18 research outputs found
Awareness of environmental legislation as a deterrent for wildlife crime : A case with Masaai pastoralists, poison use and the Kenya Wildlife Act
Illegal wildlife crime is a global phenomenon, accelerating the ongoing biodiversity crisis. In the Old World, and particularly in Africa, illegal use of poisons to eliminate carnivores is the main driver of the continental vulture crisis. Knowledge about the underlying source and drivers of this threat is lacking for most areas, including Kenya, a global vulture and biodiversity hotspot. An extensive questionnaire survey of over 1300 respondents was run, using a specialized questioning technique and quantitative analytical approaches. Results show that, while pastoralists have a positive attitude towards vultures, over 20% of them use poisons to eliminate predators. Poisoning was largely driven by livestock losses to predators, and by negative attitude towards predators. Poisoning was less prevalent among respondents aware of the Kenya Wildlife Act. Overall, we suggest that a combination of top-down, e.g. legislation, and bottom-up (such as corrals or compensation) along with awareness campaigns may help reduce poisoning on the ground.Peer reviewe
Perceptions of vulture supplementary feeding site managers and potential hidden risks to avian scavengers
Under the current African vulture crisis, supplementary feeding sites (SFS), which provide carrion resources, have become a popular conservation tool to address vulture declines. In South Africa, this practice is unregulated and the context in which SFS operate and their adherence to best management practices is currently unknown. In this study, we conducted a survey with SFS managers regarding the management of their SFS to evaluate potential conservation implications of different practices. Half of the SFS surveyed were associated with livestock farming. Overall, most managers (84%) perceived some benefit from running an SFS, largely attributed to cleaning services provided by vultures. Over half of the managers perceived no disadvantages from running SFS. We found a positive correlation between numbers of vultures seen at SFS and the amount of food provided there. Despite unintentional and intentional poisoning being identified by experts as the most critical threats to vultures in Southern Africa, only 47 and 24% of managers, respectively, listed these as potential threats to vultures, highlighting limited understanding of current vulture conservation issues. Most managers (85%) vetted carcasses for provisioning suitability based on whether they had been treated with veterinary drugs, but relatively few managers (10%) did the same for lead (Pb) contamination. Only 30% of managers considered threats to vultures when they decided on a location for their SFS. Overall, this study unveils that at many SFS, safety conditions are not met and vultures may be exposed to risks, such as the ingestion of toxic substances (e.g., Pb) or electrocution by energy infrastructure. To minimize unintended negative consequences from SFS, it will be essential to increase the interaction between SFS managers and conservation practitioners, to increase the flow of information on best management practices and enforce stringent and clear guidelines that minimize any risks to vultures.Peer reviewe
Aging traits and sustainable trophy hunting of African lions
Trophy hunting plays a significant role in wildlife conservation in some contexts in various
parts of the world. Yet excessive hunting is contributing to species declines, especially for
large carnivores. Simulation models suggest that sustainable hunting of African lions may be
achieved by restricting offtakes to males old enough to have reared a cohort of offspring. We
tested and expanded criteria for an age-based approach for sustainably regulating lion
hunting. Using photos of 228 known-age males from ten sites across Africa, we measured
change in ten phenotypic traits with age and found four age classes with distinct
characteristics: 1-2.9 years, 3-4.9 years, 5-6.9 years, and ≥7 years. We tested the aging
accuracy of professional hunters and inexperienced observers before and after training on
aging. Before training, hunters accurately aged more lion photos (63%) than inexperienced
observers (48%); after training, both groups improved (67-69%). Hunters overestimated 22%
of lions <5 years as 5-6.9 years (unsustainable) but only 4% of lions <5 years as ≥7 years
(sustainable). Due to the lower aging error for males ≥7 years, we recommend 7 years as a
practical minimum age for hunting male lions. Results indicate that age-based hunting is
feasible for sustainably managing threatened and economically significant species such as the
lion, but must be guided by rigorous training, strict monitoring of compliance and error, and
conservative quotas. Our study furthermore demonstrates methods for identifying traits to age
individuals, information that is critical for estimating demographic parameters underlying
management and conservation of age-structured species.http://www.elsevier.com/ locate/biocon2017-09-30hb2016Centre for Wildlife ManagementMammal Research InstituteZoology and Entomolog
Potential release sites and strategies for a Bearded Vulture Gypaetus barbatus reintroduction in South Africa
The southern African population of Bearded Vultures Gypaetus barbatus has declined rapidly and it is threatened with extinction. In response to this decline and the additional threats of wind farm developments in the core of the species’ range, it has been proposed to establish a reintroduced population within their historic South African range as insurance against regional extinction. To facilitate such a reintroduction, we used Maximum Entropy Modelling based on suitable nesting habitat to identify and define five potential reintroduction sites. We then compared the suitability of these sites based on the quantification of various threats and benefits within each site. The two highest-ranking sites were located mostly in the Eastern Cape Province of South Africa. We then compared different release strategies, using a Population Viability Analysis, to determine which approach would be most likely to be successful (defined as >34 individuals after 30 years). These models suggest that establishing a captive breeding programme and releasing captive-bred young would lower failure rates to 25.5–49.8%, compared with the direct releases of wild taken fledglings, without a supporting captive breeding programme (78.3–95.7%). Our models also suggest that even in the presence of high mortality rates at the reintroduction site, such a reintroduction would still be a worthwhile project, because it reduces the probability of extinction of the southern African population by approximately 30% over a 50-year period.
French Title:Sites de lâchers potentiels et stratégies pour la réintroduction du gypaète barbu en Afrique du Sud
La population de gypaètes barbus Gypaetus barbatus d’Afrique australe a rapidement diminué et est menacée d’extinction. En réponse à ce déclin et aux menaces supplémentaires liées au développement de parcs éoliens au coeur de l’aire de répartition de l’espèce, il a été proposé d’établir une population réintroduite au sein de l’aire de répartition historique de l’espèce en Afrique du Sud comme assurance contre l’extinction régionale. Pour faciliter une telle réintroduction, nous avons utilisé une modélisation de l’entropie maximale basée sur un habitat de nidification approprié pour identifier et définir cinq sites de réintroduction potentiels. Nous avons ensuite comparé l’adéquation de ces sites en nous basant sur la quantification des diverses menaces et des avantages de chaque site. Les deux sites les mieux classés étaient situés pour la plupart dans la province du Cap-Oriental en Afrique du Sud. Nous avons ensuite comparé différentes stratégies de réintroduction, en utilisant une analyse de viabilité de la population, afin de déterminer quelle approche aurait le plus de chances de réussir (définie comme >34 individus après 30 ans). Ces modèles suggèrent que la mise en place d’un programme d’élevage en captivité et le lâcher de jeunes élevés en captivité réduirait les taux d’échec à 25.5–49.8% par rapport aux lâchers directs de jeune oiseaux capturés dans la nature, sans programme de soutien à l’élevage en captivité (78.3–95.7%). Nos modèles suggèrent également que même en présence de taux de mortalité élevés sur le site de réintroduction, une telle réintroduction serait toujours un projet intéressant, car elle réduit la probabilité d’extinction de la population d’Afrique australe d’environ 30% sur une période de 50 ans.
Keywords: captive breeding, ex situ conservation, habitat suitability analysis, population viability analysis, vulture crisi
Appraisal of ozone as biologically active molecule and experimental tool in biomedical sciences
Ozone (O3) (CAS 10028-15-6) is a major air industrial pollutant and is well known for its very strong oxidative actions which affords the molecule its useful antimicrobial and deodorizing properties, but also its potential toxic effects. Knowledge of the activity and safety of ozone is important if its potential for use as a biologically active agent is to be realized, especially in view of the numerous unsubstantiated medicinal claims that are being made. To investigate ozone-induced oxidative stress as a model for investigating the neurobiology and treatment of certain central nervous system disorders, an experimental ozone inhalation model was developed to administer ozone to intact test animals following acute or chronic exposure. The model was successfully utilized to investigate the effect of dose and duration of exposure to ozone and its resultant effect on oxidative stress markers, depressive-like behaviours and response to antidepressant treatment. These studies demonstrate that the model not only is useful for studying the biological activity of ozone, but also for studying disorders of the brain associated with increased oxidative stress as well as the effects of altered redox status on drug treatment and response
Ozone modulates the effects of imipramine on immobility in the forced swim test, and nonspecific parameters of hippocampal oxidative stress in the rat
Depression has been associated with oxidative stress. There is increased awareness of the role of environmental toxins in the development of mood disorders. Ozone, a pro-oxidant and environmental pollutant, has been noted to have central nervous system effects. We investigated the effects of acute and chronic ozone inhalation on the response of imipramine in the forced-swim test (FST) and on biomarkers of oxidative stress in rat hippocampus. Sprague Dawley rats were exposed to 0, 0.25 or 0.7 ppm ozone per inhalation 4 h daily for either 30 days (chronic) or once (acute). Animals were then injected intraperitoneally with imipramine (10 mg/kg) or saline 24, 5 and 1 h before the forced-swim test. Hippocampal superoxide accumulation and lipid peroxidation were measured. Imipramine evoked an antidepressant-like effect independent of acute or chronic ozone exposure. However, 0.7 ppm acute ozone and 0.25 ppm chronic ozone attenuated the antidepressant-like effects of imipramine. The ozone exposures also elevated hippocampal superoxide accumulation and lipid peroxidation. Importantly, imipramine reversed the lipid peroxidation induced by chronic ozone, thereby preventing cellular damage induced by oxidative stress. Ozone exposure presents a feasible model with etiological validity to investigate oxidative stress in depression and antidepressant actio
Studies on cellular resilience and adaptation following acute and repetitive exposure to ozone in cultured human epithelial (HeLa) cells
Ozone is used to treat several medical conditions, while the underlying mechanisms of action are sometimes poorly understood. In the current study, we exposed cultured human epithelial (HeLa) cells acutely and repeatedly to ozone and investigated the effects thereof on cell viability. The involvement of anti-apoptotic pathways in observed adaptive responses to ozone were investigated by employing the Akt inhibitor (–)-deguelin. Cells were exposed to an ozone-saturated physiological solution using various dosing regimens, including acute exposure and various repetitive exposures. Cell viability was determined with Trypan Blue or MTT tests, or by a DNA-fragmentation (comet) assay. Acute ozone exposure compromised cell membrane integrity severely, while adaptation to reverse an initial reduction in mitochondrial activity was observed. Repetitive, short-duration exposures followed by a single long-duration exposure to ozone furnished a protective adaptation that was reversed by Akt inhibition. Extracellular and intracellular damage (and adaptation) occurs differentially. While acute ozone may decrease cell viability, multiple preexposures up-regulates cellular plasticity via induction of anti-apoptotic pathways in a treatment regimen-specific manne
De National Institute of Health Stroke Scale versus Barthel Index als voorspeller van revalidatie uitkomsten 2 maanden na een CVA
De National Institute of Health Stroke Scale versus Barthel Index als voorspeller van revalidatie uitkomsten 2 maanden na een CVA
Introduction: In the Netherlands, the National Institute of Health Stroke Scale (NIHSS) is, nowadays, used as a standard measure of stroke severity in the acute phase. Our primary aim was to evaluate whether the predictive value of the NIHSS regarding functional independence 2 months later, adds to the Barthel Index (BI); a widely used measure for functional independence, and vice versa.Methods: Data was retrieved from the Restore4Stroke Cohort study, a prospective longitudinal study in which patients from six Dutch hospitals were followed for two years after stroke. We used data on baseline stroke severity (NIHSS) and functional independence (BI), and functional independence (BI) 2 months later.Results: The baseline BI explained 31% of variance of the BI at 2 months. Adding the NIHSS explained another 6%. The baseline NIHSS explained 28% of variance of the BI at 2 months. Adding the baseline BI in the model explained another 10%. Conclusions: In general, the BI predicts functional independence better than the NIHSS. A more severe stroke and lower functional independence predict less functional independence 2 months later. Future studies should include other possible predictors, such as psychosocial or personal factors
Low organotin contamination of harbour sediment in Svalbard
Arctic sea routes are opening up for maritime transport due to sea ice retreat leading to increasing human activities in the Arctic and concomitant pressures on the environment. Organotin compounds are used in antifouling paints of large seagoing vessels and are known to leach into the marine environment and accumulate in sediments and biota. As organotin levels in Svalbard sediments have not been documented in peer-reviewed literature before, this study describes the levels in sediment of harbours around Svalbard (Ny-Ă…lesund, Longyearbyen, Svea, Pyramiden and Barentsburg). Organotin levels in sediments of Svalbard harbours were low (below the detection limit up to 14 ng Sn/g dw sum-butyltin) compared to other Arctic regions with a longer history of shipping. Levels were below known no effect levels and in accordance, no imposex was found in marine whelks from Ny-Ă…lesund harbour. Of all other analysed compounds in sediments of Kongsfjorden (polycyclic aromatic hydrocarbon (PAHs), polychlorinated biphenyls, polybrominated diphenylethers and perfluorinated compounds) PAH levels were highest and in one sample above action levels. It is advised to continue monitoring contaminant levels, for which the current results form a good basis. If contaminant levels rise, mitigation measures can be taken in time.</p