20 research outputs found

    The ecology of human-caused mortality for a protected large carnivore

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    Mitigating human-caused mortality for large carnivores is a pressing global challenge for wildlife conservation. However, mortality is almost exclusively studied at local (within-population) scales creating a mismatch between our understanding of risk and the spatial extent most relevant to conservation and management of wide-ranging species. Here, we quantified mortality for 590 radio-collared mountain lions statewide across their distribution in California to identify drivers of human-caused mortality and investigate whether human-caused mortality is additive or compensatory. Human-caused mortality, primarily from conflict management and vehicles, exceeded natural mortality despite mountain lions being protected from hunting. Our data indicate that human-caused mortality is additive to natural mortality as population-level survival decreased as a function of increasing human-caused mortality and natural mortality did not decrease with increased human-caused mortality. Mortality risk increased for mountain lions closer to rural development and decreased in areas with higher proportions of citizens voting to support environmental initiatives. Thus, the presence of human infrastructure and variation in the mindset of humans sharing landscapes with mountain lions appear to be primary drivers of risk. We show that human-caused mortality can reduce population-level survival of large carnivores across large spatial scales, even when they are protected from hunting

    Assessing the status of leopard in the Cape Fold Mountains using a Bayesian spatial capture–recapture model in Just Another Gibbs Sampler

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    Large carnivores are in decline globally. The leopard's (Panthera pardus) adaptability enabled its survival as the last remaining apex predator in the Western Cape, South Africa. Limited suitable habitat and anthropogenic activity imperil the continued survival of leopards, yet density estimates are lacking in the Western Cape, especially across unprotected areas. We employ the flexible modelling environment of Just Another Gibbs Sampler (JAGS) to implement a Bayesian spatial capture–recapture (SCR) model and generate the first density estimate for the leopard population in the Boland Mountain Complex using a dataset collected in 2010–2011. Leopard density was estimated at 1.69/100 km2 (95% CI = 1.4–1.99) with adult female leopards occurring at a higher density (0.93/100 km2 [95% CI = 0.64–1.18]) than males (0.76/100 km2 [95% CI = 0.62–0.90]). Our modelling shows that males have more extensive ranges than females, increasing their susceptibility to anthropogenic threats, which are generally more abundant at the study area's periphery. Tailored conservation efforts are recommended in conjunction with an up-to-date leopard population density reassessment. The JAGS approach to SCR also enabled a detailed investigation of animal distribution and movement, and provides a reliable methodology to monitor population trends

    Neuropeptide Y protects retinal neural cells against cell death induced by ecstasy

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    Ecstasy (3,4-methylenedioxymethamphetamine; MDMA) has potent CNS stimulant effects. Besides the acute effects of MDMA, such as psychomotor activation, euphoria, decreased appetite, and hyperthermia, long-term damage of dopaminergic and serotonergic nerve terminals in multiple brain areas have also been reported. Although some studies have demonstrated that considerable amounts of MDMA reach the vitreous humor of the eye, and that serious visual consequences can result from MDMA consumption, the toxic effect of MDMA on the retina has not been completely elucidated. Neuropeptide Y (NPY) is present in the CNS, including the retina. The aim of the present study was to evaluate the effect of MDMA on rat retinal neural cell viability and investigate the involvement of 5-HT 2A-receptor (5-HT2A) activation. Moreover, the neuroprotective role of NPY on MDMA-induced toxicity was also investigated. MDMA induced necrosis [MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) and propidium iodide assays] and apoptosis (immunoreactivity of cleaved caspase-3) in mixed cultures of retinal neural cells (neurons, macroglia and microglia), in a concentration-dependent manner. MDMA-induced toxicity was enhanced at higher temperature (40 °C) and was reduced by the 5HT2A-receptor antagonist, ketanserin (1 [mu]M). Interestingly, necrotic and apoptotic cell death induced by MDMA was inhibited by NPY (100 nM).http://www.sciencedirect.com/science/article/B6T0F-4RDS1WF-1/1/a468528fe770ad17b607773d0d0f415

    The implications of large home range size in a solitary felid, the Leopard (Panthera pardus)

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    The size of the home range of a mammal is affected by numerous factors. However, in the normally solitary, but polygynous, Leopard (Panthera pardus), home range size and maintenance is complicated by their transitory social grouping behavior, which is dependent on life history stage and/or reproductive status. In addition, the necessity to avoid competition with conspecifics and other large predators (including humans) also impacts upon home range size. We used movement data from 31 sites across Africa, comprising 147 individuals (67 males and 80 females) to estimate the home range sizes of leopards. We found that leopards with larger home ranges, and in areas with more vegetation, spent longer being active and generally traveled faster, and in straighter lines, than leopards with smaller home ranges. We suggest that a combination of bottom-up (i.e., preferred prey availability), top-down (i.e., competition with conspecifics), and reproductive (i.e., access to mates) factors likely drive the variability in Leopard home range sizes across Africa. However, the maintenance of a large home range is energetically expensive for leopards, likely resulting in a complex evolutionary trade-off between the satisfaction of basic requirements and preventing potentially dangerous encounters with conspecifics, other predators, and people

    Avaliação do crescimento e do custo da alimentação do pacu (Piaractus mesopotamicus Holmberg, 1887) submetido a ciclos alternados de restrição alimentar e realimentação Evaluation of the growth and feeding costs of pacu (Piaractus mesopotamicus) submitted to alternate cycles of feeding restriction and refeeding

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    Avaliaram-se os efeitos da utilização de ciclos alternados de restrição alimentar e realimentação no crescimento do pacu, durante o período de engorda, e a viabilidade desta prática na produção comercial da espécie. Juvenis foram distribuídos em três tanques e submetidos a diferentes manejos alimentares, constituindo os tratamentos: A (alimentado ad libitum), B (restrição alimentar de 4 semanas, realimentado por 9 semanas) e C (6 semanas de restrição alimentar, realimentado por 7 semanas), em um total de 13 semanas por ciclo (4 ciclos experimentais). No final de cada ciclo alimentar, 20 peixes de cada tratamento foram amostrados e os dados biométricos registrados. Os valores obtidos para peso, comprimento total e fator de condição (K) foram submetidos a ANOVA e as médias comparadas pelo teste de Duncan. Os resultados mostraram que o tratamento C é o mais indicado somente para outono/inverno, promovendo maior crescimento, menor custo com ração, baixa conversão alimentar e maior receita líquida parcial. Entretanto, durante as estações mais quentes do ano (primavera/verão) outros programas de alimentação devem ser testados, utilizando-se períodos mais curtos de restrição alimentar. Quando se tratou da produção anual, o tratamento A respondeu melhor em termos de biomassa produzida, apesar do maior gasto com alimentação, visto que, com o aumento da temperatura, o crescimento dos peixes dos demais tratamentos ficou prejudicado.<br>The present study evaluated the effects of alternating food restriction and refeeding cycles on the growth of pacu, during the growout phase and the viability of this practice in the commercial production of the species. Juvenile fish were distributed in 3 tanks and submitted to different feeding strategies: group A (fed ad libitum daily), B (food restricted to 4 weeks and refed for 9 weeks) and C (food restricted to 6 weeks and refed for 7 weeks) totalizing 13 weeks per cycle (4 experimental cycles). At the end of each feeding cycle, 20 fish per treatment were sampled and the biometric data were registered. Values of weight, total length and condition factor (K) were submitted to ANOVA and the averages were compared by Duncan test. The results showed that the treatment C presented better results only in autumn/winter periods, promoting better growth, lower cost ration, lower food conversion and better partial net income. Otherwise, during the warmer periods of the year (spring/summer) other feeding strategies must be tested, utilizing shorter periods of food restriction. Regarding to the annual production, the treatment A showed higher biomass, although higher feeding costs. With the increase in the temperature, the growth of the fish from the other treatments was delayed

    The Brand Likeability Effect: Can Firms make Themselves more Likeable?

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    In 2011, Lincoln Automobiles, part of the Ford Motor Company and named after President Lincoln, was voted as the most liked company in America. Lincoln's customer satisfaction ratings were the highest they had been in the past 15 years. Although brand managers implicitly emphasise the importance of likeability in branding strategies, brand likeability is a concept that is little researched, particularly at the firm level. The question of ‘what is likeable?’ has not yet been answered thoroughly and few studies have to date examined what causes a firm or brand to be perceived as liked or disliked. This paper aims to provide an understanding of the theories and concepts that explain brand likeability. The comprehensive literature review identifies two dimensions: source stimuli and psychological evaluations. Additionally, the authors propose several outcomes of brand likeability, extending existing knowledge on brand love and attitude research, offering managers defining principles of the Brand Likeability Effect. The proposed implications for managers are in four phases; implementing these into the firm's branding practices increases the likelihood that customers will perceive the firm as being more likeable
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