Behavioural syndromes, defined as suites of correlated behaviours across different contexts, are used to characterize individual variability in behaviours. Males of the weakly electric fish species, Apteronotus leptorhynchus, produce electro-communication signals called chirps. Chirps are thought to be involved in agonistic signalling, as their relative incidence increases during agonistic conspecific interactions. However, high levels of individual variability in aggression obscure the role of chirps in mediating aggression. Here, I tested the presence of an aggression-boldness behavioural syndrome, and then considered the implications such a syndrome would have on chirping behaviours. Behavioural tests in anti-predation, object novelty, feeding, conspecific intrusion and novel environment exploration contexts revealed a syndrome involving only object novelty and feeding. We found no correlation between chirping behaviour and the assessed behaviours. Our results demonstrate that chirps represent a more complex communication system than previously suggested.

Behavioural syndromes, defined as suites of correlated behaviours across different contexts, are used to characterize individual variability in behaviours. Males of the weakly electric fish species, Apteronotus leptorhynchus, produce electro-communication signals called chirps. Chirps are thought to be involved in agonistic signalling, as their relative incidence increases during agonistic conspecific interactions. However, high levels of individual variability in aggression obscure the role of chirps in mediating aggression. Here, I tested the presence of an aggression-boldness behavioural syndrome, and then considered the implications such a syndrome would have on chirping behaviours. Behavioural tests in anti-predation, object novelty, feeding, conspecific intrusion and novel environment exploration contexts revealed a syndrome involving only object novelty and feeding. We found no correlation between chirping behaviour and the assessed behaviours. Our results demonstrate that chirps represent a more complex communication system than previously suggested.

Individuals in social species commonly form dominance relationships among each other, and are often observed to differ in behaviour depending on their social status. However, whether such behavioural differences are a consequence of dominance position, or also a cause to it, remains unclear. In this thesis I therefore investigated two perspectives of the relationship between social dominance and personality in the domestic fowl (Gallus gallus domesticus), a social species that forms relatively stable dominance hierarchies. In paper I I investigated the influence of social status on the expression and consistency of behaviours by experimentally changing status between repeated personality assays. The level of vigilance, activity and exploration changed with social status, while boldness and territorial crows appeared as stable individual properties, independent of status. These results showed that social status contribute to both variation and consistency in behavioural responses. Social status should therefore be taken into account when investigating and interpreting variation in personality. In paper II I showed that behaviour in a novel arena test and during encounter with an opponent can predict social status, more specifically that fast exploration and aggressiveness predicted a dominant social position. Together, these results highlight the dynamics of the two-way relationship between social position and individual behaviour and indicate that individual behaviour can both be a cause and a consequence of social status.

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<p>In this thesis I investigate predator-induced effects on behavioural and life-history characteristics of prey. At any moment a given predator is capable of attacking a small number of prey. However, the mere presence of a predator may impact a much larger number of individuals, as prey implement various behavioural and developmental mechanisms to reduce the risk of predation. It has become increasingly clear that predator induced responses have the potential to affect patterns of species abundance and distribution as well as individual fitness of prey. I study these responses by incorporating field surveys, semi-field experiments and laboratory experiments. All experiments were done in an aquatic environment using fish or large odonate larvae as predators and damselfly-or diving beetle larvae as prey.</p><p>My work highlights the importance of monitoring prey behaviour when studying life-history characteristics. I show that fish presence is an important factor for determining species abundance and distribution of odonates, and that prey behaviour may be a good predictor for fish vulnerability. Larval damselflies react behaviourally to predator presence by reducing activity and/or restricting habitat use. I confirm that such anti-predator responses have positive effects on prey survival in the presence of a predator but negative effects on growth and development of prey. In addition, my results suggest that the increase in per capita food resources for surviving prey following a predation episode (i.e. thinning) can have a stronger positive effect on prey growth and development than the negative effect of anti-predator responses. I also show that the strength of an anti-predator response is dependent on resource availability of the prey, with prey responding less strongly when resources are scarce. My results also indicate that the strength of the anti-predator response of damselfly larvae depends on predator diet and larval age. Predators feeding on prey conspecifics induce a stronger behavioural response in young larva than predators that feed on prey heterospecifics do. This diet-effect was not found in larvae late in ontogeny, due to an increased activity of larva where predators consumed damselflies. Such increased larval activity can be explained as a reaction to a time-constraint. Finally, I found that activity of damselfly larvae is genetically determined and that this has lead to a behavioural syndrome that might limit larval plasticity to a certain activity-range. This phenomenon may have implications for how well larvae are able to react to both biotic and abiotic changes in the environment.</p>

In this thesis I investigate predator-induced effects on behavioural and life-history characteristics of prey. At any moment a given predator is capable of attacking a small number of prey. However, the mere presence of a predator may impact a much larger number of individuals, as prey implement various behavioural and developmental mechanisms to reduce the risk of predation. It has become increasingly clear that predator induced responses have the potential to affect patterns of species abundance and distribution as well as individual fitness of prey. I study these responses by incorporating field surveys, semi-field experiments and laboratory experiments. All experiments were done in an aquatic environment using fish or large odonate larvae as predators and damselfly-or diving beetle larvae as prey. My work highlights the importance of monitoring prey behaviour when studying life-history characteristics. I show that fish presence is an important factor for determining species abundance and distribution of odonates, and that prey behaviour may be a good predictor for fish vulnerability. Larval damselflies react behaviourally to predator presence by reducing activity and/or restricting habitat use. I confirm that such anti-predator responses have positive effects on prey survival in the presence of a predator but negative effects on growth and development of prey. In addition, my results suggest that the increase in per capita food resources for surviving prey following a predation episode (i.e. thinning) can have a stronger positive effect on prey growth and development than the negative effect of anti-predator responses. I also show that the strength of an anti-predator response is dependent on resource availability of the prey, with prey responding less strongly when resources are scarce. My results also indicate that the strength of the anti-predator response of damselfly larvae depends on predator diet and larval age. Predators feeding on prey conspecifics induce a stronger behavioural response in young larva than predators that feed on prey heterospecifics do. This diet-effect was not found in larvae late in ontogeny, due to an increased activity of larva where predators consumed damselflies. Such increased larval activity can be explained as a reaction to a time-constraint. Finally, I found that activity of damselfly larvae is genetically determined and that this has lead to a behavioural syndrome that might limit larval plasticity to a certain activity-range. This phenomenon may have implications for how well larvae are able to react to both biotic and abiotic changes in the environment.

Social dominance relationships are formed within numerous animal species and reduce costly fights over resources. Dominant individuals often enjoy greater access to important resources such as food and mating partners, and are generally more aggressive, bold, active and explorative compared to subdominant individuals. These behavioural traits can differ among individuals, but they can also be consistent within the individual, thereby describing the individual’s personality type. However, the causal direction of the observed correlation between dominance and personality is not well studied. One possibility is that some personality types have higher chances of obtaining a dominant social position. This would suggest that personality has consequences for fitness. Another possible explanation is that possessing different social positions gives rise to consistent behavioural differences among individuals on various timescales. If social status has a lasting effect on behaviour, social status would constitute a ‘stable state’ that explains some of the diversity of personality types that has been observed in a multitude of animal species. Dominance and personality may also share underlying proximate factors. In this thesis, I investigate the relationship between social dominance and personality using male domestic fowl, Gallus gallus domesticus. The species is group-living with pronounced dominance hierarchies, and dominance increases male access to mating partners. I show that some aspects of personality, exploration, vigilance and in particular aggressiveness, increased a male’s chances of obtaining dominance (paper III, IV, V), and that aggressiveness can be even more important than body weight and ornament size (comb size, paper V) or recent experience of winning or losing (paper IV). Winning a social interaction resulted in an increase in aggressiveness, while a decrease was seen in males that experienced a loss (paper IV). By observing behaviour before and after changes in male dominance relationships, I further show that a recent (2 days earlier) change in social status induced behavioural adjustments to the new social status in activity, exploration and vigilance (paper I). By extending the time of the new social relationship to 3 weeks, I show that such behavioural changes did not continue (paper II). Finally, I show that the social environment during juvenile development had little impact on adult male competitiveness (paper V). Social interactions appear to have several short-term effects on behaviour, but did not contribute significantly to variation and long-term consistency of personality in male fowl. Instead, a male's personality, and in particular his aggressiveness, affected the outcome of dominance interactions. Overall, my studies reveal important consequences of individual differences in behaviour, and contribute to the highly sought-after empirical testing of hypotheses explaining variation in animal personality. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: Manuscript. Paper 5: Manuscript.</p>

La dispersion est un trait d'histoire de vie clé pour les processus écologiques et évolutifs dans les populations naturelles. Les dernières recherches se sont notamment focalisées sur les corrélations entre traits comportementaux et la dispersion, ceci afin de mettre en évidence des syndromes comportementaux de dispersion, tout en démontrant la base génétique de la dispersion. Les dispersants ne seraient donc pas une part aléatoire d'une population, mais des individus montrant des stratégies particulières qui augmenteraient leur chances de succès. Cette thèse s'est orientée vers trois objectifs de recherche majeurs. Le premier est la mise en évidence d'une base génétique de la probabilité de disperser dans une population fragmentée de gobe-mouches à collier Ficedula albicollis. Les résultats nous ont montré, au-delà de l'estimation de la base génétique de la dispersion, une distribution spatiale non aléatoire de l'apparentement dans cette population, qui pourrait être dû à des effets génétiques sur les règles de décision de choix de l'habitat. Le deuxième s'intéresse à la corrélation phénotypique et génétique entre le comportement de dispersion natale et le comportement de défense du nid, chez le martinet alpin Tachymarpis melba. Nous avons montré que la dispersion natale et le comportement de défense du nid sont négativement corrélés au niveau phénotypique mais aussi génétique dans ces populations. Enfin, le troisième nous à conduit à tester l'existence de syndromes comportementaux de dispersion, c'est-à-dire si les dispersants présentent un profil comportemental particulier, leur permettant en particulier de coloniser de nouveaux sites, chez le gobe-mouche à collier / Dispersal is a key like history trait for ecological and evolutionary processes in wild population. The last researching particularly focused on the correlation between behavioural trait and dispersal, in order to emphasize the existence of behavioural syndromes of dispersal, and on the estimation of the genetic basis of the dispersal behaviour. Dispersant individuals could not be a random part of the population, but individuals showing particular strategies, that help them to succeed in their dispersal attempt. This thesis has three main aims of research. The first is to show a genetic basis of the dispersal propensity in a fragmented population of collared flycatchers (Ficedulla albicollis). We shown not only the genetic bases of the dispersal, but also a non-random spatial distribution of relationship between individuals in this population, that might be due to genetic effects on the decision rules of habitat choice in this population. The second aim concerns phenotypic and genetic correlation between the natal dispersal and a behavioural trait, the nest-defense behaviour, in the alpin swift (Tachymarpis melba). We shown that natal dispersal and nest-defense behaviour are negatively correlated at a phenotypic level, but also at a genetic level in theses populations. Finally, the third aim attempt to test the existence of behavioural syndrome of dispersal, that is if dispersant individuals have a particular behavioural profile, which enable them to colonize new sites, in the collared flycatcher

Dispersal is a key life history trait for ecological and evolutionary processes in wild populations. The latest research has particularly focused on the correlation between behavioural traits and dispersal, in order to emphasize the existence of behavioural syndromes of dispersal, and on the estimation of the genetic basis of the dispersal behaviour. Dispersing individuals are not a random part of the population, but are individuals showing particular strategies, that help them to succeed in their dispersal attempt. This thesis has three main aims of research. The first is to show a genetic basis of the dispersal propensity in a fragmented population of collared flycatchers (Ficedulla albicollis). We show, not only, the genetic bases of the dispersal, but also a non-random spatial distribution of relationship between individuals in this population, that might be due to genetic effects on the decision rules of habitat choice in this population. The second aim concerns phenotypic and a genetic correlation between the natal dispersal and a behavioural trait, the nest-defense behaviour, in the alpin swift (Tachymarptis melba). We showed that natal dispersal and nest-defense behaviour were negatively correlated at a phenotypic level, but also at a genetic level in these populations. Finally, the third aim attempts to test the existence of a behavioural syndrome of dispersal, that is if dispersing individuals have a particular behavioural profile, which enable them to colonize new sites, in the collared flycatcher. / <p>The exmination will be videolinked to seminar room 1003 Evolutionary Biology Centre, EBC, Uppsala University.</p>

En biologie évolutive, la variation phénotypique a longtemps été réduite au substrat sur lequel agissait la sélection naturelle. Toutefois, la constance intra-individuelle et le maintien intra-populationnel de certains comportements conduisirent au milieu des années 90 au développement du concept de personnalité animale, basé sur la caractérisation de traits tels que la néophobie, l’agressivité, les tendances exploratoires ou la prise de risque. De nombreuses études montrent que la personnalité est soumise à la sélection naturelle et est reliée à certaines stratégies biodémographiques, telles que la dispersion ou le comportement anti-prédateur.Les liens entre la personnalité animale et les stratégies d’appariement et d’approvisionnement, deux composantes fondamentales de la vie des organismes, ont pourtant été négligés jusqu’ici. Nous nous sommes donc attachés au cours de cette thèse à déterminer l’influence de la personnalité sur certains comportements sexuels et alimentaires à l’aide d’un organisme modèle en écologie comportementale : le Diamant mandarin (Taeniopygia guttata). Puis, à l’inverse, nous avons souligné le rôle des sélections naturelle et sexuelle dans le maintien des variations de personnalité.Nos principaux résultats indiquent que certains traits de personnalité mesurés sont inter-corrélés au niveau de notre population captive d’oiseaux, définissant un syndrome comportemental. De plus, la personnalité prédit de manière différentielle le succès d’approvisionnement entre les contextes de compétition par exploitation et par interférence. Ainsi, les individus proactifs sont dominants lors d’épisodes de compétition par interférence mais souffrent d’un plus faible succès d’approvisionnement lors de jeux producteur-chapardeur. Ces résultats soulèvent la possibilité que la sélection naturelle favorise différentes personnalités dans différents contextes, offrant un mécanisme d’explication du maintien des variations intra-populationnelles de personnalité. De plus, ils suggèrent que la personnalité contraint l’optimalité des comportements à travers les situations. Enfin, dans un contexte de choix du partenaire, nous avons montré que la personnalité des femelles utilisées dans des tests de préférence par association influence les mesures de la sélectivité, des scores de préférence et de leur répétabilité.L’étude conjointe de la personnalité animale et des stratégies d’appariement et d’approvisionnement constitue ainsi une voie prometteuse dans l’explication du maintien des variations de personnalité par sélections naturelle et sexuelle, ainsi que dans l’étude de l’influence de la personnalité sur les stratégies biodémographiques des organismes en contextes alimentaire et sexuel / In evolutionary biology, phenotypic variation has for a long time been considered as the raw material on which natural selection acts. However, research on the consistency of behaviour led to the development of the animal personality concept during the 1990s. This concept was based on the characterization of traits such as neophobia, aggressiveness, exploratory tendencies and risk-taking behaviour. Since then, several studies have shown that personality can evolve through natural selection and is related to many life-history traits, such as dispersal or anti-predator behaviour.Pairing strategies and foraging strategies are two fundamental components of an organism’s life, but their relationships with personality have so far been neglected. In this thesis, we determined the extent to which personality influences sexual and feeding behaviour, using the zebra finch (Taeniopygia guttata) as a model organism. Our work highlights the role of natural and sexual selection on the maintenance of personality variation.Some personality traits are related to each other within our sample, defining a behavioural syndrome. Moreover, personality predicted feeding success in competitive situations, but differently for scramble and interference competition. Proactive individuals were dominant in interference competition but had lower feeding success in producer-scrounger games. Interestingly, these results suggest that natural selection could favour different personalities depending on the context, perhaps explaining the maintenance of personality variation within populations. Moreover, personality could constrain behavioural optimality across situations. Finally, in a mate-choice context, we found that female personality influences selectivity, preference and its repeatability during spatial association tests.The joint study of personality and pairing and foraging strategies thus represents a promising avenue of research for understanding the maintenance of personality variation through natural and sexual selection. Moreover, personality can considerably influence some life-history traits in sexual and foraging contexts