152 research outputs found
Dermatobiose em Panthera onca : primeira descrição e regressão logística multinomial para estimar e prever o parasitismo em animais selvagens capturados
Dermatobia hominis is a parasite widely distributed in neotropical regions. The parasitic phase of the cycle is characterized by the formation of a subcutaneous nodule in the host, which can promote infestation by other dipterans and skin infections. The aim of this report is to register parasitism by D. hominis in free-ranging Panthera onca captured in the Brazilian wetland and to determine significant biological and meteorological factors that are likely to influence the presence of larval parasitism in captured wild jaguars. Between 2011 to 2020, 34 jaguars were captured and examined manually by searching for lesions characteristic of myiasis. By manual compression in the subcutaneous nodules, larvae morphologically identified as D. hominis (first and third instars) were collected from 13 jaguars. A multinomial logistic regression showed that adult jaguars had 16.49-fold higher odds of being parasitized than subadults. Thus, jaguars captured in the season of July–September have 34.01- and 11.42-fold higher odds of being parasitized compared to the seasons of October–December and April–June, respectively, which is associated with high total monthly precipitation in the previous season. The present study is the first to describe parasitism by D. hominis larvae in jaguars.Dermatobia hominis é um parasito amplamente distribuído nas regiões neotropicais. A fase parasitária do ciclo é caracterizada pela formação de um nódulo subcutâneo no hospedeiro, que pode promover infestação por outros dípteros e infecções cutâneas. O objetivo deste relato é registrar o parasitismo por D. hominis em Panthera onca de vida livre, capturado no pantanal brasileiro e determinar fatores biológicos e meteorológicos significativos que podem influenciar a presença de parasitismo larval em onças-pintadas selvagens capturadas. Entre 2011 e 2020, 34 onças-pintadas foram capturadas e examinadas manualmente em busca de lesões características de miíase. Por compressão manual nos nódulos subcutâneos, larvas classificadas morfologicamente como D. hominis (primeiro e terceiro instares) foram coletadas de 13 onças-pintadas. Uma regressão logística multinomial mostrou que onças-pintadas adultas tinham chances 16,49 vezes maiores de serem parasitadas do que subadultos. Assim, onças-pintadas capturadas na temporada de julho a setembro têm probabilidade 34,01 e 11,42 vezes maior de serem parasitadas em comparação com as temporadas de outubro a dezembro e de abril a junho, respectivamente, o que está associado à alta precipitação total mensal na temporada anterior. O presente estudo é o primeiro a descrever parasitismo por larvas de D. hominis em onças-pintadas
Pyrosequencing Unveils Cystic Fibrosis Lung Microbiome Differences Associated with a Severe Lung Function Decline
Chronic airway infection is a hallmark feature of cystic fibrosis (CF) disease. In the present study, sputum samples from CF patients were collected and characterized by 16S rRNA gene-targeted approach, to assess how lung microbiota composition changes following a severe decline in lung function. In particular, we compared the airway microbiota of two groups of patients with CF, i.e. patients with a substantial decline in their lung function (SD) and patients with a stable lung function (S). The two groups showed a different bacterial composition, with SD patients reporting a more heterogeneous community than the S ones. Pseudomonas was the dominant genus in both S and SD patients followed by Staphylococcus and Prevotella. Other than the classical CF pathogens and the most commonly identified non-classical genera in CF, we found the presence of the unusual anaerobic genus Sneathia. Moreover, the oligotyping analysis revealed the presence of other minor genera described in CF, highlighting the polymicrobial nature of CF infection. Finally, the analysis of correlation and anti-correlation networks showed the presence of antagonism and ecological independence between members of Pseudomonas genus and the rest of CF airways microbiota, with S patients showing a more interconnected community in S patients than in SD ones. This population structure suggests a higher resilience of S microbiota with respect to SD, which in turn may hinder the potential adverse impact of aggressive pathogens (e.g. Pseudomonas). In conclusion, our findings shed a new light on CF airway microbiota ecology, improving current knowledge about its composition and polymicrobial interactions in patients with CF
Predation and cathemerality. Comparing the impact of predators on the activity patterns of lemurids and ceboids.
The removal, or absence, of predatory species could be a contributing proximate factor to the rise of primate cathemerality. But predators themselves can also be cathemeral, so cathemerality could well be an evolutionary stable strategy. From a comparative perspective, it appears that the effect of predatory species cannot provide a unitary explanation for cathemerality. Varying distributions and population densities of predators, especially raptors, may be key factors in owl monkey (Aotus) cathemerality, but temperature and lunar cycle variation have also been implicated. In Madagascar, while raptors are potential predators of lemur species, the cathemerality of Eulemur species coincides with that of the fossa (Cryptoprocta ferox), a major predatory threat to lemurs. Thus, lemurid cathemerality may be more parsimoniously explained as an evolutionary stable strategy
A História do Conceito de Conservação e o Caso da Onça-Pintada no Brasil
This article is about the main changes in relation to jaguar conservation strategies in Brazil, particularly since the late 1970s. This research sought to understand which elements were incorporated into the concept of conservation and what they report about the social circumstances and practices added to it. For that, were analyzed scientific publications about jaguars in Brazil, secondary bibliographic sources and consultation of conservation project sites. We observed that the concept of conservation assumed a structure of different appropriations: the conservation thought by specialists and based on the intrinsic and ecological value of the species, as well as the conservation based on the requirements of the "real world" mainly due to the conflict with human populations. These appropriations reflect the dynamicity of the concept, which communicates with philosophical, cultural, political and economic issues.O presente artigo relaciona a história do conceito de conservação com as estratégias de conservação da onça-pintada no Brasil, desenvolvidas a partir do final da década de 1970. Buscou-se compreender os significados agregados ao conceito de conservação, quais elementos foram incorporados, os seus deslocamentos e o que eles informam acerca das interações com circunstâncias e práticas sociais. Para tanto, foram analisadas fontes bibliográficas primárias e secundárias sobre a história da conservação, publicações científicas sobre a onça-pintada no Brasil, e foram consultados sites de projetos de conservação. Observou-se que o conceito de conservação foi apropriado de diversas formas: a conservação pensada por especialistas e com base no valor intrínseco e ecológico da espécie, assim como a conservação com base nos requisitos do “mundo real”, em função, sobretudo, do conflito com populações humanas. Essas apropriações refletem a dinamicidade do conceito, que comunica com questões de cunho filosófico, cultural, político e econômico
Relative availability of natural prey versus livestock predicts landscape suitability for cheetahs Acinonyx jubatus
Fear of the dark? A mesopredator mitigates large carnivore risk through nocturnality, but humans moderate the interaction.
While constrained by endogenous rhythms, morphology and ecology, animals may still exhibit flexible activity patterns in
response to risk. Temporal avoidance of interspecific aggression can enable access to resources without spatial exclusion.
Apex predators, including humans, can affect mesopredator activity patterns. Human context might also modify temporal
interactions between predators. We explored activity patterns, nocturnality and the effects of human activity upon a guild of
carnivores (grey wolf, Canis lupus; Eurasian lynx, Lynx lynx; red fox, Vulpes vulpes) using travel routes in Plitvice Lakes
National Park, Croatia. Humans were diurnal, foxes nocturnal and large carnivores active during the night, immediately after
sunrise and before sunset. Carnivore activity patterns overlapped greatly and to a similar extent for all pairings. Activity curves
followed expectations based on interspecific killing, with activity peaks coinciding where body size differences were small (wolf
and lynx) but not when they were intermediate (foxes to large carnivores). Carnivore activity, particularly fox, overlapped much
less with that of diurnal humans. Foxes responded to higher large carnivore activity by being more nocturnal. Low light levels
likely provide safer conditions by reducing the visual detectability of mesopredators. The nocturnal effect of large carnivores was
however moderated and reduced by human activity. This could perhaps be due to temporal shielding or interference with risk
cues. Subtle temporal avoidance and nocturnality may enable mesopredators to cope with interspecific aggression at shared
spatial resources. Higher human activity moderated the effects of top-down temporal suppression which could consequently
affect the trophic interactions of mesopredators.Nacionalni Park Plitvička Jezera (Plitvice Lakes National Park), The Bernd Thies Foundation, EuroNatur, Bangor University, The UK Wolf Conservation Trust, The Coalbourn Charitable Trust, Ann Vernon Memorial Travel Fund and Sir Ian McKellen.http://link.springer.com/journal/265pm2020Centre for Wildlife Managemen
Mamíferos terrestres e aquáticos do Pantanal
Different works have registered the number of mammal species within the natural habitats of the Pantanal based on currently known records, with species richness ranging from 89 to 152 of annotated occurrences. Our present list sums 174 species. However, at least three factors have to be emphasised to deal with recorded numbers: 1) to establish the ecotone limit between the floodplain (which is the Pantanal) and its neighbouring domain like the Cerrado, besides the existence of maps recently produced; 2) the lack of intensive surveys, especially on small mammals, rodents and marsupials; and 3) the constant taxonomic revision on bats, rodents and marsupials. Some species are very abundant - for example the capybara Hydrochoerus hydrochaeris and the crab-eating fox Cerdocyon thous, and some are rare, and others are still intrinsically rare - for example, the bush dog Speothos venaticus. Abundance of species is assumed to reflect ecological resources of the habitat. Local diversity and number of individuals of wild rodents and marsupials also rely on the offering of ecological resources and behavioural specialisation to microhabitat components. A large number of species interact with the type of the vegetation of the habitat, by means of habitat selection through active patterns of ecological behaviour, resulting on dependency on arboreal and forested habitats of the Pantanal. In addition, mammals respond to seasonal shrinking-and-expansion of habitats due to flooding regime of the Pantanal. The highest number of species is observed during the dry season, when there is a considerable expansion of terrestrial habitats, mainly seasonally flooded grassland. Major threats to mammal species are the loss and alteration of habitats due to human intervention, mainly deforestation, unsustainable agricultural and cattle-ranching practices, which convert the natural vegetation into pastures. The Pantanal still harbours about a dozen of species officially listened as in danger. _________________________________________________________________________________ RESUMODiversos trabalhos têm registrado o número de espécies de mamíferos nos diferentes hábitats naturais do Pantanal, com base nos registros do conhecimento corrente, com a riqueza de espécies variando de 89 a 152 ocorrências anotadas. Nossa lista atual soma 174 espécies. Contudo pelo menos três fatores devem ser enfatizados quando se lida com os números encontrados: 1) o limite exato do ecótono entre a bacia de inundação (que é o Pantanal) e os domínios vizinhos, como o Cerrado, apesar da existência de mapas recentes; 2) a falta de levantamentos intensivos, particularmente sobre pequenos mamíferos, roedores e marsupiais; e 3) a revisão taxonômica constante de morcegos, roedores e marsupiais. Algumas espécies são abundantes, como a capivara Hydrochoerus hydrochaeris, e o lobinho Cerdocyon thous, outras são raras e outras ainda são intrinsecamente raras, como o cachorro-vinagre Speothos venaticus. Assume-se que a abundância de espécies refete os recursos ecológicos contidos nos hábitats. A diversidade local e o número de indivíduos de roedores silvestres e marsupiais também dependem da oferta ecológica de recursos e da especialização de comportamento para explorar componentes de micro-hábitats. Grande número de espécies interage com os tipos de vegetação do hábitat, por meio de seleção de hábitat com padrões ativos de comportamento ecológico, que resultam na dependência dos mamíferos de hábitats arbóreos e forestados do Pantanal. Além disso, os mamíferos respondem ao encolhimento e expansão dos hábitats devido à inundação sazonal do Pantanal, com abundância de espécies mais altas na estação seca, quando há considerável expansão de hábitats terrestres, principalmente campos inundáveis. As ameaças mais importantes para os mamíferos são a perda e alteração de hábitats devido à intervenção humana, particularmente o desmatamento, práticas de agricultura e pecuária insustentáveis, com conversão da vegetação natural em pastos. O Pantanal ainda abriga cerca de uma dúzia de espécies ofcialmente ameaçadas de extinção
High Proportion of Male Faeces in Jaguar Populations
Faeces provide relevant biological information which includes, with the application of genetic techniques, the sex and identity of individuals that defecated, thus providing potentially useful data on the behaviour and ecology of individuals, as well as the dynamics and structure of populations. This paper presents estimates of the sex ratio of different felid species (jaguar, Panthera onca; puma, Puma concolor; and ocelot/margay, Leopardus pardalis/Leopardus wiedi) as observed in field collected faeces, and proposes several hypotheses that could explain the strikingly high proportion of faeces from male jaguars. The proportion of male and female faeces was estimated using a non-invasive faecal sampling method in 14 study areas in Mexico and Brazil. Faecal samples were genetically analysed to identify the species, the sex and the individual (the latter only for samples identified as belonging to jaguars). Considering the three species, 72.6% of faeces (n = 493) were from males; however, there were significant differences among them, with the proportion from males being higher for jaguars than for pumas and ocelots/margays. A male-bias was consistently observed in all study areas for jaguar faeces, but not for the other species. For jaguars the trend was the same when considering the number of individuals identified (n = 68), with an average of 4.2±0.56 faeces per male and 2.0±0.36 per female. The observed faecal marking patterns might be related to the behaviour of female jaguars directed toward protecting litters from males, and in both male and female pumas, to prevent interspecific aggressions from male jaguars. The hypothesis that there are effectively more males than females in jaguar populations cannot be discarded, which could be due to the fact that females are territorial and males are not, or a tendency for males to disperse into suboptimal areas for the species. © 2012 Palomares et al
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