for B. anthracis, both with low spore concentrations (<= 20 colony-forming units per gram). We also detected no evidence of dust baths occurring at anthrax carcass sites, perhaps due to carcass-induced changes in soil composition that may deter dust bathing. Finally, despite observing some seasonal variation in dust bathing, preliminary evidence suggests that the seasonality of dust bathing and anthrax mortalities are not correlated. Thus, although dust bathing creates a dramatic cloud of aerosolized soil around an individual, our microbiologic, ecologic, and behavioral results in concert demonstrate that dust bathing is highly unlikely to transmit inhalational anthrax infections.
Host traits and environmental factors drive the natural variation in gut microbiota, and disruption in homeostasis can cause infections and chronic diseases. African wildlife is increasingly facing human-induced agricultural habitats, which also amplifies the contact probability with livestock with unknown consequences for wildlife gut microbiotas and the risk of transmission of potentially pathogenic bacteria. We applied high-throughput sequencing of bacterial 16S rRNA genes and microsatellite genotyping to investigate the impact of host traits and habitat use on the gut microbiotas of black-backed jackals (Canis mesomelas). This abundant carnivore inhabits livestock and game farms in central Namibia and is often persecuted as pathogen reservoir and vector. We further compared the gut microbiotas of black-backed jackals to other wild and domestic carnivores, herbivores and an omnivore, to disentangle the effects of environment, host species and dietary preference. In black-backed jackals, intrinsic host traits had a stronger impact in shaping the host-bacteria relationship than environmental factors. Nevertheless, the abundance of bacterial operational taxonomic units (OTUs) differed in individuals from livestock and game farms for specific bacterial genera such as Lactobacillus and Clostridium. We found, however, no evidence that black-backed jackals harbour abnormal levels of OTUs related to potential bacterial pathogens or that livestock farming has a negative impact on their health. We present here the first study investigating simultaneously the impact of host traits and environmental factors on gut microbiotas of a wildlife carnivore that occurs in a human-modified habitat.