<p>This thesis integrates the fields of sexual selection, parental investment and sex role theory by investigating mutual mate choice and mate competition in the sex role reversed deep snouted pipefish <i>Syngnathus typhle</i> (Pisces: Syngnathidae) through a series of laboratory experiments. In<i> S. typhle</i>, the female transfers her eggs to the male's brood pouch where they are nourished and oxygenated for about a month, when the male gives birth to the independent fry.</p><p>Mate choice was found to be adaptive. Both sexes benefited from mating with preferred partners in terms of increased offspring viability and got larger, or faster growing, offspring when mating with large fish. Females were also shown to prefer males with thicker brood pouches. Thus, females, the more competitive sex, had multiple preferences. Both male and female choice behaviour was found to be flexible and influenced by available information on partner quality. In addition, males, but not females, copied the mate choice of consexuals. </p><p>Both sexes were found to take their own quality in relation to surrounding competitors into account when deciding whether to display to potential partners. Male-male competition was found to influence both the mate choice of males and, potentially, overrule the mate choice of females. Males did not compete as intensely as females, nor did they use their sexual ornament in this context as females do. Rather, the ornament was used in interactions with females, and males that displayed more received more eggs.</p><p>The findings in this thesis emphasise the importance of not viewing mate choice and competition as opposite behaviours, but rather to apply a dynamic approach in mate choice studies, integrating choice and competition in both sex</p>

This thesis integrates the fields of sexual selection, parental investment and sex role theory by investigating mutual mate choice and mate competition in the sex role reversed deep snouted pipefish Syngnathus typhle (Pisces: Syngnathidae) through a series of laboratory experiments. In S. typhle, the female transfers her eggs to the male's brood pouch where they are nourished and oxygenated for about a month, when the male gives birth to the independent fry. Mate choice was found to be adaptive. Both sexes benefited from mating with preferred partners in terms of increased offspring viability and got larger, or faster growing, offspring when mating with large fish. Females were also shown to prefer males with thicker brood pouches. Thus, females, the more competitive sex, had multiple preferences. Both male and female choice behaviour was found to be flexible and influenced by available information on partner quality. In addition, males, but not females, copied the mate choice of consexuals. Both sexes were found to take their own quality in relation to surrounding competitors into account when deciding whether to display to potential partners. Male-male competition was found to influence both the mate choice of males and, potentially, overrule the mate choice of females. Males did not compete as intensely as females, nor did they use their sexual ornament in this context as females do. Rather, the ornament was used in interactions with females, and males that displayed more received more eggs. The findings in this thesis emphasise the importance of not viewing mate choice and competition as opposite behaviours, but rather to apply a dynamic approach in mate choice studies, integrating choice and competition in both sex

Chez les espèces où mâles et femelles portent des traits voyants et élaborés, les traits observés chez les femelles peuvent être des sous-produits non-fonctionnels de la sélection sexuelle exercée sur les traits mâles ou alors être directement soumis à la sélection. Cette thèse a eu pour objectif de tester l'hypothèse de sélection sexuelle chez les femelles de Mésange bleue (Cyanistes caeruleus) sur trois traits présents chez le mâle et la femelle : (1) la coloration structurelle UV/bleue de la tête, (2) la coloration jaune basée sur les caroténoïdes de la poitrine et (3) l'agressivité. Pour cela, nous avons testé expérimentalement (1) le lien entre les traits colorés et le transfert de composants potentiellement bénéfiques dans les ufs, (2) la condition-dépendance des traits colorés, (3) l'utilisation de la coloration du plumage dans les interactions femelle-femelle et (4) le lien entre l'agressivité des femelles et leur investissement dans la reproduction. Enfin, nous avons exploré le rôle potentiel des couleurs femelles dans le choix de partenaires mâle en testant le lien entre la couleur UV/bleue des femelles et le nombre de jeunes issus de copulations hors couple et l'appariement selon la couleur bleue et jaune dans notre population. Nos résultats suggèrent (1) qu'il existe un lien entre la qualité maternelle et la coloration de leur plumage, (2) que les couleurs UV/bleues et jaune du plumage sont conditions-dépendants, (3) que les UV/bleus de la tête sont utilisés comme badge de statut dans les interactions femelle-femelle, (4) qu'il pourrait exister un compromis entre l'agressivité femelle et son investissement dans la reproduction et (5) qu'il existe un potentiel choix mutuel de partenaires basés sur les couleurs. Au final, cette thèse a ainsi permis de mettre en évidence que chez une espèce où mâles et femelles sont ornementés, les traits colorés femelles ont le potentiel d'évoluer sous l'effet direct de la sélection sexuelle. / In mutually ornamented species, female conspicuous traits could be non-functional by-products of sexual selection acting on male traits or could be directly under selection. The aim of this PhD was to test the hypothesis of sexual selection in Blue tit (Cyanistes caeruleus) females on three traits present in both males and females: (1) the structural coloration of the UV/blue crown, (2) the yellow chest coloration based on carotenoids and (3) aggressiveness. To do so, we experimentally tested (1) the links between plumage coloration and the transfer of potentially beneficial components in egg yolks, (2) the condition-dependence of the plumage coloration, (3) the use of the plumage coloration in female-female interactions and (4) the link between female aggressiveness and investment in reproduction. Finally, we explored the role of female plumage coloration in male mate choice by testing the link between female UV/blue crown coloration and the n umber of extra-pair young in the nest and by estimating whether the individuals were assortatively mated in respect of their yellow and blue coloration in the studied population. Our results suggest that (1) there is a link between female plumage coloration and maternal quality, (2) plumage UV/blue and yellow coloration is condition-dependant, (3) the UV/blue crown is used as a badge of status in female-female interactions, (4) there could be a trade-off between female aggressiveness and female investment in reproduction and (5) there is a potential mutual mate choice based on both coloration. So, this PhD supports the hypothesis that in a mutually ornamented species, female ornaments are potentially under direct sexual selection.

O cuidado paternal exclusivo à prole é a forma mais rara de investimento parental pós-zigótico na natureza, tendo evoluído independentemente em não mais do que 14 linhagens de artrópodes. Embora muitas dessas espécies sejam facilmente observadas e manipuladas, apenas recentemente os pesquisadores começaram a prestar atenção e a testar hipóteses sobre investimento parental e evolução de papéis sexuais nesses interessantes sistemas biológicos. O principal objetivo desta tese foi investigar características individuais e populacionais que poderiam afetar o sucesso reprodutivo de machos de opiliões (Arachnida: Opiliones) com cuidado paternal. No primeiro capítulo, fazemos uma revisão teórica detalhada, desde trabalhos clássicos de papéis sexuais até os mais recentes avanços, abordando também de maneira sistemática o conhecimento atual acerca de custos e benefícios do cuidado paternal em artrópodes, assim como o papel da seleção sexual sobre a evolução do comportamento parental e dos papéis sexuais. Em seguida, nos capítulos 2 e 3, acessamos os custos energéticos e em termos de sobrevivência do cuidado paternal nos opiliões Iporangaia pustulosa e Zygopachylus albomarginis. Comparando essas duas espécies, que apresentam diferentes níveis de investimento paternal, testamos previsões direcionadas de que os machos que investem mais na prole deveriam pagar maiores custos do cuidado. No quarto capítulo, por meio de informações da história natural e parâmetros populacionais estimados para I. pustulosa, fazemos previsões sobre qual dos sexos deveria ser criterioso ao escolher parceiros e as testamos utilizando observações comportamentais de interações entre machos e fêmeas. Por fim, no capítulo 5, avaliamos a importância relativa do sítio de oviposição, assim como do tamanho e do estado parental dos machos sobre a sua atratividade. Ao final, integramos os resultados obtidos em um corpo teórico sobre a inter-relação entre aparentes demandas conflitantes entre esforço parental e esforço reprodutivo, cuidado paternal e papéis sexuais, abrangendo não apenas as espécies estudadas, mas com um escopo bem mais amplo / Exclusive paternal care is the rarest form of post-zygotic parental investment in nature, which has independently evolved in no more than 14 arthropod lineages. Although many of those species are easily observed and manipulated, only recently researchers have started to pay attention and test hypotheses on parental investment and evolution of sex roles in such interesting biological systems. The main goal of this thesis was investigating individual and population characteristics that affect the reproductive success of males of harvestmen (Arachnida: Opilioes) with paternal care. In the first chapter, we revise the theory in details, since seminal works on sex roles until the most recent advances in the area, sistematically approaching the current knowledge abot costs and benefits of paternal care in arthropods, as well as the role of sexual selection on the evolution of parental behavior and sex roles. Then, in chapters 2 and 3, we access energetic and survival costs of paternal care in the harvestmen Iporangaia pustulosa and Zygopachylus albomarginis. Comparing these two species, that show different levels of parental investment, we test directional predictions that males which invest more should also pay more intense costs rekated to care. In the fourth chapter, based on natural history information and population parameters for I. pustulosa, we predict which sex should be choosier when selecting sexual partners, and test such predictions using behavioral data on male-female interactions. Finally, in chapter 5, we evaluate the relative importance of oviposition site, males\' body size and males\' parental state on their attractiveness. At the end, we integrate all the results obtained during the five chapters into a theoretical framework about the inter-dependence among trade-offs between parental and mating efforts, paternal care and sex roles, not only regarding the pair od species studied, but in a broad way.

The evolution of elaborate male ornaments via sexual selection is well-understood while the selective pressures acting on female ornaments remains unresolved. Female ornaments in species with strong sexual selection on the male homologue of the ornament were originally thought to result from an intersexual genetic correlation. My thesis explores the evolution of ornaments in females due to direct selection by developing theoretical models and examining the biology of a neotropical mosquito (Sabethes cyaneus) with sexually homologous ornaments coinciding with male-male competition. I began by exploring the morphology of the ornaments in both sexes of S. cyaneus. Sexual dimorphism in the size and shape of the ornaments was slight and both male and female ornaments showed classic hallmarks of sexually selected traits. I then tested for direct selection on S. cyaneus male and female ornaments via mutual mate choice. I found evidence of male, but surprisingly not female, preferences for ornaments. I then further considered the evolution of male mate choice in polygynous species. First, I investigated whether male investment in courtship by S. cyaneus may result in a lower operational sex ratio and thereby reduce the costs associated with male mate choice. Male courtship did pose a significant longevity cost to male S. cyaneus. Second, I explored the possibility that a female preference for male courtship effort may contribute to the benefits of male mate choice in a series of population genetic models. The spread of a male preference gene can be driven by female preferences for male courtship when males court preferred females more. Finally, I found that female S. cyaneus are not benefitting from signalling to increase their mating rate as they are monandrous. My thesis therefore challenges standing sexual selection theory and suggests that sexual selection on females may be more widespread than previously thought. / Felaktigt tryckt som Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology 729

O cuidado paternal exclusivo à prole é a forma mais rara de investimento parental pós-zigótico na natureza, tendo evoluído independentemente em não mais do que 14 linhagens de artrópodes. Embora muitas dessas espécies sejam facilmente observadas e manipuladas, apenas recentemente os pesquisadores começaram a prestar atenção e a testar hipóteses sobre investimento parental e evolução de papéis sexuais nesses interessantes sistemas biológicos. O principal objetivo desta tese foi investigar características individuais e populacionais que poderiam afetar o sucesso reprodutivo de machos de opiliões (Arachnida: Opiliones) com cuidado paternal. No primeiro capítulo, fazemos uma revisão teórica detalhada, desde trabalhos clássicos de papéis sexuais até os mais recentes avanços, abordando também de maneira sistemática o conhecimento atual acerca de custos e benefícios do cuidado paternal em artrópodes, assim como o papel da seleção sexual sobre a evolução do comportamento parental e dos papéis sexuais. Em seguida, nos capítulos 2 e 3, acessamos os custos energéticos e em termos de sobrevivência do cuidado paternal nos opiliões Iporangaia pustulosa e Zygopachylus albomarginis. Comparando essas duas espécies, que apresentam diferentes níveis de investimento paternal, testamos previsões direcionadas de que os machos que investem mais na prole deveriam pagar maiores custos do cuidado. No quarto capítulo, por meio de informações da história natural e parâmetros populacionais estimados para I. pustulosa, fazemos previsões sobre qual dos sexos deveria ser criterioso ao escolher parceiros e as testamos utilizando observações comportamentais de interações entre machos e fêmeas. Por fim, no capítulo 5, avaliamos a importância relativa do sítio de oviposição, assim como do tamanho e do estado parental dos machos sobre a sua atratividade. Ao final, integramos os resultados obtidos em um corpo teórico sobre a inter-relação entre aparentes demandas conflitantes entre esforço parental e esforço reprodutivo, cuidado paternal e papéis sexuais, abrangendo não apenas as espécies estudadas, mas com um escopo bem mais amplo / Exclusive paternal care is the rarest form of post-zygotic parental investment in nature, which has independently evolved in no more than 14 arthropod lineages. Although many of those species are easily observed and manipulated, only recently researchers have started to pay attention and test hypotheses on parental investment and evolution of sex roles in such interesting biological systems. The main goal of this thesis was investigating individual and population characteristics that affect the reproductive success of males of harvestmen (Arachnida: Opilioes) with paternal care. In the first chapter, we revise the theory in details, since seminal works on sex roles until the most recent advances in the area, sistematically approaching the current knowledge abot costs and benefits of paternal care in arthropods, as well as the role of sexual selection on the evolution of parental behavior and sex roles. Then, in chapters 2 and 3, we access energetic and survival costs of paternal care in the harvestmen Iporangaia pustulosa and Zygopachylus albomarginis. Comparing these two species, that show different levels of parental investment, we test directional predictions that males which invest more should also pay more intense costs rekated to care. In the fourth chapter, based on natural history information and population parameters for I. pustulosa, we predict which sex should be choosier when selecting sexual partners, and test such predictions using behavioral data on male-female interactions. Finally, in chapter 5, we evaluate the relative importance of oviposition site, males\' body size and males\' parental state on their attractiveness. At the end, we integrate all the results obtained during the five chapters into a theoretical framework about the inter-dependence among trade-offs between parental and mating efforts, paternal care and sex roles, not only regarding the pair od species studied, but in a broad way.

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