Estrutura do sub-bosque em manchas florestais no Pantanal da Nhecolândia: efeitos da presença de gado.

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Ocupação de manchas florestais por espécies de pica-paus e arapaçus no Pantanal.

Neste estudo avaliamos a influência de algumas variáveis de paisagem e habitat nas probabildades de ocupação de manchas florestais naturais por seis espécies deste tipo de aves no Pantanal da Nhecolândia. O estudo foi realizado em 2008 na fazenda Nhumirim e arredores, nas estações chuvosa e seca

A recipe for postfledging survival in great tits Parus major: be large and be early (but not too much)

Survival of juveniles during the postfledging period can be markedly low, which may have major consequences on avian population dynamics. Knowing which factors operating during the nesting phase affect postfledging survival is crucial to understand avian breeding strategies. We aimed to obtain a robust set of predictors of postfledging local survival using the great tit (Parus major) as a model species. We used mark–recapture models to analyze the effect of hatching date, temperatures experienced during the nestling period, fledging size and body mass on first-year postfledging survival probability of great tit juveniles. We used data from 5192 nestlings of first clutches ringed between 1993 and 2010. Mean first-year postfledging survival probability was 15.2%, and it was lower for smaller individuals, as well as for those born in either very early or late broods. Our results stress the importance of choosing an optimum hatching period, and raising large chicks to increase first-year local survival probability in the studied population.Secretaría de Estado de Investigación, Desarrollo e Innovación (Grant/Award Number: ‘CGL2013-48001-C2-1-P’)Peer reviewe

Ocupação de manchas florestais por jaó (Crypturellus undulatus) no oeste do Pantanal da Nhecolândia, Corumbá, MS.

ABSTRACT: Forest patch occupancy by Undulated Tinamou (Crypturellus undulatus) in west of Pantanal da Nhecolândia, Corumbá, MS. The deforestation process and changes in the structure of forest habitats in Pantanal have caused decline in the biological diversity. The goal of this study was to evaluate the influence of landscape and forest patches structure on the occupancy probabilities of Undulated Tinamou Crypturellus undulatus (Temminck, 1815) in the western ?Pantanal da Nhecolândia?, Mato Grosso do Sul, Brazil. From January to October 2008 we sampled 40 sites in forest patches in four areas of different ecological and management conditions. In each point we obtained landscape (area and distance between forest patches) and habitat variables (understory and litter biomass), as well as presence/absence data of C. undulatus. The highest probabilities of occupation were obtained in large forest patches (> 800 ha), connected ( 0.8 kg / m3 ) and with accumulated litter biomass (> 1.5 kg / m2). The results suggest that human impacts (deforestation, range thinning of cordilheiras, replacement of native vegetation by exotic pastures, and changes in structure of forest habitats due to livestok action) in Pantanal negatively influence the probabilities of occupancy by C. undulatus. Management practices that help the conservation of suitable habitats for wildlife are fundamental to achieve and maintain the ecological sustainability of cattle ranches in the Pantanal wetland. RESUMO: A fragmentação e as alterações na estrutura dos habitats florestais no Pantanal têm promovido significativas mudanças nos processos ecológicos e diversidade biológica regional. Este estudo objetivou avaliar como as variáveis da paisagem e do habitat afetam as probabilidades de ocupação de manchas florestais pelo jaó Crypturellus undulatus (Temminck, 1815) no oeste do Pantanal da Nhecolândia, Mato Grosso do Sul. De janeiro a outubro de 2008 foram amostrados 40 pontos distribuídos em manchas florestais em quatro áreas com diferentes condições de manejo. Nestes pontos foram obtidas variáveis da paisagem (área e distância entre as manchas florestais) e do habitat (biomassas de sub-bosque e serrapilheira), bem como dados de presença/ausência de C. undulatus. As maiores probabilidades de ocupação foram obtidas em manchas florestais grandes (> 800 ha), conectadas ( 0,8 kg/m3 de biomassa) e com elevado acúmulo de biomassa de serrapilheira (> 1,5 kg/m2 ). Os resultados sugerem que as intervenções humanas na paisagem (raleamento de cordilheiras, substituição de pastagens nativas por pastagens cultivadas exóticas e alteração na estrutura do habitat florestal por impacto do forrageio e pisoteio de gado bovino) no Pantanal podem afetar negativamente as populações de C. undulatus. Práticas de manejo que auxiliem a conservação de habitats favoráveis à vida selvagem são fundamentais para alcançar ou manter a sustentabilidade ecológica em fazendas de pecuária no Pantanal

Analysis of events with b-jets and a pair of leptons of the same charge in pp collisions at √s=8 TeV with the ATLAS detector

An analysis is presented of events containing jets including at least one b-tagged jet, sizeable missing transverse momentum, and at least two leptons including a pair of the same electric charge, with the scalar sum of the jet and lepton transverse momenta being large. A data sample with an integrated luminosity of 20.3 fb−1 of pp collisions at √s=8 TeV recorded by the ATLAS detector at the Large Hadron Collider is used. Standard Model processes rarely produce these final states, but there are several models of physics beyond the Standard Model that predict an enhanced rate of production of such events; the ones considered here are production of vector-like quarks, enhanced four-top-quark production, pair production of chiral b′-quarks, and production of two positively charged top quarks. Eleven signal regions are defined; subsets of these regions are combined when searching for each class of models. In the three signal regions primarily sensitive to positively charged top quark pair production, the data yield is consistent with the background expectation. There are more data events than expected from background in the set of eight signal regions defined for searching for vector-like quarks and chiral b′-quarks, but the significance of the discrepancy is less than two standard deviations. The discrepancy reaches 2.5 standard deviations in the set of five signal regions defined for searching for four-top-quark production. The results are used to set 95% CL limits on various models