Thesis (M.S.)--University of Nevada, Reno, 2007. / "December, 2007." Includes bibliographical references. Online version available on the World Wide Web.

Scientific knowledge on a population's religious composition is essential to understand the challenges faced by societies today. It arises in opposition to speculations about the actual size of religious groups that have been increasingly present in the public discourse in Europe for many years. This is particularly the case in Austria where the flows of refugees and migrants coming from the Middle East and Afghanistan have intensified since 2011 and culminated in 2015. These sparked a debate on the actual size of the Muslim population in Austria. This study fills the gap by presenting estimates of the religious composition for 2016 and projections until 2046 based on several scenarios related to the three major forces affecting the religious composition: migration (including asylum seekers), differential fertility and secularisation. The projections demonstrate that religious diversity is bound to increase, mostly through immigration and fertility. We further focus on the role and implications of international migration on the age and sex composition within the six religious groups: Roman Catholics, Protestants, Orthodox, Muslims, other religions and unaffiliated. We find that the volume and composition of international migrants can maintain youthful age compositions in minority religions - Muslims and Orthodox. Sustained immigration leads to slower ageing but does not stop or reverse the process. The disparity between older majority and younger minority religious groups will further increase the cultural generation gap.

Thesis advisor: Arthur Lewbel / This dissertation consists of two independent studies that seek to improve public policies in developing country context. I first study how anti-poverty programs in developing countries can improve their screening procedure so that they can better direct resources to the poor over time. Then, I investigate the impacts of trade openness on fertility decisions in countries known for son preference, thereby informing governments in those countries of the unintended consequences of such growth-focused trade policies. In the first chapter, “Bunching and Learning in Targeting Poverty: Evidence from Vietnam,” I examine how households manipulate eligibility criteria in order to appear eligible for an anti-poverty program. Despite ample evidence that households manipulate these criteria, little is known about how such behaviors evolve over time in a long-term program. Using data from Vietnam, I find that, early on in each phase of its National Anti-Poverty Program, about 1-2% of the population (or 8-18% relative to the program size) bunch at the official income cutoff in order to appear eligible. However, this fraction falls by 60-100% towards the end of the phase, only to increase yet again when a new phase starts with a new income cutoff. To explain this temporal pattern of bunching, I develop a model in which over time the program staff learn to rely on housing conditions, a less-manipulable criteria, to select households. This refined information, in turns, discourages households from manipulating their income. I find that an increase of 0.5 standard deviation in the housing quality index further reduces the chance of being accepted to the program by 25.11% after two years. Meanwhile, other criteria, including reported income and asset holdings, do not contribute any additional predictive power to the program status over the same period. Without this learning process, the program would have misallocated about 1.7%, or equivalently 32.3-36.4 million USD (PPP), of its budget to non-poor households during the first phase of the program. In the second chapter, “Why does the sex ratio at birth rise? Evidence from Vietnam,” joint with Nghiem Huynh, we investigate the causal link between a major trade agreement between the US and Vietnam and the rise in sex ratio at birth in Vietnam. We test three theories of the rise in sex ratio at birth and find evidence that the fertility mechanism explains the recent increase in Vietnam. Using the 2001 US-Vietnam Bilateral Trade Agreement as an exogenous shock, we show that mothers exposed to larger tariff cuts are more likely to have boys, work more hours and less likely to give birth. These results hold up when we account for other competing mechanisms, including changes in fathers' exposure to the policy and daughters’ economic returns in repeated cross-sectional and panel data. This chapter highlights the trade-off between work and children for mothers, and the potential role of trade policy in heightening this trade-off, leading to lower fertility and higher sex selection. Although both studies are situated in Vietnam, their results and implications are relevant to policy discussions in many developing countries. / Thesis (PhD) — Boston College, 2023. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Economics.

Depuis les années 2000, le secteur de la santé de la reproduction, longtemps délaissé par le gouvernement indien, semble constituer un sujet d’inquiétude, notamment dans le nord du pays. Les taux de mortalité encore élevés discréditent l’image de superpuissance que l’État indien aime afficher, le déséquilibre du sex-ratio continue de se creuser en dépit des mesures législatives en vigueur et, malgré une importante baisse du taux de fécondité, le pays doit faire face à une population de plus d’un milliard deux cent millions d’habitants. À partir d’un terrain ethnographique d’un an et demi dans un hôpital public et dans des bidonvilles de Jaipur où une ONG œuvrait pour l’institutionnalisation de la santé maternelle, cette étude analyse les réactions des femmes et de leur famille face aux techniques persuasives et au pouvoir discrétionnaire que le personnel hospitalier et les membres de l’ONG utilisent à leur égard. Elle montre également en quoi les programmes de santé, censés garantir l’accès aux soins, tendent paradoxalement à rendre les bénéficiaires les plus vulnérables davantage conscients des inégalités socio-économiques dans leur vie quotidienne et renforcent les stéréotypes existants. À travers l’expérience des femmes, la santé de la reproduction apparaît comme un domaine sensible où des tensions sociales (castes, classes) et religieuses s’expriment et se cristallisent. La prise en charge de la santé de la reproduction ne se réduit pas à la santé materno-infantile mais englobe les questions de discrimination à l’égard des petites filles, du faible pouvoir décisionnel des femmes et du recours limité à la contraception, enjeux cruciaux qui attisent les différences au sein de la société indienne, sous couvert de progrès et au nom de l’intérêt de la nation. / Since the 2000s, the Indian government’s long-neglected reproductive health sector has been a subject of growing concern, especially in the northern part of the country. Mortality rates remain high, calling India’s superpower image into question; the sex ratio imbalance keeps growing despite legislative measures to correct it; and, despite a significant dip in the fertility rate, the country now has a population of over one-billion-two-hundred-million inhabitants. Drawing on one-and-a-half years of ethnographic fieldwork in a public hospital and several slums in Jaipur, this study analyses the reactions of women and their families to the techniques of persuasion and decision-making power used by hospital staff and NGO workers who institutionalise maternal health. The study also shows how health programmes meant to secure universal access to care paradoxically reinforce existing stereotypes and tend to make vulnerable patients even more aware of socioeconomic inequalities in their daily lives. Through the lens of women’s experiences, reproductive health appears to be a sensitive node where religious and social tensions of caste and class get expressed and crystallised. Thus, reproductive health is not confined to maternal and child healthcare; it includes core issues of discrimination toward young girls, the limited decision-making power of women, and ambivalence about contraception among women. While often presented in the guise of progress and the national interest, the institutionalisation of reproductive health actually maintains social disparities within Indian society

Le bar (Dicentrarchus labrax) est une espèce majeure de l'aquaculture méditerranéenne, dont la production est passée de presque rien en 1985 à plus de 100 000 tonnes annuelles aujourd'hui. Dans un grand nombre de cas, des géniteurs sauvages sont encore utilisés pour produire des juvéniles chez cette espèce, et l'on constate une forte prédominance des mâles, aux performances zootechniques inférieures, dans les populations d'élevage. Le but du présent travail de recherche était tout d'abord de quantifier les variations génétiques de la croissance et du sex ratio entre familles de bar produites par fécondation artificielle et élevées en commun, en utilisant le génotypage de locus microsatellites pour reconstruire les pedigrees des animaux mesurés. Dans un second temps, nous avons également étudié la réponse en termes de croissance et de sex ratio à une sélection expérimentale sur la croissance en longueur. Nous avons tout d'abord pu montrer que la technique expérimentale choisie (fécondation artificielle, élevage en commun et reconstruction des pedigrees par génotypage) était efficace et susceptible d'être appliquée non seulement en expérimentation, mais aussi pour la mise en place de programmes de sélection chez le bar. La croissance chez le bar montre une héritabilité élevée pour le poids à taille commerciale de 400g environ (h²=0.38-0.44), mais plus modeste pour le taux de croissance de 35 à 400g (0.16-0.34), montrant l'importance de la croissance précoce, très héritable (h²=0.61) dans la construction de la performance à taille commerciale. Par ailleurs, la croissance du bar n'est pas significativement influencée par des effets maternels non génétiques ou de dominance. Nous avons estimé les interactions génotype-milieu pour la croissance entre des sites de grossissement très différents, et si ces interactions se sont révélées modestes pour le poids à taille commerciale (rA=0.70-0.99 entre sites), elles étaient beaucoup plus fortes pour le taux de croissance (rA=0.21-0.61 entre sites). Bien que nous ayons à dessein choisi des environnements très différents pour ce test, ceci souligne l'importance de conduire les programmes de sélection dans un environnement proche de l'environnement d'élevage. Nous avons montré que le sex-ratio des populations naturelles de bar ne différait pas de 50-50 en moyenne, mais que certaines classes d'âge pouvaient avoir un sex-ratio biaisé, vraisemblablement du fait d'effets environnementaux. En élevage, les sex-ratios sont variables entre familles et influencés à la fois par le père et par la mère. Aucun modèle purement génétique ne permet d'expliquer les distributions observées, qui peuvent être décrites soit par un modèle ayant au moins deux loci bialléliques et une variance micro-environnementale, soit par un modèle polygénique à seuil (h²=0.62 pour la tendance sexuelle sur l'échelle sous-jacente). Avec ce dernier modèle, on note une corrélation génétique positive (rA=0.50) entre tendance sexuelle et croissance. Ceci permet de prédire que la domestication devrait permettre un rééquilibrage du sex-ratio vers 50-50, la sélection croissance biaisant le sex-ratio vers plus de femelles. C'est ce que nous observons ensuite dans notre expérience de réponse à la sélection pour la croissance. Cette même expérience nous permet de confirmer le potentiel de l'espèce pour une amélioration génétique de la croissance, avec un gain de 23% en première génération. Le modèle polygénique (ou à tout le moins polyfactoriel) de déterminisme du sexe est a priori rare chez les Vertébrés. Après avoir développé son utilisation possible pour obtenir à terme des populations de bars d'élevage monosexes femelles, le modèle polygénique est replacé dans la théorie du déterminisme du sexe chez les Vertébrés ectothermes, où il semble pouvoir être considéré comme beaucoup plus répandu qu'on ne le considère classiquement. [...] Suite et fin du résumé dans la thèse. / The European sea bass (Dicentrarchus labrax) is a major species of Mediterranean aquaculture, the production of which rose from almost nothing in 1985 to more than 100.000 tonnes annually at present. In many cases, wild-caught broodstock is still used to produce juveniles for aquaculture, and farmed population are predominantly male – which unfortunately perform less than females. The aim of the present research was first to quantify the genetic variation of growth and sex ratio between families of sea bass produced by artificial fertilization and reared in a “common garden” approach, using the genotyping of microsatellite markers to reconstruct the pedigrees. In a second phase, we also studied the response in terms of growth and sex ratio to an experimental selection applied on body length.We first could show that the experimental technique chosen (artificial fertilization, common garden rearing and pedigree reconstruction by genotyping) was efficient and could be applicable not only to conduct experiments but also to set up breeding programmes in sea bass.Growth is a heritable trait in sea bass, with a high heritability for body weight at commercial size (h²=0.38-0.44 around 400 g mean weight), but a lower value for growth rate from 35 to 400g (0.16-0.34), showing the importance of the highly heritable (h²=0.61) early growth in the building of the performance at commercial size. Additionally, we showed that sea bass growth was not significantly impacted by dominance or non genetic maternal effects. We estimated genotype by environment interactions for growth between highly divergent ongrowing sites, showing that although interactions were moderate for body weight at commercial size (rA= 0.70-0.99 between sites), they were much higher for growth rate (rA=0.21-0.61 between sites). Although we purposely chose very divergent ongrowing environments, this highlights the importance of conducting breeding programs in environments resembling the production environment.We showed that the sex ratio of natural populations in the wild did not differ from 50-50 on average, although some age classes could have a biased sex ratio, probably due to environmental effects. In a farmed population, sex ratios were shown to differ between families and to be equally influenced by the sire and the dam. No purely genetic model could account for the distributions observed, which could fit either to a model with a minimum of two bi-allelic loci plus micro-environmental variance, or to a polygenic threshold model with h²=0.62 for sex tendency on the underlying scale. This last model also revealed a positive genetic correlation (rA=0.50) between sex tendency and growth. This allowed us to predict that domestication should tend towards a balancing of the sex ratio at 50-50, while selection for faster growth should bias population sex ratios towards females. This is precisely what we observed later on in our selection response experiment, which also confirmed the potential of the species to be selected for faster growth, with a 23% gain in body weight in the first generation.The polygenic (or at least polyfactorial) model of sex determination is considered rare in Vertebrates. After developing its possible use to tend towards monosex female farmed populations of sea bass, we assessed its position in the theory of sex determination in ectotherm Vertebrates, where it seems that it could well be more frequent as initially thought. Polygenic sex determination could be a means for species and populations to move along the ESD-GSD continuum (Environmental or Genetic Sex Determination).

Zhang, Jiayu. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (p. 136-147). / Abstract also in Chinese. / Abstract --- p.iiii / Table of Contents --- p.viii / List of Abbreviations --- p.ix / List of Figures --- p.x / List of Tables --- p.x / Chapter Chapter I: --- Introduction --- p.1 / Chapter 1. 1 --- What happened to China´ةs SRB? --- p.1 / Chapter 1. 2 --- Women´ةs Human Rights as important Human Rights --- p.3 / Chapter 1. 3 --- SRB and Women´ةs Rights --- p.6 / Chapter 1. 4 --- Research Purpose and Methods --- p.7 / Chapter 1. 5 --- Research Outline --- p.17 / Chapter Chapter II. --- The Particular Features in China´ةs SRB --- p.20 / Chapter 2. 1 --- The Regional Features in SRB --- p.20 / Chapter 2. 2 --- The Ethnic Features in SRB --- p.23 / Chapter 2. 3 --- The Features by Birth Order --- p.24 / Chapter Chapter III. --- The Causes of Imbalanced SRB --- p.26 / Chapter 3. 1 --- The Proximal Causes --- p.26 / Chapter 3. 2 --- The Fundamental Cause --- p.31 / What Encourage son preference in China? --- p.32 / Chapter 3.2.1 --- Cultural and Historical Factors --- p.33 / Chapter 3.2.2 --- Economic Factors --- p.38 / Chapter 3.2.3 --- Law and policy as a Structural Factor --- p.40 / Political Silence --- p.42 / Economic Subordination --- p.43 / Sexual Subordination --- p.48 / Birth Control --- p.50 / Chapter Chapter IV. --- The Consequences of Imbalanced SRB from a Human Rights Perspective --- p.58 / Human Rights Violation against Women in the SRB Issues --- p.59 / Chapter 4.1 --- Rights Violations Which Cause the Distorted SRB --- p.59 / Chapter 4.2 --- Rights Violations for Which the Abnormal SRB is a Cause --- p.66 / Chapter 4.2.1 --- Trafficking in Women --- p.70 / Chapter 4.2.2 --- Sexual Crimes --- p.72 / Chapter 4.2.3 --- Women´ةs Civil and Political Rights --- p.73 / Chapter Chapter V. --- Women´ةs Human Rights Mechanism and Domestic Measures Adopted to Control Abnormal SRB --- p.76 / Chapter 5.1 --- The International Human Rights Fundamental for Protecting Women's Human Rights --- p.77 / Chapter 5.1.1 --- International Human Rights Treaties --- p.77 / Charter of the United Nations --- p.77 / The ICCPR and the ICESCR --- p.79 / CEDAW --- p.80 / Chapter 5.1.2 --- Monitoring Treaty Bodies and Monitoring Mechanism --- p.85 / Chapter 5.2 --- Domestic Laws and Policies Adopted by Chinese Government to Control the Abnormal SRB --- p.88 / What are the Chinese Government´ةs Responses to SRB issue? --- p.89 / Chapter 5.2.1 --- Laws and Policies that Aim to Control Prenatal Sex Selection and Infanticide --- p.90 / Chapter 5.2.2 --- Measures that Aim to Dilute Son Preference --- p.96 / Political Participation --- p.98 / Economic Situation --- p.100 / Provide Some Resolution to Women's Sexual Subordination --- p.107 / Extra-Legal Measures Government Used to Change Son Preference Culture --- p.109 / Chapter 5. 3 --- Implications and Suggestions --- p.113 / Chapter 5.3.1 --- Forbidding Prenatal Sex Selection Can not Pull up the Roots --- p.115 / Chapter 5.3.2 --- Gender-Equal Laws are Still Problematic --- p.115 / States Parties´ة Responsibilities and Legal Remedies --- p.116 / Equal Treatment vs. Special Protection --- p.118 / Other Problems in Domestic Law --- p.123 / Chapter 5.3.3 --- Extra-legal Actions Failed to Touch Patriarchal Culture --- p.124 / Chapter 5.3.4 --- Loose the Birth Control Policy --- p.127 / Chapter Chapter VI. --- Conclusion --- p.130 / Bibliography --- p.136 / List of Abbreviations / SRB: Sex Ratio at Birth / NPFPCC : National Population and Family Planning Commission of China / PFPCC: Population and Family Planning Commission of China / NPC: National People´ةs Congress / TAR: Tibet Autonomous Region / UDHR: Universal Declaration of Human Rights / ICCPR: International Covenant on Civil and Political Rights / "ICESCR: International Covenant on Economic, Social and Cultural Rights" / CEDAW: The Convention on the Elimination of All Forms of Discrimination against Women / List of Figures / "Figure 1-1: Sex Ratio at Birth in China, 1982-2005" / Figure 2-1: Overall SRB Tendency and Regional Differences in Chin / "Figure 2-2: SRB by Province in 1982, 1990, 2000, 2005" / "Figure 2-3: SRB by Birth Order, 1982-2005" / "Figure 3-1: SRB by Birth Order: South Korea, 1980-2001" / "Figure 3-2: SRB by Birth Order: China, 1982-2000" / List of Tables / Table 3-1: Investigation to parents' gender expectation to first birth child / "Table 4-1: Surplus Males, Aged 15-34, China" / "Table 5-1: Female Participation in Political Decision-making, 1995-2000" / "Table 5-2: Number of Female Student by Level of Regular School, 1998-2001"

Yi, Junjian. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (leaves 88-98). / Abstracts in English and Chinese. / Chapter 1 --- The Effect of the One-Child Policy on the Sex Ratios Imbalance in China --- p.1 / Chapter 1.1 --- Introduction --- p.2 / Chapter 1.2 --- Background --- p.9 / Chapter 1.2.1 --- The One-Child Policy in China --- p.9 / Chapter 1.2.2 --- The Increase of the Sex Ratio in China --- p.13 / Chapter 1.3 --- Empirical Strategy and Data Description --- p.16 / Chapter 1.3.1 --- Empirical Strategy --- p.16 / Chapter 1.3.2 --- Data Description --- p.21 / Chapter 1.4 --- Empirical Results --- p.25 / Chapter 1.4.1 --- Basic Results --- p.25 / Chapter 1.4.2 --- The Effect of the One-Child Policy by Registration Type --- p.29 / Chapter 1.4.3 --- The Effect of the One-Child Policy by Birth Order --- p.32 / Chapter 1.5 --- Sensitivity Analysis --- p.36 / Chapter 1.5.1 --- The Dynamic Pattern of the DD estimates by Birth Year --- p.37 / Chapter 1.5.2 --- The Geographic Pattern of the DD Estimates by Provinces and Autonomous Regions --- p.41 / Chapter 1.6 --- Conclusion --- p.43 / Chapter 2 --- The Effect of Sex Ratios Imbalance on Criminal Behavior --- p.45 / Chapter 2.1 --- Introduction --- p.46 / Chapter 2.2 --- The Mechanism by which High Sex Ratios Increase Crime Rates --- p.53 / Chapter 2.2.1 --- Demographic Composition Effect --- p.54 / Chapter 2.2.2 --- Marriage Threshold Effect --- p.58 / Chapter 2.3 --- Empirical Strategy and Data Description --- p.64 / Chapter 2.3.1 --- Empirical strategy --- p.64 / Chapter 2.3.2 --- Data Description --- p.67 / Chapter 2.4 --- Empirical Results --- p.72 / Chapter 2.4.1 --- Fixed Effects Estimation --- p.72 / Chapter 2.4.2 --- Fixed Effects Instrumental Variables Estimation --- p.75 / Chapter 2.5 --- Robust Tests --- p.82 / Chapter 2.5.1 --- Measurement Error of Sex Ratios --- p.82 / Chapter 2.5.2 --- Measurement Error of Crime Rates --- p.84 / Chapter 2.5.3 --- Omitted Variables --- p.85 / Chapter 2.6 --- Conclusion --- p.86

Doctor of Philosophy / Department of Psychological Sciences / Gary L. Brase / Operational Sex Ratio (OSR: the ratio of reproductively viable males to females in a given population) has been theorized and studied as a construct that may influence behaviors. The encoding of sex ratio was examined in order to determine whether the cognitive process underlying it is automatic or effortful. Further, the current work examines whether OSR or Adult Sex Ratio (ASR: the ratio of adult males to females) is encoded. The current work involved four experiments; two using frequency tracking methodology and two using summary statistic methodology. Experiment 1 found a strong correlation between OSR of conditions and estimates of sex ratio. Participants in Experiment 1 were uninformed on the purpose of the experiment, thus the strong correlations between actual and estimated sex ratio suggest a level of automaticity. Experiment 2 found a strong correlation between the ASR of conditions and estimates, suggesting that individuals do not encode OSR over ASR. Experiments 3.a. and 3.b. demonstrated automaticity in estimates of sex ratio from briefly presented sets of faces, for two different durations: 1000ms and 330ms, the later of which is widely accepted as the length of a single eye fixation. Overall this work demonstrated a human ability to recall proportion of sexes from arrays of serially presented individuals (Experiments 1 and 2), and that ASR is encoded when participants are presented with conditions including older adults. This work found the encoding of sex ratio to be highly automatic, particularly stemming from the results of Experiments 3.a. and 3.b. Conclusions from this work help to verify previous research on sex ratio’s effect on mating strategies through evidence supporting the automatic nature of encoding sex ratio. Further, the current work is a foundation for future research regarding sex ratio, and leads to several proposals for future endeavors.

Pour une étude de population un sex-ratio à la naissance déviant de la parité peut avoir un impact important dans un contexte de conservation. En effet, un plus grand nombre d’individus d’un sexe peu affecter les dynamiques de population chez une espèce donnée. Plus d’une dizaine d’hypothèses tentent d’expliquer la variation du sex-ratio à la naissance chez les mammifères. La plupart de celles-ci sont construites sur l’idée qu’un investissement parental différentiel selon le sexe du jeune devrait affecter la valeur adaptative du ou des parents (Clutton-Brock and Iason, 1986; Frank, 1990; Clutton-Brock, 1991; West, 2009). Ce mémoire vise à étudier la variation du sex-ratio chez le kangourou gris de l’Est (Macropus giganteus) principalement selon des caractéristiques liées à la mère, au jeune et à l’environnement. L’hypothèse de Trivers et Willard (1973) sera aussi testée dans le cadre de ma maîtrise. Cette hypothèse stipule que pour un mammifère polygyne ayant un dimorphisme sexuel, les mères ayant la capacité de fournir un niveau élevé de soins maternels devraient produire plus de fils. Pour ce faire, un suivi longitudinal de deux populations a été effectué, de 2008 à 2013 au Wilsons Promontory National Park (Prom) et de 2007 à 2013 au Anglesea Golf Club, tous deux dans l’état du Victoria, en Australie. Au total, au sein de la population du Prom, 324 jeunes sont de sexe connu et les analyses ont été effectuées sur 166 paires de mères-jeunes. Un effet important de la masse ainsi que de la longueur de la jambe de la mère sur le sexe de son jeune a été trouvé. Les femelles plus lourdes ou ayant une plus longue jambe ont plus de chance de donner naissance à des fils. Pour un individu, une augmentation de 2 kg par rapport à la moyenne populationnelle en masse (27,5 kg) équivaut à une augmentation de 11 % en probabilité de produire un fils alors qu’une augmentation de 10 mm par rapport à la moyenne populationnelle en longueur de jambe (520 mm) correspond à 8 % d’augmentation en probabilité d’avoir un fils. Ces effets ne sont pas retrouvés chez les primipares, qui pourtant sont en moyennes plus petites et plus légères. Je ne suis pas en mesure d’expliquer ce résultat inattendu chez les femelles primipares. Contrairement à la masse, la condition corporelle de la mère, définie comme étant un reflet des réserves énergétiques d’une femelle et mesurée par un indice de condition relative, n’a aucun effet sur le sexe de son jeune. À ce sujet, je soulève un questionnement quant au choix d’un indice de condition corporelle pour une espèce ayant une croissance indéterminée comme le kangourou. En effet, les indices de condition corporelle lient la masse d’un individu à une longueur corporelle. Toutefois, lorsque ces deux variables varient annuellement, les changements d’indice ne sont donc pas clairement attribuables à l’une ou à l’autre de ces variables. Aucun des résultats obtenus pour la population du Prom n’est présent dans celle d’Anglesea. En fait, aucune des variables testées n’avaient d’effet sur le sexe de la progéniture. Ce projet ne supporte donc pas l’hypothèse de Trivers et Willard au sens strict puisque nous n’avons pas trouvé d’effet de la condition sur le sex-ratio. Nous suggérons plutôt que pour la population du Prom, la taille structurelle ainsi que la masse d’une femelle sont liées à son potentiel reproducteur. Donc, cette maîtrise supporte l’idée générale de cette hypothèse puisque les femelles ayant un plus grand potentiel reproducteur ont des fils. Ce projet souligne également l’importance des conditions environnementales au sein d’une population et à la fois pour deux populations retrouvées dans des conditions environnementales différentes qui présentait des résultats distincts. En effet, les résultats sur la variation du sex-ratio au Wilsons Promontory sont différents de ceux du Anglesea Golf Club, où il n’y a pas de lien entre masse ou taille maternelle et sex-ratio. Ce mémoire présente un portrait complexe du sex-ratio chez le kangourou gris de l’Est variant avec des effets très forts affectant celui-ci. De plus, de nouvelles réflexions émergent du projet notamment concernant le choix d’un indice de condition corporelle pour cette espèce, l’identification des variables environnementales affectant le sex-ratio et l’explication d’un résultat surprenant pour les primipares par rapport au sex-ratio. En conclusion, il sera intéressant de vérifier si les effets de la taille et la masse des femelles sur la progéniture étudiés dans ce projet de maîtrise persistent ou non à travers les années.

The important part of life history of species is number and size of offspring, which is limited by size of maternal investment. Family of boas (Boidae) comprises species with various maternal investments. The species of study was Cuban boa (Chilabothrus angulifer) having small litter size, but producing one of the biggest neonates from family Boidae. The aim of the thesis was to analyze relationships between life-history parameters and try to find possible evolutionary causes of this huge maternal investment. Results show, that the female's decision to reproduce is under "Capital breeder" strategy, when size of the female positively influence litter size and offspring size. Surprising result is that smaller (younger) females are producing more sons than daughters in accordance with "Local resource competition" hypothesis. Fitness of the young should increase with birth size. That was confirmed only in interspecific survival rate being very high in Cuban boa. Keywords: snakes, Cuban boa, maternal investment, life history, SSD, sex ratio