http://www.bdtd.uerj.br/handle/1/5784 2026-04-21T00:49:09Z 2026-04-21T00:49:09Z Nascimento, Thamires Proença do http://www.bdtd.uerj.br/handle/1/24832 2026-01-13T17:45:01Z 2020-11-30T00:00:00Z

Título: Haemosporida em Turdus albicollis (AVES: Turdidae) e Pyriglena leucoptera (AVES: Thamnophilidae) na Mata Atlântica da Costa Verde do Estado do Rio de Janeiro Autor: Nascimento, Thamires Proença do Primeiro orientador: Alves, Maria Alice dos Santos Abstract: Hemoparasites like Haemosporida order are causative agents of malaria in birds and humans and can generate significant effects in avian hosts. They are considered good models for studies of parasite-vector-host interactions and coevolution. The present study aimed to: evaluate the prevalence of Haemoproteus sp., Plasmodium sp. and Leucocytozoon sp. in Turdus albicollis and Pyriglena leucoptera; test whether the prevalence of infection by hemoparasites can be influenced by climatic factors or ecological aspects of the hosts; to test differences in the prevalence and composition of hemoparasitic strains between island and continent in P. leucoptera in the Atlantic Forest in the Costa Verde Region of Rio de Janeiro. The study was carried out in Ilha Grande State Park, RJ (PEIG) and Cantagalo District (Angra dos Reis, RJ). Individuals of P. leucoptera were captured, banded and blood samples were collected for molecular analysis of presence of blood parasites. Blood samples of T. albicollis were analyzed molecularly and by blood smears stained with Giemsa for detection and identification of hemoparasites. The presence of hemoparasites in the DNA of both bird species was detected by means of nested-PCR (Polymerase Chain Reaction) amplifying the hemoparasites cytochrome b gene. PCR positive samples were sequenced to identify the hemoparasite strains. The prevalence of infection in birds and the prevalence for the variables: sex, seasonality and location were calculated. The relationships between these variables and the prevalence of hemoparasites were tested using the Chi- square test. To confirm the identification of the hemoparasite strains, a genetic distance matrix was generated and a Maximum Likelihood analysis was performed using the bootstrap method. Parasites of the gender Plasmodium was the most prevalent parasite in both species, 28% for P. leucoptera and 26% for T. albicollis, and possible new Haemoproteus strains were found in P. leucoptera. Fourteen individuals (20%) of Turdus albicollis were infected by more than one genus of hemoparasites. Individuals of P. leucoptera from Ilha Grande had a greater diversity of hemoparasites, but less prevalence (24%) in comparison to the continent (44%). There was no significant difference in the prevalence of blood parasites between rainy and less rainy periods and between sexes. However, males and females differed in prevalence during the phases of the reproductive period, which may be associated with exposure to vectors and differentiated energy demand between the sexes in this period. Through the results obtained, it is suggested that the ecology of hemosporid infection for the two species studied depends on a set of climatic factors, such as precipitation and the reproductive ecology of hosts and vectors. Instituição: Universidade do Estado do Rio de Janeiro Tipo do documento: Dissertação

2020-11-30T00:00:00Z Almeida, Júlia Mendonça de http://www.bdtd.uerj.br/handle/1/24341 2025-09-26T17:06:44Z 2024-02-24T00:00:00Z

Título: Efeitos do roubo de néctar em um sistema de polinização tropical: quantificando as implicações para a planta e para os visitantes florais Autor: Almeida, Júlia Mendonça de Primeiro orientador: Alves, Maria Alice dos Santos Abstract: Nectar robbery can be important, whether direct or indirectly, for structuring interaction networks between plants and its floral visitors. The effects of this behaviour on the reproduction of plant species primarily depend on factors related to the life history of the plant species itself and the dynamics of floral visitors, while the effect on the foraging dynamics of floral visitors generally occurs through depletions in nectar. In this study, two manipulative experiments were conducted to quantify the effects of nectar robbery by hummingbirds on the female fitness of an ornithophilous plant species, Heliconia spathocircinata, and on the foraging of floral visitors. Additionally, a deterministic model, based on the results obtained in the experiments, was proposed to simulate the implications for the interaction system, given the differences in the behavioural choices of floral visitors, displaying mixed foraging tactics in the studied system. The results highlighted that H. spathocircinata was highly self-compatible in the studied population, and the effect of nectar robbery ws neutral, while cross-pollination has a negative impact on the female fitness of this plant species. Regarding the effect on the activity of floral visitors, the dynamics were minimally altered concerning legitimate and illegitimate visitation activities, but it showed that hummingbirds seem more inclined to choose situations with little nectar robbery for foraging. The proposed conceptual model demonstrated that when one foraging behaviour is more favoured than another by the visitor, the favoured and unfavoured behaviours oscillate in different orders of magnitude. However, when both are equally chosen, they fluctuate in similar orders of magnitude. These results suggest that autogamy in H. spathocircinata may have evolved from its high self-compatibility and, possibly, from pollen limitation, especially in locations where nectar robbery is a significant part of the interactions. It is also possible that the neutral effect of nectar robbery in hummingbird foraging is due to the high unpredictability of nectar resource availability in H. spathocircinata in the study area, rather than the level of robbery itself. As the foraging choice of visitors varies between legitimate and illegitimate visits in the studied system, the costs of these two behaviours may be similar or even equal. In this context, nectar robbery could function as commensalism in the H. spathocircinata – hummingbirds system. Instituição: Universidade do Estado do Rio de Janeiro Tipo do documento: Dissertação

2024-02-24T00:00:00Z Mendes, Luisa de Brito http://www.bdtd.uerj.br/handle/1/24265 2025-09-26T14:22:36Z 2023-01-27T00:00:00Z

Título: Efeitos da construção de linhas de transmissão previstas na Amazônia: uma perspectiva para a riqueza de mamíferos arborícolas, RJ Autor: Mendes, Luisa de Brito Primeiro orientador: Geise, Lena Abstract: Rapid urbanization and population expansion are viewed as threats to sustainability. Due to the increased energy demand caused by these processes, more electricity must be produced, and power lines must be extended (LTs). Even while these activities only slightly alter the habitat, they significantly alter the landscape, exacerbating the impacts of habitat fragmentation through edge effects and loss of conectivity. In the last 14 years, 2020 had the highest rate of deforestation in the Amazon rainforest. Arboreal mammals may be particularly impacted by habitat loss and fragmentation since they rely on forested habitats for movement, reproduction, and shelter. Even though there is an increasing need for more LTs, nothing is known about how their installation would affect the diversity of arboreal mammals, which is why this study's goal is to fill that knowledge gap. Following the selection of LTs from the IBAMA online database, analysis was conducted considering the two criteria of being in the Brazilian Amazon biome and not having an installation license. An analysis of the literature was done to identify the arboreal species that might exist in the area, and information on taxonomy, habitat use, distribution, conservation status, body weight, and home range was recorded into a spreadsheet. Expert researchers in each order verified these data. ICMBio provided the current geographic distribution of each species. For the analysis, the six collections of MapBiomas' land use map were employed. The shapefile of each species' distribution and the design of the LTs were overlaid to determine the species richness. A six-kilometer margin was planned for each LT. As a result, we chose four LTs: Oriximiná (LT1), Xingu (LT2), Tucuruí (LT3), and Manaus-Boa Vista (LT4) (LT4). 178 species were recognized in the initial study, distributed among five orders: five (Carnivora), 27 (Didelphimorpha), six (Pilosa), 91 (Primates), and 50 (Rodentia). Expert confirmation of the distribution and habitat utilization of this species list was done. LT’s richness was 38 species (LT1), 35 (LT2), 29 (LT3), and 47 (LT4) (LT4). LT1 therefore had the greatest richness, whereas LT3 had the least. The most threatened species were found in LT4 (9), then in LT3 (8), and finally in LT1 and LT2 (4). With LT installation, functional connectivity decreased across all LTs examined. LT1 reduced the average size of the connected pieces by 1.2%, LT2 by 0.9%, LT3 by 0.7%, and LT4 by 0.8%. For species with a limited geographic range, LTs will further divide their range, which may increase the process of population decline. Therefore, it is advised that this study be included in linear project EIAs. Instituição: Universidade do Estado do Rio de Janeiro Tipo do documento: Dissertação

2023-01-27T00:00:00Z Tiburtino, Raissa de Freitas http://www.bdtd.uerj.br/handle/1/24261 2025-07-09T13:59:11Z 2024-02-29T00:00:00Z

Título: Consequências funcionais da variação intraespecífica: as respostas de uma palmeira ameaçada de extinção Autor: Tiburtino, Raissa de Freitas Primeiro orientador: Rosado, Bruno Henrique Pimentel Abstract: Understanding the mechanisms that cause plant mortality due to drought constitutes one of the biggest gaps in plant ecology. One of the associated mechanisms is described as the Hydraulic Limitation Hypothesis in which vulnerability to drought increases with plant height due to greater restrictions on the flow of water from the roots to the leaves. Such restrictions can limit carbon assimilation, biomass production and individual growth. Because they have an anatomical structure distinct from trees, palms may have different mechanisms to deal with water stress throughout their ontogeny. The forecast scenario for the Atlantic Forest of Southeastern Brazil includes a reduction in precipitation by up to 50% at the end of the century, which further threatens the vegetation of this biodiversity hotspot. We used the palm tree Euterpe edulis Martius, popularly known as juçara palm, to understand its vulnerability to drought at different stages of development by carrying out sequential monthly measurements of water potential and, simultaneously, measurements of stomatal conductance and chlorophyll a and b content. The study was carried out in the Tijuca National Park (PNT), located in the state of Rio de Janeiro. The functional characteristics of up to 16 individuals with heights ranging from 0.07 to 13.71 meters were collected - an important factor for developing environmental restoration plans based on the detection of the phases most susceptible to drought. We found a positive relationship between chlorophyll a and b concentrations, stomatal conductance and height, indicating that the increase in the height of individuals, in addition to implying greater photosynthetic pigments, does not impose stomatal restrictions and, therefore, there would be no limitation to carbon gain. These data corroborate what was recently found in the Atlantic Forest for this species, in which taller individuals develop a more competitive strategy in the context of Grime's CSR Triangle Theory. More specifically, taller individuals of the juçara palm appeared to be able to maintain their metabolic functions under greater degrees of dehydration (e.g. greater evaporative air demand), which could suggest greater resistance to embolism when accompanied by greater carbon gain. Small individuals, focused on the ruderality strategy, are probably unable to acquire as many resources as possible even if such a strategy is acquisitive, since these individuals located in the shade did not open their stomata during the study period, which could result in death due to deprivation. of carbon. This study shows how essential it is to assess the vulnerability of plants to drought to predict possible losses of species and changes in the structure and functioning of plant communities. In addition to the relevance of this study of intraspecific variation in the water and carbon use characteristics of a palm species threatened with extinction over time, it can improve the understanding of how unfavorable drought conditions can distance it from its metabolic optimum in an environment to predictions of an increase in the frequency, duration and intensity of drought events, adding to the understanding of the resilience and variability of growth response during drought. Instituição: Universidade do Estado do Rio de Janeiro Tipo do documento: Dissertação

2024-02-29T00:00:00Z