Made available in DSpace on 2014-06-11T19:23:02Z (GMT). No. of bitstreams: 0 Previous issue date: 2005-11-21Bitstream added on 2014-06-13T19:49:34Z : No. of bitstreams: 1 guerra_tja_me_rcla.pdf: 836270 bytes, checksum: 2402cb0eed7929d47514213313a9e1f5 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / A investigação das interações entre plantas e seus agentes dispersores têm implicações para a compreensão da diversidade biológica e sua conservação, e é um importante tema da ecologia evolutiva. Este estudo teve como objetivo investigar os componentes quantitativos e qualitativos na dispersão de sementes de Struthanthus flexicaulis (Loranthaceae), uma erva-de-passarinho dióica, hemiparasita generalista e de ampla distribuição no cerrado do Brasil central. O estudo foi realizado entre janeiro de 2004 e abril de 2005 em um afloramento rochoso na Serra do Cipó, Minas Gerais. Foram realizadas observações sobre a fenologia dos indivíduos femininos, observações focais para a avaliação dos parâmetros comportamentais dos dispersores, censos para avaliação da abundância relativa, sazonalidade e parâmetros comportamentais dos dispersores, observação direta e amostragem por procura ativa para avaliar a deposição das sementes de S. flexicaulis. Observou-se uma variação individual em S. flexicaulis com relação à duração do período e quantidade de produção de flores e frutos. A população estudada, no entanto, apresentou reprodução contínua ao longo do ano, porém de baixa intensidade na maioria dos indivíduos. Struthanthus flexicaulis teve seus frutos consumidos por um número bastante restrito de frugívoros: Elaenia cristata e Elaenia obscura (Tyrannidae), Mimus saturninus (Mimidae) e Schistochlamys ruficapillus (Thraupidae). No entanto, E. cristata foi o visitante mais freqüente e abundante ao longo do ano, responsável por mais de 96% das sementes dispersadas. Na área de estudo E. cristata apresentou uma dieta predominantemente frugívora, complementada pelo consumo de artrópodes... . / Quantity and quality components of seed dispersal in Struthanthus flexicaulis (Loranthaceae) in a rupestrian field in southeastern Brazil. The investigation of interactions between plants and their seed dispersers has implications for the understanding of the biological diversity, its conservation and is an important issue in evolutionary ecology. The goal of this study is to investigate the components of quality and quantity in the seed dispersal of Struthanthus flexicaulis (Loranthaceae), a generalist dioceous mistletoe with wide distribution in central Brazil. The study was conducted between January 2004 and April 2005 in a rocky outcrop in Serra do Cipó, Minas Gerais, southeastern Brazil. I conducted observations on female plant reproductive phenology, focal observations on fruiting plants to record behavioral parameters of seed dispersers, censuses to record the relative abundance, seasonality and behavioral parameters of seed dispersers, a direct observations and search on random established plots to evaluate seed deposition. Individual variation in the duration and quantity of flower and fruit production was detected. At the population level, reproduction was continuous, but in low intensity for most of the individuals. The fruits of S. flexicaulis were consumed by a small set of avian frugivores: Elaenia cristata and Elaenia obscura (Tyrannidae), Mimus saturninus (Mimidae) and Schistochlamys ruficapillus (Thraupidae), but E. cristata was the most frequent and abundant visitor throughout the year, responsible for more than 96% of the dispersed seeds. In the study site this bird was highly frugivorous, but also consuming a small proportion of arthropods... (Complete abstract, click electronic address below).

Submitted by (ana.araujo@ufrpe.br) on 2016-08-19T14:51:01Z No. of bitstreams: 1 Andre Ribeiro de Arruda.pdf: 727947 bytes, checksum: 086e100ef31d60e213fe354354dd92fd (MD5) / Made available in DSpace on 2016-08-19T14:51:01Z (GMT). No. of bitstreams: 1 Andre Ribeiro de Arruda.pdf: 727947 bytes, checksum: 086e100ef31d60e213fe354354dd92fd (MD5) Previous issue date: 2013-02-26 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Given the strong relationship between the birds and the environments where they live, this study aimed to characterize the temporal dynamics of molts, breeding, abundance and vocalizations of Pseusoseisura cristata, as well as the influence of climatic periods under these aspects. Data collection was monthly between June 2011 and May 2012. The Caatinga area studied is located in the municipality of São José do Egito, Pernambuco - Brazil. Nine mist nets were used to capture and record brood patch and molts. The sampling effort was equal to 3564 hours/net. The abundance was estimated through three "strip transects" and the temporal structure of vocalizations were recorded through sound contacts with unlimited radius. It was verified that the climatic periods influence the molts and breeding. Both occur during the rainy season, since they require a large supply of resources to meet the energy demands of the processes. The seasonality also exerts a subtle influence on the temporal structure of vocalizations, forming different patterns for the dry and rainy seasons. However, these patterns must be further linked to breeding the rainfall itself. The abundance in turn, was not altered as a function of climate, revealed that this species is better adapted to climatic variations of the environment. / Diante da forte relação entre as aves e os ambientes onde vivem, esta pesquisa objetivou caracterizar bioecologicamente a dinâmica temporal de mudas, reprodução, vocalizações e abundância de Pseusoseisura cristata, bem como a influência dos períodos climáticos sob estes aspectos. A coleta de dados foi mensal entre junho de 2011 e maio de 2012. A área de Caatinga estudada localiza-se no município de São José do Egito, Pernambuco - Brasil. Nove redes de neblina foram utilizadas para captura e registro de mudas e placas de incubação, sendo o esforço amostral igual a 3564 horas/rede. A abundância foi estimada através de três “strip transects” e a estrutura temporal de vocalizações foi registrada através de contatos sonoros com raio ilimitado. Pôde-se verificar que há influência dos períodos climáticos sobre as mudas e sobre a reprodução. Ambos ocorrem durante o período chuvoso, pois necessitam de uma grande oferta de recursos para suprir a demanda energética dos processos. A sazonalidade também exerce uma sutil influência sobre a estrutura temporal das vocalizações, formando padrões diferentes para os períodos seco e chuvoso. No entanto, estes padrões devem estar mais ligados à reprodução do que à pluviosidade propriamente dita. A abundância por sua vez, não foi alterada em função do clima, revelando que a espécie apresenta adaptabilidade às variações climáticas do ambiente.

The Raso lark is a Critically Endangered bird endemic to the islet of Raso, Cape Verde. This thesis investigates two phenomena that particularly put the species at risk: its extreme fluctuations in population size, and its potentially very low genetic diversity arising from small population size and severe past population contraction. More specifically, two chapters estimate year-to-year survival and explore the factors - environmental and individual - that influence it, while two other chapters examine the lark’s genetic characteristics compared to its two continental closest relatives, including phylogenetic relationships and levels of genetic diversity. The conclusion of the thesis then uses these results to make recommendations for the conservation of the Raso lark. Each of the data chapters is summarized below: Chapter 3 estimates adult survival in the Raso lark and tests whether it could be linked to two population phenomena observed in the field: a highly variable population size and a male-biased sex ratio in certain years. Using a dataset spanning 10 years, I estimated survival for both sexes to fluctuate between 0.76 and 0.94 over this period. This is much higher than the survival rate of its closest relative, the skylark. I also found strong evidence for survival fluctuating over time and differing between males and females (with males having higher survival until 2011, at which point the trend inverted), which could play a role in the aforementioned population size fluctuations and male-biased sex ratio, respectively. Chapter 4 aims at understanding which factors shape survival in the Raso lark. Two types of variables were considered: year-dependent (rainfall, population size, population mean clutch size) and individual-dependent (age, body size characters, size ratio with mate, Ase18 genotype). Amongst the year-dependent variables, only sameyear rainfall impacted survival, with a 13% decrease in survival in the wettest year compared to the driest year, making it the most likely explanation for the inter-annual fluctuations in survival found in Chapter 3. Results also hint at some of the individual factors - morphological measurements and Ase18 genotype - influencing survival. The picture that emerges is that of a species whose life history strategy is to invest heavily in maintenance and survival, but less into fecundity, which stands in sharp contrast with the mainland-dwelling skylark. This is consistent with the theory that island birds generally have slower life history strategies than their continental counterparts. Chapter 5 determines the precise relationship between members of the Alauda clade, resolving a node on the phylogenetic tree of all larks that the study by Alström et al. (2013) was unable to resolve. My RADseq results indicate that the Raso lark and the skylark are sister species, and that the Oriental lark is likely to be a subpopulation, or maybe a subspecies, of the skylark. Chapter 6 compares the population genetics of the Raso lark with those of the skylark. In particular, it estimates the genetic diversity of the Raso lark and investigates the drivers behind it. I found unexpectedly high nucleotide diversity in the Raso lark, and explain this by showing that the population contraction that the species underwent was recent enough for most of the diversity to still be present. Moreover, 16% of the Raso lark genome has levels of heterozygosity on average 6.6 times higher than elsewhere on the genome, likely due to suppressed recombination and the existence of a neo-sex chromosome in larks. Despite this, I found high levels of relatedness and of linkage disequilibrium in the Raso lark, two clear genetic signs that it underwent a severe population contraction several centuries ago.