Apesar de a monogamia social ser dominante entre as aves, análises genéticas revelaram relações de parentesco inesperadas, evidenciando diferentes estratégias de reprodução, como a paternidade extra-par e o parasitismo de ninho. Espécies de passeriformes estão entre as mais promíscuas, com altas taxas de paternidade extra-par, enquanto em aves marinhas esse comportamento demonstrou ser menos frequente. Pinguins (Família Spheniscidae) compõem um grupo de 18 espécies de aves marinhas pelágicas e que tem em comum a filopatria, fidelidade a um parceiro e intenso cuidado biparental. Portanto, espera-se que apresentem um comportamento estritamente monogâmico e taxas de paternidade extra-par insignificantes. Avaliamos pela primeira vez o sistema reprodutivo dos Pinguins-de-Magalhães através de uma abordagem genética, buscando investigar a existência e frequência de paternidade extra-par e parasitismo de ninho. O parentesco de 88 filhotes de 44 ninhos de uma colônia na Ilha Quiroga (Argentina) foi determinado com base em análises de 9 marcadores microssatélites. Encontramos baixas taxas de parasitismo de ninho (6%), mas altas taxas de paternidade extra-par (31% e 48% dos ninhos com pelo menos 1 filhote extra-par). Entre os dois anos coletados, encontramos uma pequena diferença na incidência de infidelidade (29% em 2010; 32% em 2011), mas não houve relação com as condições climáticas do período de reprodução da espécie. Além disso, apesar da alta taxa de filhotes extra-par, não encontramos diferença significativa na diversidade genética e nem viés da razão sexual secundária. Acreditamos que a alta taxa de paternidade extra-par encontrada possa ter relação com o comportamento reprodutivo em colônia, a densidade populacional, o sincronismo reprodutivo, ou que parte da paternidade que não correspondeu aos pais sociais seja resultado de troca de parceiros antes da definição final dos casais em cada estação reprodutiva. Nosso estudo pode ajudar a melhor entender e caracterizar o sistema reprodutivo dos Pinguins-de-Magalhães e indica que a espécie é socialmente, mas não geneticamente monogâmica. / Despite the social monogamy being dominant among birds, genetic analysis revealed unexpected kinship relations, showing different reproductive strategies, such as extra-pair paternity and brood parasitism. Passerine species are among the most promiscuous, with high extra-pair paternity rates, while in seabirds this behavior is typically rather less frequent. Penguins (Spheniscidae Family) are a group of 18 species of pelagic seabirds that have in common philopatric behavior, faithfulness to one partner and intense biparental care. Therefore, they are expected to have a strictly monogamous behavior and insignificant rates of extra-pair paternity. For the first time, we evaluated the reproductive system of Magellanic Penguins (Spheniscus magellanicus) through genetic analysis in order to investigate the existence and frequency of extra-pair paternity and brood parasitism. The kinship of 88 offspring of 44 nests from a colony on Quiroga Island (Argentina) was determined based on the analyses of 9 microsatellite markers. We found low rates of brood parasitism (6%), but high extra-pair paternity rates (31% and 48% of nests with at least one extra-pair offspring). Between the two years sampled, we found a small difference in the incidence of infidelity (29% in 2010; 32% in 2011), but no connection with the climatic conditions of each breeding season. In addition, despite the high rate of extra-pair offspring, we found no significant difference in the genetic diversity and no bias in the secondary sex ratio. We believe that the high rate of extra-pair paternity found in our study may be a result of their reproductive behavior of nesting in colonies, breeding synchrony, density, or that part of the mismatching paternity is due mate switching. Our study may help to better understand and characterize the reproductive system of Magellanic penguins and indicates that this species is socially but not sexually monogamous.

Syftet med uppsatsen är att undersöka och analysera hur kejsarpingviner representeras i naturfilmerna March of the Penguins (2005) och Snow Chick: A Penguin's Tale (2015). Uppsatsen fokuserar främst på hur föreställningar om genus och mänskliga normer om familjestrukturer syns i filmerna samt hur kejsarpingvinernas relation och beteenden till varandra representeras. Vi använder genus som den teoretiska utgångspunkten i uppsatsen. De filmer som analyseras är March of the Penguins och Snow Chick: A Penguin’s Tale. Vi analyserar filmerna utifrån Roland Barthes semiotiska teori genom begreppen denotation och konnotation. Resultatet av analysen visar att de två filmerna representerar pingvinerna på liknande sätt, genom att tillskriva förmänskligande egenskaper och beteenden på djuren utifrån föreställningar om genus och mänskliga normer om familjestrukturer. Resultat av analysen visar främst att filmerna endast skildrar det heterosexuella förhållandet och den traditionella kärnfamiljen.

As concentrações de HPAs foram analisadas em invertebrados (Laternula elliptica, Nacella concinna, Yoldia eightsi, Glyptonotus antarcticus, Serolis polita, Euphausia superba, Bovalia gigantea, Sterechinus neumayeri, Odontaster validus e Ophionotus victoriae), peixes (Notothenia rossii), e aves (Pygoscelis Adélia, P. papua, P. antarcticus, Macronectes giganteus, Catharacta sp. e Larus dominicanus) da Baía do Almirantado. As análises de HPAs foram realizadas através de GC/MS. A ocorrência de HPAs nas amostras indicou a biodisponibilidade destes compostos para os organismos da região. As concentrações de HPAs totais para os invertebrados (3,09-174,4 ng g -1 pu) foram maiores que em peixes (0,97-58,9 ng g -1 pu) e menores que em aves (60,1-6861,0 ng g-1 pu), porém apresentaram similaridade entre si. As aves voadoras adultas apresentaram maiores concentrações que os pinguins. Compostos leves e alquilados predominaram em quase todas as amostras, principalmente os alquilnaftalenos. A principal fonte de HPAs para os organismos foi o DFA utilizado na EACF. Espécies predadoras/necrófagas apresentaram HPAs individuais diferentes das espécies suspensívoras/depositívoras. Não ocorreu relação entre o aumento da concentração de HPAs e o aumento do nível trófico dos grupos, e a absorção de HPAs pelas espécies sofreu a influência de fatores como metabolismo, fisiologia, hábito alimentar e teor de lipídio das espécies analisadas. / The concentrations of PAHs had been analyzed in invertebrates (Laternula elliptica, Nacella concinna, Yoldia eightsi, Glyptonotus antarcticus, Serolis polita, Euphausia superba, Bovalia gigantea, Sterechinus neumayeri, Odontaster validus and Ophionotus victoriae), fish (Notothenia rossii) and birds (Pygoscelis adélia, P. papua, P. antarcticus, Macronectes giganteus, Catharacta sp. and Larus dominicanus) Admiralty Bay. The analyses of HPAs had been carried through GC/MS. The occurrence of PAHs in the samples indicated the bioavailability of these compounds for the organisms of the region. The concentration of total PAHs for the invertebrates (3,09 to 174,4 ng g-1 pu) were higher than fish (0,97 to 58,9 ng g-1 pu) and lower than in birds (60,1- 6861,0 ng g-1 pu) however, they had presented similarity between themselves. The adult flying birds had presented higher concentrations than penguins. Light and alkylated compounds had predominated in almost all samples, mainly the alkylnaphthalenes. The main source of PAHs for the organism was the DFA used in the EACF. Predators/necrophagous species had presented different individual PAHs from the feeder/deposit species. There was no relation between the increase of concentrations of PAHs and the increase of the trophic level of the groups, and the absorption of PAHs for the species had the influence of factors such as metabolism, physiology, alimentary habits and lipid content of the analyzed species.

L’océan Austral abrite encore des populations exceptionnelles de prédateurs marins (manchots, albatros, phoques…). Bien qu’activement étudiés, l’approche fonctionnelle des relations proies-prédateurs souffre encore d’un manque de connaissances chez les prédateurs marins. Etudier comment ces animaux utilisent les habitats est essentiel pour mieux comprendre leur écologie. Par ailleurs, dans une période où les écosystèmes sont soumis à d’importantes pressions d’origine anthropique (surpêche, pollutions, changement climatique), la connaissance de l’écologie d’une espèce est primordiale pour bien caractériser les aires à protéger. Le gorfou macaroni Eudyptes chrysoplophus est un oiseau marin pélagique et constitue l’espèce de manchot la plus abondante dans l’océan Austral (> 6 millions de couples). Au cours des 30 dernières années, les effectifs des populations de Géorgie du Sud et de l’île Marion ont fait face à une diminution drastique (> 30%). Actuellement, les populations de gorfou macaroni des Terres Australes et Antarctiques Françaises (archipel des îles Crozet et îles Kerguelen) abritent encore plus de 50% des effectifs mondiaux. Cependant, les comportements de recherche alimentaire de ces deux populations étaient jusqu’à présent encore mal connues. Au cours de cette thèse, nous avons étudié les stratégies de recherche alimentaire du gorfou macaroni, au cours de l’intégralité de son cycle de reproduction (incubation, élevage et crèche) de Kerguelen et Crozet, îles caractérisées par des environnements océanographiques contrastés. Les ajustements du comportement alimentaire face aux contraintes énergétiques liées à la reproduction et aux variations de la production biologique de leurs environnements ont été examinés en détail. Grace à des mesures biologiques d’origine télémétrique et/ou d’appareil embarqué (trajectoires, comportement de plongées) couplées à des données satellitaires (données environnementales), nous avons pu mettre en évidence l’existence : 1) d’un comportement de recherche alimentaire spécifique et de genre : sur les 2 sites étudiés, un ajustement similaire des déplacements, de l’effort d’approvisionnement, du régime alimentaire a été observé en réponse aux contraintes énergétiques imposées par la reproduction. En incubation, les deux sexes ciblent principalement les fronts océanographiques, les tourbillons et les zones filamentaires situées en eaux pélagiques au cours de longs trajets. En période d’élevage, les femelles s’approvisionnent plus près des côtes, majoritairement sur le plateau et au bord des talus afin de pouvoir alimenter régulièrement la progéniture. En crèche, les mâles ciblent à nouveau les structures frontales tandis que les femelles s’éloignent tout en restant inféodées aux talus. A l’aide de la littérature, nous avons pu observer que cette stratégie semble opérer à l’échelle de l’aire de répartition de l’espèce. 2) d’une plasticité phénotypique inattendue : l’approche comparative entre les îles Kerguelen et Crozet a permis d’étudier les points communs et les différences des stratégies d’approvisionnement entre les deux localités, liées aux conditions environnementales locales. Les deux populations semblent toutes deux très dépendantes des pics saisonniers de productivité primaire. En revanche, des variations d’éloignements à la colonie inter - site et intra – sexe plus importantes qu’attendues ont été observées mettant en évidence une flexibilité phénotypique insoupçonnée pour un prédateur marin pélagique. Cette étude est l’une des rares ayant couvert l’ensemble d’un cycle de reproduction chez les manchots. L’importante variabilité comportementale démontrée réitère le besoin impératif de prendre en compte l’intégralité d’un cycle pour mieux comprendre et définir les stratégies d’approvisionnement d’une espèce. / The Austral Ocean still hosts a great population of marine predators (i.e. penguins, albatross, and seals). Despite well studied, the functional approach investigating the relationship between prey and predators in the marine ecosystem is still poorly known. Knowledge on habitat selection and use of marine species is essential to better understand their ecology and behaviour. The knowledge about the ecology of key species is essential to characterise and identify the areas to protect and to predict the future of populations that may be affected by global changes. This is particularly true in an area where the natural ecosystems are more and more perturbed by anthropogenic activities (i.e. over-fishing, pollution, and climate change). The Macaroni penguin is the most abundant penguin species in the Austral Ocean (> 6 millions pairs). It is also the biggest consumer of secondary resources, in terms of biomass, in the world. Over the past 30 years the Macaroni penguin populations situated in South Georgia and Marion Island suffered of 30% population decline. At the moment, Kerguelen and Crozet Islands (French Southern Territories) still host more than 50% of their global population, however the foraging behaviour of this species is still poorly known. The objective of this research is to study the different foraging behaviour strategies of a pelagic seabird : the Macaroni penguin Eudyptes chrysoplophus during its whole breeding cycle (incubation, brood, crèche). The populations’object of study breed in different oceanographic conditions : the Kerguelen and Crozet archipelagos. The variation in foraging behaviour driven by energetic constraints, which is associated to the reproduction and to the biological production, has been studied in details. Telemetry data (i e. trajectories and diving behaviour) combined with environmental data obtained by remote sensing allowed determining that : 1) Foraging strategies of Macaroni penguin breeding in two different locations differ in terms of movement, foraging effort and foraging niche during their breeding cycle in response to reproduction constraints. In incubation, both sexes carried out long journeys and targeted large oceanographic structures such as fronts, eddy and transport fronts. During the brooding phase, the females foraged closer to the colony adjusting their foraging behaviour based on their offspring needs, targeting the shelf and the slope. When crèche started, males targeted large scale structures whereas females still foraged on the slope. At this time, a shift in the diet composition was observed. 2) The comparative approach between Kerguelen and Crozet allowed to highlighting differences in foraging strategies, in response to local environmental conditions. However, greater than expected variations in foraging areas were observed inter-site and inter-sex. These results have pointed out an unexpected phenotypic flexibility for a pelagic marine predator. This research investigated the entire breeding cycle of a penguin, a fact still rare in ecology. The observed degree of behavioural variability reiterates the imperative to take into account an entire cycle to better understand and define the foraging strategies of a species.

Microbial infection of eggs was originally investigated in terms of human health only. Recently, however, it was found that it can also cause early embryo mortality in birds, mainly through trans-shell infection prior to incubation. Trans-shell infection is highly dependent upon environmental conditions, egg temperature and egg properties such as shell quality and antimicrobial defences. Microbial infection of eggs is more likely to occur in synchronously incubating species as first laid eggs can be exposed for up to several days prior to full incubation. One example of a population that seems at particular risk of egg microbial infection is New Zealand’s little blue penguin (Eudyptula minor) from Tiritiri Matangi Island. This bird lays two eggs on average three days apart, and is believed to begin full incubation only after the second egg has been laid. Both eggs are laid in particularly humid and soiled nests and contain only low levels of lysozyme, an important antimicrobial protein. The aims of this study were therefore to 1) obtain a first examination of the rates of shell and trans-shell microbial infection of chicken eggs in New Zealand and assess the effects of cleaning on those rates, 2) investigate the role of microbes in hatching failure of little blue penguin eggs and 3) investigate other factors affecting little blue penguin egg viability. This study revealed that shell infection in chicken eggs significantly increased with exposure and significantly decreased with cleaning; however, trans-shell infection was only marginally affected by exposure and cleaning. On Tiritiri Matangi Island, Hauraki Gulf, New Zealand, nest type, egg order and shell cleaning did not affect hatching success, suggesting that nest conditions and microbial infection prior to incubation were not a major cause of egg mortality in this population. Temporary abandonment during incubation, however, was very frequent in the second half of the breeding season and fatal to most eggs. These temporary abandonments seemed to be caused by resource limitations, an aspect that should be investigated in future studies.

As concentrações de HPAs foram analisadas em invertebrados (Laternula elliptica, Nacella concinna, Yoldia eightsi, Glyptonotus antarcticus, Serolis polita, Euphausia superba, Bovalia gigantea, Sterechinus neumayeri, Odontaster validus e Ophionotus victoriae), peixes (Notothenia rossii), e aves (Pygoscelis Adélia, P. papua, P. antarcticus, Macronectes giganteus, Catharacta sp. e Larus dominicanus) da Baía do Almirantado. As análises de HPAs foram realizadas através de GC/MS. A ocorrência de HPAs nas amostras indicou a biodisponibilidade destes compostos para os organismos da região. As concentrações de HPAs totais para os invertebrados (3,09-174,4 ng g -1 pu) foram maiores que em peixes (0,97-58,9 ng g -1 pu) e menores que em aves (60,1-6861,0 ng g-1 pu), porém apresentaram similaridade entre si. As aves voadoras adultas apresentaram maiores concentrações que os pinguins. Compostos leves e alquilados predominaram em quase todas as amostras, principalmente os alquilnaftalenos. A principal fonte de HPAs para os organismos foi o DFA utilizado na EACF. Espécies predadoras/necrófagas apresentaram HPAs individuais diferentes das espécies suspensívoras/depositívoras. Não ocorreu relação entre o aumento da concentração de HPAs e o aumento do nível trófico dos grupos, e a absorção de HPAs pelas espécies sofreu a influência de fatores como metabolismo, fisiologia, hábito alimentar e teor de lipídio das espécies analisadas. / The concentrations of PAHs had been analyzed in invertebrates (Laternula elliptica, Nacella concinna, Yoldia eightsi, Glyptonotus antarcticus, Serolis polita, Euphausia superba, Bovalia gigantea, Sterechinus neumayeri, Odontaster validus and Ophionotus victoriae), fish (Notothenia rossii) and birds (Pygoscelis adélia, P. papua, P. antarcticus, Macronectes giganteus, Catharacta sp. and Larus dominicanus) Admiralty Bay. The analyses of HPAs had been carried through GC/MS. The occurrence of PAHs in the samples indicated the bioavailability of these compounds for the organisms of the region. The concentration of total PAHs for the invertebrates (3,09 to 174,4 ng g-1 pu) were higher than fish (0,97 to 58,9 ng g-1 pu) and lower than in birds (60,1- 6861,0 ng g-1 pu) however, they had presented similarity between themselves. The adult flying birds had presented higher concentrations than penguins. Light and alkylated compounds had predominated in almost all samples, mainly the alkylnaphthalenes. The main source of PAHs for the organism was the DFA used in the EACF. Predators/necrophagous species had presented different individual PAHs from the feeder/deposit species. There was no relation between the increase of concentrations of PAHs and the increase of the trophic level of the groups, and the absorption of PAHs for the species had the influence of factors such as metabolism, physiology, alimentary habits and lipid content of the analyzed species.

To study the impact of environmental changes in a coastal marine ecosystem, it is necessary to use indicator species. It is crucial to understand the foraging performances that proceed from environmental changes. The aim of my thesis was to examine the influence of intrinsic and extrinsic factors on the foraging activity of the little penguins (Eudyptula minor). The thermocline allowed birds to approach optimal behaviour. However, the thermocline is an unstable element. I did not find any effect of individual characteristics on their foraging behaviour and success. My work suggests that environmental conditions are major factors that will influence the behaviour of little penguins, allowing me to conclude that little penguins are good ecological indicators.

O Vírus da influenza, apesar de todas as epidemias e pandemias referirem-se a infecções em seres humanos, não está restrita a espécie humana e é capaz de causar debilidade ou mortalidade em várias outras espécies, incluindo cavalos, suínos, mamíferos marinhos e aves, entre outros. Estudos ecológicos das viroses de influenza conduziram a hipótese que todas as que acometem mamíferos derivam de reservatórios destes vírus em aves. Mesmo com programas de monitoramento contínuo de aves silvestres em alguns países do mundo que possuem casos originados pelos vírus aviário H5N1, pouco foi feito na Antártica e por isso, o presente trabalho foi realizado nas estações de verão antártico de 2006, 2007 e 2008 em duas localidades no território Antártico, a Península Keller, localizada na Ilha Rei George e na ilha Elefante 61°08S, 55°07W, a primeira onde está situada a Estação Antártica Comandante Ferraz-EACF e a segunda onde está localizada uma base de apoio a estudos avançados. Para este estudo foi realizada a coleta de 283 amostras de quatro diferentes espécies de pinguins: Pygoscelis adeliae; P. papua; P. antarctica; Aptenodytes patagonicus. Para o diagnóstico das amostras colhidas, foi aplicada a detecção direta dos produtos amplificados pelo método de RT-PCR em gel de agarose confirmados pelo método de Real-Time PCR (Applied Biosystems) e pelo RT-PCR-GeneScan no laboratório de Virologia Clínica e Molecular, do Departamento de Microbiologia, da Universidade de São Paulo. Os resultados obtidos em nosso estudo foram 8 amostras positivas em pinguins para o vírus Influenza A. As amostras positivas por RT-PCR foram encaminhadas para o laboratório de Influenza do Department of Infectious Diseases, St. Jude Children\'s Research Hospital, Memphis, TN, USA, para isolamento em ovos embrionados, não havendo crescimento de vírus da influenza A. Quatro destas amostras positivas puderam ser sequenciadas e comparadas com sequências de Influenza A depositadas no Genbank apresentando uma identidade de 96,8 % a 100 % entre elas e o controle tendo este último uma identidade de 100% com as do banco de dados, confirmando a presença do vírus nestas aves. / Epidemics and pandemics of influenza usually refer to infections in human beings. The influenza virus is not, however, restricted to humans and can cause infirmity and death in other species including horses, swine, marine mammals, birds, and others. Ecological studies of viral infections have led to the hypothesis that the influenza viruses that attack mammals have their origin in the accumulation of these viruses in birds (avian flu). In some countries with influenza cases caused by the avian H5N1 virus, there was monitoring of wild birds but little had been done in Antarctica. The present work was therefore carried out during the Antarctic summer seasons of 2006, 2007, and 2008 in two Antarctic locations: The Commander Ferraz Antarctic Station, on the Keller Peninsula of King George Island, and at the Base of Advanced Studies located on Elephant Island (61°08S, 55°07W). Two hundred eighty-three (283) samples from four different penguin species Pygoscelis adeliae, Pygoscelis papua, Pygoscelis antarctica; and Aptenodytes patagonicus were collected for this study. Diagnoses of the samples were performed not only by application of direct detection and amplification according to the RT-PCR method in agar-gel, but also by Real-Time PCR (Applied Biosystems), and by RT-PCR gene scan at the Laboratory of Clinical and Molecular Virology of the Department of Microbiology of the University of Sao Paulo. Eight of the penguin samples tested positive for the Influenza-A virus. The positive samples, as determined by RT-PCR, were sent to the Influenza Laboratory of the Department of Infectious Diseases of the St. Jude Research Hospital in Memphis, Tennessee, USA, to be isolated in egg embryos where no further growth of the Influenza-A virus took place. Four of these positive samples could be sequenced and compared with those of Influenza-A on deposit at the Gene Bank and ranged from 96.85 to 100% when compared with the control samples (100% positive), thus confirming the presence of the virus in the tested birds.

O Vírus da influenza, apesar de todas as epidemias e pandemias referirem-se a infecções em seres humanos, não está restrita a espécie humana e é capaz de causar debilidade ou mortalidade em várias outras espécies, incluindo cavalos, suínos, mamíferos marinhos e aves, entre outros. Estudos ecológicos das viroses de influenza conduziram a hipótese que todas as que acometem mamíferos derivam de reservatórios destes vírus em aves. Mesmo com programas de monitoramento contínuo de aves silvestres em alguns países do mundo que possuem casos originados pelos vírus aviário H5N1, pouco foi feito na Antártica e por isso, o presente trabalho foi realizado nas estações de verão antártico de 2006, 2007 e 2008 em duas localidades no território Antártico, a Península Keller, localizada na Ilha Rei George e na ilha Elefante 61°08S, 55°07W, a primeira onde está situada a Estação Antártica Comandante Ferraz-EACF e a segunda onde está localizada uma base de apoio a estudos avançados. Para este estudo foi realizada a coleta de 283 amostras de quatro diferentes espécies de pinguins: Pygoscelis adeliae; P. papua; P. antarctica; Aptenodytes patagonicus. Para o diagnóstico das amostras colhidas, foi aplicada a detecção direta dos produtos amplificados pelo método de RT-PCR em gel de agarose confirmados pelo método de Real-Time PCR (Applied Biosystems) e pelo RT-PCR-GeneScan no laboratório de Virologia Clínica e Molecular, do Departamento de Microbiologia, da Universidade de São Paulo. Os resultados obtidos em nosso estudo foram 8 amostras positivas em pinguins para o vírus Influenza A. As amostras positivas por RT-PCR foram encaminhadas para o laboratório de Influenza do Department of Infectious Diseases, St. Jude Children\'s Research Hospital, Memphis, TN, USA, para isolamento em ovos embrionados, não havendo crescimento de vírus da influenza A. Quatro destas amostras positivas puderam ser sequenciadas e comparadas com sequências de Influenza A depositadas no Genbank apresentando uma identidade de 96,8 % a 100 % entre elas e o controle tendo este último uma identidade de 100% com as do banco de dados, confirmando a presença do vírus nestas aves. / Epidemics and pandemics of influenza usually refer to infections in human beings. The influenza virus is not, however, restricted to humans and can cause infirmity and death in other species including horses, swine, marine mammals, birds, and others. Ecological studies of viral infections have led to the hypothesis that the influenza viruses that attack mammals have their origin in the accumulation of these viruses in birds (avian flu). In some countries with influenza cases caused by the avian H5N1 virus, there was monitoring of wild birds but little had been done in Antarctica. The present work was therefore carried out during the Antarctic summer seasons of 2006, 2007, and 2008 in two Antarctic locations: The Commander Ferraz Antarctic Station, on the Keller Peninsula of King George Island, and at the Base of Advanced Studies located on Elephant Island (61°08S, 55°07W). Two hundred eighty-three (283) samples from four different penguin species Pygoscelis adeliae, Pygoscelis papua, Pygoscelis antarctica; and Aptenodytes patagonicus were collected for this study. Diagnoses of the samples were performed not only by application of direct detection and amplification according to the RT-PCR method in agar-gel, but also by Real-Time PCR (Applied Biosystems), and by RT-PCR gene scan at the Laboratory of Clinical and Molecular Virology of the Department of Microbiology of the University of Sao Paulo. Eight of the penguin samples tested positive for the Influenza-A virus. The positive samples, as determined by RT-PCR, were sent to the Influenza Laboratory of the Department of Infectious Diseases of the St. Jude Research Hospital in Memphis, Tennessee, USA, to be isolated in egg embryos where no further growth of the Influenza-A virus took place. Four of these positive samples could be sequenced and compared with those of Influenza-A on deposit at the Gene Bank and ranged from 96.85 to 100% when compared with the control samples (100% positive), thus confirming the presence of the virus in the tested birds.

Depuis 157 ans et la publication originelle de la théorie de l’évolution par sélection naturelle de Charles Darwin, ce concept n’a cessé d’évoluer. Un principe fondamental suggère que des traits handicapants aient évolués dans la mesure où ils informent de manière honnête les congénères sur la qualité intrinsèque du porteur. Le manchot royal est un modèle exceptionnel permettant de tester la valeur sélective de ce signal dans un contexte sexuel et social (non-reproductif). Mes résultats suggèrent que l’apparition et le maintien de certains de ces traits au cours de l’évolution se sont opérés sous l’influence de la sélection sexuelle et d’un choix mutuel du partenaire, tandis que d’autre, non contraint par la condition fluctuante de l’individu, aurait évolué sous l’influence de la sélection sociale. Ce travail de recherche participe à la compréhension des mécanismes impliqués dans l’évolution de signaux coûteux, et à la nature des bénéfices ultimes que ces traits procurent. / Darwin’s seminal theory of evolution by means of natural selection, first published 157 years ago, has been in constant refinement ever since. The production and maintenance of extravagant ornaments is widely suggested to evolve by conspecific preference providing information on individual intrinsic quality in sexual contexts or on individual social quality in non-reproductive contexts. The king penguin is a monomorphic bird species and an outstanding model to study ornament evolution. My results show that those ornaments are partly condition-dependent, and reliable traits that may be used to assess the quality of a potential sexual partner, implying that their evolution and maintenance is partly determined by sexual selection. On the other hand, some traits remained condition-independent in their production, suggesting that the cost associated with their expression was deferred over time and the evolution of those ornaments likely shaped by non-sexual social selection.