The coloration of plumage and ornaments in the groups Numididae, Odonthophoridae and Phasianidae (within the order Galliformes) was detailled described and analyzed. The ecological factors affecting the evolution of dichromatism and conspicuousness were tested.

Microorganisms are considered to be a significant selective factor affecting bird's life strategies. The body cover, including feather, is occupied by a wide range of bacteria that are in their host in different interactions. Group of microorganisms degradate keratins of feather is still most studied and most species of birds have them in feather. This feather degrading bacteria can disrupt the wear and its function and thus cause great losses to its fitness. Therefore, it seems likely that these feathers degrading bacteria and microorganisms generally play a significant role in creating defence mechanisms against their negative effects. One of the most important defence mechanisms to protect feathers against the action of microorganisms is the deposition of melanin pigments. This diploma thesis deals with the analysis of the total bacterial load in feathers and its resistance against bacterial degradation in 47 species of birds trapped in afromontan areas of western Cameroon. The specific aim of the thesis was to determine differences in the total number of bacteria in plumage in species with different life strategies, especially feeding and reproductive strategies. At the same time, the phtilochronological analysis of the quality of the plumage was performed and in vitro experiments were tested...

Ornamental traits are considered honest advertisements of fitness, and their evolution is usually explained in terms of sexual selection. This explanation remains unsatisfactory in some instances, for example, juvenile birds whose plumage is molted prior to adulthood and breeding. I first evaluate whether juvenile plumage reflectance signals dominance status in the Federally Threatened Florida scrub-jay (Aphelocoma coerulescens) using a combination of observational and experimental methods. Then I estimate the heritability, non-genetic maternal and environmental effects, and strength of selection on juvenile plumage reflectance using archived feather samples and a pedigree constructed from historical nest records. Finally, I compare plumage reflectance and its use as a signal between a wildland and suburban population of scrubjays. I conclude that plumage reflectance is a signal of dominance, and that social selection can also drive the evolution of sexually dimorphic traits. In this species, plumage reflectance is heritable and influenced by maternal effects, but environmental effects are inconsequential. Although this trait appears to have an important function, only mean brightness and female hue are associated with lifetime reproductive success. Plumage reflectance was more UV-shifted in the suburban birds, but there is no reason to believe that urbanization decreases the value of this plumage as a signal. However, these plumage differences may facilitate dispersal from suburban areas, contributing to the decline of suburban populations.

La recherche en écologie comportementale est affectée par un biais notoire en faveur des oiseaux des zones tempérées, en dépit de la plus grande diversité des espèces tropicales et des conditions naturelles radicalement éloignées qui rendent les connaissances sur les espèces tempérées peu pertinentes pour les espèces tropicales.Nous proposons de combler le manque d’informations concernant les oiseaux tropicaux via l’étude d’une espèce socialement monogame, se reproduisant et défendant un territoire toute l’année, la Tourterelle à queue carrée, Zenaida aurita. Pour commencer, nous avons cherché à déterminer le caractère sexuellement mono- ou dichromatique de la coloration du plumage et si celui-ci reflétait la qualité individuelle. Nous avons ensuite exploré les patterns d’appariements au sein des couples selon le degré d’hétérozygotie et la taille du corps. Afin d’établir la force des liens du couple, nous avons évalué le taux de divorce, les hypothèses pouvant expliquer les cas répertoriés, et les conséquences du changement de partenaire. Ceci a été suivi par la caractérisation des rôles des sexes au sein des couples selon diverses activités. Des analyses de capture-marquage-recapture ont permis d’estimer le taux de survie ainsi que l’influence du degré d’hétérozygotie et de la taille de l’aile sur la survie. La Tourterelle à queue carrée paraît suivre les spécificités comportementales, écologiques et démographiques caractérisant les espèces tropicales à monogamie pérenne / Research in avian behavioral ecology is affected by a known bias in favour of temperate species despite the greatest diversity of tropical species and the radically remote natural conditions which make knowledge of temperate species hardly relevant to tropical species.We propose to reduce the lack of information about tropical birds through the study of a socially monogamous species, reproducing and defending an all-purpose territory all year round, the Zenaida dove, Zenaida aurita. We used monitoring data from a population of ringed birds in Barbados for six years. First, we focused on plumage coloration both to ascertain their sexually mono- or dichromatic nature and whether plumage colour reflects individual quality. We then explored pairing patterns in relation to genome-wide heterozygosity and body size (tarsus length, wing chord). To determine the strength of pair bonding, we assessed divorce rate, evaluated which hypotheses could explain divorce cases and listed the consequences of mate loss and mate switching. It was followed by the characterization of sex roles within pairs during various activities (singing, nest building, juvenile care, territorial defence). Capture-mark-recapture analysis allowed us to estimate survival rate as well as influence of heterozygosity degree and wing chord on individual survival. Zenaida dove appears to conform to the behavioral, ecological and demographic features characterizing tropical species with perennial monogamy

Ammomanes cinctura (Bar-tailed Lark) is a lark species with a wide distribution in the Palearctic. One of its subspecies, A. c. arenicolor, has a wide range across northern Africa, within which it shows very minor morphological variation but deep divergence in the mitochondrial cytochrome b locus between two geographically widely separated populations. There are two additional allopatric subspecies, A. c. cinctura (Cape Verde Islands) and A. c. zarudnyi (Iran to Pakistan), which differ slightly more in morphology. The genomic population structure, evolutionary history, and taxonomic status of the different populations within this species remain unclear. I applied an integrative approach, using genomic single nucleotide polymorphisms (SNPs), mtDNA and morphological data, to investigate the evolutionary divergence within Ammomanes cinctura. I acquired whole-genome sequence data from twelve individuals from Morocco (n=2), Saudi Arabia (n=7), and Iran (n=3), and performed phylogenetic and population structure analyses. Mitochondrial genomes were assembled and cytochrome b was extracted for phylogeny. Biometric measurements and quantified plumage analysis were conducted on museum specimens of all three subspecies. According to the mitochondrial data, the samples from Saudi Arabia and Iran form a clade that is deeply diverged (5.94 Mya, 95%HPD 3.15–8.95 Mya) from a clade comprising the samples from Morocco and Cape Verde Islands. In contrast, the nuclear SNPs recovered a very shallow divergence (0.095 Mya, 95%HPD 0.04-0.16 Mya) and weak population structure between the samples from Morocco vs. Saudi Arabia–Iran. Morphological results indicated that zarudnyi is slightly differentiated from the other two subspecies, with a larger body size, and the three subspecies are slightly divergent in plumage. The close similarity between Moroccan and Saudi Arabian birds in morphology was also confirmed, in conflict with the molecular data – highlighting the problem with trinomials in this case. The results suggest that the deep divergence in mitochondrial DNA is due to a complex evolutionary history.

<p>The purpose of gene mapping is to understand the underlying genetics of simple and complex traits like plumage colour and growth. This thesis is based on a cross between the wild ancestor of the modern chicken, the red junglefowl, and a White Leghorn line selected for high egg mass. There are obvious phenotypic differences between these two breeds in several aspects such as growth, egg production and behaviour. These complex traits are often influenced by a number of genes or Quantitative Trait Loci (QTL) as well as environmental factors.</p><p>Identification of QTL regions involves testing of association between genetic markers and the phenotype of interest. The QTL identified in this study explain most of the difference in adult body weight between the red junglefowl and the White Leghorn, but less of the difference at earlier age. By applying a different method for detection of QTL, including gene interactions, epistasis, we can understand more of the genetics behind early growth. The allele coming from the red junglefowl is generally associated with lower weight, egg production and food consumption.</p><p>In this study we have also identified two genes explaining the difference in plumage colour in the cross. The <i>Extension</i> locus, encoded by the melanocortin receptor 1 (<i>MC1R</i>), controls the amount of pigment produced has shown to be associated with plumage colour. A mutation in the <i>MC1R</i> gene causes black pigmentation of the plumage. </p><p>We have also found association between the <i>PMEL17</i> gene, known to be involved in normal pigmentation, and the <i>Dominant white</i> phenotype present in the White Leghorn. After comparison of sequences from different alleles at the <i>Dominant white</i> locus, amino acid alteration caused by insertion and deletion in the transmembrane region of the <i>PMEL17</i> protein has been revealed. These mutations are associated with alleles representing different plumage colour variants.</p>

The purpose of gene mapping is to understand the underlying genetics of simple and complex traits like plumage colour and growth. This thesis is based on a cross between the wild ancestor of the modern chicken, the red junglefowl, and a White Leghorn line selected for high egg mass. There are obvious phenotypic differences between these two breeds in several aspects such as growth, egg production and behaviour. These complex traits are often influenced by a number of genes or Quantitative Trait Loci (QTL) as well as environmental factors. Identification of QTL regions involves testing of association between genetic markers and the phenotype of interest. The QTL identified in this study explain most of the difference in adult body weight between the red junglefowl and the White Leghorn, but less of the difference at earlier age. By applying a different method for detection of QTL, including gene interactions, epistasis, we can understand more of the genetics behind early growth. The allele coming from the red junglefowl is generally associated with lower weight, egg production and food consumption. In this study we have also identified two genes explaining the difference in plumage colour in the cross. The Extension locus, encoded by the melanocortin receptor 1 (MC1R), controls the amount of pigment produced has shown to be associated with plumage colour. A mutation in the MC1R gene causes black pigmentation of the plumage. We have also found association between the PMEL17 gene, known to be involved in normal pigmentation, and the Dominant white phenotype present in the White Leghorn. After comparison of sequences from different alleles at the Dominant white locus, amino acid alteration caused by insertion and deletion in the transmembrane region of the PMEL17 protein has been revealed. These mutations are associated with alleles representing different plumage colour variants.

In the tradition of previous studies of threatened species, this thesis was undertaken with the aim of improving our understanding of the ecology of the White-winged Nightjar Caprimulgus candicans, and providing the information necessary to facilitate conservation efforts on its behalf. In 1998-2001, I studied a population of White-winged Nightjars at Aguará Ñu, an area of cerrado habitats within the Reserva Natural del Bosque Mbaracayù, eastern Paraguay. Over the course of three fieldwork seasons, I captured and ringed a total of 49 nightjars (34 adults and 15 young birds). Young females first bred at approximately one year old, while still in pre-definitive plumage. Young males exhibited a form of delayed plumage maturation, whereby they only attained definitive plumage following a prolonged moult spanning much of their first potential breeding season. No evidence was obtained to suggest that they succeeded in breeding while in this conspicuously intermediate state of moult. Considerable variation was noted in the plumage whiteness of definitive males, but no clear evidence was found for consistent age-related increases in white. During the breeding season, males defended small aggregated display territories, at which they conducted nuptial display flights between late August and early January. Female nightjars were responsible for all the parental care, and apparently visited male display arenas solely to obtain copulations. Chick paternity data confirmed that the study population was polygynous, with patterns of male aggregation suggestive of an exploded lek or 'landmark' mating system. Radio-telemetry studies showed that nightjars utilised home ranges of at least 20 to 40 hectares during the eight to ten months for which they were monitored. Home ranges contained a disproportionately large amount of young campo cerrado vegetation, but no forest or old campo cerrado habitats. When selecting foraging sites within their ranges, nightjars preferred younger and avoided older campo cerrado vegetation; wet grassland was utilised roughly in proportion to its availability. Observed patterns of habitat selection were potentially explained by the greater abundance of insect prey in younger habitats. When selecting daytime roost sites, nightjars preferred vegetation of intermediate age, reflecting their need for a balance between cover and ease of access. A more general analysis of patterns of sexual dimorphism within the Caprimulgidae showed that, although almost 80% of nightjar species exhibit some dimorphism of plumage whiteness, the study species was by far the most extreme case. The striking plumage of the male was partly explained by a strong positive relationship between wing white and openness of breeding habitats within the family. However, this failed to explain the complete absence of white in the female plumage, or the extent of white dimorphism shown by the species. The most likely explanation would appear to be that extreme plumage dimorphism occurred in conjunction with the evolution of polygyny and female-only care in this open-country species. The implications of these findings for the conservation of the White-winged Nightjar are highlighted, and recommendations are proposed for future work and conservation action.

Understanding the relationships between species traits and the environment is essential for assessment of functional diversity. The variation in avian plumage colouration has attracted much scientific attention for a long time. It is thought that the colouration of birds is a product of interaction between environmental and sexual selection forces. Using two complementary three-matrix approaches (fourth-corner and RLQ analyses) I investigate geographical variation in plumage colouration of birds living along environmental gradient of productivity in South Africa. I suppose that productivity of environment could explain the part of variation in colouration of species at large geographical scales. I compiled information about 14 plumage traits for 649 species. Co- inertia analysis revealed that more vari-coloured species (e.g. with more saturated and vivid plumage), species with carotenoids in feather, blue-green or predominantly black species occur mainly in productive habitats such as moist savannas and woodlands in the north-east of the country. On the contrary pale species (e.g. greyishbrown), whose feathers are brighter (have higher values of brightness), occupy arid habitats in the west. It shows that another pattern such as iridescence, sexual dimorphism and brightness of particular body region exhibit...

La recherche en écologie comportementale est affectée par un biais notoire en faveur des oiseaux des zones tempérées, en dépit de la plus grande diversité des espèces tropicales et des conditions naturelles radicalement éloignées qui rendent les connaissances sur les espèces tempérées peu pertinentes pour les espèces tropicales.Nous proposons de combler le manque d'informations concernant les oiseaux tropicaux via l'étude d'une espèce socialement monogame, se reproduisant et défendant un territoire toute l'année, la Tourterelle à queue carrée, Zenaida aurita. Pour commencer, nous avons cherché à déterminer le caractère sexuellement mono- ou dichromatique de la coloration du plumage et si celui-ci reflétait la qualité individuelle. Nous avons ensuite exploré les patterns d'appariements au sein des couples selon le degré d'hétérozygotie et la taille du corps. Afin d'établir la force des liens du couple, nous avons évalué le taux de divorce, les hypothèses pouvant expliquer les cas répertoriés, et les conséquences du changement de partenaire. Ceci a été suivi par la caractérisation des rôles des sexes au sein des couples selon diverses activités. Des analyses de capture-marquage-recapture ont permis d'estimer le taux de survie ainsi que l'influence du degré d'hétérozygotie et de la taille de l'aile sur la survie. La Tourterelle à queue carrée paraît suivre les spécificités comportementales, écologiques et démographiques caractérisant les espèces tropicales à monogamie pérenne