The northern Norwegian killer whale (Orcinus orca) is an important predator but little is known about its population dynamics, particular in response to changes in its main prey, the highly dynamic Norwegian spring spawning (NSS) herring (Clupea harengus). The main aims of this thesis were to estimate killer whale population parameters, to explore the future viability of the population, and to explore the response of this predator to changes in distribution and abundance of its main prey over the last 25 years. Population size was estimated as ~ 700 individuals, taking heterogeneity of capture probabilities into account and correcting for unmarked animals. Apparent survival rates of 0.974 (SE = 0.006) for adult males and 0.984 (SE = 0.006) for adult females were estimated accounting for temporary emigration, transience and trap-dependency. Temporary emigration was greater for males than females. Calving intervals ranged from 3 to 14 years (mean = 5.06); equivalent to 0.197 calves per mature female per year. Future viability of the killer whale population was evaluated under various plausible scenarios. The baseline scenario using the best available information predicted a viable population and indicated that the population may be increasing size. Analysis of data on naval sonar activity, killer whale sightings and herring abundance showed that naval sonar activity appeared to have a negative effect on killer whale presence during a period of low prey availability. A time lag of four years was found between the first sign of NSS herring changing its distribution and reduced killer whale presence inside the fjord system. Analysis of energy budgets showed that killer whales spent more time travelling/foraging in 2005/06 than the 1990s. The fjord system was inferred to be a preferred habitat for killer whales when there was a higher density of NSS herring in this area compared to offshore area.

In killer whales, fish- versus mammal-eating ecological differences are regarded as key ecological drivers of sociality, but the potential influence of specific target prey characteristics remains unclear. This thesis aimed to study the social patterns and dynamics of Icelandic killer whales feeding upon herring, a schooling prey that undergoes frequent changes in distribution and school size. I used a multi-disciplinary approach combining photo-identification and genetic data to understand the sociality, role of kinship and genetic differentiation within the population. Individuals sighted in summer-spawning and overwintering herring grounds during at least five separate days (N = 198) were considered associated if photographed within 20 seconds of each other. Photo-identified individuals were genotyped (N = 61) for 22 microsatellites and mitochondrial DNA control region (611 bp). The population had weak but non-random associations, fission-fusion dynamics at the individual level and seasonal patterns of preferred associations. The society was significantly structured but not hierarchically. Social clusters were highly diverse and, whilst kinship was correlated with association, it was not a prerequisite for social membership. Indeed, some cluster members had different mitochondrial haplotypes, representing separate maternal lineages. Individuals with different observed movement patterns were genetically distinct, but associated with each other. No sex-biased dispersal or inbreeding was detected. This study revealed that the Icelandic population has a multilevel society without clear hierarchical tiers or nested coherent social units, different from the well-studied salmon- (‘residents') and seal-eating populations in the Northeast Pacific. In the Icelandic population kinship drives social structure less strongly than in residents. These findings suggest effective foraging on schooling herring in seasonal grounds promotes the formation of flexible social groupings which can include non-kin. Killer whale sociality may be strongly influenced by local ecological context, such as the characteristics of the specific target prey (e.g., predictability, biomass, and density) and subsequent foraging strategies of the population.

Conservation is the number one goal of modern zoos and aquaria. Public education is the primary means through which zoos and aquaria attempt to fulfill their conservation goal. Yet, nearly two decades after its initial adoption, conservation education fails to be effectively translated into practice. This thesis argues that the entertainment paradigm in which zoos and aquaria have traditionally operated is at odds with their contemporary goal of conservation education, thus continued adherence to this entertainment paradigm prevents zoos and aquaria from effectively implementing conservation education. The thesis proposes an alternative paradigm in which conservation education may be successfully achieved. Killer whales present an ideal case example through which to explore the impact of the entertainment paradigm on conservation education. Since they were first displayed in 1964, these animals have been consistently presented in a show format. Today, the Vancouver Aquarium is the only institution in the world to present killer whales outside the context of a show. This thesis uses examples from the Vancouver Aquarium to describe how innovations within an alternative paradigm resulted in the Aquarium's unique approach to killer whale interpretation and animal care, and how these innovations have been successfully implemented into the practice of conservation education in the Vancouver Aquarium's public galleries.

C'est dans le contexte délicat du milieu marin, marqué par l'écroulement des stocks halieutiques et la conservation urgente des espèces de prédateurs marins, que s'inscrit cette étude sur la déprédation (i.e. prélèvement des poissons capturés) par les orques et les cachalots sur la pêche à la palangre dans la ZEE de l'Archipel de Crozet. Le premier objectif a été d'évaluer les conséquences socio-économiques du phénomène. Entre 2003 et 2010 les orques ont interagi avec un total de 43,3% des palangres relevées et les cachalots avec 57,5%, les deux espèces étant présentes simultanément sur 27.8% des palangres (n =5 438). Les orques, seules ou associées aux cachalots ont été estimées prélever 926 ± 76 tonnes de légines sur l'ensemble de la période, représentant un taux de déprédation de 17,7%. Trois facteurs opérationnels ont été identifiés comme faisant varier la déprédation par les orques : i) utilisation de palangres courtes (<5 000 m) en absence d'orques, ii) déplacement du navire sur des distances supérieures à 75 km pour quitter une zone confrontée à la déprédation et changer de zone, iii) utilisation de vitesse de remontée des hameçons à bord supérieures à 50 ham.min-1. Le deuxième objectif de cette étude a été d'évaluer les conséquences démographiques de la déprédation sur la population d'orques de Crozet. Le suivi à long terme des individus a permis de mettre en évidence des réponses différentielles des unités sociales en fonction de leur degré d'interaction avec les pêcheries. En effet, les années 1990 sont d'abord marquées par une sur-mortalité des orques interagissant à des hauts niveaux avec les pêcheries, confirmant l'effet de réponses de type létales de la part des navires braconniers sur les individus. Cette tendance s'inverse à partir de 2003 avec une survie et une reproduction supérieure dans les unités à fort taux d'interaction, suggérant un effet bénéfique de la déprédation. Avec l'augmentation des cas de déprédation dans le monde, la portée de cette étude est globale, d'une part par ses résultats positifs issus d'une collaboration entre pêcheurs, gestionnaires et scientifiques, et d'autre part par la précision des priorités de conservation impliquées.

Conservation is the number one goal of modern zoos and aquaria. Public education is the primary means through which zoos and aquaria attempt to fulfill their conservation goal. Yet, nearly two decades after its initial adoption, conservation education fails to be effectively translated into practice. This thesis argues that the entertainment paradigm in which zoos and aquaria have traditionally operated is at odds with their contemporary goal of conservation education, thus continued adherence to this entertainment paradigm prevents zoos and aquaria from effectively implementing conservation education. The thesis proposes an alternative paradigm in which conservation education may be successfully achieved. Killer whales present an ideal case example through which to explore the impact of the entertainment paradigm on conservation education. Since they were first displayed in 1964, these animals have been consistently presented in a show format. Today, the Vancouver Aquarium is the only institution in the world to present killer whales outside the context of a show. This thesis uses examples from the Vancouver Aquarium to describe how innovations within an alternative paradigm resulted in the Aquarium's unique approach to killer whale interpretation and animal care, and how these innovations have been successfully implemented into the practice of conservation education in the Vancouver Aquarium's public galleries. / Education, Faculty of / Graduate

Group living is a social strategy adopted by many species, where individuals can exhibit long-term social affiliation with others, strengthened through cooperative behaviour and often kinship. For highly social mammals, changes in group membership may have significant consequences for the long-term viability and functioning of a population. Detecting significant social events is essential for monitoring the social dynamics of such populations and is crucial to determining the factors underlying these events. Detecting when changes in social organization occur, especially with incomplete data, poses significant analytical challenges. To resolve this issue, I developed and assessed a straightforward, multi-stage and generalizable method with broad utility for ecologists interested in detecting and subsequently investigating causes of changes in social organization. My approach illustrates the frequency and ecological relevance of group fission and fusion events in a population of fish-eating ‘Resident’ killer whales (Orcinus orca). Group fission is a process commonly found in social mammals, yet is poorly described in many taxa, and has never been formally described in killer whales. To address this gap, I provided the first description of matrilineal fission in killer whales, from a threatened but growing Northern Resident killer whale population in which matrilineal fission has been observed for the past three decades. I also undertook the first comprehensive assessment of how killer whale intragroup cohesion is influenced by group structure, demography and resource abundance. Fission in Northern Resident killer whales occurred both along and across maternal lines, where animals dispersed in parallel with their closest maternal kin. I show that fission in this population is driven primarily by population growth and the demographic conditions of groups, particularly those dictating the nutritional requirements of the group. I posit that intragroup food competition is the most likely explanation for group fission in this population, where prey abundance also has ancillary effects. As group fission can have a direct impact on the fitness of group members and the long-term viability of a population, my findings underscore the importance of incorporating studies of sociality into the management of threatened populations of social mammals. / Graduate / 0329 / 0472

The mitochondrial DNA restriction fragment patterns of killer whales (Orcinus orca) were investigated in order to determine the level of genetic differentiation that exists between killer whales from various geographic locations. Twenty one killer whales were examined, seventeen of which were captive killer whales that originated from the North Atlantic and Northeast Pacific Oceans. Two were captive-born animals and two were killer whales that stranded along the Northeast Pacific coast. DNA was extracted from blood and/or tissue samples, cleaved with a variety of restriction endonucleases and the DNA fragments were separated by horizontal agarose gel electrophoresis. The DNA was then transferred to nylon membranes and the killer whale mitochondrial DNA was visualized by hybridization to the complete mitochondrial DNA genome of Commerson's dolphin (Cephalorhynchus commersonii). The resultant restriction fragment patterns were analyzed to determine whether mitochondrial DNA variation was present between killer whales from different geographic regions or between communities and pods of killer whales from the same geographic location.

C'est dans le contexte délicat du milieu marin, marqué par l'écroulement des stockshalieutiques et la conservation urgente des espèces de prédateurs marins, que s'inscrit cette étude sur la déprédation (i.e. prélèvement des poissons capturés) par les orques et les cachalots sur la pêche à lapalangre dans la ZEE de l'Archipel de Crozet.Le premier objectif a été d'évaluer les conséquences socio-économiques du phénomène. Entre 2003 et2010 les orques ont interagi avec un total de 43,3% des palangres relevées et les cachalots avec 57,5%,les deux espèces étant présentes simultanément sur 27.8% des palangres (n=5438). Les orques, seulesou associées aux cachalots ont été estimées prélever 926 ± 76 tonnes de légines sur l'ensemble de lapériode, représentant un taux de déprédation de 17,7%.Trois facteurs opérationnels ont été identifiés comme faisant varier la déprédation par les orques : i)utilisation de palangres courtes (<5000m) en absence d'orques, ii) déplacement du navire sur desdistances supérieures à 40nq pour quitter une zone confrontée à la déprédation et changer de zone, iii)utilisation de vitesse de remontée des hameçons à bord supérieures à 50 H.min-1.Le deuxième objectif de cette étude a été d'évaluer les conséquences démographiques de ladéprédation sur la population d'orques de Crozet. Le suivi à long terme des individus a permis demettre en évidence des réponses différentielles des unités sociales en fonction de leur degréd'interaction avec les pêcheries. / Over the last 50 years, fisheries have undergone a major decline worldwide. With an increasedcompetition for resource, depredation (i.e. removal of catches on fishing gear) has recently become amajor case of conflict between humans and marine predators. In this study I focused on thedepredation on Patagonian toothfish fisheries by killer and sperm whales in the Crozet EEZ. The firstpart of the study aimed at assessing the socio-economic consequences of this issue. Killer and spermwhales have interacted with 43.3% and 57.5% of longlines (n=6751) respectively from 2003 to 2010.Killer whales, alone or co-occurring with sperm whales were responsible for an estimated loss of 926± 76 tons of toothfish over that period, which represents 17.7% of the total catch.Three operational factors were identified as influencing significantly depredation levels: i) the use ofshort longlines (<5000m) in absence of killer whales, ii) the displacement of vessels on distances>40nq to leave the whales behind and iii) the use of longline hauling speed > 50 H.min-1.The second aim of the study was to investigate the consequences of depredation on the Crozet killerwhale population. The long term monitoring of individuals showed divergent demographic trajectoriesrelated to the depredation level of matrilines. During the 1990s, matrilines interacting with fisherieshave undergone a high mortality due to lethal interactions with illegal fishing vessels using explosivesto repel the whales.

Species are vital entities in biology. Species are generally considered to be discrete entities, consisting of a group of (usually interbreeding) individuals that are similar in phenotype and genetic composition, yet differ in significant ways from other species. The study of speciation has focussed on understanding general evolutionary mechanisms involved in the accumulation of differences both at the genetic and phenotypic level. In this thesis, I investigate incipient speciation, an early stage of divergence towards evolutionary independence in closely related natural populations. I make ample use of recent advances in sequencing technology that allow 1) characterizing phenotypic divergence at the level of the transcriptome and 2) delineate patterns of genetic variation at genome-scale from which processes are inferred by using principles of population genetic theory. In the first paper, we assembled a draft genome of the hooded crow and investigated population differentiation across a famous European hybrid zone. Comparing sequence differentiation peaks between and within the colour morphs, we could identify regions of the genome that show differentiation only between colour morphs and that could be related to gene expression profiles of the melanogenesis pathway coding for colour differences. The second paper expands on the first paper in that it includes crow population samples from across the entire Palaearctic distribution spanning two additional zones of contact between colour morphs. The results suggest that regions associated with selection against gene flow between colour morphs were largely idiosyncratic to each contact zone and emerged against a background of conserved 'islands of differentiation' due to shared linked selection. The third paper focusses on five killer whale ecotypes with distinct feeding and habitat specific adaptations. Differing levels of sequence differentiation between these ecotypes places them along a speciation continuum and provides a unique temporal cross-section of the speciation process. Using genome scans we identified regions of the genome that show ecotype specific differentiation patterns which might contain candidate genes involved in adaptation. In the fourth and final paper, I assumed a comparative genomic perspective to the problem of heterogeneous genomic differentiation during population divergence. The relatively high correlations in the diversity landscapes as well as differentiation patterns between crow, flycatcher and Darwin's Finch populations is best explained by conservation in broad-scale recombination rate and/or  association with telomeres and centromeres conducive to shared, linked selection.

De nombreux prédateurs marins se nourrissent directement des prises des pêcheurs. Ces interactions, définies comme de la déprédation, engendrent des conséquences socio-économiques considérables pour les pêcheurs ainsi que des implications de conservation pour la faune sauvage. D’un côté, la déprédation endommage le matériel et augmente l’effort de pêche pour atteindre les quotas. D’un autre côté, la déprédation augmente le risque de mortalité des prédateurs marins (prise accidentelle ou rétorsion létale par les pécheurs). La pêcherie à la palangre est la plus impactée par la déprédation, principalement par les odontocètes, ce qui incite à trouver des solutions. La majorité des études se concentrant sur la déprédation s’est principalement basée sur des observations en surface, de ce fait la manière dont les prédateurs retirent les poissons sur les lignes reste confuse. Par ailleurs, l’impact de la déprédation sur le comportement des pêcheurs ainsi que les facteurs expliquant leur détectabilité n’ont reçu que peu d’intérêt. L’objectif de cette thèse est donc d’étudier ces problématiques par un suivi acoustique, une utilisation de balises et une approche en écologie comportementale humaine, en se concentrant sur la pêcherie palangrière française ciblant la légine australe (Dissostichus eleginoides) impactée par la déprédation des orques (Orcinus orca) et des cachalots (Physeter macrocephalus). Les capitaines ont été décrits comme recherchant leur ressource selon la théorie de « l’optimal foraging », mais avec des perceptions de la compétition et du succès de pêche qui divergent. Certains capitaines seraient ainsi plus enclins à remonter les palangres au plus proche et à rester sur une zone, même en présence de compétition, augmentant alors le risque d’interaction. L’acoustique des navires a révélé que certaines manoeuvres (marche arrière par exemple) propagent différemment sous l’eau. La manière dont les capitaines manoeuvrent leur palangrier influencerait ainsi leur détectabilité et donc leur risque d’interaction avec les prédateurs. D’autre part, l’utilisation de capteurs sur les palangres et les animaux a révélé que les orques et les cachalots sont capables de déprédater sur les palangres posées sur le fond marin. Ces observations laissent à penser que les odontocètes sont en mesure de localiser l’activité de pêche bien avant la remontée de la ligne, ce qui pourrait être expliqué par une signature acoustique spécifique du déploiement de la ligne. L’ensemble des résultats de cette thèse suggère que la déprédation sur les palangres démersales est très probablement sous-estimée. Cette thèse apporte également des éléments importants pour la lutte contre la déprédation, en montrant la nécessité de protéger les palangres dans l’intégralité du processus de pêche. / Many marine predator species feed on fish caught by fishers directly from the fishing gear. Known as depredation this interaction issue has substantial socio-economic consequences for fishermen and conservation implications for the wildlife. Costs for fishers include damages to the fishing gear and increased fishing effort to complete quotas. For marine predators, depredation increases risks of mortality (lethal retaliation from fishers or bycatch on the gear). Longline fisheries are the most impacted worldwide, primarily by odontocetes (toothed whales) depredation, urging the need for mitigation solutions to be developed. Most of studies assessing depredation have primarily relied on surface observation data, thus the way odontocetes interact with longlines underwater remains unclear. Besides, the way fishermen respond to depredation during fishing operations, or can influence their detectability to odontocetes, have been poorly investigated. This thesis therefore aimed at investigating these aspects through a passive acoustic monitoring, bio-logging and human ecology approaches, focusing on the French Patagonian toothfish (Dissostichus eleginoides) longline fisheries impacted by killer whales (Orcinus orca) and sperm whales (Physeter macrocephalus). Firstly, this thesis reveals that captains behave as optimal foragers but with different personal perception of competition and fishing fulfilment. Some captains would thus be more likely to stay within a patch or to haul closest longline even in presence of competition, suggesting these captains would show higher interaction rates. Additionally, the propagation of vessels’ acoustics varied depending on the type of manoeuvre (e.g. going backward vs. forward). The way captains use their vessels to navigate may therefore influence their detectability and so their depredation level. Secondly, loggers deployed on both the longlines (accelerometers) and odontocetes (GPS-TDR) revealed that killer whales and sperm whales are able to depredate on longlines while soaking on the seafloor. These observations suggest, therefore, that odontocetes can localise fishing activity before the hauling, which could be partially explained by specific acoustic signatures recorded during the setting process. Altogether, the results of the thesis suggest that depredation rates on demersal longlines are most likely underestimated. The thesis also brings some important insights for mitigation measures, suggesting that countermeasures should start from setting to hauling.