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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
481

Escolha de alvos coespecíficos na observação do uso de ferramentas por macacos-prego (Cebus libidinosus) selvagens / Choice of conspecific targets in the observation of tool use by wild bearded capuchin monkeys (Cebus libidinosus)

Silva, Eduardo Darvin Ramos da 02 July 2008 (has links)
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.
482

Aspectos temporais da organização coletiva do forrageamento em formigas saúvas (Atta sexdens rubropilosa) / Temporal aspects of collective organization of foraging in leaf-cutting ants (Atta sexdens rubropilosa)

Toledo, Marcelo Arruda Fiuza de 14 March 2013 (has links)
Ao observarmos uma trilha de forrageamento de formigas saúvas parece bastante claro que ela consiste no tráfego de muitos indivíduos que buscam alimento numa mesma fonte e o trazem para a colônia. No entanto, a organização presente numa trilha vai muito além do fato de que formigas operárias transportam folhas para o ninho. Desde os mecanismos de formação e manutenção de trilhas baseados no recrutamento e em retroalimentação positiva da marcação feromonal, até a forma com que formigas de tamanhos diferentes se dividem entre as tarefas de corte, transporte e patrulhamento, as trilhas de forrageamento exibem uma organização muito sofisticada, que reflete a complexidade característica dos de organismos eussociais. Neste cenário, é particularmente desafiador identificar a relação entre os comportamentos individuais, característicos de formigas de um dado morfotipo, e os padrões globais coletivos observados na colônia, como por exemplo, o padrão temporal da atividade de forrageamento. No caso de formigas Atta sexdens, apesar de ser reconhecida a importância do polimorfismo na divisão de tarefas, não foi investigado o seu papel na determinação do padrão temporal com que as tarefas são realizadas. Esta questão é especialmente interessante no caso das trilhas, sob a perspectiva de que soldados, que são formigas maiores, desempenham uma tarefa cuja demanda temporal é constante, e que formigas de tamanhos intermediários são responsáveis pelo forrageamento, realizado em horários preferenciais. Para avaliar se formigas de tamanhos diferentes diferem quanto a suas respectivas distribuições temporais de atividade nas trilhas, o presente trabalho gravou em vídeo por alguns dias uma trilha de forrageamento de uma colônia mantida em laboratório em condições controladas de fotoperíodo. Através da análise computacional dos vídeos, foi possível contar os indivíduos e medir o tamanho de cada uma das formigas gravadas. Os seguintes resultados foram observados: (i) a atividade é mais intensa durante a fase fase escura do que durante a clara; (ii) a intensidade da atividade não é temporalmente uniforme dentro das fases, apresentando transientes relacionados à antecipação da transições entre fases, apesar da ausência de crepúsculo; (iii) formigas de tamanhos diferentes distinguem-se quanto as suas distribuições temporais de atividade, ainda que não forma esperada expressa anteriormente; (iv) uma consequência global deste fato pode ser observada na variação do tamanho médio de formigas ao longo do experimento. As diferenças observadas no padrão temporal de atividade de formigas de tamanhos diferentes podem ser decorrentes de mecanismos endógenos de ritmicidade, e ou de mecanismos comportamentais de divisão de tarefas baseado em diferenças entre limiares para respostas / When we look at a leaf-cutting ant foraging trail it seems quite clear that it consists on the traffic of many individuals collecting food from a same source and bringing it to the colonies nest. However, the foraging trail organization goes much beyond the fact that worker ants transport leaves to the nest. From the trail formation and maintenance mechanisms, based in recruitment and in pheromone marking positive feedback, to how workers of different size divide themselves among cutting, transporting and patrolling, the foraging trail presents a sophisticated organization, reflecting the typical complexity of eusocial organisms. In this condition, it\'s particularly challenging to identify the relationship between individual behaviours, particular of ants of a given morphotype, and the global, collective patterns, observed in the colony, for example, the foraging temporal pattern. In the case of Atta sexdens, despite the widely known importance of polymorphism in division of labour, its role in determining the temporal activity patterns has not been investigated. It\'s a matter of major interest in foraging trails, considered the perspective that soldiers, which are big ants patrolling trails, perform a task whose demand is time constant, at least in non adverse conditions, while medias are largely responsible for foraging, which has preferential time for performance. In order to access if different size worker ants distinguish among their respective temporal activity patterns in trails, in this work we recorded a laboratory captive colony foraging trail, under a set photoperiod, and controlled temperature. By computational video analysis, we could count the ants and measure each of them. The following results may be highlighted : (I) trail activity is more intense during darkness than during light; (ii) activity intensity within each phase is not uniform in time, showing phase anticipation related transients, despite the absence of twilight; (iii) ants of different size distinguish among their temporal activity distributions, although not as the previously stated expectations; (iv) a global consequence of this may be seen in the mean ant size variation observed throughout the experiment. The differences of temporal activity patterns among ants of different size may result from endogenous rhythm mechanisms, and or from behavioural mechanisms of division of labour based in differential response thresholds
483

Aprendizado do forrageamento e desenvolvimento da dieta de potros

Bolzan, Anderson Michel Soares January 2016 (has links)
O conhecimento dos mecanismos de pastejo dos equinos em pastos nativos é fator relevante para a melhor compreensão das relações dos animais com a complexidade da vegetação, possibilitando a otimização das funções ecossistêmicas e viabilização da criação. Com este propósito, foi avaliado por meio de monitoramento contínuo, o comportamento ingestivo de seis potros ao pé de éguas Crioulas, do nascimento aos 130 dias de idade, com intervalos 15 dias. Os animais foram divididos em duas manadas, manejadas em pastoreio contínuo, com oferta de forragem não-limitante, em pastagem natural do Bioma Pampa, região de Campos de solos rasos, Santana do Livramento, RS. Foram verificadas as relações e fatores de influência no aprendizado de pastejo do potro. O monitoramento contínuo por observação direta permitiu avaliar instantaneamente os bocados realizados pelos potros, durante quatro horas a partir do amanhecer, e quatro horas antes do anoitecer. Foram realizadas simulações de bocados para estimativa de MS de cada categoria de bocado e taxas de ingestão de MS instantânea dos animais. A composição e diversidade da dieta do potro em relação à mãe e aos pares demonstrou padrões de distanciamento que evidenciam funções definidas com a idade na evolução da herbivoria do potro. Verificaram-se duas fases bem definidas na evolução do pastejo do potro. A primeira fase exploratória, entre 0 e 60 dias, caracterizada pela grande diversidade de bocados e baixa ingestão de MS vegetal. Neste período, a base do aporte nutricional é via amamentação, e evidencia o maior distanciamento entre componentes da dieta de mãe e respectivo potro. O índice de diversidade da dieta do potro é maior que o índice de diversidade da vegetação, o que ratifica o caráter exploratório. A segunda fase, de especialização, inicia a partir dos 60 dias, onde ocorre uma especialização para a função ingestão de MS, preconizada pelo aumento na MS e diminuição na diversidade dos bocados. O grande aumento na ingestão de MS pelo potro entre 60 e 80 dias de vida denota um alinhamento das funções de égua e potro, com os padrões de composição da dieta semelhantes, se estabilizando ao redor de 100 dias. Entretanto, há diferenças entre as dietas dos grupos familiares (égua-potro), confererindo um fator cultural materno filial. A identificação dos períodos e fatores de aprendizagem do potro pode respaldar estratégias de manejo para melhor condução dos métodos de pastoreio dos equinos em ambientes pastoris, especialmente em pastagens naturais com grande biodiversidade, visando contemplar e ampliar funções ecossistêmicas. / Understanding the foraging mechanisms of horses in native pastures is a relevant factor for better comprehending the relationship of those animals in response to the vegetation complexity. It allows for optimizing ecosystem functions and livestock production. The ingestive behavior of six pairs of Criolo mares and foals was evaluated using continuous bite monitoring, from birth to 130 days, in 15 days intervals. The animals were divided in two groups, managed under continuous stocking, with non-limiting herbage allowance, in the shallow soil Pampa Grasslands, in southern Brazil. The relationships between and within pairs, and other influencing factors for the foraging learning process were assessed. The continuous monitoring allowed for evaluating bites for four hours after dawn and four hours before dusk. Bite simulations were done for estimating bite mass for each category, and calculating instantaneous dry matter intake rate. The diverging patterns of the foals’ diet composition and diversity in relation to their dams and to other peers indicated defined functions that varied with age in the evolution of herbivory. Two distinct phases were identified. First, an exploratory phase from 0 to 60 days, characterized by a great diversity of bites with low herbage intake and very distinct from the dam. During this period, milk is the main dietary component, and the diet (herbal) diversity index was larger than the diversity index for the vegetation. A second phase started at 60 days of age, where dry matter intake increased, by a specialization towards less diverse bites, but with higher mass. The large increase in dry matter intake between 60 and 80 days denoted an alignment of the intake functions of the mare and the foal, with similar diet composition, stabilizing at around 100 days. On the other hand, there was a difference on diet composition between family groups, indicating a cultural maternal filial influence. The identification of periods and factors affecting the foraging learning process of the foals can allow for improving pasture management strategies, especially on high-diversity, natural grasslands, contemplating and amplifying ecosystem functions.
484

Novas informações sobre a história natural da maria-da-restinga (Phylloscartes kronei) (Aves, Tyrannidae) /

Gussoni, Carlos Otávio Araújo. January 2010 (has links)
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
485

Stratégies de réussite parasitaire du parasitoïde larvaire Therophilus javanus et de ses potentialités d’utilisation en lutte biologique contre Maruca vitrata le lépidoptère foreur de gousse de niébé Vigna unguiculata en Afrique de l’Ouest / Assessing the potential of Therophilus javanus, a biological control candidate against the cowpea pod borer Maruca vitrata in West Africa

Aboubakar Souna, Djibril 22 November 2018 (has links)
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.
486

Ecologie et conservation du puffin d'Audubon (Puffinus lherminieri lherminieri) de la réserve naturelle des îlets de Sainte-Anne(Martinique) / Ecology and conservervation of Audubon's shearwater (Puffinus therminieri) from the nature reserve of Sainte-Anne islet (Martinique)

Precheur, Carine 17 December 2015 (has links)
Dans l’optique de la gestion de population du puffin d’Audubon de Martinique, cette thèse a permis d’établir un diagnostic démographique et d’apporter des connaissances indispensables sur l’écologie marine de cette espèce. La population a connu une croissance assez marquée les dernières années, correspondant à une période où les rats ont été exterminés et le suivi de la colonie réduit pour limiter le dérangement. Cependant, le principal facteur ayant expliqué cette augmentation de la population, a été une amélioration des conditions marines favorisant une disponibilité des proies plus importante, particulièrement hors reproduction. L’augmentation de la survie des adultes a été alors expliquée en grande partie par un effet positif des variations de température d’eau de surface de l’océan (SST) hors reproduction et un effet positif du débit de l’Amazone avec un décalage d’un an. En mer, on remarque que le puffin d’Audubon de Martinique a un comportement sédentaire avec une distribution très régionale limitée aux Petites Antilles et proche des côtes du nord de l’Amérique du Sud. Sa niche alimentaire est sous la forte influence d’apports fluviaux de l’Amazone et de l’Orénoque, milieux à faible salinité et à SST élevée. De plus, les zones d’alimentation de la population de Martinique diffèrent de celle de Bahamas et cela suggère une double problématique de gestion de la sous-espèce de la Caraïbe. Ces nouvelles connaissances permettront de mieux orienter les mesures de conservation mais soulignent également le besoin de clarifier la taxonomie de cette espèce à l’échelle de la Caraïbe, la dynamique de la population et d’évaluer plus précisément les menaces en mer. / In the context of management of Audubon’s shearwater population from Martinique, this thesis has established a demographic diagnosis and provided essential knowledge on the marine ecology of this species. The population has experienced a fairly marked growth in recent years, corresponding to a period where the rats were exterminated and monitoring of colony was limited to reduce the disturbance. However, the main factor that explained the increase in population was improved marine conditions favoring greater availability of prey, especially outside reproduction. The increase in adult survival was then explained in large part by a positive effect of changes in ocean surface water temperature (SST) out of reproduction and a positive effect of the flow of the Amazon with a lag one year. At sea, we notice that the puffin Audubon Martinique has sedentary behavior with very limited regional distribution and the Lesser Antilles near the northern coast of South America. Its food niche is under the strong influence of riverine inputs of the Amazon and Orinoco, low salinity and high SST environments. In addition, foraging areas of Audubon's Shearwater from Martinique differ from that of the Bahamas and this suggests a double subspecies of the Caribbean management problematic. This new knowledge will help guide conservation measures but also underline the need to clarify the taxonomy of this species throughout the Caribbean, the dynamics of the population and to more accurately assess its threats at sea.
487

Morcegos frugívoros no uso do hábitat fragmentado e seu potencial para recuperação de áreas degradadas : subsídios para uma nova ferramenta voltada à conservação /

Bianconi, Gledson Vigiano. January 2009 (has links)
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
488

Variabilité du comportement de recherche alimentaire d’un oiseau marin tropical : le fou à pieds rouges (Sula sula) / Variability in foraging behaviour of a tropical seabird : the red-footed booby (Sula sula)

Mendez, Loriane 17 October 2017 (has links)
Le comportement de recherche alimentaire varie tout au long de la vie des oiseaux marins selon divers facteurs qui peuvent être liés au cycle de vie ou à l’habitat. Cependant, aucune étude n’avait auparavant abordé ces différents facteurs de variation chez une seule et même espèce. L’objectif de cette thèse était de distinguer la part fixe du comportement de recherche alimentaire de ses différents degrés de plasticité chez un oiseau marin pantropical, le fou à pieds rouges (Sula sula). Pour cela, des adultes et des juvéniles issus de différentes colonies ont été équipés de balises GPS afin d’étudier leurs trajets selon différents facteurs de variation intrinsèques (âge et stade de reproduction) et extrinsèques (forçages physiques, productivité primaire, compétition pour la ressource). Le comportement de recherche alimentaire des adultes variait de façon importante au sein d’une même colonie selon le stade de reproduction. Les trajets étaient plus courts pendant l'élevage du poussin, connu pour être particulièrement contraignant d’un point de vue énergétique, et plus longs pendant l’incubation et la période post-envol. Le suivi pluriannuel d’une des colonies a pu mettre en évidence la flexibilité du comportement lors de conditions environnementales défavorables. Des trajets plus longs étaient observés lors de la saison de reproduction qui présentait une diminution de la productivité et de l’activité tourbillonnaire locale. Une importante plasticité du comportement en fonction de l’habitat a pu être mise en évidence à l’échelle de l’aire de répartition de l’espèce. La durée et le rayon de prospection des trajets des adultes variaient considérablement selon les colonies, allant de trajets strictement diurnes à des trajets beaucoup plus longs qui incluaient plusieurs nuits passées en mer. Les fous à pieds rouges ne semblaient pas cibler des zones particulièrement productives et la compétition intra- et interspécifique semblait expliquer en partie les différences observées entre les colonies. En revanche, tous les trajets possédaient généralement une structure similaire et augmentaient leur effort de recherche alimentaire en adoptant un comportement de recherche en zone restreinte (ARS). Le comportement des juvéniles, encore nourris par leurs parents après leur envol pendant une longue période de transition, a pu être décrit pour la première fois. Avec le temps, les juvéniles augmentaient le rayon de prospection de leurs trajets, qui restait considérablement inférieur à celui des adultes. Des associations en mer avec d’autres juvéniles étaient fréquemment identifiées. Cette longue période d’apprentissage semble permettre l’acquisition progressive de compétences complexes nécessaires à la recherche et à la capture de leurs proies. Si la plasticité comportementale des individus tend généralement à amortir les effets des conditions défavorables sur l'état de santé moyen d’une population, cette flexibilité est tout de même limitée. Dans le contexte actuel de changement global, l’évaluation de la plasticité comportementale s’avère alors nécessaire afin de mieux prévoir les conséquences de ces changements sur les populations. / Seabird foraging behaviour varies through time according to factors that may be related to life cycle stage and/or habitat. However, no study has previously investigated variation in these different factors and how they impact foraging behaviour in a single species simultaneously. The aim of this thesis was to distinguish the fixed part of foraging behaviour from its different degrees of plasticity in a pantropical seabird, the Red-footed booby (Sula sula). Adults and juveniles from different colonies were equipped with GPS tags to track their foraging trips according to several intrinsic (age and breeding stage) and extrinsic factors (physical forcing, primary productivity and competition for resources). Adult foraging behaviour varied significantly within the same colony according to breeding stage. Tracks were shorter during brooding, which is known to be a particularly energy-constraining time period, and longer during incubation and fledging. Multi-year monitoring at one of the colonies revealed flexibility in behaviour under adverse environmental conditions. Longer tracks were observed during breeding seasons with decreased productivity and eddy activity. High plasticity in foraging behaviour according to habitat was observed across the range of the species. The length and range of adult trips varied considerably among colonies, ranging from strictly diurnal to longer trips that included several nights spent at sea. Red-footed boobies did not appear to target particularly productive areas, and intra- and interspecific competition seemed to explain partly the differences observed between colonies. On the other hand, all the individuals showed similar trip structuring and increased searching effort by adopting area-restricted search (ARS) behaviours. The behaviour of juveniles, still fed by their parents after fledging during a long transition period, was described for the first time. Over time, juveniles increased trip ranges, which were considerably lower than that of adults. Associations at sea with other juveniles were frequently identified. This long learning period seems to be an adaptation allowing the gradual acquisition of the skills necessary for the search and capture of prey. While the behavioural plasticity of individuals tends to cushion the effects of unfavourable conditions at the population scale, this flexibility is still limited. In the current context of global change, assessment of behavioural plasticity is necessary in order to better predict the consequences of these changes on populations.
489

Stratégies alimentaires et énergétiques de la prédation chez les mammifères marins / Foraging strategies and energetic of predation among marine mammals

Spitz, Jérôme 30 September 2010 (has links)
Les stratégies alimentaires peuvent être définies comme la mise en place d'ensembles cohérents de réponses morphologiques, physiologiques, écologiques ou comportementales permettant d’optimiser le succès alimentaire d’une espèce. Le présent travail s'est proposé d'aller au-delà de la simple analyse taxonomique des régimes alimentaires en utilisant les caractéristiques des proies pour explorer certains aspects des stratégies alimentaires et de l’énergétique de la prédation chez les mammifères marins de l’atlantique nord-est. L'objectif majeur était de contribuer à une meilleure compréhension du "pourquoi une proie est une proie ?" La valeur énergétique des proies est apparue comme un élément central des stratégies de prédation. Il en résulte que des coûts d'existence importants chez les mammifères marins doivent être soutenus par une alimentation de qualité élevée et ne peuvent pas être satisfaits simplement par une plus grande quantité de proies de qualité moyenne ou faible. Les résultats obtenus lors de cette thèse ont ainsi permis de progresser de la description des régimes alimentaires vers la compréhension de certaines relations fonctionnelles entre proies et prédateurs. Ainsi, les traits descriptifs de la qualité des proies, comme la teneur en lipides et la valeur énergétique, et les traits descriptifs des coûts d’existence des mammifères marins, comme l’indice mitochondrial et la teneur en lipides des muscles, sont significativement corrélés. Enfin, ce travail souligne que pour comprendre l'écologie alimentaire d'un prédateur, il faut surtout bien connaitre les caractéristiques de ses proies. / Foraging strategies can be defined as the establishment of a consistent set of morphological, physiological, ecological and behavioural responses allowing the optimization of foraging success. Beyond the simple description of the diet, the present work attempted to explore some aspects of foraging strategies and of the energetic of predation among northeast Atlantic marine mammals. The main goal of the study was to contribute to a better understanding of "why a prey is a prey?" Prey energy density appeared to be a key point of predation strategies. Hence, marine mammal species with high existence costs would need high quality prey items, and cannot fulfil their energy requirement just by ingesting more prey items of low to medium quality. The results of this thesis permitted to progress from a taxonomic description of marine mammal diets to the identification of functional relationships between prey and predators. Hence, traits of prey quality such as lipid content or energy density, and traits of predator cost of existence such as muscle mitochondrial density or muscle lipid content, were significantly correlated. Finally, this work underlines that in order to understand the foraging ecology of a predator, its prey characteristics have to be known.
490

Termitofauna (Blattodea: Termitidae) associada a esp?cies arb?reas em ?rea de reserva da Ilha do Catal?o da UFRJ, RJ / Termitofauna (Blattodea:Termitidae) Associated Tree Species in Reserve Area of the UFRJ Catalan Island, RJ

Santos, Aline Barreto 15 December 2015 (has links)
Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2017-03-13T13:52:35Z No. of bitstreams: 1 2015 - Aline Barreto Santos.pdf: 883584 bytes, checksum: 8c172d2d89cd730277fc41a3b05b4e69 (MD5) / Made available in DSpace on 2017-03-13T13:52:35Z (GMT). No. of bitstreams: 1 2015 - Aline Barreto Santos.pdf: 883584 bytes, checksum: 8c172d2d89cd730277fc41a3b05b4e69 (MD5) Previous issue date: 2015-12-15 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / The arboreal termites that are part of the Brazilian fauna attack urban areas that have expanded into areas of wild vegetation. The urban trees when not follow the proper principles of planting and management, transforms the trees into nesting sites and feeding termites. Thus, arboreal species of termites begin to assume increasing importance as pests. This study aimed to identify the species of termites associated with tree species and verify, under field conditions, if these termites exhibit preference for nesting and foraging, in the sandbank area of Catalan Island, in the municipality of Rio de Janeiro, RJ. For this, 95 were chosen randomly planting rows of trees located in this area. These lines has traveled a path of 100 m, also randomly chosen, and during that route all the trees were inspected to verify the occurrence of termites. Termites found were collected, preserved in 70% alcohol for later identification. To assess the preferred nesting, all the trees were inspected for the presence nests of N. corniger. The occurrence of termites was registered in all tree rows sampled (n = 95). Of the total of 545 inspected trees, 77% were infested by termites, identified four species distributed into two families: three native species Termitidae (Nasutitermes corniger Motschulsky, Nasutitermes jaraguae Holmgren and Microcerotermes strunckii Soerensen) and an exotic species of Rhinotermitidae (Coptotermes gestroi Wasmann). The most frequent species was N. corniger (?2 = 82.04, df = 3, p <0.001), occurring in 79% of infested trees, followed by N. jaraguae (6% of infested trees). The termite species least infested trees were found in C. gestroi (1%) and M. strunckii (1%). In general , the exotic tree species Albizia Lebeck is the most infested by termites and also exotic Leucaena leucocephala is less infested. 114 Nest establishment of N. corniger were identified, and the tree species Schinus terebinthifolius the most nidificada. So the trees of the Catalan's Island salt marsh area are infested with native and exotic termites, however, the native termite N. corniger is predominant. / Os t?rmitas arbor?colas que fazem parte da fauna brasileira atacam ?reas urbanas que expandiram sobre ?reas de vegeta??o silvestre. A arboriza??o urbana quando n?o segue os preceitos adequados de plantio e manejo, transforma as ?rvores em locais de nidifica??o e alimenta??o dos cupins. Dessa forma, esp?cies arbor?colas de cupins passam a assumir import?ncia crescente como pragas. Esse estudo objetivou identificar as esp?cies de cupins associadas a esp?cies arb?reas e verificar, em condi??es de campo, se esses t?rmitas exibem prefer?ncia para nidifica??o e forrageamento, na ?rea de restinga da Ilha do Catal?o, no munic?pio do Rio de Janeiro, RJ. Para isso, foram sorteadas aleatoriamente 95 linhas de plantio de ?rvores localizadas nessa ?rea. Nestas linhas foi percorrido um trajeto de 100 m, tamb?m escolhido aleatoriamente, e durante esse percurso todas as ?rvores foram inspecionadas para verificar a ocorr?ncia de cupins. Os cupins encontrados foram coletados, preservados em ?lcool 70% para posterior identifica??o. Para avaliar a prefer?ncia de nidifica??o, todas as ?rvores foram inspecionadas quanto a presen?a de ninhos de N. corniger. A ocorr?ncia de t?rmitas foi registrada em todas as linhas de plantio amostradas (n=95). Do total de 545 ?rvores inspecionadas, 77% estavam infestadas por cupins, sendo identificadas quatro esp?cies distribu?das em duas fam?lias: tr?s esp?cies nativas de Termitidae (Nasutitermes corniger Motschulsky, Nasutitermes jaraguae Holmgren e Microcerotermes strunckii Soerensen) e uma esp?cie ex?tica de Rhinotermitidae (Coptotermes gestroi Wasmann). A esp?cie mais frequente foi N. corniger (?2 =82,04; g.l.=3; p<0,001), ocorrendo em 79% das ?rvores infestadas, seguida por N. jaraguae (6% das ?rvores infestadas). As esp?cies de t?rmitas menos encontradas nas ?rvores infestadas foram C. gestroi (1%) e M. strunckii (1%). De maneira geral, a esp?cie arb?rea ex?tica Albizia lebeck ? a mais infestada pelos t?rmitas e a tamb?m ex?tica Leucaena leucocephala ? a menos infestada. Foram identificadas 114 nidifica??es de N. corniger, sendo a esp?cie arb?rea Schimus terebinthifolius a mais nidificada. Portanto, as ?rvores da ?rea de restinga da Ilha do Catal?o s?o infestadas por t?rmitas nativos e ex?ticos, no entanto, o t?rmita nativo N. corniger ? predominante

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