Ce travail de thèse explore les influences maternelles non génétiques chez un oiseau nidifuge, la caille japonaise Coturnix c. japonica. Un premier axe s'intéresse à l'influence d'un facteur intrinsèque sur le comportement de la femelle pondeuse, les caractéristiques de ses œufs et le développement de ses descendants. Nos travaux montrent que les caractéristiques intrinsèques du comportement de ponte modulent l'émotivité des femelles. Les œufs pondus par des femelles présentant un profil de ponte stable (i.e. ovipositions à la même heure chaque jour) diffèrent des œufs pondus par des femelles présentant un profil de ponte décalé (i.e. ovipositions un peu plus tard chaque jour). Les descendants de ces femelles montrent une plus grande émotivité face à la nouveauté et à la séparation sociale. De plus, il existe des variations des caractéristiques des œufs spécifiques à chaque profil de ponte. Le second axe s'intéresse à une influence environnementale. Au sein de l'environnement biotique, le partenaire sexuel est un congénère particulier pour la femelle. Lorsque les deux partenaires ont la possibilité de développer un lien (par un appariement permanent), leurs descendants sont moins émotifs et plus sociaux comparés à des jeunes dont les parents ont été appariés de façon ponctuelle et n'ont pas développé de lien. Enfin, le dernier axe explore pour la première fois chez l'oiseau nidifuge l'interaction entre des influences maternelles prénatales et postnatales. Ainsi, des jeunes stressés prénatalement ont une émotivité moindre face à la nouveauté et à la séparation sociale si ils sont maternés après l'éclosion, comparés à des jeunes non maternés. L'ensemble de ce travail améliore nos connaissances des facteurs de variations des influences maternelles, leurs mécanismes et leurs conséquences, permettant de mieux comprendre la variabilité phénotypique des individus et l'évolution des populations. / This thesis explored non-genetic maternal influences in a precocial bird, the Japanese quail Coturnix c. japonica. A first approach investigated the influence of an intrinsic factor on the behaviour of a laying female, its eggs' characteristics and its offspring's development. Our results demonstrate that intrinsic characteristics of egg laying behaviour influence females' emotivity. Eggs laid by females that present a stable laying profile (i.e. ovoposition at the same time each day) differed from eggs laid by females that present a delayed laying profile (i.e. oviposition later each day). Offspring of females delayed laying profile showed higher emotivity in novel situations and social isolation. Moreover, eggs presented specific characteristics within each of both egg laying profiles. A second approach focused on the biotic environment. For a female, the mating partner is a particular congener. When mates could develop a pair bond (by continuous pairing), their offspring were more emotive and less social compared to chicks whose parents were not continuously paired and thus did not develop a pair bond. In a final approach and for the first time in a precocial bird, interactions between prenatal and postnatal maternal influences were explored. Chicks that were prenatally stressed showed lower emotivity in novel situations and social isolation when they are mothered after hatching compared to non-mothered, prenatally stressed chicks. Overall, our work improves the knowledge about maternal influence factors of variation, their mechanisms and consequences, allowing a better understanding of individuals' phenotypic variability and populations' evolution.

Knowledge of offspring production (recruitment) is fundamental to understanding and forecasting the dynamics of a population. In this thesis, I focus on two demographic characteristics of fish stocks that are important to recruitment: population density and age structure. First, populations produce more recruits at low density, but quantifying this response has proven difficult. Using data from hundreds of populations of walleye (Sander vitreus), an economically important freshwater fish, I demonstrate that the growing-degree-day metric (a temperature index) is better than age at explaining variation in density-dependent growth and maturity both within and among populations. I then incorporate multi-lake measures of density-dependent life history change into a temperature-based biphasic model of growth and reproduction to predict sustainable rates of mortality for walleye throughout most of their range. Second, the age (or size) structure of a population may also affect recruitment because of positive effects of maternal age on offspring production and survival; however, evidence for these ‘maternal influences’ on recruitment is limited. Using both an analytical model and a meta-analysis of stock-recruitment data from 25 species of exploited marine fish, I show that (i) maximum reproductive rate increased with the mean age of adults in a population, and (ii) the importance of age structure increased with a species’ longevity. I then demonstrate a similar effect of maternal influences on reproductive rate in a detailed study of Lake Erie walleye. By highlighting the importance of fisheries-induced demographic change to recruitment, this thesis provides insight into past and present failures. However, it also demonstrates clearly the benefits of proactive management strategies that (i) identify and respect the limits of exploitation, (ii) protect from exploitation reproductively valuable individuals—principles that apply generally to any freshwater, marine, or terrestrial species that is of recreational, commercial, or conservation value.

Knowledge of offspring production (recruitment) is fundamental to understanding and forecasting the dynamics of a population. In this thesis, I focus on two demographic characteristics of fish stocks that are important to recruitment: population density and age structure. First, populations produce more recruits at low density, but quantifying this response has proven difficult. Using data from hundreds of populations of walleye (Sander vitreus), an economically important freshwater fish, I demonstrate that the growing-degree-day metric (a temperature index) is better than age at explaining variation in density-dependent growth and maturity both within and among populations. I then incorporate multi-lake measures of density-dependent life history change into a temperature-based biphasic model of growth and reproduction to predict sustainable rates of mortality for walleye throughout most of their range. Second, the age (or size) structure of a population may also affect recruitment because of positive effects of maternal age on offspring production and survival; however, evidence for these ‘maternal influences’ on recruitment is limited. Using both an analytical model and a meta-analysis of stock-recruitment data from 25 species of exploited marine fish, I show that (i) maximum reproductive rate increased with the mean age of adults in a population, and (ii) the importance of age structure increased with a species’ longevity. I then demonstrate a similar effect of maternal influences on reproductive rate in a detailed study of Lake Erie walleye. By highlighting the importance of fisheries-induced demographic change to recruitment, this thesis provides insight into past and present failures. However, it also demonstrates clearly the benefits of proactive management strategies that (i) identify and respect the limits of exploitation, (ii) protect from exploitation reproductively valuable individuals—principles that apply generally to any freshwater, marine, or terrestrial species that is of recreational, commercial, or conservation value.