HABITAT ASSOCIATIONS OF LAND BIRDS IN FERNANDO DE NORONHA, BRAZIL

ABSTRACT Fernando de Noronha is one of few archipelagos of Brazil. These islands harbor five species of land birds: two introduced species (House Sparrow, Passer domesticus, and Cattle Egret, Bubulcus ibis), one widespread dove (Eared Dove, Zenaida auriculata) and two endemic passerines. The two endemic species, Noronha Vireo (Vireo gracilirostris) and Noronha Elaenia (Elaenia ridleyana), have been classified as ‘Near Threatened’ and ‘Vulnerable’, respectively. Here, we quantified the abundance of land birds and correlated it to habitat features to assess potential habitat preferences. We carried out 120 five‐minute point counts in October 2009, and correlated bird abundance with percentages of woodland, bushes, low herbs, bare ground, and man‐made habitats in each sample. The abundance of Noronha Vireo and Noronha Elaenia was positively correlated with woodland and bushes cover. The Eared Dove was associated to sites with bare ground, the House Sparrow with man‐made habitats, and the Cattle Egret with low vegetation sites. Abundances of Noronha Vireo and Noronha Elaenia were significantly higher in sites with natural vegetation than in human‐influenced areas. The association between these species and areas with high native vegetation cover highlights their potential vulnerability to human disturbance. RESUMO ∙ Associações entre os ambientes e as aves terrestres de Fernando de Noronha, BrasilFernando de Noronha é um dos poucos arquipélagos do Brasil. Estas ilhas abrigam cinco espécies de aves terrestres: duas espécies introduzidas (Passer domesticus e Bubulcus ibis), uma pomba com ampla distribuição (Zenaida auriculata) e duas espécies de passeriformes endêmicos (Vireo gracilirostris e Elaenia ridleyana). Estas duas espécies são classificadas como “quase ameaçada” (V. gracilirostris) e “vulnerável” (E. ridleyana). Neste estudo, quantificamos a abundancia das aves terrestres e correlacionamos com as características de habitat do arquipélago de Fernando de Noronha. Fizemos 120 pontos de escuta de cinco minutos em outubro de 2009, comparamos a abundancia de aves com a porcentagem de ambientes contendo vegetação árvobórea, arbustos, vegetação rasteira, solo aberto e construções amostradas em um raio de 25m. A abundancia de V. gracilirostris e de E. ridleyana é positivamente correlacionada com porcentagem de cobertura de árvores e arbustos. A abundancia de Z. auriculata está positivamente correlacionada com a porcentagem de solo aberto, a abundancia de P. domesticus com construções e de B. ibis com a porcentagem de vegetação rasteira. As abundancias de V. gracilirostris e E. ridleyana são significativamente maiores em locais com vegetação conservada, distante das vilas. As associações entre as es

Bird conservation on Santa Catarina Island, southern Brazil

The island of Santa Catarina lies in the Atlantic Forest Domain of southern Brazil, one of the most threatened ecosystems on the planet. It holds a wide variety of habitats, ranging from sand dune 'restingas' to mature rain forest. We report, for the first time, a survey of the bird species and their conservation status for the different habitats present on the island. We recorded 269 bird species of 54 families (25 species were seabirds). More than 50% (140) of the total number of species were residents or probable residents, 20% (58) were visitors and a relatively high number of species (61, 23%) had indeterminate residential status. Nearly 15% (35 species) of the 244 landbird species observed were endemic to the Atlantic Forest. Habitat specificity was recorded for 40% (97 species). We recorded one Endangered (Solitary Tinamou Tinamus solitarius), one Vulnerable (White-necked Hawk Leucopternis lacernulata), and three Near-threatened species (Azure Jay Cyanocorax caeruleus, Azure-shouldered Tanager Thraupis cyanoptera, Black-backed Tanager Tangara peruviana). We also recorded six locally threatened species that we predict will become extinct in the near future. The future for the birds of the island is uncertain, especially for habitat specialists, due to habitat loss for resort developments, and a lack of concern by the government and local people

Measurement of the cross-section and charge asymmetry of WW bosons produced in proton-proton collisions at s=8\sqrt{s}=8 TeV with the ATLAS detector

This paper presents measurements of the $W^+ \rightarrow \mu^+\nu$ and $W^- \rightarrow \mu^-\nu$ cross-sections and the associated charge asymmetry as a function of the absolute pseudorapidity of the decay muon. The data were collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with the ATLAS experiment at the LHC and correspond to a total integrated luminosity of 20.2~\mbox{fb^{-1}}. The precision of the cross-section measurements varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the 1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured with an uncertainty between 0.002 and 0.003. The results are compared with predictions based on next-to-next-to-leading-order calculations with various parton distribution functions and have the sensitivity to discriminate between them.Comment: 38 pages in total, author list starting page 22, 5 figures, 4 tables, submitted to EPJC. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2017-13

Search for chargino-neutralino production with mass splittings near the electroweak scale in three-lepton final states in √s=13 TeV pp collisions with the ATLAS detector

A search for supersymmetry through the pair production of electroweakinos with mass splittings near the electroweak scale and decaying via on-shell W and Z bosons is presented for a three-lepton final state. The analyzed proton-proton collision data taken at a center-of-mass energy of √s=13  TeV were collected between 2015 and 2018 by the ATLAS experiment at the Large Hadron Collider, corresponding to an integrated luminosity of 139  fb−1. A search, emulating the recursive jigsaw reconstruction technique with easily reproducible laboratory-frame variables, is performed. The two excesses observed in the 2015–2016 data recursive jigsaw analysis in the low-mass three-lepton phase space are reproduced. Results with the full data set are in agreement with the Standard Model expectations. They are interpreted to set exclusion limits at the 95% confidence level on simplified models of chargino-neutralino pair production for masses up to 345 GeV

Search for squarks and gluinos in events with isolated leptons, jets and missing transverse momentum at s√=8 TeV with the ATLAS detector

The results of a search for supersymmetry in final states containing at least one isolated lepton (electron or muon), jets and large missing transverse momentum with the ATLAS detector at the Large Hadron Collider are reported. The search is based on proton-proton collision data at a centre-of-mass energy s√=8 TeV collected in 2012, corresponding to an integrated luminosity of 20 fb−1. No significant excess above the Standard Model expectation is observed. Limits are set on supersymmetric particle masses for various supersymmetric models. Depending on the model, the search excludes gluino masses up to 1.32 TeV and squark masses up to 840 GeV. Limits are also set on the parameters of a minimal universal extra dimension model, excluding a compactification radius of 1/R c = 950 GeV for a cut-off scale times radius (ΛR c) of approximately 30

Evidence for the Higgs-boson Yukawa coupling to tau leptons with the ATLAS detector

Results of a search for H → τ τ decays are presented, based on the full set of proton-proton collision data recorded by the ATLAS experiment at the LHC during 2011 and 2012. The data correspond to integrated luminosities of 4.5 fb−1 and 20.3 fb−1 at centre-of-mass energies of √s = 7 TeV and √s = 8 TeV respectively. All combinations of leptonic (τ → `νν¯ with ` = e, µ) and hadronic (τ → hadrons ν) tau decays are considered. An excess of events over the expected background from other Standard Model processes is found with an observed (expected) significance of 4.5 (3.4) standard deviations. This excess provides evidence for the direct coupling of the recently discovered Higgs boson to fermions. The measured signal strength, normalised to the Standard Model expectation, of µ = 1.43 +0.43 −0.37 is consistent with the predicted Yukawa coupling strength in the Standard Model

Measurements of fiducial and differential cross sections for Higgs boson production in the diphoton decay channel at s√=8 TeV with ATLAS

Measurements of fiducial and differential cross sections are presented for Higgs boson production in proton-proton collisions at a centre-of-mass energy of s√=8 TeV. The analysis is performed in the H → γγ decay channel using 20.3 fb−1 of data recorded by the ATLAS experiment at the CERN Large Hadron Collider. The signal is extracted using a fit to the diphoton invariant mass spectrum assuming that the width of the resonance is much smaller than the experimental resolution. The signal yields are corrected for the effects of detector inefficiency and resolution. The pp → H → γγ fiducial cross section is measured to be 43.2 ±9.4(stat.) − 2.9 + 3.2 (syst.) ±1.2(lumi)fb for a Higgs boson of mass 125.4GeV decaying to two isolated photons that have transverse momentum greater than 35% and 25% of the diphoton invariant mass and each with absolute pseudorapidity less than 2.37. Four additional fiducial cross sections and two cross-section limits are presented in phase space regions that test the theoretical modelling of different Higgs boson production mechanisms, or are sensitive to physics beyond the Standard Model. Differential cross sections are also presented, as a function of variables related to the diphoton kinematics and the jet activity produced in the Higgs boson events. The observed spectra are statistically limited but broadly in line with the theoretical expectations

Measurement of the top pair production cross section in 8 TeV proton-proton collisions using kinematic information in the lepton plus jets final state with ATLAS

A measurement is presented of the $t\bar{t}$ inclusive production cross-section in $pp$ collisions at a center-of-mass energy of $\sqrt{s}=8$ TeV using data collected by the ATLAS detector at the CERN Large Hadron Collider. The measurement was performed in the lepton+jets final state using a data set corresponding to an integrated luminosity of 20.3 fb$^{-1}$. The cross-section was obtained using a likelihood discriminant fit and $b$-jet identification was used to improve the signal-to-background ratio. The inclusive $t\bar{t}$ production cross-section was measured to be $260\pm 1{\textrm{(stat.)}} ^{+22}_{-23} {\textrm{(syst.)}}\pm 8{\textrm{(lumi.)}}\pm 4{\mathrm{(beam)}}$ pb assuming a top-quark mass of 172.5 GeV, in good agreement with the theoretical prediction of $253^{+13}_{-15}$ pb. The $t\bar{t}\to (e,\mu)+{\mathrm{jets}}$ production cross-section in the fiducial region determined by the detector acceptance is also reported.Comment: Published version, 19 pages plus author list (35 pages total), 3 figures, 2 tables, all figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/TOPQ-2013-06

Measurement of χ c1 and χ c2 production with s√ = 7 TeV pp collisions at ATLAS

The prompt and non-prompt production cross-sections for the χ c1 and χ c2 charmonium states are measured in pp collisions at s√ = 7 TeV with the ATLAS detector at the LHC using 4.5 fb−1 of integrated luminosity. The χ c states are reconstructed through the radiative decay χ c → J/ψγ (with J/ψ → μ + μ −) where photons are reconstructed from γ → e + e − conversions. The production rate of the χ c2 state relative to the χ c1 state is measured for prompt and non-prompt χ c as a function of J/ψ transverse momentum. The prompt χ c cross-sections are combined with existing measurements of prompt J/ψ production to derive the fraction of prompt J/ψ produced in feed-down from χ c decays. The fractions of χ c1 and χ c2 produced in b-hadron decays are also measured

Search for squarks and gluinos with the ATLAS detector in final states with jets and missing transverse momentum using √s=8 TeV proton-proton collision data

A search for squarks and gluinos in final states containing high-p T jets, missing transverse momentum and no electrons or muons is presented. The data were recorded in 2012 by the ATLAS experiment in s√=8 TeV proton-proton collisions at the Large Hadron Collider, with a total integrated luminosity of 20.3 fb−1. Results are interpreted in a variety of simplified and specific supersymmetry-breaking models assuming that R-parity is conserved and that the lightest neutralino is the lightest supersymmetric particle. An exclusion limit at the 95% confidence level on the mass of the gluino is set at 1330 GeV for a simplified model incorporating only a gluino and the lightest neutralino. For a simplified model involving the strong production of first- and second-generation squarks, squark masses below 850 GeV (440 GeV) are excluded for a massless lightest neutralino, assuming mass degenerate (single light-flavour) squarks. In mSUGRA/CMSSM models with tan β = 30, A 0 = −2m 0 and μ > 0, squarks and gluinos of equal mass are excluded for masses below 1700 GeV. Additional limits are set for non-universal Higgs mass models with gaugino mediation and for simplified models involving the pair production of gluinos, each decaying to a top squark and a top quark, with the top squark decaying to a charm quark and a neutralino. These limits extend the region of supersymmetric parameter space excluded by previous searches with the ATLAS detector