Two crucial issues related to personality in non-human animals have been identified: firstly, the underlying 'causes' of personality and,secondly, the stability of behavioural repertoires (essentially the defining feature of personality) have both been the subject of long-standing debate. This thesis is focused on investigating stable inter- and intra- individual differences in the behaviour of wildcaught bank voles, Myodes glareolus (that varied according to mtDNA type), and in common voles, Microtus arvalis. The first study, using wild voles, revealed empirical evidence about the effects of sex and mtDNA type on individual differences in basal metabolic rate and in behaviour in the open field which provides measures of approach and avoidance (here, generically termed 'proactivity') and which relate to several theoretical conceptualisations of animal personality. The second study demonstrated the presence of stable individual differences in reactions to exposure to open field test and radial maze in common voles, which were shaped by the social environment and in turn, related to cognitive efficiency. The same species was used in the third study documenting the distinct temporal patterns of behavioural plasticity that manifested over repeated exposures to the open field test. We suggest that this distinct temporal patterning in habituation, whilst it varied over time, was predictable in nature and therefore a reflection of a stable underlying personality. To conclude, this body of thesis work draws together a number of influencing factors, and considers their contribution to animal personality.

Anthropogenic environmental changes are occurring globally and are having dramatic effects on wildlife. Successful urban animals can alter behaviours to adjust to these conditions, but it is not well understood how these modifications arise. In particular, exploratory personality and behavioural plasticity are predicted to facilitate colonization in urban areas. The link between exploratory personality, cognition, and plasticity has received little attention, and has never been examined in urban animals. The first objective of this thesis was to examine the relationship between exploratory personality and habituation in a novel environment, and determine whether variation at the individual-level is predicted by urbanization. The second objective was to explore the association between exploratory personality and spatial cognition within scatter hoarders, and assess spatial memory along an urban gradient. At the individual-level, I report significant inter-individual differences in exploratory personality and habituation. I found evidence that fast initial explorers tend to habituate in a novel environment over time while slow explorers do not. There was no significant relationship between exploratory personality and spatial cognition within individuals. At the population level, urbanization did not significantly predict habituation or spatial cognition. I do report a significant positive relationship between urbanization and exploration. Overall, I conclude that urban individuals are significantly faster explorers, but are not more behaviourally plastic and do not show differences in spatial memory. Further work examining personality, cognition, and plasticity within individuals is needed to determine whether these traits have implications for populations under different environmental conditions.

In the wolf spider Rabidosa punctulata, upon encountering a female, males use one of two distinct strategies: (1) they court the female in an attempt to elicit a mating, or (2) they engage in a direct-mount tactic that involves extensive grappling with the female until a mating is achieved. The latter tactic appears more sexually aggressive, and both tactics come with the risk of being cannibalized. We explored the physiological mechanisms underlying this behavioural variation by assessing the relationship between circulating levels of the biogenic amine octopamine (OA), a neuromodulator suggested to play a role in 'fight or flight' responses of arthropods and male mating tactic expression. We predicted, and found support for, a relationship between OA levels and tactic expression, with males adopting the direct-mount tactic expressing higher OA levels than courting males. Male mating tactic and mass also showed a significant interaction, with a negative trend in direct-mounting males and no relationship in courting males. Males had considerably higher levels of OA circulating in their haemolymph than females and female OA level increased with female mass. Our experimental design cannot disentangle cause from effect, but our results are consistent with the hypothesis that OA plays a role in regulating mating tactic expression in R.punctulata.

Afin de se maintenir au sein d'un environnement changeant, les individus doivent mettre en place une réponse adéquate. Il est connu que les animaux ont la capacité d'ajuster leur comportement à leur environnement. Cette plasticité comportementale, permet une réponse adaptée et relativement rapide aux variations de l'environnement, maximisant ainsi les chances de survie et de transmission des gènes. Elle met en jeu des processus cérébraux couteux en énergie rendant ces adaptations particulièrement sensibles à des changements alimentaires. Le but de cette thèse a été de mieux comprendre les facteurs qui contraignent ces réponses chez une espèce à laquelle s'applique une forte pression de sélection. Pour ce faire, nous avons étudié les réponses comportementales d'un primate malgache, le microcèbe gris (Microcebus murinus) soumis à des changements dans la quantité ou la qualité des ressources alimentaires disponibles. La première partie de ce travail s'est intéressée aux effets à court terme d'une restriction alimentaire sans malnutrition. Cette partie comprenait deux études. La première s'intéressant aux effets d'une restriction alimentaire à 60% sans malnutrition sur la plasticité comportementale innée via l’étude de l'horloge biologique. Les résultats de cette étude montrent une diminution de la capacité à se resynchroniser après un décalage horaire en lien avec la perte de poids. Ainsi, les individus perdant le plus de poids sont le moins à même de se resynchroniser sur les cycles lumineux après un décalage horaire de 6 heures. La seconde s'intéressait aux effets d'une restriction alimentaire de 40% sans malnutrition sur la plasticité comportementale acquise et montre une diminution de la capacité d'apprentissage des individus restreints après 19 jours de traitement alimentaire sans influence sur la mémoire à long terme. La moindre capacité d’apprentissage chez les individus en restriction calorique est corrélée à la perte de poids, les individus perdant le plus de poids étant les moins performants. Dans une seconde partie j’ai étudié l'effet de modifications qualitatives de l'alimentation à travers une supplémentation à long terme des individus en acides gras polyinsaturés n-3. Cette partie m’a permis de mettre en évidence une amélioration des performances d'apprentissage chez les individus supplémentés après 18 mois de traitement alimentaire accompagnée d'une diminution de l'anxiété et d'une augmentation de la neurogenèse adulte dans trois zones cérébrales.Ces travaux démontrent que les variations nutritionnelles, qu’elles soient quantitatives ou qualitatives sont capables d’influencer les différentes formes de plasticités comportementales et donc les grandes fonctions cérébrales et constituent ainsi un paramètre clé dans l’adaptation et la survie des individus. / In order to survive in a changing environment, individuals have to express an appropriate response. It is known that animals have the ability to adjust their behaviour to their environment. This behavioural plasticity allows a quick and adapted response to environmental variations, maximizing the individual'ssurvival and gene transmission. This plasticity relies on costly brain processes making these adaptations particularly dependent of food availability and maybe quality.This thesis project aimed at better understanding the constraints of these responses in a species under a strong selection pressure. To investigate this problematic, we studied the behavioural responses of a small Malagasy primate, the grey mouse lemur (Microcebus murinus), to both quantitative and qualitative changes in food resources. The first part of this work investigated the effect of a short-term caloric restriction without malnutrition over two studies. In the first one, we studied the effects of a 60% caloric restriction without malnutrition on innate behavioural plasticity via the study of the biological clock. The results show a decrease in the ability to resynchronize on a light/dark cycle following a time-shift. This difficulty to resynchronize was linked to body mass loss, the individuals loosing the more weight being the one unable to resynchronize after the 6-hours time shift. In the second study, we investigated the effect of a 40% caloric restriction without malnutrition on acquired behavioural plasticity. This study show a decrease in learning abilities of the restricted individuals after 19 days of dietary treatment and no influence on long term memory. This decrease in learning abilities was also linked with body mass loss, with the individuals loosing the more weight being the one with the worst success rate during this task. The second part focused on the effects of a qualitative variation in food supply via a long-term supplementation with n-3 polyunsaturated fatty acids. This part allowed us to show an increase in learning abilities associated with increased neurogenesis in three brain zones for supplemented animals after 18 month of treatment as well as a decrease of their anxiety level.This thesis work show that both quantitative and qualitative nutritional variations are able to influence different forms of behavioural plasticity and their cerebral basis and are of particular importance in the adaptation and survival of individuals.

Les rythmes biologiques aident les organismes vivants à programmer la plupart des processus comportementaux dans la fenêtre temporelle la plus appropriée. Les données de la littérature sur la rythmicité du chat domestique sont rares et conflictuelles. Pour approfondir nos connaissances sur le sujet, nous avons utilisé de récentes technologies de télémétrie pour enregistrer et caractériser les rythmes journaliers d'activité locomotrice et de prises alimentaire chez des chats en fonction des saisons et des conditions d’hébergement. Les rythmes des chats étaient modifiés par la photopériode et la présence humaine. Suivant une périodicité de 24 heures, ils ont affiché une bimodalité dans leurs rythmes quotidiens, avec des creux d'activité locomotrice et de consommation au milieu de la journée et de la nuit. Les deux périodes principales d'activité/alimentaires correspondaient à l'aube et au crépuscule à chaque saison, indépendamment de leur horaire, confirmant la nature intrinsèque crépusculaire de l'espèce. Le rythme alimentaire des chats était plus variable au cours du cycle que celui de leur activité locomotrice, rappelant ainsi le caractère opportuniste de ce prédateur. Les chats ont présenté une plasticité comportementale caractérisée par des rythmes plus faibles et un comportement d'exploration plus nocturne en milieu extérieur qu’en milieu intérieur, au sein duquel ils étaient plus enclins à la routine. Nos résultats ouvrent la voie au développement de solutions nutritionnelles et des recommandations d’hébergement adaptées aux rythmes du chat en respectant les besoins physiologiques de l’animal. / Biological rhythms are of importance for living organisms as they help to schedule most behavioural processes within the most suitable temporal window. Literature on daily rhythmicity is scarce and conflicting regarding domestic cats. To sharpen our knowledge on the subject, we used advanced telemetry technologies to record and characterise the daily rhythms of locomotor activity and feeding in cats according to the seasons and housing conditions. The cats were sensitive to photoperiod and to human presence. Along 24-hour periodicity, they displayed bimodality in their daily patterns, with mid-day and mid-night troughs of locomotor activity and food consumption. The two main activity/eating periods corresponded to dawn and dusk at each season, regardless of the twilight timings, confirming the crepuscular intrinsic nature of the species. The feeding rhythm of the cats was more variable daily than their locomotor activity one, recalling the opportunistic character of this predator. Cats displayed plasticity in their behaviour, such as weaker daily rhythms and more nocturnal exploratory behaviour outdoors, compared to indoors where they were more prone to routine. Our results open new avenues for developing nutritional and housing guidelines fitted to the rhythms of the cats according to their way of life.

In this thesis, the evolution of adaptive behaviour in artificial agents is studied. More specifically, two types of adaptive behaviours are studied: articulated and cognitive ones. Chapter 1 presents a general introduction together with a brief presentation of the research area of this thesis, its main goals and a brief overview of the experimental studies done, the results and conclusions obtained. On chapter 2, I briefly present some promising methods that automatically generate robot controllers and/or body plans and potentially could help in the development of adaptive robots. Among these methods I present in details evolutionary robotics, a method inspired on natural evolution, and the biological background regarding adaptive behaviours in biological organisms, which provided inspiration for the studies presented in this thesis. On chapter 3, I present a detailed study regarding the evolution of articulated behaviours, i.e., behaviours that are organized in functional sub-parts, and that are combined and used in a sequential and context-dependent way, regardless if there is a structural division in the robot controller or not. The experiments performed with a single goal task, a cleaning task, showed that it is possible to evolve articulated behaviours even in this condition and without structural division of the robot controller. Also the analysis of the results showed that this type of integrated modular behaviours brought performance advantages compared to structural divided controllers. Analysis of robots' behaviours helped to clarify that the evolution of this type of behaviour depended on the characteristics of the neural network controllers and the robot's sensorimotor capacities, that in turn defined the capacity of the robot to generate opportunity for actions, which in psychological literature is often called affordances. In chapter 4, a study seeking to understand the role of reactive strategies in the evolution of cognitive solutions, i.e. those capable of integrating information over time encoding it on internal states that will regulate the robot's behaviour in the future, is presented. More specifically I tried to understand whether the existence of sub-optimal reactive strategies prevent the development of cognitive solutions, or they can promote the evolution of solutions capable of combining reactive strategies and the use of internal information for solving a response delayed task, the double t-maze. The results obtained showed that reactive strategies capable of offloading cognitive work to the agent/environmental relation can promote, rather than prevent the evolution of solutions relying on internal information. The analysis of these results clarified how these two mechanisms interact producing a hybrid superior and robust solution for the delayed response task.

Thèse numérisée par la Division de la gestion de documents et des archives de l'Université de Montréal.

La plasticité comportementale et les interactions entre organismes sont connues pour avoir une influence sur l’utilisation de l’espace, notamment la sélection de l’habitat de chasse. Dans l’Atlantique Nord-Est, les phoques gris et veaux marins vivent en sympatrie. Ces deux espèces sont réparties dans différentes colonies où les interactions entre organismes (liées à la taille de la colonie et à la présence simultanée ou non des deux espèces) ainsi que la disponibilité de l’habitat (et donc des proies) varient localement. L’objectif de cette thèse était d’étudier l’utilisation spatiale et la sélection d’habitat de chasse à l’échelle locale de ces deux espèces dans des situations contrastées de dynamique de colonies. Pour cela, plusieurs individus de différentes colonies situées en Irlande, en Écosse et en France ont été équipés de balises GPS/GSM. Les données récoltées ont permis de caractériser leurs trajets en mer ainsi que d’identifier les zones de chasse permettant par la suite la sélection d’habitat. Contrairement aux veaux marins, qui ont réalisé des déplacements restreints aux alentours des colonies, la plupart des phoques gris se sont déplacés entre différentes colonies. Ainsi, l’étude de la sélection d’habitat à l’échelle individuelle pour les individus se déplaçant entre différentes colonies a mis en évidence l’influence de la plasticité comportementale et suggéré celle de la personnalité de l’animal. A l’échelle de la colonie, chez les deux espèces, les résultats ont mis en évidence l’influence de la disponibilité de l’habitat (et indirectement de la disponibilité des proies) ainsi que des interactions intra-spécifiques (liée à l’effet de densité dépendance) sur l’utilisation spatiale et la sélection de l’habitat de chasse. Cependant, la sélection de l’habitat de chasse était principalement liée à la distance au reposoir et la bathymétrie. Ces deux paramètres sont liés aux caractères de chasseur à place centrale et benthique des phoques. Cette étude a également mis en évidence, pour les sites où les deux espèces étaient présentes, une certaine ségrégation spatiale et des différences de sélection d’habitat entre les deux espèces. / The behavioural plasticity and the interactions between organisms are known to influence foraging habitat selection and spatial usage. In the Northeast Atlantic, greyand harbour seals live in sympatry. These two species are spread into different colonies where interactions between organisms (linked to the colony size et and the presence of one or both species) and habitat availability (linked to the prey distribution) vary locally. The objective of this PhD was to study the spatial usage and foraging habitat selection of these two species at the local scale, in contrasted situations of population dynamics. Several individuals were tagged with GPS/GSM tags in different colonies located in Ireland, Scotland and France. Telemetry data was used to characterize the seals’ trips at sea and to identify their foraging areas in order to model foraging habitat selection. While harbour seals only performed trips restricted around their haulout sites, grey seals moved between colonies. Studying habitat selection at the individual scale, for individuals moving between colonies, highlighted the influence of behavioural plasticity and suggested the influence of individual personality. At the colony scale, for both species, results highlighted the influence of habitat availability (indirectly linked to prey availability) and intra-specific interactions (linked to density dependence effects) on spatial usage and foraging habitat selection. However, the foraging habitat selection was mainly explained by the distance from the last haulout and the bathymetry. These two parameters are linked to the central place forager and benthic feeder characteristics of the seals. Furthermore, this study also highlighted, for study sites where both species occur, a spatial segregation and differences in foraging habitat selection between grey and harbourseals.

Thèse numérisée par la Division de la gestion de documents et des archives de l'Université de Montréal