Seabirds are often used as indicator species for changes in marine ecosystems due to the species visibility and sensitivity to changing conditions, such as changes in prey abundance. They often reside in habitats affected by anthropogenic impacts such as large-scale fisheries and pollution. Understanding the connection between seabirds and their surrounding environment can give us important insight about the ecology of the ocean and how anthropogenic pressures affects it. Studying feeding habits, and foraging behavior especially, is useful for understanding seabird´s responses to changing environments. Feeding studies are commonly used in seabird monitoring and requires a lot of time and resources. Monitoring of seabirds are also logistically challenging, and the risk of disturbing bird colonies must be considered. It can be especially complicated when studying cliff nesting seabirds such as the common murre, Uria aalge, the study species for this thesis. Photography as a method for monitoring seabirds may limit the need of people on site, hence minimize disturbance and save time and resources. This study provides insight in whether it is a viable option to use photography instead of on-site field studies when monitoring sea birds. This was accomplished by installing cameras and monitor a feeding study at Stora Karlsö, Sweden, parallel with performing the usual monitoring in the field. This thesis makes it clear that a camera study very well could replace the field study without any larger concerns, although, improvements need to be considered if the study is to maintain a high quality and for results to be reliable.

A quebra de frutos encapsulados por macacos-prego com o auxílio de ferramentas é tipicamente objeto de observação e scrounging por coespecíficos, bastante tolerados e em geral mais jovens e menos proficientes. O presente estudo teve como objetivo examinar o processo de escolha, pelos observadores, dos alvos de observação, e se esta escolha pode otimizar as oportunidades de scrounging. A pesquisa foi realizada com um grupo de macacos-prego selvagens (Cebus libidinosus) na Fazenda Boa Vista (Piauí - Brasil), numa área de ecótono cerrado/caatinga. A partilha de alimento fora dos episódios de quebra de cocos e o uso de ferramentas para a quebra de outros itens alimentares encapsulados também foram abordados. Indivíduos de todas as classes de idade e sexo se envolveram na observação da quebra de cocos, havendo uma grande variação individual. Nossas análises mostram que os macacos preferencialmente escolhidos como alvos de observação foram aqueles que apresentaram maior Freqüência, Proficiência e Produtividade na quebra de cocos. Apesar de haver interações agonísticas durante os eventos de observação, os alvos se mostram muito tolerantes à observação e ao scrounging - 25% dos episódios de quebra são observados e mais da metade destes eventos de observação resultam em scrounging. Os observadores tiveram a oportunidade de comer os restos dos cocos e de manipular os itens do sítio de quebra. Estas observações reforçam a noção de que as condições e possibilidades vivenciadas pelo observador-scrounger otimizam as oportunidades para que ocorram processos de aprendizagem socialmente mediada, ao menos por realce de estímulo. Tal exposição próxima ao comportamento do alvo poderia influenciar aspectos mais finos do comportamento dos observadores, ao longo de sua história de aprendizagem. O presente estudo aborda estas interações entre manipuladores de ferramentas e observadores/scroungers pela primeira vez em uma população selvagem e discute as semelhanças e discrepâncias em relação aos resultados anteriormente obtidos com uma população em semil-liberdade. / The tool-aided cracking of encapsulated fruit by capuchin monkeys is a frequent target of observation and scrounging by conspecifics, well-tolerated and usually younger and less proficient. The present study aimed to examine the process of observational targets choice by the observers, and whether this choice can optimize scrounging opportunities. The research was conducted with a group of wild bearded capuchin monkeys (Cebus libidinosus) in Fazenda Boa Vista (Piauí, Brazil), in an ecotone area between cerrado and caatinga savanna-like environments. Food sharing in contexts other than nut cracking, as well as the use of tools to crack open other food items were also analyzed. Individuals from all age and sex classes were involved in nut cracking observation. Our analyses show that the monkeys preferentially chosen as observational targets were the ones exhibiting the greater Frequency, Proficiency, and Productivity in nut cracking. In spite of a few agonistic interactions during observation events, the targets tend to be very tolerant to observation and to scrounging (25% of the nut cracking events are observed, and more than half of these resulted in scrounging). The observers had the opportunity of eating nuts leftovers and of manipulating items from the cracking sites, both in the presence and in the absence of the targets. These findings strengthen the idea that the conditions and possibilities experienced by the observers-scroungers optimize the opportunities for socially biased learning processes, at least by stimulus enhancement. Such close exposure to the targets behavior could also influence finer details of the observers behavior in the long run. The present study is the first one to deal with these interactions between tool manipulators and observers/scroungers in a wild population and discusses the similarities and differences from previous observations from a semi-free population.

Orientador: Marcos César de Oliveira Santos / Banca: Marco Aurelio Pizo Ferreira / Banca: Pedro Ferreira Develey / Resumo: A maria-da-restinga (Phylloscartes kronei) é uma espécie da família Tyrannidae descrita recentemente e considerada como globalmente ameaçada de extinção, cuja história natural é pouco conhecida. Visando preencher parte desta lacuna, o objetivo deste estudo foi de caracterizar o comportamento de forrageamento da maria-da-restinga, descrever os bandos mistos aos quais ela se associa, bem como descrever alguns outros aspectos de sua história natural como seus hábitos alimentares, o comportamento de dormir, insights sobre a biologia reprodutiva, o alcance de vôo, encontros agonísticos interespecíficos e a muda. No período de agosto de 2008 a julho de 2009 foram realizadas excursões mensais ao município de Ilha Comprida (~24º S), Estado de São Paulo. Aliado ao esforço anual mencionado, uma visita ao município de Guaraqueçaba (25º18'S e 48º19'W), Estado do Paraná, foi conduzida entre os dias 25 de julho e 1º de agosto de 2008. Foram coletadas 613 amostras de forrageamento, através de observações diretas com auxílio de binóculos com aumento de 10 vezes. Durante os períodos de coleta de dados sobre o forrageamento da espécie, para cada encontro com a mesma foi anotado se esta se encontrava só, aos pares, em grupos ou associada a bandos mistos de aves. Quando em bandos mistos, foram anotadas todas as espécies ocorrentes, visando caracterizar os bandos aos quais se associa. Para a descrição do hábito alimentar da espécie foram analisados os conteúdos estomacais de cinco exemplares coletados na década de 1990 no Estado do Paraná, tendo sido identificados 116 ítens alimentares. Através da análise dos dados obtidos, conclui-se que P. kronei captura suas presas principalmente em folhas verdes, entre 0,5 e 15m acima do solo, utilizando a manobra "investir-atingir". Alimenta-se predominantemente de artrópodes, sendo que os insetos das ordens Coleoptera... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The Restinga Tyrannulet (Phylloscartes kronei) is a recently described and globally threatened species of the family Tyrannidae, whose natural history is poorly known. In this study several information on the natural history of P. kronei were gathered such as several aspects on foraging behavior, association with mixed species bird flocks, feeding habits, the description of the roosting behavior, insights on the reproductive biology, the flying range, interespecific agonistic encounters and moulting. From August 2008 to July 2009, data on this species were collected on a monthly basis in Ilha Comprida (~24º S), São Paulo state, Brazil. In addition, a visit to Guaraqueçaba (25º18'S e 48º19'W), Paraná state, was conducted between 25 July and 01 August 2008. A total of 613 foraging maneuvers were gathered by direct observations with the aid of binoculars with 10x magnification. In all meetings with the species it was reported if individuals were alone, in pairs, in groups or associated with mixed species bird flocks. When mixed species flocks with Restinga Tyrannulets were observed, all species in the flock were identified. Five stomach contents collected in the 1990s in Paraná state were evaluated and 116 food items were identified. The Restinga Tyrannulet captures preys mainly with sally-strikes in green leaves between 0.5 and 15m above the ground. This species feeds mainly on arthropods, especially Coleoptera and Hymenoptera. The observed foraging behaviors and feeding habits were similar to the ones observed in other species of Phylloscartes, but new food items are described for this genus: Anobiidae (Coleoptera), Coccinelidae (Coleoptera), Chalcidoidea (Hymenoptera), Microhymenoptera and two species of fruits (Clusia criuva and Ternstroemia brasiliensis). P. kronei is a sporadic follower of mixed species bird flocks, which had the inclusion of 25 species on their compositions... (Complete abstract click electronic access below) / Mestre

Maruca vitrata Fabricius (Lepidoptera: Crambidae) est un des ravageurs majeurs du niébé (Vigna unguiculata L. Walp. (Fabales: Fabaceae)). Au stade larvaire, ce ravageur peut détruire les boutons floraux, les fleurs et les gousses en développement, et causer, à lui seul, des pertes de rendement allant jusqu’à 80% dans un champ de niébé. Pour lutter contre cet insecte, une collaboration entre WorldVeg et l’IITA a permis d’identifier un agent potentiel de lutte biologique contre M. vitrata en Afrique de l’Ouest, le parasitoïde Therophilus javanus (Bhat & Gupta, 1977) (Hymenoptera: Braconidae). Mais aucune information n’était jusqu’alors disponible sur la biologie de ce parasitoïde.Mes travaux de thèse visaient donc à étudier certains des paramètres biologiques de T. javanus afin d’optimiser aussi bien sa production au laboratoire que son utilisation comme agent de lutte biologique au champ. Nous avons d’abord analysé le développement et le potentiel reproductif de T. javanus, mais aussi son comportement de localisation de l’hôte. En parallèle, nous avons étudié l’organisation de la glande à venin et recherché les gènes transcrits dans cette glande, car le venin peut jouer un rôle dans la réussite du parasitisme.Nous avons décrit le développement de T. javanus, qui comprend trois stades larvaires : les deux premiers stades se développent à l’intérieur de la chenille, mais seule une partie du troisième stade est endoparasite. Nous avons montré que l’âge de la chenille de M. vitrata lors du parasitisme influence significativement la durée de développement de T. javanus (de l’œuf à l’adulte) ainsi que le potentiel reproductif de l’adulte femelle. T. javanus est une espèce synovigénique chez qui la maturation des œufs s’effectue graduellement après l’émergence. Toutefois, ni le sex ratio de la progéniture ni la longévité des adultes ne sont influencés par l’âge de l’hôte au moment du parasitisme.Nos résultats concernant le comportement de localisation de l’hôte ont montré que la femelle de T. javanus visite les bourgeons foliaires, les boutons floraux et la gousse sur la plante de niébé. La localisation de l’hôte est influencée par l’espèce de la plante infestée par la chenille de M. vitrata.Nos travaux ont permis de décrire la glande à venin de T. javanus qui est filiforme et en forme de Y. Au niveau ultrastructural, les cellules de la glande contiennent plusieurs canaux collecteurs ainsi que de nombreuses vésicules. L’étude du transcriptome a révélé que la moitié des séquences identifiées dans la glande à venin de T. javanus présentent de similarités avec certaines enzymes et protéines observées chez d’autres hyménoptères, parmi lesquels le plus fréquemment représenté est l’endoparasitoïde Microplitis demolitor Wilkinson (Hymenoptera: Braconidae). Nous avons également identifié une famille de protéines fortement exprimées dans la glande à venin de T. javanus qui sont similaires à des protéines du venin identifiées chez un hyménoptère ectoparasitoïde, Ampulex compressa (Fabr.) (Hymenoptera: Ampulicidae). Ces séquences ont été utilisées pour dessiner des amorces de PCR (polymerase chain reaction) permettant de détecter T. javanus de façon spécifique et reproductible à partir d’ADN génomique d’adulte de T. javanus et de la chenille de M. vitrata parasitée par la femelle de T. javanus.Ces résultats ont été discutés dans la perspective d’optimiser la production en masse de T. javanus au laboratoire et la méthode de lâcher, et de mettre en place un outil moléculaire pouvant permettre la détection du parasitoïde à partir de chenilles parasitées. La présente thèse représente une première documentation consacrée à la physiologie et la bioécologie de T. javanus. Cependant de nombreuses questions restent encore à aborder afin de pouvoir optimiser l’utilisation de T. javanus comme agent de lutte biologique en Afrique. / Maruca vitrata Fabricius (Lepidoptera: Crambidae) is one of the most important insect pests in West Africa causing severe damage to cowpea (Vigna unguiculata L. Walp. (Fabales: Fabaceae)). The pest alone can cause up to 80 % yield losses. Damage is done by caterpillars on flower buds, flowers and developing pods. To develop the biological control of M. vitrata in West Africa, a collaboration has been established between WorldVeg and IITA that resulted in the identification of one promising parasitoid species namely Therophilus javanus (Bhat & Gupta, 1977) (Hymenoptera: Braconidae). Because of a dearth of data concerning T. javanus biology, the present work was initiated to assess the suitability of T. javanus as a classical biological control agent against M. vitrata in West Africa.In order to help for decision making regarding the use of T. javanus as a biological control agent against the pod borer, my thesis focused on some biological parameters as egg production capacity in females, immature development, the impact of host stage on the adult life cycle and the ability of adult female to localize M. vitrata on infested host plant organs based on olfactory stimuli. I’ve also investigated the morphology, ultrastructural organization and the transcriptome of the venom gland in females, and designed a PCR method for detection of M. vitrata caterpillars parasitized by T. javanus.Our study has demonstrated that T. javanus is a synovigenic species that mature eggs gradually after emergence and that egg production in progeny is influenced by the size or instar of the caterpillar host at parasitism. T. javanus is a koinobiont endoparasitoid that has three larval instars: the first and the second instars are completed inside the host whereas the third instar is achieved outside the host. Development time and fecundity were influenced by the size or instar of the caterpillar at the moment of parasitism whereas mother longevity and progeny sex ratio were not influenced. The females explored different parts of the cowpea plant but invested more time for searching on the buds. Female attraction by M. vitrata-damaged host plants odors was impacted by the plants species. Odors released from M. vitrata-infested host plant parts were discriminated from non-infested parts in selected plants, cowpea and Tephrosia platycarpa Guill & Perr (Fabales: Fabaceae), respectively. Finally we have shown that the venom gland produces proteins with similarities with venom proteins from other hymenoptera, in particular with the endoparasitoid Microplitis demolitor Wilkinson (Hymenoptera: Braconidae). However, the highly transcribed sequences were related to venom proteins in the ectoparasitoid Ampulex compressa (Fabr.) (Hymenoptera: Ampulicidae). Primers designed based on the sequence of the most expressed venom protein in T. javanus allowed to discriminate adult T. javanus from other adult hymenoptera parasitoids. Similarly, parasitized M. vitrata caterpillar could be distinguished from non parasitized M. vitrata caterpillar.These findings are discussed in the frame of improving mass rearing of the parasitoid in laboratory, and optimizing release strategies, but also of developing an approach for investigation of the parasitoid establishment. This thesis represents the first documentation devoted to the physiology and bioecology of T. javanus. However, some questions still remain to be addressed in order to decide on the possibility of using T. javanus as biological control agent against M. vitrata in West Africa.

Resumo: Filostomídeos frugívoros são considerados elementos-chave na conservação e restauração florestal dado à sua representatividade numérica (espécies e indivíduos), alto potencial de deslocamento e eficiência na dispersão de sementes. Técnicas que potencializem esse papel ecológico podem ter grande aplicação na recuperação de hábitats degradados, comuns à Mata Atlântica brasileira. Estudos com óleos essenciais isolados de frutos quiropterocóricos maduros sugeriram que eles podem ser utilizados para atrair e capturar morcegos frugívoros no interior de áreas florestais. Assim, a presente tese foi desenvolvida para fundamentar o caráter prático-funcional desta nova ferramenta, na medida em que se propôs a investigar os movimentos e o uso do hábitat fragmentado por espécies frugívoras, bem como as suas respostas a atrativos odoríferos instalados na matriz agropecuária de uma paisagem intensamente fragmentada no sul do Brasil (municípios de Fênix e São Pedro do Ivaí, estado do Paraná). Seus resultados indicaram uma atração altamente significativa dos morcegos aos óleos, um elevado potencial de dispersão de um grande número e diversidade de propágulos, e a possibilidade de manter os indivíduos por algum tempo sobrevoando pontos específicos da matriz, o que incrementaria, sobremaneira, a chuva-de-sementes no local. Os métodos de marcação/recaptura e radiotelemetria demonstraram existir uma alta mobilidade de Artibeus lituratus (Olfers, 1818) e Carollia perspicillata (Linnaeus, 1758), morcegos frugívoros mais comuns na região, dentro e entre os remanescentes florestais, com a utilização conjunta de diferentes elementos da paisagem (fragmentos, matriz agropecuária, pomares, rios, etc.). A matriz agropecuária da região parece não inibir os deslocamentos das espécies, padrão este relevante para o processo de dispersão de sementes e para a eficácia... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Frugivorous phyllostomids are considered key elements to forest conservation and restoration due to their representative number (species and individuals), high mobility, and efficiency as seed dispersers. Techniques to improve this ecological role can find great application in the recovery of degraded habitats, usually found in the Brazilian Atlantic Forest. Previous tests with essential oils from ripe chiropterochoric fruits suggested they can be used to attract and capture fruit-eating bats inside forest remnants. The present thesis was conducted to provide the basis to functional and practical characteristics of this new tool. Thus, we investigated the movements and use of a fragmented habitat by frugivorous species, as well as bats' response to odor attractives installed in the agropecuary matrix of an extremely fragmented field at South Brazil (city of Fênix and São Pedro do Ivaí, State of Paraná). The results indicate a significant bat attraction to the essential oils, a great potential for dispersion of a large number and diversified seeds, the possibility of keeping bats flying for some time over specific locations of the matrix, which can increase significantly seeds dispersion in specific spots. By using mark/recapture and radiotelemetry techniques we observed high mobility of Artibeus lituratus (Olfers, 1818) and Carollia perspicillata (Linnaeus, 1758), the most common frugivorous bats in the study region , inside and between forests remnants with the combined use of different habitat attributes (fragments, agropecuary matrix, orchards, rivers, etc.). So, the regional agropecuary matrix does not seem to inhibit the movement of the species, which is an important behavior for seed dispersal and for the efficacy of the tool used for restoration of degraded areas. / Orientador: Ariovaldo Pereira da Cruz Neto / Coorientador: Sandra Bos Mikich / Banca: Wagner Andre Pedro / Banca: Eleonora Trajano / Banca: Marco Aurélio Ribeiro de Mello / Banca: Mauro Galetti Rodrigues / Doutor

Submitted by Ricardo Cedraz Duque Moliterno (ricardo.moliterno@uefs.br) on 2015-07-31T21:39:35Z No. of bitstreams: 1 Disserta??o Final_Fernando Flores.pdf: 2552427 bytes, checksum: 56e64e9a4e8e38fa82bdf2d85f521c8b (MD5) / Made available in DSpace on 2015-07-31T21:39:35Z (GMT). No. of bitstreams: 1 Disserta??o Final_Fernando Flores.pdf: 2552427 bytes, checksum: 56e64e9a4e8e38fa82bdf2d85f521c8b (MD5) Previous issue date: 2014-03-21 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Mixed flocks of birds are clusters of two or more species whose formation and cohesion depend on behavioral interactions among members. This study investigated the specific composition of mixed flocks in the Atlantic Forest area of Bahia, Brazil, considering the seasonal dynamics of flocks, the vertical distribution of their species, and the determination of species-nucleus, which are responsible for attracting and maintaining the cohesionof other species flocks. From August 2012 to August 2013, monthly expeditions of five days were conducted at the region of the Ecopolo I,in Pratigi Environmental Protection Area (Ibirapitanga, Bahia).The following data were recorded for each mixed-flock contacted: the specific composition, the number of individuals of each species and, when it was possible, the height of foraging, the occurrence of agonistic interactions, estimated intensity of movement and vocalization for each species. Furthermore, the contacts of mixed-flocks component species were recorded when they were seen out of the flocks, observing the foraging height and evidences of reproductive behavior.Was registered 113 contacts with mixed flocks, with a total of 51 species of birds, representing about 30% of the species recorded in the study area.In flocks, the most representative families were Thraupidae and Thamnophilidae - counting this one with two endangered species. Mixed flocks occurred throughout the whole year, being more frequent in August and less frequent from September to April.Due to the constantly rainfall throughoutyear in the study area, there was no correlation between frequency, richness and size of flocks with the monthly pluviosity. There was a negative correlation with the frequency of flocks and temperature. The richness and the size of flocks did not correlate with the temperature.The average richness in flocks was 5,1 ? 2,6 species, and the average size of 5 ? 5,2, individuals, these two variables were correlated positively (r = 0.81, p = <0.0001). The richness was different between the vegetation strato, being the understory flocks richer than the ones in canopy. However, in relation to size of individual numbers, the understory and canopy flocks didn?t present significant difference, because the canopy flocks were composed by a great number of Thraupidaespecies, that happened in large intraspecific group. Inside or outside of mixed flocks, all species foraged in the same height range of vegetation.Among the five most frequent flocks species, three were considered to be species-nucleus(Herpsilochmus rufimarginatus, Lanio cristatusandMyrmotherula urosticta),presenting a higher degree of associations between all species, and capable of recruiting more species for flocks when they took place; flocks where these species-nucleus occurred were richer, indicating that, when put together, these species increased the ability to recruit other species. / Bandos mistos de aves s?o agrupamentos de duas ou mais esp?cies cuja forma??o e coes?o se devema intera??es comportamentais entre seus integrantes. Este estudo investigou a composi??o espec?fica dos bandos mistos em uma ?rea de Mata Atl?ntica da Bahia, considerando a din?mica sazonal dos bandos, a distribui??o vertical de suas esp?cies e a determina??o das esp?cies-n?cleo, que s?o as respons?veis por atrair e manter coesas as demais esp?cies nos bandos. Foram realizadas, de agosto de 2012 a agosto de 2013, expedi??es mensais de cinco dias para a regi?o do Ecopolo I da ?rea de Prote??o Ambiental do Pratigi (Ibirapitanga, Bahia), quando eram registrados os dados de cada bando misto contatado: composi??o espec?fica, n?mero de indiv?duos de cada esp?cie e, sempre que poss?vel, a altura de forrageamento, a ocorr?ncia de agonismos e intensidades estimadas de movimenta??o e vocaliza??o de cada esp?cie; al?m disto, eram registrados os contatos com as esp?cies participantes de bandos mistos quando vistas fora destes, sendo observadas suas alturas de forrageio e evid?ncias de comportamentos reprodutivos. Foram feitos 113 contatos com bandos mistos, dos quais 51 esp?cies de aves, que representam cerca de 30% das esp?cies registradas na ?rea de estudo, participaram. Nos bandos, as fam?lias mais representadas foram Thraupidae e Thamnophilidae ? dentre esta ?ltima, duas esp?cies amea?adas de extin??o. Os bandos mistos ocorreram durante o ano todo, sendo mais frequentes no m?s de agosto e menos frequentes nos meses de setembro a abril. Devido ? ocorr?ncia de chuvas ao longo do ano todo na ?rea de estudo, n?o houve correla??o entre frequ?ncia, riqueza e tamanho dos bandos com a pluviosidade mensal; houve correla??o negativa entre a frequ?ncia dos bandos e a temperatura, n?o havendo correla??o da temperatura com riqueza e tamanho dos bandos. A riqueza m?dia nos bandos foi 5,1? 2,6esp?cies e o tamanho m?dio de,5 ? 5,2, indiv?duos, sendo estas duas vari?veis correlacionadas positivamente(r = 0,81; p = < 0,0001). Houve diferen?a na riqueza entre os estratos da vegeta??o, sendo que no sub-bosque os bandos eram mais ricos que os de dossel. No entanto, quanto ao tamanho, em n?mero de indiv?duos, os bandos de sub-bosque e dossel n?o apresentaram diferen?a significativa, pois os bandos de dossel eram compostos por um grande n?mero de esp?cies de traup?deos que ocorriam em grupos intraespec?ficos grandes. Dentro ou fora dos bandos mistos, todas as esp?cies forrageavam na mesma faixa de altura da vegeta??o. Das cinco esp?cies mais frequentes nos bandos, tr?s foram consideradas como esp?cies-n?cleo (Herpsilochmus rufimarginatus, Lanio cristatus e Myrmotherula urosticta), apresentando um maior grau de associa??es entre todas as esp?cies e capazes de arregimentar mais esp?cies para os bandos onde ocorriam; os bandos onde estas esp?cies-n?cleo ocorriam eram mais ricos, indicando que, quando juntas, estas esp?cies aumentavam a capacidade de arregimentar outras esp?cies.

Plant-pollinator interactions figure as key elements promoting the natural regeneration of terrestrial vegetation, as most plants depend on animals to transfer their gametes between flowers and produce seeds. Bees are the most common pollinators of plants and their interactions with flowers have served as model systems for the study of specialized mutualisms since Darwin's time. While most plants offer nectar as a reward and attract a variety of floral visitors, others produce distinctive types of resources which are sought by particular groups of pollinators. Such associations may involve specialization at the morphological, behavioral, or physiological levels and are especially common in tropical habitats. The interactions between oil-producing flowers of Neotropical Malpighiaceae and oil-collecting bees are an example of a specialized mutualism in which plants offer lipids to attract pollinators that use the resource to build nest cells and feed their offspring. Although several studies have focused on specialized pollination at the species level, their effects on the organization of tropical communities remain largely unexplored. This dissertation aims to help fill this gap through an analysis of the mechanisms of pollinator partitioning in multi-species assemblages of specialists as well as a study of the organization of communities in which they occur. The motivation for pursuing the study of specialized interactions using Neotropical species of Malpighiaceae as a model system is outlined in the first chapter. In Chapter 2, I present an evaluation of the structural properties of a plant-pollinator community from the Cerrado, a seasonal ecosystem that hosts a large diversity of oil flowers. The third chapter analyzes pollinator partitioning and reproductive strategies promoting the coexistence of closely related Malpighiaceae. A possible outcome for the selective pressures imposed by the coexistence of specialists is presented in Chapter 4 by a case study providing evidence for a shift from specialized to generalized pollination in a Neotropical Malpighiaceae species. The last chapter includes reports of active floral oil foraging by males of Tetrapedia and a description of an oil storage structure without precedence among bees and unique to males of this genus suggesting that floral oils may also play a role in bees mating systems. / text

I investigated effects of environmental change on disease, and effects of disease on ecosystems, using a freshwater zooplankton host and its fungal parasite. This research involved lake surveys, manipulative experiments, and mathematical models. My results indicate that ecosystem characteristics such as habitat structure, nutrient availability, and quality of a host’s resources (here, phytoplankton) can affect the spread of disease. For example, a survey of epidemics in lakes revealed direct and indirect links between habitat structure and epidemic size, where indirect connections were mediated by non-host species. Then, in a mesocosm experiment in a lake, manipulations of habitat structure and nutrient availability interactively affected the spread of disease, and nutrient enrichment increased densities of infected hosts. In a separate laboratory experiment, poor quality resources were shown to decrease parasite transmission rate by altering host foraging behavior. My experimental results also suggest that disease can affect ecosystems through effects on host densities and host traits. In the mesocosm experiment, the parasite indirectly increased abundance of algal resources by decreasing densities of the zooplankton host. Disease in the experimental zooplankton populations also impacted nutrient stoichiometry of algae, which could entail a parasite-mediated shift in food quality for grazers such as the host. Additionally, I showed that infection dramatically reduces host feeding rate, and used a dynamic epidemiological model to illustrate how this parasite-mediated trait change could affect densities of resources and hosts, as well as the spread of disease. I discuss the implications of these ecosystem–disease interactions in light of ongoing changes to habitat and nutrient regimes in freshwater ecosystems.

Made available in DSpace on 2014-06-11T19:30:14Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-03-12Bitstream added on 2014-06-13T20:39:57Z : No. of bitstreams: 1 gussoni_coa_me_rcla.pdf: 665002 bytes, checksum: 041131facf35002a9f8926d9867069d7 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / A maria-da-restinga (Phylloscartes kronei) é uma espécie da família Tyrannidae descrita recentemente e considerada como globalmente ameaçada de extinção, cuja história natural é pouco conhecida. Visando preencher parte desta lacuna, o objetivo deste estudo foi de caracterizar o comportamento de forrageamento da maria-da-restinga, descrever os bandos mistos aos quais ela se associa, bem como descrever alguns outros aspectos de sua história natural como seus hábitos alimentares, o comportamento de dormir, insights sobre a biologia reprodutiva, o alcance de vôo, encontros agonísticos interespecíficos e a muda. No período de agosto de 2008 a julho de 2009 foram realizadas excursões mensais ao município de Ilha Comprida (~24º S), Estado de São Paulo. Aliado ao esforço anual mencionado, uma visita ao município de Guaraqueçaba (25º18'S e 48º19'W), Estado do Paraná, foi conduzida entre os dias 25 de julho e 1º de agosto de 2008. Foram coletadas 613 amostras de forrageamento, através de observações diretas com auxílio de binóculos com aumento de 10 vezes. Durante os períodos de coleta de dados sobre o forrageamento da espécie, para cada encontro com a mesma foi anotado se esta se encontrava só, aos pares, em grupos ou associada a bandos mistos de aves. Quando em bandos mistos, foram anotadas todas as espécies ocorrentes, visando caracterizar os bandos aos quais se associa. Para a descrição do hábito alimentar da espécie foram analisados os conteúdos estomacais de cinco exemplares coletados na década de 1990 no Estado do Paraná, tendo sido identificados 116 ítens alimentares. Através da análise dos dados obtidos, conclui-se que P. kronei captura suas presas principalmente em folhas verdes, entre 0,5 e 15m acima do solo, utilizando a manobra “investir-atingir”. Alimenta-se predominantemente de artrópodes, sendo que os insetos das ordens Coleoptera... / The Restinga Tyrannulet (Phylloscartes kronei) is a recently described and globally threatened species of the family Tyrannidae, whose natural history is poorly known. In this study several information on the natural history of P. kronei were gathered such as several aspects on foraging behavior, association with mixed species bird flocks, feeding habits, the description of the roosting behavior, insights on the reproductive biology, the flying range, interespecific agonistic encounters and moulting. From August 2008 to July 2009, data on this species were collected on a monthly basis in Ilha Comprida (~24º S), São Paulo state, Brazil. In addition, a visit to Guaraqueçaba (25º18'S e 48º19'W), Paraná state, was conducted between 25 July and 01 August 2008. A total of 613 foraging maneuvers were gathered by direct observations with the aid of binoculars with 10x magnification. In all meetings with the species it was reported if individuals were alone, in pairs, in groups or associated with mixed species bird flocks. When mixed species flocks with Restinga Tyrannulets were observed, all species in the flock were identified. Five stomach contents collected in the 1990s in Paraná state were evaluated and 116 food items were identified. The Restinga Tyrannulet captures preys mainly with sally-strikes in green leaves between 0.5 and 15m above the ground. This species feeds mainly on arthropods, especially Coleoptera and Hymenoptera. The observed foraging behaviors and feeding habits were similar to the ones observed in other species of Phylloscartes, but new food items are described for this genus: Anobiidae (Coleoptera), Coccinelidae (Coleoptera), Chalcidoidea (Hymenoptera), Microhymenoptera and two species of fruits (Clusia criuva and Ternstroemia brasiliensis). P. kronei is a sporadic follower of mixed species bird flocks, which had the inclusion of 25 species on their compositions... (Complete abstract click electronic access below)

A quebra de frutos encapsulados por macacos-prego com o auxílio de ferramentas é tipicamente objeto de observação e scrounging por coespecíficos, bastante tolerados e em geral mais jovens e menos proficientes. O presente estudo teve como objetivo examinar o processo de escolha, pelos observadores, dos alvos de observação, e se esta escolha pode otimizar as oportunidades de scrounging. A pesquisa foi realizada com um grupo de macacos-prego selvagens (Cebus libidinosus) na Fazenda Boa Vista (Piauí - Brasil), numa área de ecótono cerrado/caatinga. A partilha de alimento fora dos episódios de quebra de cocos e o uso de ferramentas para a quebra de outros itens alimentares encapsulados também foram abordados. Indivíduos de todas as classes de idade e sexo se envolveram na observação da quebra de cocos, havendo uma grande variação individual. Nossas análises mostram que os macacos preferencialmente escolhidos como alvos de observação foram aqueles que apresentaram maior Freqüência, Proficiência e Produtividade na quebra de cocos. Apesar de haver interações agonísticas durante os eventos de observação, os alvos se mostram muito tolerantes à observação e ao scrounging - 25% dos episódios de quebra são observados e mais da metade destes eventos de observação resultam em scrounging. Os observadores tiveram a oportunidade de comer os restos dos cocos e de manipular os itens do sítio de quebra. Estas observações reforçam a noção de que as condições e possibilidades vivenciadas pelo observador-scrounger otimizam as oportunidades para que ocorram processos de aprendizagem socialmente mediada, ao menos por realce de estímulo. Tal exposição próxima ao comportamento do alvo poderia influenciar aspectos mais finos do comportamento dos observadores, ao longo de sua história de aprendizagem. O presente estudo aborda estas interações entre manipuladores de ferramentas e observadores/scroungers pela primeira vez em uma população selvagem e discute as semelhanças e discrepâncias em relação aos resultados anteriormente obtidos com uma população em semil-liberdade. / The tool-aided cracking of encapsulated fruit by capuchin monkeys is a frequent target of observation and scrounging by conspecifics, well-tolerated and usually younger and less proficient. The present study aimed to examine the process of observational targets choice by the observers, and whether this choice can optimize scrounging opportunities. The research was conducted with a group of wild bearded capuchin monkeys (Cebus libidinosus) in Fazenda Boa Vista (Piauí, Brazil), in an ecotone area between cerrado and caatinga savanna-like environments. Food sharing in contexts other than nut cracking, as well as the use of tools to crack open other food items were also analyzed. Individuals from all age and sex classes were involved in nut cracking observation. Our analyses show that the monkeys preferentially chosen as observational targets were the ones exhibiting the greater Frequency, Proficiency, and Productivity in nut cracking. In spite of a few agonistic interactions during observation events, the targets tend to be very tolerant to observation and to scrounging (25% of the nut cracking events are observed, and more than half of these resulted in scrounging). The observers had the opportunity of eating nuts leftovers and of manipulating items from the cracking sites, both in the presence and in the absence of the targets. These findings strengthen the idea that the conditions and possibilities experienced by the observers-scroungers optimize the opportunities for socially biased learning processes, at least by stimulus enhancement. Such close exposure to the targets behavior could also influence finer details of the observers behavior in the long run. The present study is the first one to deal with these interactions between tool manipulators and observers/scroungers in a wild population and discusses the similarities and differences from previous observations from a semi-free population.