23 research outputs found

    The golden lancehead Bothrops insularis

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    Adult individuals of the island pitviper Bothrops insularis have a diet based on birds. We analysed bird species recorded in the gut of this snake and found that it relies on two out of 41 bird species recorded on the island. When present, these two prey species were among the most abundant passerine birds on the island. A few other migrant birds were very occasionally recorded as prey. A resident bird species (Troglodytes musculus) is the most abundant passerine on the island, but seems able to avoid predation by the viper. Bothrops insularis is most commonly found on the ground. However, during the abundance peak of the tyrannid passerine Elaenia chilensis on the island, more snakes were found on vegetation than on the ground. We suggest that one cause may be that these birds forage mostly on vegetation, and thus cause the snakes to search for prey on this arboreal substratum.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Inst Butantan, Lab Ecol & Evolucao, BR-05503900 São Paulo, BrazilUniv São Paulo, Dept Ecol, BR-05508090 São Paulo, BrazilBirdLife SAVE Brasil, BR-05427010 São Paulo, BrazilUniv Estadual Paulista, Programa Pos Grad Biol Anim, Inst Biociencias Letras & Ciencias Exatas, BR-15054000 Sao Jose do Rio Preto, SP, BrazilUniv Estadual Campinas, Museu Zool, BR-13083970 Campinas, SP, BrazilUniv Estadual Paulista, Programa Pos Grad Biol Anim, Inst Biociencias Letras & Ciencias Exatas, BR-15054000 Sao Jose do Rio Preto, SP, Brazi

    Dosagem de metabólitos de glucocorticoides e progesterona em fezes de papagaio-verdadeiro (Amazona aestiva)

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    The objectives of the present study were to evaluate fecal concentrations of metabolites of glucocorticoids, measured by enzyme immunoassay with a cortisol antibody and by radioimmunoassay with a corticosterone antibody, and progesterone by radioimmunoassay with a progesterone antibody in blue-fronted parrot (Amazona aestiva) after ACTH challenge.The adrenal stimulation with ACTH (25 UI/animal) resulted in an increase of fecal glucocorticoids metabolites concentration, but it did not affect the concentrations of fecal progesterone metabolites. Although there were no synchronized peaks of glucocorticoid metabolites excretion measured by enzyme immunoassay and radioimmunoassay, there were two peaks of excretion, one at 2-4 hours and other at 8-10 hours. Despite the occurrence of peaks, the analysis of fecal glucocorticoids metabolites and progesterone metabolites showed no effect of group (control and treatment), moment (hours of sampling) and sex.Os objetivos do presente trabalho foram avaliar as concentrações fecais de metabólitos de glicocorticoides, mensurados por enzimaimunoensaio, empregando-se anticorpos contra cortisol, e por radioimunoensaio, empregando-se anticorpo contra corticosterona, e dos metabólitos da progesterona, mensurados por raioimunoensaio empregando-se anticorpo contra progesterona, em papagaios-verdadeiros (Amazona aestiva) após desafio com ACTH. A estimulação da adrenal com 25 UI/animal de ACTH resultou na elevação das concentrações de metabólitos de glicocorticoides, mas não modificou a dos metabólitos da progesterona fecal em papagaio-verdadeiro. Embora não tenha sido observada a sincronização dos picos de excreção fecal dos metabólitos de glicocorticoides mensurados por enzimaimunoensaio e radioimunoensaio, houve dois picos de excreção, um entre 2 e 4 horas e outro entre 8 e 10 horas. Apesar dos picos, não foram detectados efeitos de Grupos (Tratamento x Controle), momento (horas de coleta) ou sexo (macho x fêmea) nos resultados observados nas concentrações fecais de metabólitos de glicocorticoides e de progesterona, com os métodos empregados.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Unesp Faculdade de Medicina Veterinária e ZootecniaFiscal Estadual Agropecuário da Agência de Defesa Agropecuária do Estado do CearáUniversidade Federal da BahiaUSP Faculdade de Medicina Veterinária e ZootecniaUnesP Faculdade de Medicina Veterinária e ZootecniaUnesp Faculdade de Medicina Veterinária e ZootecniaUnesP Faculdade de Medicina Veterinária e Zootecni

    Breaking Functional Connectivity into Components: A Novel Approach Using an Individual-Based Model, and First Outcomes

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    Landscape connectivity is a key factor determining the viability of populations in fragmented landscapes. Predicting ‘functional connectivity’, namely whether a patch or a landscape functions as connected from the perspective of a focal species, poses various challenges. First, empirical data on the movement behaviour of species is often scarce. Second, animal-landscape interactions are bound to yield complex patterns. Lastly, functional connectivity involves various components that are rarely assessed separately. We introduce the spatially explicit, individual-based model FunCon as means to distinguish between components of functional connectivity and to assess how each of them affects the sensitivity of species and communities to landscape structures. We then present the results of exploratory simulations over six landscapes of different fragmentation levels and across a range of hypothetical bird species that differ in their response to habitat edges. i) Our results demonstrate that estimations of functional connectivity depend not only on the response of species to edges (avoidance versus penetration into the matrix), the movement mode investigated (home range movements versus dispersal), and the way in which the matrix is being crossed (random walk versus gap crossing), but also on the choice of connectivity measure (in this case, the model output examined). ii) We further show a strong effect of the mortality scenario applied, indicating that movement decisions that do not fully match the mortality risks are likely to reduce connectivity and enhance sensitivity to fragmentation. iii) Despite these complexities, some consistent patterns emerged. For instance, the ranking order of landscapes in terms of functional connectivity was mostly consistent across the entire range of hypothetical species, indicating that simple landscape indices can potentially serve as valuable surrogates for functional connectivity. Yet such simplifications must be carefully evaluated in terms of the components of functional connectivity they actually predict

    Bird-termite interactions in Brazil: A review with perspectives for future studies

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    Publisher Correction: Distance to range edge determines sensitivity to deforestation

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    Correction to: Nature Ecology & Evolution https://doi.org/10.1038/s41559-019-0889-z, published online 06 May 2019
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