Navegando por Assunto "Aves - Habitat"

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Acesso aberto (Open Access)
As aves do estado do Maranhão: atualização do conhecimento e conservação em uma região de ecótono entre a floresta Amazônica e Cerrado
(Universidade Federal do Pará, 2018-09-12) CARVALHO, Dorinny Lisboa de; SILVA, Daniel de Paiva; http://lattes.cnpq.br/1409353191899248; SANTOS, Marcos Pérsio Dantas; http://lattes.cnpq.br/7941154223198901
The state of Maranhão is located between the eastern Amazon and the northern Cerrado, presenting a wide variety of environments in its ecotonal area. Due to this environmental heterogeneity, Maranhão has one of the richest avifaunas in Brazil. Furthermore, this region includes one of the world's most endangered biogeographical provinces. In order to contribute to the knowledge and conservation of avifauna in this region, this study has as its main objectives: 1) review and update the checklist of birds species from Maranhão to identify possiblesampling gaps in the state; 2) test the effectiveness of the State Protected Areas (PAs) and Indigenous Lands (TIs) system in the protection of threatened and endemic bird species using SDMs and; 3) assess the potential impact of climate change on the distribution and conservation of 24 threatened bird taxa occurring in the state, comparing current and future distributions (2070) with the current reserve system, in order to identify potentially stable areas that can serve as dispersal corridors for the evaluated taxa. In chapter 1) we recorded the occurrence of 750 bird species, distributed into 88 families and 30 orders. We added 114 new species (95 residents, 13 migratory and 6 vagrants) to the last list compiled 27 years ago for the same region. In chapter 2) we observed that taxa with wider distributions are protected equally as taxa with smaller distributions and larger PAs are more efficient than smaller. Our results also showed that most Cerrado PAs are poorly allocated. We suggest six priority areas for conservation of Neotropical birds and highlight the importance of indigenous lands in conserving Neotropical biodiversity. In chapter 3) our results indicated that, although threatened Amazon and Cerrado taxa are potentially protected, for both present and future scenarios, most of the taxa are likely to suffer drastic population size declines or even global extinction in the near future. We highlight the importance of creating a system of dispersal corridors that interconnect PAs in this region, as well as the implementation of public policies for maintenance and mitigation of the areas adjacent to these corridors, aiming at the conservation of the richness and diversity of species in this region.
Acesso aberto (Open Access)
Efeitos ecológicos e evolutivos nos padrões de diversidade de aves na Amazônia
(Universidade Federal do Pará, 2018-09-20) ALMEIDA, Sara Miranda; SANTOS, Marcos Pérsio Dantas; http://lattes.cnpq.br/7941154223198901
Studies covering phylogenetic and functional diversity have been increasingly used to explain patterns of species diversity and organization of biological assemblages, constituting complementary tools to the traditional taxonomic approach (e.g. species richness). Biogeographical knowledge may also contribute to the understanding of these patterns, since the geographical distribution of different taxa depends on historical processes related to dispersion and speciation, in this manner influencing the formation of regional pools of species. In this thesis we evaluated the influence of historical processes and environmental factors on the diversity of Amazon bird assemblages. We compiled compositional data from 80 bird assemblages, 12 in savannas and 68 in terra firme forests, totaling 878 species. In Chapter 1 we evaluated the phylogenetic and functional diversity of passerine birds (Passeriformes order) considering two factors: the biogeographical history of each suborder (Passeri and Tyranni) and the habitat type (forest and savanna). We verified the importance of the different habitats for the maintenance of bird diversity since, although Amazonian savannas present low species richness when compared to forests, this habitat presents assemblages with unique combinations of ecological traits and specific lineages. We showed through the results found in this chapter that the greater functional diversity of Passeri assemblages in both habitats and the greater phylogenetic diversity of Tyranni in terra firme forests are related to the biogeographic history of each suborder and their adaptation to the habitat. In Chapter 2, we assessed the contribution of Amazonian biogeographic regions (a.k.a., endemism areas) and climatic variables to species composition and to the phylogenetic structure of canopy and forest understory bird assemblages. We hypothesized that differences in species composition are greater between interfluves for understory bird assemblages, which are composed of species with lower dispersion capacity, than for canopy birds. In this chapter, we found that the understory bird assemblages were more influenced by biogeographic barriers than canopy birds, corroborating our hypothesis. The climatic variables were important to explain the species diversity and phylogenetic structure of both groups. With the results generated in this thesis I concluded that the Amazonian bird diversity is result of processes related to biogeographic history, ecological traits of species, and environmental conditions.