La dynamique des populations peut être définie comme l'étude des forces responsables de la taille et de la structure d'une population. Plusieurs facteurs influençant la dynamique des populations ont déjà été identifiés. Ces facteurs peuvent être classés de par leur niveau d'influence, d'une influence à l'échelle de la population toute entière, comme par exemple les changements climatiques ou la densité de population, jusqu'à des facteurs individuels comme l'âge ou le sexe. Récemment, de nombreuses études ont insisté sur l'importance de la structure en âge pour cette dynamique.Chez les espèces sociales, un niveau supplémentaire de structuration de la population est le groupe. Cependant,les conséquences de cette structuration en groupes sociaux est encore mal connue.Au cours de ma thèse, j'ai tenté de répondre a cette question de différentes manières. J'ai tout d'abord étudié comment les paramètres démographiques individuels étaient influencés par la taille et la composition du groupe. J'ai pu notamment mettre en évidence un effet négatif du nombre de juvéniles femelles présent lors du développement sur la probabilité de devenir dominant une fois à l'age adulte. Dans une deuxième temps, j'ai étudié l'importance des interactions entre groupes en quantifiant l'impact d'un changement de dominant sur la dispersion des subordonnés. Enfin, j'ai également quantifié l'influence des différents groupes au sein de la population démontrant que les grands groupes contribuent relativement moins au taux de croissance de la population. Ces différents résultats sont ensuite discuté dans un cadre de démographie évolutive et de nouvelles pistes de recherche sont proposées / Population dynamics can be defined as the study of the forces responsible for the size and structure of a population. Several factors influencing population dynamics have already been identified. These factors can be categorized according to their level of influence. Some factors have a population-wide influence, such as climate change or population density, while others affect the individual level such as age or sex. Recently, many studies have emphasized the importance of this age structure for population dynamics.In social species, an additional level of structuring of the population is the group. However, the consequences of this social group structuring are still poorly understood.In this thesis, I try to answer this question in different ways. I first studied how the individual demographic parameters were influenced by the size and composition of the group. I was able to highlight in particular a negative effect of the number of juvenile females present during development on the probability of becoming dominant once in adulthood. In a second step, I studied the importance of interactions between groups by quantifying the impact of a change of dominant on the dispersion of subordinates. Finally, I also quantified the influence of different groups within the population showing that large groups contribute relatively less to the population growth rate. These various results are then discussed in a context of evolutionary demography and new avenues of research are proposed

of the Ph.D. thesis Autor: Jan Matějů Name: Sociality and ecology in ground squirrels (tribe Marmotini) Ground-dwelling squirrels are parafyletic group of rodents from the family Sciuridae (tribes Marmotini and Xerini). Ground-dwelling squirrels are semi-fossorial inhabitants of treeless biotopes. They share most aspects of general biology. They usually breed once a year, have exclusively diurnal activity and are omnivorous. On the contrary, ground-dwelling squirrels display different levels of sociality, which makes them an ideal model to study different ecological aspects connected with evolution of sociality. The first part of the Ph.D. thesis is focused on the relationship between sociality and sexual size dimorphism and relative and absolute size of brain. At first, supposing that different levels of sociality are connected with differences in intensity of sexual selection acting on males, we tested association between sociality and sexual size dimorphism as well as association between sexual size dimorphism and body size - so called Rensch rule. Next, we tested correlation between sociality and relative brain size. In agreement with the Social brain hypothesis, we assumed that e.g. solitarily living species should have smaller relative brain size than species living in stable pairs. We found...

Quels sont les facteurs qui peuvent retarder ou accélérer la sénescence? Les chercheurs tentent d'y apporter des réponses à différents niveaux moléculaires, cellulaires et également au niveau des traits d'histoire de vie. Tl est établi que différents facteurs ont un impact significatif sur les patrons de sénescence tels que le continuum lent-rapide, la sélection sexuelle, ou encore la disponibilité en ressources. De façon surprenante, peu d'intérêt a été porté sur l'influence de la socialité sur les patrons de sénescence. L'objet de cette thèse est de combler cette lacune et d'étudier l'influence de la socialité sur la sénescence grâce à un suivi exceptionnel d'une population de marmottes alpines (Marmota Marmota), mammifère hautement social et longévif. En effet, cette espèce est organisée en groupes familiaux, composés d'un couple dominant reproducteur socialement monogame despotique, et de subordonnés des deux sexes. La marmotte alpine pratique l'élevage coopératif. En effet, les subordonnés mâles participent à l'élevage des jeunes, ils sont aussi appelés helpers. Nous avons mis en évidence une sénescence de la taille de portée à partir de 10 ans et du succès reproducteur vers 8 ans chez les femelles dominantes et une sénescence de survie à partir de 6 ans chez les dominants mâles et femelles. Nous avons montré que le nombre de helpers durant l'année de naissance et durant la vie adulte étaient indépendants et augmentaient additivement le succès reproducteur sur toute la vie et la longévité des femelles dominantes. Nous avons apporté la preuve que les helpers présents l'année de naissance avaient une influence sexe-spécifique sur les patrons de sénescence de survie des dominants. En effet, les mâles nés avec des helpers vieillissaient plus vite et plus tôt que ceux nés sans helpers. Les femelles ayant bénéficié de helpers l'année de naissance présentaient une sénescence tardive et moins intense que celles sans helpers. Également, les helpers présents durant la vie adulte retardait la sénescence des dominants des deux sexes et diminuaient son intensité. Les coûts et bénéfices liés à l'élevage coopératif expliquent en partie la variabilité de la sénescence de survie chez la marmotte alpine. Pour finir, nous nous sommes placés à l'échelle interspécifique et nous avons montré que la socialité chez les mammifères retardait l'âge de début de sénescence / What are factors that can delay or accelerate senescence? Researchers are seeking these factors at molecular, cellular and life history traits level. Recent studies have firmly showed that the slow-fast continuum, sexual selection and food availability are factors shaping variability in senescence patterns. Surprisingly, the influence of sociality on senescence has been less investigated. The aim of this thesis is to fill this gap and to study the influence of sociality on senescence thanks to an extensive dataset spanning 25 years of study on free-ranging Alpine marmots (Marmota Marmota), a long-lived and highly social mammal. Alpine marmots live in family groups typically composed of a dominant pair, of sexually mature and immature (yearling) subordinates, and of pups of the year. Male subordinates help to raise pups, they are also called helpers. We showed in dominant females that litter size declined at 10 years of age and reproductive success at 8 years of age. In both sexes, survival was constant with age until dominants were between 6 and 8 years of age and declined markedly thereafter. We also showed that the number of helpers at birth and during adult life were independent and additively increased female dominant longevity and lifetime reproductive success. Moreover, we provided evidence that the presence of helpers at birth and during adult life strongly influenced survival senescence and that this influence was sex-specific. Indeed, females benefiting from the presence of helpers at birth showed a delayed and less intense senescence while males born with helpers showed a earlier and faster senescence. The presence of helpers during adult life was beneficial for both sexes by delaying senescence and decreasing its intensity. Sociality, more specifically cooperative breeding and its benefits and costs associated, is an important predictor of the diversity of survival senescence in Alpine marmot. Finally, we worked at the interspecific level and showed that sociality in mammals delayed the onset of senescence

Comprendre la réponse des populations aux variations environnementales est un défi central en écologie et est devenu un enjeu indéniable ces dernières années avec le changement climatique. Dans ce contexte, nous pouvons nous attendre à ce que certaines caractéristiques écologiques propres aux espèces, comme le mode de vie, qui ont évolué en réponse à des contraintes environnementales et qui influencent les traits d'histoire de vie des espèces, puissent façonner la démographie des populations en environnement variable. Pourtant, cette influence du mode de vie sur la réponse démographique des populations demeure encore mal comprise. J'ai essayé de combler cette lacune au cours de ma thèse, principalement par l'analyse d'un jeu de données exceptionnel obtenu grâce à un suivi à long terme d'une population de marmottes alpines (Marmota marmota) dans les Alpes Françaises. La marmotte alpine présente un mode de vie très particulier. Les individus vivent au sein de groupes familiaux de taille variable, généralement composés d'un couple de dominants reproducteurs, de subordonnés et de juvéniles. Ils hibernent durant la moitié de l'année, et pratiquent l'élevage coopératif ; les subordonnés mâles participent activement à la survie des jeunes durant l'hibernation, et sont alors appelés helpers. J'ai d'abord étudié comment le mode de vie de la marmotte (qui allie hibernation et socialité) a influencé les effets des fluctuations météorologiques sur les variations de survie de chaque classe d'âge. Les résultats ont alors révélé une forte diminution de la survie des juvéniles au fil des ans, et cela du fait d'effets interactifs entre facteurs environnementaux (i.e., hivers de plus en plus rudes) et sociaux (i.e., diminution de la présence des helpers). Dans un deuxième temps, j'ai étudié la valeur adaptative de l'élevage coopératif au sein de cette population de marmottes alpines et j'ai pu montrer que les effets bénéfiques de la présence des helpers sur la survie des juvéniles tendaient à disparaître du fait du changement climatique. En conséquence de cela, la population de marmottes alpines semble être actuellement en déclin. Cependant, l'impact du changement climatique semble avoir été en partie limité par une plus grande probabilité d'accéder à la dominance pour les subordonnés au cours des dernières années, ce qui démontre une influence complexe de la socialité sur la réponse de cette espèce. Enfin, j'ai comparé la démographie de la population de marmottes alpines avec celle d'une population de chamois (Rupicapra rupicapra) soumise à des variations météorologiques similaires dans les Alpes. J'ai été en mesure de montrer que le mode de vie et la stratégie de reproduction de ces espèces ont façonné différemment leurs réponses démographiques aux variations environnementales, et ainsi au changement climatique / Understanding populations' response to environmental variation is a central issue of ecology, and has become a compelling goal in the last years due to climate change. In this broad context we could expect some species-specific ecological characteristics known to influence life history traits, such as lifestyle, to shape the demography of populations in variable environments as well as structure between-species differences in response to environmental change. Yet, the influence of species' lifestyle on population demographic responses to environmental variation is still poorly understood. During my PhD, I tried to fill this gap primarily through the analysis of an extensive data set of an Alpine marmot (Marmota marmota) population in the Alps. Alpine marmots present a particular lifestyle. 1ndividuals live in family groups of variable size, typically composed of one dominant breeding pair, of sexually mature and immature subordinates and of pups of the year. Half the year, they hibernate together in burrows and practise cooperative breeding with male subordinates acting as helpers for the pups, increasing their survival probability during hibernation. I first investigated how the marmot's lifestyle (hibernation and sociality) mediated the effects of weather fluctuations on age-specific survival variation. I found that juvenile survival strongly decreased over the years because of inter-related effects of harsher winter weather conditions and social factors (i.e., decrease in helpers' presence). In a second step, I studied the adaptive value of cooperative breeding in this Alpine marmot population, and showed that the positive influence of helpers' presence on juvenile survival was vanishing with climate change. The Alpine marmot population is currently decreasing accordingly. However, in parallel to the latter changes, I found a better access to dominance for subordinate individuals over the years, compensating in part this decrease, and highlighting a complex influence of sociality on marmot response to climate change. Finally, I compared the demography of the Alpine marmot population with that of an Alpine chamois (Rupicapra rupicapra) population, subjected to similar weather conditions in the Alps. I was able to show that the difference in lifestyle and reproductive tactic between these species shaped their demographic responses to environmental variation, providing them with differentresistance to current environmental change

Population dynamics of yellow-bellied marmots (Marmota flaviventris) were studied at Watch Lake, British Columbia. I attempted to determine how population size was regulated and compared life history tactics of the Watch Lake populations with those in other areas. Ninety-three percent of adult females and eight percent of yearling females had litters. The mean litter size was 6'. 1 ± .38. The size and weight of a female's litter were negatively correlated with her reproductive effort in the previous year. The annual mortality rate of juveniles was 62%; mortality of yearlings and adults was 33%. Most yearling males and a few yearling females emigrated. . The populations were expanding at a rate of increase of approximately .27. The Watch Lake colonies were generally larger and denser than those reported from other areas. Adult males were territorial throughout the active season. Adult females defended territories during pregnancy and lactation. This is the first report of female territoriality in Marmota flaviventris. Experiments indicated that' (1) adult males caused yearling males to emmigrate and (2) adult females inhibited reproduction of yearling females. I predict that numbers will stabilize through the territorial behaviour of breeding females either reducing the breeding success of females or increasing the emigration rate of yearling females. I describe an experiment to test this hypothesis. Marmot numbers near Watch Lake have been increasing for several decades as new habitat becomes available. Life history tactics of these populations differs from those inhabiting the stable environment of subalpine Colorado. Marmots at Watch Lake suffered greater mortality. They began breeding at a younger age than those in other populations. They allocated relatively more energy to.reproduction, produced larger litters of smaller young, and grew to smaller adult size. These differences are consistent with those predicted by the theory of r- and K- selection for colonizing and stable populations. / Science, Faculty of / Zoology, Department of / Unknown

Esta dissertação tem o objetivo de analisar, de maneira sincrônica e diacrônica, o livro A carteira de meu tio de Joaquim Manuel de Macedo. Sincrônica no sentido de aproximar a obra à produção literária do período, compreendendo o discurso literário presente, que dialoga diretamente com o movimento romântico do início do século XIX. A atmosfera cultural do momento contribuiu muito para a produção do autor, mas sem perder de vista que ele possuía características peculiares, individuais. Diacrônico no sentido de compreender como esta obra também dialoga com nosso século e, portanto, permanece atual, tanto nos aspectos temáticos quanto nos aspectos composicionais. Ademais, não se perderá de vista o meio de difusão que veiculou a primeira versão da obra, o jornal. / This thesis aim to analyze synchronously and diachronically Joaquim Manuel de Macedos literary work A carteira de meu tio. Synchronic with the intention of approaching the text to its literary production of the period, comprising the literary speech that adresses directly the (Romantic Movement from the beginning of the XIX century) literary romance genre and the romanticism. The culture atmosphere of its time contributes to the writers production, without losing sight of his individuals characteristics. Diachronic in the sense of comprehending this literary work in the contemporary moment, therefore remaining meaningful nowadays, in the thematic and compositional aspects. Furthermore, the means for spreading that published the first version of the literary work, the journal (newspaper), will be part of the analysis.

Esta dissertação tem o objetivo de analisar, de maneira sincrônica e diacrônica, o livro A carteira de meu tio de Joaquim Manuel de Macedo. Sincrônica no sentido de aproximar a obra à produção literária do período, compreendendo o discurso literário presente, que dialoga diretamente com o movimento romântico do início do século XIX. A atmosfera cultural do momento contribuiu muito para a produção do autor, mas sem perder de vista que ele possuía características peculiares, individuais. Diacrônico no sentido de compreender como esta obra também dialoga com nosso século e, portanto, permanece atual, tanto nos aspectos temáticos quanto nos aspectos composicionais. Ademais, não se perderá de vista o meio de difusão que veiculou a primeira versão da obra, o jornal. / This thesis aim to analyze synchronously and diachronically Joaquim Manuel de Macedos literary work A carteira de meu tio. Synchronic with the intention of approaching the text to its literary production of the period, comprising the literary speech that adresses directly the (Romantic Movement from the beginning of the XIX century) literary romance genre and the romanticism. The culture atmosphere of its time contributes to the writers production, without losing sight of his individuals characteristics. Diachronic in the sense of comprehending this literary work in the contemporary moment, therefore remaining meaningful nowadays, in the thematic and compositional aspects. Furthermore, the means for spreading that published the first version of the literary work, the journal (newspaper), will be part of the analysis.

Au Tardiglaciaire, pendant les périodes les plus froides, le développement en altitude de vastes colonies de marmottes est à mettre en relation avec l’évolution de la limite supérieure de la forêt. Des groupes humains (Magdalénien, Azilien et Laborien) se sont focalisés sur l’exploitation préférentielle de ce petit gibier. À partir de plusieurs collections actuelles de marmottes, nous avons pu établir deux référentiels permettant de déterminer l’âge et la saison d’abattage. Ces outils méthodologiques ont ensuite été appliqués à sept séries archéologiques : Colomb et la Passagère (Méaudre), l’Olette (Lans-en-Vercors), les Freydières (Saint-Agnan-en-Vercors), Bobache (La Chapelle-en-Vercors), Jean-Pierre 1 (Saint-Thibaud-de-Couz), la Chênelaz (Hostiaz). Des analyses cémentochronologiques et squelettochronologique sur un échantillon du matériel archéologique ont permis de confirmer les résultats obtenus à partir des référentiels. Ce travail a permis de mettre en évidence la saison préférentielle de la chasse à la marmotte. Pour l’ensemble des séries archéologiques, cette saison d’abattage intervient avant l’hibernation (de la fin août à début octobre). Ainsi les marmottes ont été abattues pendant la période où elles possèdent en termes de ressources le plus fort potentiel qualitatif et quantitatif, à la fois pour les produits techniques (fourrure et graisse) et pour les produits alimentaires (graisse et viande). De plus l’étude archéozoologique confirme une intense activité de boucherie, dans une perspective de récupération de ces différents produits en vue d’une consommation différée et d’une exportation vers les sites de plaine. / During the coldest periods of the Late Glacial, in alitude the development of vast colonies of marmots is to be linked with the evolution of the upper limit of the forest. Human groups (Magdalenian, Azilian and Laborien) have focused on the preferential use of this small game.From several current collections marmots, we have established two referentials for determining the age and slaughtering season. Then, the methodological tools were applied to seven archaeological series: Colomb and the Passagère (Méaudre), Olette (Lans-en-Vercors), the Freydières (Saint-Agnan-en-Vercors), Bobache (La Chapelle-en-Vercors), Jean-Pierre 1 (SaintThibaud-de-Couz), La Chênelaz (Hostiaz). Skeletochronology analysis on a sample of archaeological material has confirmed the results obtained from the referentials. This work has highlighted the preferred hunting season to the groundhog. For all archaeological series, the season of death occurs before hibernation (from late August to early October). Thus marmots were shot during the time they have in terms of the highest quality and quantity of potential resources, for both technical products (fur and fat) and for foods (fat and meat). Moreover zooarchaeological study confirms intense butchery, with a view to recovering these different products for a deferred consumption and export to lower altitude sites.

No description available.

O objetivo do presente estudo foi reunir os textos de Machado de Assis publicados no jornal carioca Marmota, entre 1855 e 1861. Embora todo esse material já tenha sido editado, encontra-se disperso em diversas obras, muitas delas já esgotadas. O trabalho também buscou definir o quadro de produção dessas colaborações por meio de um ensaio sobre a Marmota - periódico atualmente pouco conhecido que esteve ativo entre 1849 e 1861 - e sua função cultural dentro do Segundo Reinado. Igualmente, tentou-se recompor a imagem do tipógrafo carioca Francisco de Paula Brito (1809-1861), proprietário e editor da Marmota. / O objetivo do presente estudo foi reunir os textos de Machado de Assis publicados no jornal carioca Marmota, entre 1855 e 1861. Embora todo esse material já tenha sido editado, encontra-se disperso em diversas obras, muitas delas já esgotadas. O trabalho também buscou definir o quadro de produção dessas colaborações por meio de um ensaio sobre a Marmota - periódico atualmente pouco conhecido que esteve ativo entre 1849 e 1861 - e sua função cultural dentro do Segundo Reinado. Igualmente, tentou-se recompor a imagem do tipógrafo carioca Francisco de Paula Brito (1809-1861), proprietário e editor da Marmota.