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Registros recuperados: 11 | |
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Harris, Sarah; Kervinen, Matti; Lebigre, Christophe; Pike, Thomas W.; Soulsbury, Carl D.. |
Male ornaments function as honest cues of male quality in many species and are subject to intra‐ and intersexual selection. These ornaments are generally studied during peak expression, however their size outside the breeding season may determine ultimate ornament size and costliness, and as such reproductive success. We investigated whether male black grouse Lyrurus tetrix eye comb size was related to age, condition and measures of male dominance before and during the breeding season. Total combined eye comb size began to increase ~70 days before the start of the breeding season. Adult males (aged ≥ 2 years old) had consistently larger eye combs than younger males (1 year old) both before and during the breeding season. Heavier and more dominant adult... |
Tipo: Text |
Palavras-chave: Age; Ornament expression; Dominance. |
Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00440/55121/56577.pdf |
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Soulsbury, Carl D.; Lebigre, Christophe. |
There is widespread interest in the relationship between individual genetic diversity and fitness-related traits (heterozygosity-fitness correlations; HFCs). Most studies have found weak continuous increases of fitness with increasing heterozygosity, while negative HFCs have rarely been reported. Negative HFCs are expected in cases of outbreeding depression, but outbreeding is rare in natural populations. Negative HFCs may also arise through viability selection acting on low heterozygosity individuals at an early stage producing a skew in the heterozygosity distribution. We tested this idea using survival and clutch parameters (egg mass, egg volume, chick mass, clutch size) in female Black Grouse Lyrurus tetrix and carried out simulations to determine how... |
Tipo: Text |
Palavras-chave: Inbreeding; Outbreeding; Neutral loci; Selective mortality; Genetic diversity. |
Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00423/53448/54340.pdf |
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Soulsbury, Carl D.; Siitari, Heli; Lebigre, Christophe. |
Illnesses caused by a variety of micro- and macro- organisms can negatively affect individuals' fitness, leading to the expectation that immunity is under positive selection. However, immune responses are costly and individuals must trade-off their immune response with other fitness components (e.g. survival or reproductive success) meaning that individuals with intermediate response may have the greatest overall fitness. Such a process might be particularly acute in species with strong sexual selection because the condition-dependence of male secondary sexual-traits might lead to striking phenotypic differences amongst males of different immune response levels. We tested whether there is selection on immune response by survival and reproduction in... |
Tipo: Text |
Palavras-chave: Ecological immunology; ELISA; Immunocompetance; Life history theory; Stabilising selection. |
Ano: 2018 |
URL: http://archimer.ifremer.fr/doc/00426/53761/54653.pdf |
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Veron, Matthieu; Lebigre, Christophe; Bertignac, Michel; Doray, Mathieu; Duhamel, Erwan; Huret, Martin; Pawlowski, Lionel. |
Peu de modèles d'évaluation de stock intègrent une description fine des processus biologiques régissant les populations exploitées par la pêche au sein des écosystèmes. Ce manque est particulièrement regrettable dans le cas des petits pélagiques dont la dynamique est fortement influencée par les conditions environnementales. En effet, la pêche et les fluctuations environnementales et climatiques impactent fortement la dynamique de population de la sardine du golfe de Gascogne. Pour comprendre la dynamique de cette population au sein de l'écosystème et les effets des pêcheries, il est donc nécessaire d'identifier et de caractériser cet ensemble de pressions. Afin d'améliorer la gestion et le suivi de la dynamique de ce stock, le développement d'un modèle... |
Tipo: Text |
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Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00410/52133/52842.pdf |
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Huret, Martin; Duhamel, Erwan; Gatti, Paul; Lebigre, Christophe; Le Mestre, Sophie; Petitgas, Pierre; Rabiller, Manuella; Guigue, Thierry; Joguet, Manon; Maillet, Jérome. |
Le projet FFP Captain visait à l’amélioration des connaissances biologiques et sur la connectivité des stocks de sardine et d’anchois sur la façade Atlantique française (Manche et golfe de Gascogne). Il a reposé sur la collecte de données au travers d’une collaboration avec les professionnels de la pêche (organisations de producteurs et pêcheurs) et de l’exploitation opportuniste des pêches sur l’ensemble des campagnes halieutiques de la zone (PELGAS, EVHOE, CGFS). Ceci a permis une couverture spatiale et saisonnière optimale. Nous avons ainsi affiné la description spatio-temporelle de la reproduction pour les deux espèces, et montré une plus forte croissance ainsi qu’une densité énergétique plus élevées en Manche que dans le golfe de Gascogne. Cette... |
Tipo: Text |
Palavras-chave: Anchois; Sardine; Petts pélagiques; Golfe de Gascogne; Manche; Collaboraton scientifques–pêcheurs; Génétque; Calorimétrie. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00586/69764/67655.pdf |
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Registros recuperados: 11 | |
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