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Conselho Nacional de Desenvolvimento Científico e Tecnológico / The interaction between frugivorous birds and plants is one of the most important mutualisms in tropical regions. However, the way these groups interact varies according to temporal availability of fruit. In seasonal sites, it is expected that a specialization in a particular type of fruit is not viable, because this feature is not available throughout the year, and species that occupy these sites have a broad trophic niche. With a more stable supply of resources, a greater level of specialization is expected, which would be reflected in a narrower niche width. A relationship between the morphology of birds and type of fruit consumed can also be associated with the specialization level of diet and niche width of the birds. This relationship might possibly be more evident in local with reduced seasonality. The goal of this paper is to investigate the relationships, both ecological as morphological, between frugivorous birds and plants consumed in sites with different levels of resource seasonality. Cerrado sensu stricto were considered the most seasonal, followed by seasonal deciduous and semi-deciduous forests, which were grouped as \"seasonal forests\". Atlantic forest was seen as a site less seasonal. We tested the hypothesis that species of the guild \"frugivorous\" will be more representative of the number of species and interactions in less seasonal area, and that species of more seasonal areas would have a more generalist diet and broader trophic niche than that observed for species less seasonal site. In Chapter 2 we investigated the existence of relationships between morphology of the birds beak and size of fruits eaten by them, testing the hypothesis that this combination was more evident in local whose species exhibit lower niche amplitude than in that have species with broader niche width. In this study the community structure of each site was described and was observed narrower trophic niche for species of seasonal forests and Atlantic forest (more specialized diet) than that found for species of cerrado ss (more generalist diet). However, morphological specialization was found only in species of seasonal forests, where we observed an association between the width and depth of the tip with the size of the fruit consumed. The variation observed for specialization in diet and morphology may be related to temporal availability of resources among different sites. Furthermore, other features in the selection of fruits, behavioral traits of birds and ecological interactions with other community members also seem to influence the consumption patterns of birds. / A interação entre aves frugívoras e plantas é uma dos mutualismos mais importantes em ambientes tropicais. No entanto, a forma com que esses grupos se relacionam pode variar de acordo com a disponibilidade dos frutos ao longo do ano. Em ambientes sazonais, espera-se que uma especialização em determinado tipo de fruto seja inviável, uma vez que esse recurso não está disponível durante todo ano; e que as espécies que ocupam esses ambientes teriam uma maior amplitude de nicho trófico. Já em ambientes com uma oferta de recursos mais estável, um maior nível de especialização é esperado, o que refletiria em uma amplitude de nicho mais estreita. Associado ao nível de especialização da dieta, e consequentemente, à amplitude de nicho exibida pelas aves em cada ambiente, pode existir também uma relação entre a morfologia da avifauna e o tipo de fruto consumido, que possivelmente seria mais evidente em ambientes com sazonalidade reduzida. O objetivo central deste trabalho é investigar interações entre aves frugívoras e as plantas consumidas, e possíveis relações morfológicas, em ambientes com diferentes níveis de sazonalidade de recursos. Áreas de cerrado stricto sensu foram consideradas as mais sazonais, seguidas de matas estacionais decíduas e semidecíduas, que foram agrupadas como matas sazonais . Mata atlântica foi considerada como um ambiente menos sazonal. No capítulo 1, foram analisadas as interações entre as espécies vegetais e aves frugívora nos três ambientes citados acima. Nós testamos as hipóteses que espécies pertencentes à guilda frugívora serão mais representativas, quanto ao número de espécies e interações, em ambientes menos sazonais; e que espécies de áreas mais sazonais teriam uma dieta mais generalista e um nicho trófico mais amplo do que o observado para espécies de ambientes menos sazonais. No capítulo 2 foi investigada a existência de relações entre a morfológica do bico das aves e o tamanho dos frutos consumidos por elas, testando a hipótese que essa associação seria mais evidente em ambientes cujas espécies exibem menor amplitude de nicho, comparado a ambientes que possuem espécies com maior amplitude de nicho. No presente estudo, a estrutura das comunidades de cada ambiente foi descrita e foi observado um nicho trófico mais estreito para espécies de matas sazonais e mata atlântica (dieta mais especializada) do que o encontrado para espécies de cerrado ss (dieta mais generalista). No entanto, especialização na dieta somente foi refletida em uma especialização morfológica em espécies de matas sazonais. Nesse ambiente foi possível observar associação entre a largura e altura do bico com o tamanho do fruto consumido. Essa variação observada quanto à especialização na dieta e na morfologia pode estar relacionada à disponibilidade temporal de recursos distinta entre os ambientes. Além disso, outros critérios na seleção dos frutos, características comportamentais das aves e interações ecológicas com outros elementos da comunidade parecem influenciar também os padrões de consumo da avifauna. / Mestre em Ecologia e Conservação de Recursos Naturais

Our alarming rate of resource exploitation and its consequences on the environment is fuelling an increase in sustainable energy production around the world. Wind power appears to be a particularly promising energy source relative to its environmental footprint, with the exception of potential negative effects of wind power on birds. Varying results from impact assessments around the world indicate that knowledge of both abiotic and biotic factors, as well as bird behavior and ecology, is required to assess the cumulative impact of any given wind farm on local bird communities. This study aims to assess the cumulative impact of a proposed wind farm on a threatened seabird, the red-throated diver (Gavia stellata), at one of its breeding "hotspots" in Sweden: the Holmöarna islands. Measurements of environmental variables in lakes on Holmöarna are combined with breeding surveys from 2012 to 2015 to assess which environmental variables may be associated with lakes that red-throated divers do or do not breed in, and which variables are correlated with breeding success. These results are combined with a literature review to assess the potential negative effects of the proposed wind farm on the breeding population on Holmöarna. The results show that average breeding success over the survey period was 0.35 fledged young per pair per year. No difference was found in environmental variables between lakes that divers had or had not bred in. Lake area/perimeter ratio and distance to the sea were significantly negatively correlated with breeding success, although distance to the sea was only significant for lakes with at least one successful breeding attempt during the survey period. Based on these correlations, 33 of a total 40 breeding lakes are shown to have relatively high area/perimeter ratios and long distances to the sea, which may pre-dispose divers breeding within them to low breeding success. These lakes are, therefore, identified as being at high-to-moderate risk of increased breeding failure if breeding success is further reduced as a result of external factors, including that of any negative impacts of the proposed wind farm. 31 of the 40 breeding lakes are also within 1 km of the proposed wind turbine sites, which may render red-throated divers breeding within them vulnerable to displacement as a result of wind farm-related disturbance. The literature review highlights the mechanisms that may determine the cumulative impact of the wind farm on red-throated divers in terms of collision mortality, habitat displacement, and barriers to movement. The strong sensitivity of red-throated divers to disturbance is considered to be the most likely driver of any negative effects of the wind farm. In this context, I thus argue the need for a precautionary approach to planning wind power developments in the vicinity of breeding red-throated diver populations.

The Ortolan Bunting (Emberiza hortulana) is a farmland bird species, whose population size has declined very sharply in recent decades, especia ll y in Western and Central European countries. The aim of our study in 2015 was to record where the last populations of this critically endangered species in the Czech Republic are located and also what habitat the species associated with. We examined nine areas (925 km2 in total). Two main areas of occurrence (surface mines in northern Bohemia and farmland landscape of Silesia) and two small isolated populations in central Bohemia were registered for this species. In contrast, observations in some traditional areas of its occurence (České středohoří in northern Bohemia, Hovorany-Čejkovice region in southe r n Moravia and Javoricko region in Silesia) were negative. Altogether, we counted 75-79 singing males. Our estimation of the size of the Czech population in 2015 is 75-100 singing males, which indicates further population decline compared to the last mapping in 2001-2003. Furthermore, habitat associat io ns were investigated at two spatial scales and we made habitat compar is o n between farmland and post-mining landscape. Our research highlights a high degree of flexibility in habitat selection of Ortolan Bunting and also positive association with high...

Structural colours arise from the interaction of visible light with nano-structured materials. The occurrence of such structures in nature has been known for over a century, but it is only in the last few decades that the study of natural photonic structures has fully matured due to the advances in imagining techniques and computational modelling. Even though a plethora of different colour-producing architectures in a variety of species has been investigated, a few significant questions are still open: how do these structures develop in living organisms? Does disorder play a functional role in biological photonics? If so, is it possible to say that the optical response of natural disordered photonics has been optimised under evolutionary pressure? And, finally, can we exploit the well-adapted photonic design principles that we observe in Nature to fabricate functional materials with optimised scattering response? In my thesis I try to answer the questions above: I microscopically investigate $\textit{in vivo}$ the growth of a cuticular multilayer, one of the most common colour-producing strategies in nature, in the green beetles $\textit{Gastrophysa viridula}$ showing how the interplay between different materials varies during the various life stages of the beetles; I further investigate two types of disordered photonic structures and their biological role, the random array of spherical air inclusions in the eggshells of the honeyguide $\textit{Prodotiscus regulus}$, a species under unique evolutionary pressure to produce blue eggs, and the anisotropic chitinous network of fibres in the white beetle $\textit{Cyphochilus}$, the whitest low-refractive index material; finally, inspired by these natural designs, I fabricate and study light transport in biocompatible highly-scattering materials.