The ability to understand the complex mechanisms by which species communicate has been the focus of study for many years. The Adélie penguin (Pygoscelis adeliae) breeds in vocally challenging Antarctic colonies and has evolved a complex system of intra- and intersexual visual and vocal behaviours. Unique to the Adélie penguin, is the presence of two distinct display calls, the Loud Mutual Display (LMD) call and male Ecstatic Display Call (EDC). The EDC is used for both mate choice and territory defence; but apart from general structure and function this call remains basically unstudied. Therefore, the aim of this study is to examine the EDC with regard to its function (during mate choice) and variability over time, with location and with changing conditions. It is predicted that the EDC will be an individual call that is distinct from the LMD call. Additionally, the effects of an inclement breeding season on factors that affect breeding success will be examined using a logistic regression approach. The study took place over two breeding seasons(2000/1 & 2002/3) on Ross Island, Antarctica, with the majority of research being conducted at Cape Bird. Results of the study indicate that the EDC is an individual call that cannot reliably be described as a male display as females also give an EDC that is acoustically comparable. The similarities between the EDC and the LMD call seem to relate only to syllabic organisation (structure), as almost every call parameter was different between call types. Furthermore, several call parameters differed between Ross Island colonies. These parameters varied with both geographical location and colony size. In conjunction with variation in call parameters, the health and breeding success of the colonies was different. The stability of call parameters (from Cape Bird) indicated that parameters that separate colonies not only alter between breeding years, but also vary during a single breeding season. The function of the EDC as an honest signal during mate choice was supported by spectral analyses. These analyses found heavier males had significantly lower Frequency Modulation (FM) in the short repeated syllables of their calls than lighter males. Furthermore, a male’s breeding success could be predicted during the early breeding season by the FM. Logistic regression models showed that early male arrival, weight and good nest quality were most influential in predicting fledging success. The logistic regression method also showed that the parameters measured varied in their predictive ability as the season progressed. This study has not only enhanced the wealth of knowledge regarding Adélie breeding behaviour and developed our understanding of the vocal repertoire of this species, but also has implications for honest signalling theory, and the evolution and stability of vocal variation at different spatial and temporal scales.

The ability to understand the complex mechanisms by which species communicate has been the focus of study for many years. The Adélie penguin (Pygoscelis adeliae) breeds in vocally challenging Antarctic colonies and has evolved a complex system of intra- and intersexual visual and vocal behaviours. Unique to the Adélie penguin, is the presence of two distinct display calls, the Loud Mutual Display (LMD) call and male Ecstatic Display Call (EDC). The EDC is used for both mate choice and territory defence; but apart from general structure and function this call remains basically unstudied. Therefore, the aim of this study is to examine the EDC with regard to its function (during mate choice) and variability over time, with location and with changing conditions. It is predicted that the EDC will be an individual call that is distinct from the LMD call. Additionally, the effects of an inclement breeding season on factors that affect breeding success will be examined using a logistic regression approach. The study took place over two breeding seasons(2000/1 & 2002/3) on Ross Island, Antarctica, with the majority of research being conducted at Cape Bird. Results of the study indicate that the EDC is an individual call that cannot reliably be described as a male display as females also give an EDC that is acoustically comparable. The similarities between the EDC and the LMD call seem to relate only to syllabic organisation (structure), as almost every call parameter was different between call types. Furthermore, several call parameters differed between Ross Island colonies. These parameters varied with both geographical location and colony size. In conjunction with variation in call parameters, the health and breeding success of the colonies was different. The stability of call parameters (from Cape Bird) indicated that parameters that separate colonies not only alter between breeding years, but also vary during a single breeding season. The function of the EDC as an honest signal during mate choice was supported by spectral analyses. These analyses found heavier males had significantly lower Frequency Modulation (FM) in the short repeated syllables of their calls than lighter males. Furthermore, a male’s breeding success could be predicted during the early breeding season by the FM. Logistic regression models showed that early male arrival, weight and good nest quality were most influential in predicting fledging success. The logistic regression method also showed that the parameters measured varied in their predictive ability as the season progressed. This study has not only enhanced the wealth of knowledge regarding Adélie breeding behaviour and developed our understanding of the vocal repertoire of this species, but also has implications for honest signalling theory, and the evolution and stability of vocal variation at different spatial and temporal scales.

The ability to understand the complex mechanisms by which species communicate has been the focus of study for many years. The Adélie penguin (Pygoscelis adeliae) breeds in vocally challenging Antarctic colonies and has evolved a complex system of intra- and intersexual visual and vocal behaviours. Unique to the Adélie penguin, is the presence of two distinct display calls, the Loud Mutual Display (LMD) call and male Ecstatic Display Call (EDC). The EDC is used for both mate choice and territory defence; but apart from general structure and function this call remains basically unstudied. Therefore, the aim of this study is to examine the EDC with regard to its function (during mate choice) and variability over time, with location and with changing conditions. It is predicted that the EDC will be an individual call that is distinct from the LMD call. Additionally, the effects of an inclement breeding season on factors that affect breeding success will be examined using a logistic regression approach. The study took place over two breeding seasons(2000/1 & 2002/3) on Ross Island, Antarctica, with the majority of research being conducted at Cape Bird. Results of the study indicate that the EDC is an individual call that cannot reliably be described as a male display as females also give an EDC that is acoustically comparable. The similarities between the EDC and the LMD call seem to relate only to syllabic organisation (structure), as almost every call parameter was different between call types. Furthermore, several call parameters differed between Ross Island colonies. These parameters varied with both geographical location and colony size. In conjunction with variation in call parameters, the health and breeding success of the colonies was different. The stability of call parameters (from Cape Bird) indicated that parameters that separate colonies not only alter between breeding years, but also vary during a single breeding season. The function of the EDC as an honest signal during mate choice was supported by spectral analyses. These analyses found heavier males had significantly lower Frequency Modulation (FM) in the short repeated syllables of their calls than lighter males. Furthermore, a male’s breeding success could be predicted during the early breeding season by the FM. Logistic regression models showed that early male arrival, weight and good nest quality were most influential in predicting fledging success. The logistic regression method also showed that the parameters measured varied in their predictive ability as the season progressed. This study has not only enhanced the wealth of knowledge regarding Adélie breeding behaviour and developed our understanding of the vocal repertoire of this species, but also has implications for honest signalling theory, and the evolution and stability of vocal variation at different spatial and temporal scales.

abstract: Differences between males and females can evolve through a variety of mechanisms, including sexual and ecological selection. Because coloration is evolutionarily labile, sexually dichromatic species are good models for understanding the evolution of sex differences. While many jumping spiders exhibit diverse and brilliant coloration, they have been notably absent from such studies. In the genus Habronattus, females are drab and cryptic while males are brilliantly colored, displaying some of these colors to females during elaborate courtship dances. Here I test multiple hypotheses for the control and function of male color. In the field, I found that Habronattus males indiscriminately court any female they encounter (including other species), so I first examined the role that colors play in species recognition. I manipulated male colors in H. pyrrithrix and found that while they are not required for species recognition, the presence of red facial coloration improves courtship success, but only if males are courting in the sun. Because light environment affects transmission of color signals, the multi-colored displays of males may facilitate communication in variable and unpredictable environments. Because these colors can be costly to produce and maintain, they also have the potential to signal reliable information about male quality to potential female mates. I found that both red facial and green leg coloration is condition dependent in H. pyrrithrix and thus has the potential to signal quality. Yet, surprisingly, this variation in male color does not appear to be important to females. Males of many Habronattus species also exhibit conspicuous markings on the dorsal surface of their abdomens that are not present in females and are oriented away from females during courtship. In the field, I found that these markings are paired with increased leg-waving behavior in a way that resembles the pattern and behavior of wasps; this may provide protection by exploiting the aversions of predators. My data also suggest that different activity levels between the sexes have placed different selection pressures on their dorsal color patterns. Overall, these findings challenge some of the traditional ways that we think about color signaling and provide novel insights into the evolution of animal coloration. / Dissertation/Thesis / Ph.D. Biology 2012

The master thesis works measures of phenotypic traits and unique data of pairing of wild living grey partridges. The secondary sexual traits and theirs variability is described. Especially the relationship between the ornamental traits and the pairing success was researched. The results proved the greater pairing success of males with the larger melanin breast patch and the greater quality of the mate in females with the larger breast patch. The strategy of male floaters, which are realatively well ornamented is discussed.

La consanguinité est connue par les biologistes pour diminuer la valeur sélective des individus en diminuant par exemple leur survie ou leur fertilité. De ce fait, la sélection naturelle devrait favoriser l'apparition de comportements permettant l'évitement des accouplements entre apparentes pour limiter les conséquences néfastes dues à la dépression de consanguinité. Cette dépression de consanguinité est particulièrement visible chez les Hyménoptères avec un système de détermination du sexe appelé single-locus Complementary Sex Determination (sl-CSD), où elle amène à la production de males diploïdes non viables ou stériles. Mon travail de thèse a ainsi consiste à étudier le phénomène d'évitement d'accouplements entre apparentes dans des populations naturelles d'un hyménoptère parasitoïde avec sl-CSD, Venturia canescens, ainsi que des signaux utilisés par les femelles pour déterminer l'apparentement qu'elles ont avec les individus qu'elles rencontrent. Nous avons d'abord étudié le lien unissant type d'habitat (continental, iles ou laboratoire), diversité génétique et production de males diploïdes dans 11 populations de V. canescens. En effet, un cadre théorique nomme "Vortex d'extinction du aux males diploïdes" prédit une corrélation négative entre isolations des populations, diversité génétique et production de males diploïdes pouvant amener à l'extinction de populations d'Hyménoptères. Nous avons ainsi démontré une corrélation négative entre diversité génétique et production de males diploïdes dans les populations isolées de V. canescens. Ensuite, il a été montré précédemment que les femelles de cette espèce étaient capables de discriminer les males qui leur étaient apparentes et d'éviter les accouplements entre apparentes en laboratoire. Nous nous sommes ainsi intéressés à ce phénomène d'évitement d'accouplement entre apparentes dans des populations naturelles grâce au génotypage de 450 individus du terrain et leur descendants. Nous avons montré que les femelles toléraient les accouplements entre apparentes sur le terrain ainsi qu'en laboratoire en présence de plusieurs males, nous permettant de mettre en lumière l'importance des conditions environnementales sur le choix du partenaire sexuel. Nous nous sommes enfin concentrés sur le système de reconnaissance des apparentes au niveau mécanistique en étudiant les signaux chimiques utilisés par les femelles pour reconnaitre leurs apparentes dans deux contextes écologiques différents, le choix du partenaire sexuel et l'évitement du superparasitisme lors de la ponte. Nous avons ainsi montré des similitudes entre les compositions chimiques de ces deux signaux mais aussi qu'ils n'étaient pas interchangeables entre les deux contextes écologiques étudiés. Au final, les résultats obtenus apportent un nouvel éclairage sur les conditions nécessaires à l'apparition d'un évitement d'accouplements entre apparentes dans des populations naturelles ainsi que sur les signaux utilisés lors de la reconnaissance de parentèle chez un hyménoptère parasitoïde / Inbreeding is well known by biologists to lower the fitness of individuals by or example decreasing survival or fertility. Therefore, natural selection should favour behaviours preventing the reproduction of genetically-related individuals or mitigating harmful consequences, called inbreeding depression. Inbreeding depression is particularly visible in Hymenoptera with a sex-determination system called single-locus Complementary Sex Determination (sl-CSD), where it leads to the production of diploid males that are either unviable or sterile. My PhD work has thus been devoted to the study of sib-mating avoidance in natural populations of a parasitoid with sl-CSD, Venturia canescens, and to understand the cues used by females recognize their kin. We first studied the link between habitat type (continental, island or captive), genetic diversity and diploid male production in 11 V. canescens populations. Indeed, a theoretical framework called "Diploid male extinction vortex" predict a negative correlation between populations’ isolation, genetic diversity and diploid male production that could lead to the extinction of hymenopteran populations.We actually showed a negative correlation between genetic diversity and diploid male production in isolated populations. Previous studies have furthermore demonstrated kin discrimination and sib-mating avoidance by V. canescens females in the laboratory. We therefore studied the sibmating avoidance behaviour in natural populations of this species by genotyping more than 450 wild individuals and their offsprings. We demonstrated that females tolerated inbreeding in the wild as well as in the laboratory when several males were present. We highlighted the importance of environmental conditions on mate choice. At last, we were interested in the kin recognition system and researched the chemical cues used by females in two ecological contexts, mate choice and superparasitism avoidance. This allowed us to identify similarities in the composition of the two chemical signals and that they were not interchangeable between the two studied ecological contexts. In the end, the results we obtained shed new light on the necessary conditions for the apparition of sib-mating avoidance in natural populations, as well as on the cues used for kin recognition in a parasitoid

Abstract Divergence of behavioral traits (e.g. courtship rituals, habitat choice) has had a major impact on species formation and isolation. Species-specific courtship rituals preventing species hybridization may arise as a by-product of natural selection during spatial isolation or through direct action of natural selection to prevent species hybridization after a secondary contact. Coordination leading to the assumption of coevolution of signals and preferences is a prerequisite for effective courtship signaling between a male and a female of the same species. We found a reasonable amount of variation in the mate traits within the Drosophila montana and D. virilis species, but our findings did not reveal evidence of the coevolution between the male courtship signals and female preference for these signals. Variation also did not cause isolation within species. The form of female preference for carrier frequency of male song was found to be stabilizing even in changing environments, when female preference for the carrier frequency and pulse length of the male song was measured at ambient temperature. D. montana females always preferred males with high frequency songs, which probably advertises the male condition. The frequency of male song decreased due to male aging, although males with larger body size were able to maintain frequencies better. Ageing also had a deterioration effect on male reproductive success. The importance of male courtship song was not only highlighted in mate choice, but also in species-recognition. We were able to persuade D. montana females to copulate with alien D. lummei species by playing them simulated song resembling the song of conspecific males. Simulated courtship songs were demonstrated to be a practical tool in studies of preference between sexually isolated Drosophila species. / Tiivistelmä Kosintapiirteiden (esim. kosintarituaalit, habitaatin valinta) vaihtelevuudella on ollut suuri vaikutus lajien muodostumisessa ja eriytymisessä. Lajien välisiä risteytymisiä estäviä lajispesifisiä kosintarituaaleja voi syntyä luonnonvalinnan sivutuotteena spatiaalisen eristäytymisen aikana tai luonnonvalinnan suoralla vaikutuksella estämään lajiristeymät lajien uudelleen kohdatessa. Tehokkaan koiraan ja naaraan välisen kosintaviestinnän edellytyksenä on koordinointi, minkä vuoksi on oletettavaa, että signaalien ja vasteiden välillä on yhteisevoluutiota. Löysimme kohtuullisen määrän vaihtelevuutta kosintapiirteissä Drosophila montana – ja D. virilis – lajeilla, mutta emme löytäneet todisteita koiraan kosintasignaalien ja naaraan näihin signaaleihin kohdistamien vasteiden välisestä yhteisevoluutiosta. Vaihtelu ei myöskään aiheuttanut isolaatiota lajien välille. Naaraan koiraan kosintalaulun kantofrekvenssiin osoittaman vasteen funktion muodon havaittiin olevan tasapainottava jopa vaihtelevissa ympäristöissä, kun naaraan kantotaajuuteen osoittamaa vastetta mitattiin eri lämpötiloissa. D. montana naaraat suosivat koiraita, joilla oli korkeataajuinen kosintalaulu. Laulun korkea taajuus kertoo luultavasti naaraalle koiraan fyysisestä kunnosta. Koiraan laulun frekvenssin havaittiin laskevan koiraan ikääntyessä, mutta isommat koiraat pystyivät paremmin säilyttämään korkean taajuuden laulussaan. Ikääntyminen heikensi myös koiraan lisääntymismenestystä. Koiraan kosintalaulun tärkeys ei korostunut pelkästään parinvalinnassa, vaan myös lajintunnistuksessa. Pystyimme suostuttelemaan D. montana –naaraat parittelemaan vieraan D. lummei –lajin kanssa käyttämällä simuloituja kosintalauluja, jotka osoittautuivat käytännöllisiksi välineiksi tutkittaessa naaraan vasteita seksuaalisesti eriytyneillä Drosophila-lajeilla.

Doctor of Philosophy / Department of Biology / Brett K. Sandercock / Sexual selection via female choice and male-male aggression leads to elaboration of male traits. If male traits correlated with reproductive success are honest signals of male quality, survival costs may be associated with the expression of those traits. Testosterone (hereafter ‘T’) may enhance male breeding success, but T can also reduce immunocompetence and survival. Socially monogamous male birds with higher circulating T experience reproductive advantages, but the role of T in lek mating systems is largely unknown. To address these issues, I individually marked and conducted focal behavioral observations of greater prairie-chickens (Tympanuchus cupido) at five lek sites over a 5-year period. Females were fitted with radio-telemetry to monitor nesting success and survival. I examined the relationship between male traits and mating success using multinomial discrete choice models, a statistical method not previously applied to studies of sexual selection. Male mating success was highly skewed at greater prairie-chicken leks with 18.5% of males obtaining 87.2% of all successful copulations (n = 108 males; 85 copulations). Mating success was influenced most by male behavior, followed by several morphological attributes. The role of T was quantified using blood samples and by experimentally implanting a subset of males with T. T did not consistently affect mating success. Non-territorial males had lower T levels than territorial males. Among territory holders, T was unexpectedly negatively correlated with mating success. However, the odds of receiving a copulation were 4.3 times (0.42 to 45.3) greater for T-implanted males than males with sham implants. Future work should explore the interactions among the immune system, parasite load, and mating success of prairie-chickens. Annual survival of male prairie-chickens was not related to mating success, behavior, age or T level, suggesting there is no cost of increased male mating success. Like males, reproductive success of females was also highly skewed because < 10% of nests successfully hatched young. Comparisons of seasonal and annual survival rates indicate that females experience increased mortality during the breeding season relative to the nonbreeding season. Synthesis of field estimates of demographic parameters indicates prairie-chicken populations will decline without changes in rangeland management to reduce predator numbers or provide more nesting cover.

Dans le cadre du choix de partenaire, les préférences sont des mécanismes psychologiques permettant aux individus de choisir un (ou une) partenaire susceptible d'augmenter leur succès reproducteur. Comme le nombre de descendants d'un homme dépend largement de la fertilité de la (ou des) partenaire(s) qu'il choisit, la capacité à détecter et à préférer les femmes ayant une fertilité importante a été sélectionnée. Et puisque la fertilité d'une femme est en partie déductible de certaines caractéristiques physiques, l'attractivité féminine est en grande partie physique. Une approche expérimentale a été utilisée afin d'identifier les traits physiques influençant l'attractivité féminine, ainsi que les composantes de la fertilité desquelles ils sont les indices. En plus des indices connus de fertilité immédiate (c'est à dire la capacité d'une femme à engendrer un descendant à un moment donné), nos résultats montrent que les hommes sont également sensibles à des indices de fertilité résiduelle (nombre potentiel d'enfants qu'une femme pourra avoir dans le futur), partiellement définie par l'âge à la ménopause. Les moyens de détection de ces traits par les hommes ont également été analysés, démontrant l'importance de la vision périphérique lors de l'évaluation de l'attractivité d'un corps féminin. La question de l'universalité de ces critères d'attractivité a ensuite été abordée. Les différentes études montrent que les préférences masculines varient temporellement (la silhouette idéale, mesurée par le ratio taille/hanche, varie depuis le XVe siècle), géographiquement (les préférences pour la fertilité résiduelle diffèrent entre la France et l'Indonésie) et individuellement (on observe une préférence pour l'homogamie pour les traits du visage). Si nos résultats réfutent donc l'idée d'une beauté unique, universelle et biologiquement fixée, ces variations sont loin d'être arbitraires. Les variations des préférences s'expliquent par différents compromis et enjeux évolutifs, variant en fonction de conditions environnementales, culturelles, et individuelles. / In a context of mate choice, preferences are psychological mechanisms allowing individuals to choose a partner who can enhance their reproductive success. As a man's number of children greatly depends on the fertility of his mate(s), the ability to detect and prefer women with a high fertility has been selected. Moreover, as a woman's fertility is linked to various physical features, female attractiveness is largely physical. An experimental approach has been used to identify the physical traits influencing women's attractiveness, as well as the fertility characteristics of which they are the cues. In addition to well known cues of current fertility (i.e. a woman's ability to conceive a child at that given time), our results show that men are also sensitive to cues for residual fertility (i.e. the potential number of children a woman could have in the future), which is partially determined by age at menopause. Male means of detecting these features have been analysed too, highlighting the crucial role of the peripheral vision when judging the attractiveness of a woman's body. Furthermore, the issue of whether these attractiveness standards are universal has been addressed. Our studies show that men's preferences vary through time (the ideal body shape, determined by the waist-to-hip ratio, has changed since the 15th century), geographically (preferences concerning the residual fertility differ between France and Indonesia), and individually (a preference for homogamy has been found within facial features). Thus, our results disprove the notion of a single, universal and biologically fixed idea of beauty. But these variations of preferences are not arbitrary, and can be explained by evolutionary stakes and trade-offs, linked to environmental, cultural and individual conditions.

Extra-pair paternity, resulting from sexual promiscuity, is frequently detected in socially monogamous passerines. Previous studies on extra-pair paternity in birds have identified several traits correlated with increased fertilization success of males. However, the effect of experimental manipulation of ornament expression on male fertilization success has only seldom been evaluated. The aim of this thesis is to reveal the potential link between the size of a trait suposedly playing a role in female mate choice decision and male fertilization success in collared flycatchers (Ficedula albicollis), using experimental manipulation of male forehead white patch size. In addition, mating success, mating speed of the manipulated and control individuals and size of a brood (a proxy for female reproductive investments) were evaluated. Results indicate that forehead patch size manipulation did not affect male social pairing success (mating speed), his social mate reproductive investments (brood size) or male extra-pair and within-pair fertilization success. Keywords: extra-pair paternity, sexual selection, reproductive success, collared flycatcher