97 research outputs found

    Nestling White-backed Vulture (Gyps africanus) eaten by a Verreaux’s Eagle (Aquila verreauxii) at a nest occupied for a record 21 years.

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    An adult Verreaux’s Eagle (Aquila verreauxii) was observed eating a White-backed Vulture (Gyps africanus) nestling at a nest at Sango in the Savé Valley Conservancy, south-eastern Zimbabwe on 13 October 2017. This nest has been regularly occupied for 21 successive breeding seasons. To our knowledge, this observation represents a previously unrecorded species in the diet of Verreaux’s Eagle, and it is also apparently the longest known continually-occupied White-backed Vulture nest

    Trade in vulture parts in West Africa:Burkina Faso may be one of the main sources of vulture carcasses

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    The current catastrophic decline in African vultures is caused mainly by poisoning, and killing for consumption and belief-based use (traditional medicine). To find out more about the key threats to vultures in West Africa, we assessed the main anthropogenic causes of vulture mortality in Burkina Faso. We analysed incidents of mass vulture mortality, based on interviews conducted in 2016 with local butchers, veterinarians, foresters, and abattoir watchmen at 44 sites across the country. A total of 730 interviews revealed that poisoning was the main cause of mortality of vultures in Burkina Faso (20 of the 23 mass mortality incidents described by respondents were caused by poisoning). Poisoning was also the most lethal threat to vultures (779 out of 879 known vulture deaths were due to poisoning). According to the survey, intentional poisoning of vultures with poisoned baits (which comprised 15 out of 23 mass mortality incidents) produced the highest number of victims (577 out of 879 dead vultures). The number of vultures killed by poisoned baits was higher closer to the borders than elsewhere in Burkina Faso and we believe these recent intentional vulture poisoning events in Burkina Faso were intended to meet the growing demand for vulture body parts in West Africa. The survey showed that unintentional poisoning was the second main cause of vulture mass mortality (5 out of 23 mass mortality incidents comprising 202 of 879 dead vultures). Other important anthropogenic causes of vulture mortality included electrocution at electricity poles and motor vehicle collisions. Our results highlight the need for awareness campaigns, improved policy and legislation, and stronger commitment from governments in West Africa, to halt the trade in vultures and prevent their extirpation.</p

    Revisando el papel de los buitres en al interfaz de enfermedades que afectan a humanos, animales salvajes y ganado : una perspectiva africana

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    Vultures are a key component of an effective scavenger guild and have evolved a number of adaptations that allow them to locate and dispose of carcasses quickly and efficiently. The continuing decline of African vultures is threatening the stability of the African scavenger guild, which may result in increased carcass decomposition times and thus, more rapid development of pathogenic bacteria. The absence of competitive regulation by these apex scavengers may also result in changes in the composition of the vertebrate scavenger guild, with an increase in mammalian scavengers giving rise to increased contact rates at carcasses, which may increase the risk of viral disease transmission to humans, livestock, and other wildlife. Although the economic value of vultures in terms of the sanitation services they provide has been evaluated, their contribution to the economics of human health and veterinary care remains to be quantified. Efforts to do so are hampered by lack of data, as well as a number of confounding factors that may mask causality, such as improved disease prevention and surveillance systems. However, the circumstantial nature of the link between vultures and disease prevention should not deter efforts to conserve them, as their regulation of mammalian scavengers and the sanitation services they provide place them firmly within the sphere of One Health, thereby warranting their urgent protection. The restoration of vulture populations and the ecosystem services they provide will benefit the welfare of all humans, but particularly those who are most vulnerable to economic instability and the spillover of disease at the human-wildlife-livestock interface.This review article is a product of an investigation entitled ‘‘There is still time to save Africa’s vultures,’’ hosted and funded by the National Socio-Environmental Synthesis Center (SESYNC) in Annapolis, MD USA.https://bioone.org/journals/journal-of-raptor-researcham2022Zoology and Entomolog

    The impacts of a global pandemic on the efficacy and stability of contemporary wildlife conservation : South Africa as a case study

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    DATA AVAILABILITY: The data belong to the University of KwaZulu-Natal and the various provincial conservation bodies and non-government organisations. These data are available from the corresponding author upon reasonable request.Conservationists speculated on potential benefits to wildlife of lockdown restrictions because of the COVID-19 pandemic but voiced concern that restrictions impeded nature conservation. We assessed the effects of lockdown restrictions on biodiversity conservation in South Africa, a biodiverse country with economic inequality and reliance on wildlife resources. We solicited expert opinion using the IUCN’s Threats Classification Scheme to structure a questionnaire and illustrated responses with individual case studies from government parastatal and non-governmental conservation organisations. The most highly reported threats were biological resource use, residential/commercial developments, invasive species, and human intrusions. The trends reported by 90 survey respondents were supported by case studies using environmental compliance data from parastatal conservation organisations. Lack of tourism revenue and funding were cited as hindrances to conservation. Mechanisms to prevent environmental degradation in the face of global emergencies must be implemented and ‘ring-fenced’ to ensure conservation is not a casualty during future global crises.National Research Foundation and Inyuvesi Yakwazulu-Natali.http://link.springer.com/journal/13280Mammal Research InstituteZoology and Entomolog

    Understanding continent-wide variation in vulture ranging behavior to assess feasibility of Vulture Safe Zones in Africa: Challenges and possibilities

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    Protected areas are intended as tools in reducing threats to wildlife and preserving habitat for their long-term population persistence. Studies on ranging behavior provide insight into the utility of protected areas. Vultures are one of the fastest declining groups of birds globally and are popular subjects for telemetry studies, but continent-wide studies are lacking. To address how vultures use space and identify the areas and location of possible vulture safe zones, we assess home range size and their overlap with protected areas by species, age, breeding status, season, and region using a large continent-wide telemetry datasets that includes 163 individuals of three species of threatened Gyps vulture. Immature vultures of all three species had larger home ranges and used a greater area outside of protected areas than breeding and non-breeding adults. Cape vultures had the smallest home range sizes and the lowest level of overlap with protected areas. Rüppell\u27s vultures had larger home range sizes in the wet season, when poisoning may increase due to human-carnivore conflict. Overall, our study suggests challenges for the creation of Vulture Safe Zones to protect African vultures. At a minimum, areas of 24,000 km2 would be needed to protect the entire range of an adult African White-backed vulture and areas of more than 75,000 km2 for wider-ranging Rüppell\u27s vultures. Vulture Safe Zones in Africa would generally need to be larger than existing protected areas, which would require widespread conservation activities outside of protected areas to be successful

    Estrategia para conservar las poblaciones de buitres del viejo mundo utilizando el enfoque de una salud

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    One Health brings the powerful interrelationship between human and wildlife health together with ecosystem health. The initial concept of One Health was formulated decades ago and focused on disease transfer from wildlife to human populations. More recently, the concept has been used to associate resilience to disease with the health of the ecosystem and resilience to environmental stressors. The need for a One Health approach is particularly evident in the plight of Old World vultures, which are facing a conservation crisis due to drastic reductions in populations across their entire range. Moreover, vulture conservation exemplifies many contemporary tenets of One Health; vultures are critical to a sustainable and resilient ecosystem, which in turn is essential for the socio-ecological health of human communities. In this review, we examine the complex factors contributing to the demise of Old World vulture populations, using the lens of One Health to conceptualize the primary drivers impacting the health and sustainability of these populations. The One Health concept provides the basis for the development of a framework that incorporates a multidimensional approach and includes human health, wildlife health, environmental and disease-related stressors, disease incidences, societal pressures, and environmental contaminants. Integrating societal needs with management aimed at maintaining healthy vulture populations is key for successfully using a One Health framework to optimize the health of human and wildlife populations and ensure ecosystem health.El enfoque ‘‘Una Salud’’ promueve una poderosa interrelacio´n entre la salud de los humanos y de la fauna salvaje asociados a la salud de los ecosistemas. El concepto inicial de Una Salud fue formulado de´cadas atra´s y se enfocaba en la transferencia de enfermedades de la fauna salvaje a las poblaciones humanas. Ma´s recientemente, el concepto ha sido usado para asociar la resiliencia a las enfermedades con la salud de los ecosistemas y la resiliencia a factores de estre´s ambiental. La necesidad de utilizar el enfoque de Una Salud es particularmente evidente ante la dif´ıcil situacio´n de los buitres del Viejo Mundo, los cuales se enfrentan a una situacio´n de crisis de conservacio´n debido a la reduccio´n dra´stica en sus poblaciones a lo largo de toda su a´rea de distribucio´n. Adema´s, la conservacio´n de los buitres ejemplifica mucho de los principios contempora´neos de Una Salud; los buitres son cr´ıticos para un ecosistema sostenible y resiliente, lo que a su vez es esencial para la salud socio-ecolo´gica de las comunidades humanas. En esta revisio´n, examinamos los factores complejos que contribuyen al descenso de las poblaciones de buitres del Viejo Mundo, usando el enfoque de Una Salud para conceptualizar los factores principales que impactan en la salud y la sostenibilidad de estas poblaciones. El concepto de Una Salud proporciona las bases para el desarrollo de un marco de referencia que incorpora un enfoque multidimensional, incluyendo la salud humana y de la vida silvestre, factores estresantes ambientales y de enfermedades, incidencia de enfermedades, presiones sociales y qu´ımicos ambientales. Integrar las necesidades de la sociedad con la gestio´n destinada a mantener poblaciones saludables de buitres es clave para usar exitosamente el marco de referencia de Una Salud y as´ı optimizar la salud de las poblaciones humanas y de la fauna salvaje asegurando la salud del ecosistema.The National Science Foundationhttps://bioone.org/journals/journal-of-raptor-researcham2022Zoology and Entomolog

    Phenotypic continuum of NFU1-related disorders.

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    Bi-allelic variants in Iron-Sulfur Cluster Scaffold (NFU1) have previously been associated with multiple mitochondrial dysfunctions syndrome 1 (MMDS1) characterized by early-onset rapidly fatal leukoencephalopathy. We report 19 affected individuals from 10 independent families with ultra-rare bi-allelic NFU1 missense variants associated with a spectrum of early-onset pure to complex hereditary spastic paraplegia (HSP) phenotype with a longer survival (16/19) on one end and neurodevelopmental delay with severe hypotonia (3/19) on the other. Reversible or irreversible neurological decompensation after a febrile illness was common in the cohort, and there were invariable white matter abnormalities on neuroimaging. The study suggests that MMDS1 and HSP could be the two ends of the NFU1-related phenotypic continuum

    A Universal Power-law Prescription for Variability from Synthetic Images of Black Hole Accretion Flows

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    We present a framework for characterizing the spatiotemporal power spectrum of the variability expected from the horizon-scale emission structure around supermassive black holes, and we apply this framework to a library of general relativistic magnetohydrodynamic (GRMHD) simulations and associated general relativistic ray-traced images relevant for Event Horizon Telescope (EHT) observations of Sgr A*. We find that the variability power spectrum is generically a red-noise process in both the temporal and spatial dimensions, with the peak in power occurring on the longest timescales and largest spatial scales. When both the time-averaged source structure and the spatially integrated light-curve variability are removed, the residual power spectrum exhibits a universal broken power-law behavior. On small spatial frequencies, the residual power spectrum rises as the square of the spatial frequency and is proportional to the variance in the centroid of emission. Beyond some peak in variability power, the residual power spectrum falls as that of the time-averaged source structure, which is similar across simulations; this behavior can be naturally explained if the variability arises from a multiplicative random field that has a steeper high-frequency power-law index than that of the time-averaged source structure. We briefly explore the ability of power spectral variability studies to constrain physical parameters relevant for the GRMHD simulations, which can be scaled to provide predictions for black holes in a range of systems in the optically thin regime. We present specific expectations for the behavior of the M87* and Sgr A* accretion flows as observed by the EHT

    Monitoring the Morphology of M87* in 2009–2017 with the Event Horizon Telescope

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    The Event Horizon Telescope (EHT) has recently delivered the first resolved images of M87*, the supermassive black hole in the center of the M87 galaxy. These images were produced using 230 GHz observations performed in 2017 April. Additional observations are required to investigate the persistence of the primary image feature—a ring with azimuthal brightness asymmetry—and to quantify the image variability on event horizon scales. To address this need, we analyze M87* data collected with prototype EHT arrays in 2009, 2011, 2012, and 2013. While these observations do not contain enough information to produce images, they are sufficient to constrain simple geometric models. We develop a modeling approach based on the framework utilized for the 2017 EHT data analysis and validate our procedures using synthetic data. Applying the same approach to the observational data sets, we find the M87* morphology in 2009–2017 to be consistent with a persistent asymmetric ring of ~40 μas diameter. The position angle of the peak intensity varies in time. In particular, we find a significant difference between the position angle measured in 2013 and 2017. These variations are in broad agreement with predictions of a subset of general relativistic magnetohydrodynamic simulations. We show that quantifying the variability across multiple observational epochs has the potential to constrain the physical properties of the source, such as the accretion state or the black hole spin
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