55 research outputs found

    HABITAT ASSOCIATIONS OF LAND BIRDS IN FERNANDO DE NORONHA, BRAZIL

    Get PDF
    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

    Soft Range Limits Shape Sensitivity to Forest Cover More Strongly Than Hard Range Limits

    Get PDF
    Aim: Land‐use change is a major threat to biodiversity, yet there remains considerable unexplained variation in how it affects different populations of the same species. Here, we examine how sensitivity to forest cover changes depending on proximity to different limits of a species' range. By comparing responses as species approach their coastal (‘hard’) and inland (‘soft’) range limits, we aim to provide insight into the relative influence of mass effects, as compared to abiotic and biotic environmental suitability in shaping population sensitivity. Location: Global. Time Period: 1996–2019. Major Taxa Studied: Birds. Methods: We combined data from several large databases to obtain a dataset of 2543 bird species surveyed across 116 studies, spanning six continents. Using expert‐verified range maps, we calculated the position of populations relative to their species' nearest inland (‘soft’) and coastal (‘hard’) range limits and categorised the inland limits as equatorward‐ or poleward‐ facing. We investigated how distance to range limits and forest cover, derived from a 30 m‐resolution global dataset, affect the probability of species' incidence. Results: We found that bird populations are more sensitive to forest cover when located closer to their species' inland (‘soft’) range limits, whereas this was not the case at coastal (‘hard’) range limits. The heightened sensitivity to forest cover at soft range limits was similar regardless of whether the range limit faced equatorward or poleward. Main Conclusions: These results highlight how populations close to the soft limits of their species' ranges are at higher risk of extirpation resulting from loss of forest cover. This suggests that environmental conditions (e.g., climate), which become more challenging away from the core of the species' range, drive variability in sensitivity to forest cover

    Pervasive gaps in Amazonian ecological research

    Get PDF

    Pervasive gaps in Amazonian ecological research

    Get PDF
    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

    O império dos mil anos e a arte do "tempo barroco": a águia bicéfala como emblema da Cristandade

    Get PDF
    The article reveals that between the mid-17th century and the mid-18th century, in the ecclesiastical world of the religious orders (Jesuits, franciscans, Carmelites, Cistercians, Augustinian, etc.) and the episcopate, there was the progressive adoption of the imperial symbol, the double-headed eagle, attribute of the Christian Empire, the germanic Holy Roman Empire emblem. However, in the religious field, this imperial eagle of the baroque time appears without the political insignia (sword, scepter and the imperial orb), adorning altars, monstrances, trumphal archs, facades of temples, doors, walls, domes, pulpits, sacred washbasins, sculptures and paintings of the Virgin and Child, liturgical robes, etc.; therefore related to the cult and the dogmas of the Catholic faith - in artistic works, the association between the double eagle and the flesh-spirit or human-divine unity, axial principle of the Catholic faith, represented by Virgin-Mother and Christ, is often indicated directly. The research has located and identified numerous remnants of the double eagle emblem in religious field in Portugal and Spain and in their conquests and dominions in America, Asia and Africa, and also in Italy, and the historiography on painful birth of the modern era in the West has never realized this phenomenon. Symbolizing absolute power, universal power, these works with sacred significance, as the ecclesiastical discourse of the time, demonstrate movement occurred in religious plane. With the aim to assert not only spiritual but also temporal power of Christ and his mystical body, the Church was impelled by the idea of restoring the "Republica Christiana" or Christendon - disrupted by conflicts of power and faith - and of introducing a Universal Apostolic Monarchy extended to all mankind: the Empire of the Last Days, the Empire of Christ in the world, the fifth Empire

    More than 10,000 pre-Columbian earthworks are still hidden throughout Amazonia

    Get PDF
    Indigenous societies are known to have occupied the Amazon basin for more than 12,000 years, but the scale of their influence on Amazonian forests remains uncertain. We report the discovery, using LIDAR (light detection and ranging) information from across the basin, of 24 previously undetected pre-Columbian earthworks beneath the forest canopy. Modeled distribution and abundance of large-scale archaeological sites across Amazonia suggest that between 10,272 and 23,648 sites remain to be discovered and that most will be found in the southwest. We also identified 53 domesticated tree species significantly associated with earthwork occurrence probability, likely suggesting past management practices. Closed-canopy forests across Amazonia are likely to contain thousands of undiscovered archaeological sites around which pre-Columbian societies actively modified forests, a discovery that opens opportunities for better understanding the magnitude of ancient human influence on Amazonia and its current state

    Pervasive gaps in Amazonian ecological research

    Get PDF
    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

    Pervasive gaps in Amazonian ecological research

    Get PDF
    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost
    corecore