Navegando por Assunto "Tatus"

Agora exibindo 1 - 2 de 2

Acesso aberto (Open Access)
Fatores determinantes para a abundância de espécies de mamíferos ameaçados em área de alta pressão antrópica na Amazônia Oriental
(Universidade Federal do Pará, 2019-04-17) SANTOS, Juliana Januária Teixeira; WIIG, Oystein; http://lattes.cnpq.br/6664624762387564; OLIVEIRA, Ana Cristina Mendes de; http://lattes.cnpq.br/1199691414821581
On the latest 60 years the degradation and fragmentation of native habitats have been modifying the landscape in the eastern Brazilian Amazon. The adaptive plasticity of an organism has been crucial for its long-term survival and success in these novel ecosystems. In this study, we investigated the response of four endangered species of large terrestrial mammals to the variations in the quality of their original habitats, in a context of high anthropogenic pressure. The distribution of the Myrmecophaga tridactyla (Giant anteater), Priodontes maximus (Giant armadillo), Tapirus terrestris (Lowland tapir) and Tayassu pecari (White-lipped peccary) in all sampled habitats suggests their tolerance to degradation. However, the survival ability of each species in the different habitats was not the same. Among the four species, T. pecari seems to be the one with the least ability to survive in more altered environments. The positive influence of the anthropogenically altered habitats on abundances of three of the four species studied, as observed at the regeneration areas, can be considered as a potential indication of the ecological trap phenomenon. This study reinforces the importance of the forest remnants for the survival of endangered mammal species, in regions of high anthropogenic pressure, as in the eastern Brazilian Amazon.
Acesso aberto (Open Access)
O papel de mamíferos de médio e grande porte como modificadores do habitat na Amazônia Ocidental
(Universidade Federal do Pará, 2019-12) BORGES, Luiz Henrique Medeiros; OLIVEIRA, Ana Cristina Mendes; http://lattes.cnpq.br/1199691414821581; https://orcid.org/0000-0002-7863-9678; SILVA, Carlos Augusto Peres da; http://lattes.cnpq.br/9267735737569372; https://orcid.org/0000-0002-1588-8765
Medium to large-bodied terrestrial mammals have a wide diversity of forms, life history, behaviour, physiology, and consequently a high diversity of ecological roles played in natural and human-modified ecosystems. Ecological functions such as seed dispersal, seed predation, pollination, population control, nutrient cycling and transport, and ecosystem engineering help maintain tropical ecosystems and regulate species diversity. Ecosystem engineers are species that by their presence and/or activity alter the biotic and abiotic environment, modulating the availability of resources and modifying habitat structure for other species. The way organisms can affect each other is diverse and occurs mainly through ecological interactions such as predation, competition and commensalism or facilitation, which in turn encompass several ecological processes such as pollination, dispersal, herbivory and prey control. The first chapter of this thesis assessed the role of Priodontes maximus (Giant Armadillo; tatu canastra) as an ecosystem engineer in southwestern Amazonian forests. Our results showed that a wide diversity of terrestrial vertebrates benefit from P. maximus burrows. Sites with high local diversity tend to increase the amount of interactions between vertebrate species and armadillo burrows. In addition, we identified the purpose for which most vertebrates use the burrows of this large excavator, showing that the interaction established in the burrows is broadly and strongly connected for a variety of purposes. In the second chapter of this thesis, I examine how medium and large-bodied mammals can interfere with the regeneration process of man-made treefall clearings formed by low-impact selective logging in southwestern Amazonia. Based on the relative abundance of species, damage to artificial seedlings was measured within both clearings and otherwise comparable shaded-understorey environments. Based on the results, I can infer that medium and large mammals affect seedling recruitment process in clearings. The impact of mammal-induced seedling mortality (via trampling and/or herbivory) is much greater within natural and logging clearings than in closed understorey environments.