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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

L'influence de la compétition alimentaire, des pressions de prédation, d'infanticide et de copulation sur les comportements dirigés vers soi des femelles Colobus vellerosus

St-Onge, Charlotte 12 1900 (has links)
Les comportements dirigés vers soi (CDS) tels que l'autotoilettage, les grattements et les bâillements peuvent être des indicateurs indirects de stress chez les mammifères. Comprendre si ces comportements associés au stress coïncident avec des facteurs de stress sociaux ou écologiques devrait permettre d'identifier les éléments de la vie en groupe qui causent plus de stress chez les femelles. Pour déterminer les pressions de la vie en groupe pouvant générer du stress chez les femelles Colobus vellerosus à Boabeng-Fiema Monkey Sanctuary (BFMS), au Ghana, j’ai cherché à savoir si les CDS variaient selon : H1) La compétition alimentaire, qui peut augmenter en intensité avec le nombre de congénères qui sont en compétition pour les mêmes ressources nutritionnelles ; H2) La pression de prédation, qui peut augmenter avec un nombre total d'individus moins élevé, car cela réduit la détection des prédateurs; H3) Le risque d'infanticide, qui augmente avec le nombre de mâles adultes et les renversements de pouvoir par les mâles, car les relations de dominance masculine sont souvent contestées dans les groupes multimâles ; et H4) La pression de copulation, qui augmente lorsque les femelles sont en oestrus et s'engagent dans des comportements sexuels, ce qui peut conduire les mâles à être agressifs et coercitifs envers elles. Pour ce faire, j'ai utilisé des données longitudinales sur les grattements, l’autotoilettage et les bâillements collectées auprès de 64 femelles adultes à BFMS de 2004 à 2019. J'ai comparé les taux mensuels de CDS des femelles en fonction de la taille des groupes, de l'interaction entre le nombre de mâles et la survenue ou non d'un renversement par les mâles, et de la présence de comportements sexuels féminins. Alors que l'autotoilettage et le bâillement ne variaient pas de manière significative en fonction de nos variables, les femelles se grattaient davantage au cours des mois où il y avait plus de mâles et/ou un renversement (équations d'estimation généralisées : P < 0,05), ainsi que lorsqu'elles ont exprimé plus de comportements sexuels (P < 0,05). Ces résultats soutiennent les hypothèses du risque d'infanticide et de la pression de copulation suggérant que les stratégies reproductives des mâles expliquent le mieux le stress chez les femelles. Ceci apporte une évidence supplémentaire que la pression d'infanticide, déjà connue pour influencer la composition des groupes et le développement de la progéniture chez C. vellerosus, affecte les comportements des femelles et leur réponse au stress. Cela permet donc une meilleure compréhension de la socialité chez les primates par l’étude des facteurs de stress vécus par les femelles qui déterminent, dans une certaine mesure, la formation des groupes. / Self-directed behaviors (SDB) such as self-grooming, scratching, and yawning can be indirect stress indicators in mammals. Understanding whether behaviors associated with stress co-occur with social or ecological pressures can help identify the elements of group life that cause more stress for females. To determine which pressures of group-living may lead to stress in female Colobus vellerosus at Boabeng-Fiema Monkey Sanctuary (BFMS), Ghana, I investigated whether SDBs varied according to: H1) Feeding competition, which may increase in intensity with the number of conspecifics competing for the same nutritional resources; H2) Predation pressure, which may increase with fewer total individuals, as this reduces predator detection; H3) Infanticide risk, which increases during male group take-over and with the number of adult males because male dominance relationships are often contested in multi-male groups in this population; and H4) Mating pressure, which increases when females are in estrus and engage in copulations, and may lead to males being aggressive and coercive toward females. I used longitudinal data on three SDBs, namely scratching, self-grooming and yawning, by 64 adult females at BFMS from 2004 to 2019. I compared female monthly SDB rates according to group size, an interaction effect between the number of males and whether a male group takeover occurred, and the presence of female sexual behaviors. While self-grooming and yawning did not vary significantly with the predictor variables, females scratched themselves more during months in which more males were present and/or a takeover occurred (Generalized Estimating Equations: P < 0.05), as well as when more sexual behaviors occurred (P < 0.05). The results support the infanticide risk and mating pressure hypotheses and suggest that the reproductive strategies of adult males best explain female stress. This provides further evidence that infanticide pressure, already known to influence group composition and offspring development in C. vellerosus, affects female behaviors and their stress response. This allows a better understanding of sociality in primates by studying the stressors experienced by females that determine, to some extent, group formation.
62

Determinants of host use in tachinid parasitoids (Diptera: Tachinidae) of stink bugs (Hemiptera: Pentatomidae) in Southwest Ohio

Duncan, Matthew W. 07 June 2017 (has links)
No description available.
63

The Feeding and Behavioral Ecology of Black Spider Monkey Subgroups (Ateles paniscus paniscus) in the Context of Illegal Artisinal Goldmining Activities in the Brownsberg Nature Park, Suriname

Vreedzaam, Arioene Uncas 06 August 2013 (has links)
No description available.
64

THE FEEDING AND BEHAVIORAL ECOLOGY OF BLACK SPIDER MONKEY SUBGROUPS (Ateles paniscus paniscus) IN THE CONTEXT OF ILLEGAL ARTISINAL GOLDMINING ACTIVITIES IN THE BROWNSBERG NATURE PARK, SURINAME

Vreedzaam, Arioene Uncas 30 July 2013 (has links)
No description available.
65

Optimal Foraging Theory Revisited

Pavlic, Theodore P. 15 June 2007 (has links)
No description available.
66

La compétition et l’exploitation optimale des ressources chez les parasitoïdes

Robert, Félix-Antoine 09 1900 (has links)
Les femelles parasitoïdes exploitant un agrégat d’hôtes doivent ajuster leurs comportements en fonction des facteurs environnementaux auxquels elles sont soumises, dont la présence de compétiteurs dans l’environnement. L’objectif de cette étude est de mesurer les impacts de la compétition sur les stratégies d’exploitation d’agrégats chez deux espèces de parasitoïdes non agressives. Les espèces Trichogramma pintoi et T. minutum (Hymenoptera : Trichogrammatidae), des parasitoïdes d’œufs de lépidoptères, furent utilisées et leurs temps de résidence dans l’agrégat, leurs mécanismes de prise de décision et le sexe des descendants alloués furent mesurés en l'absence de compétition et en situation de compétition directe et indirecte, intra- et interspécifique. Trichogramma pintoi privilégie une stratégie générale basée uniquement sur la qualité perçue de l’agrégat. À l’inverse, T. minutum privilégie une stratégie adaptée au type de la compétition (directe ou indirecte) et à la nature des compétiteurs (intra ou interspécifiques), sans égards à la qualité de l’agrégat. La distinction de ces deux stratégies amène des perspectives de recherche intéressantes sur les impacts de la compétition à l’échelle du paysage, et est d’un intérêt certain pour ceux voulant améliorer l’efficacité des programmes et des élevages de masse utilisés en lutte biologique. / Female parasitoids must adjust their behavior in response to different environmental factors when foraging for hosts. One of the most important factors they must cope with is the presence of competitors in their environment. The objective of this study is to measure the effects competition has on the foraging strategies of non-aggressive parasitoids. We used the species Trichogramma pintoi and T. minutum (Hymenoptera: Trichogrammatidae), two egg parasitoids of lepidoteran species. We measured patch residence times, patch-leaving mechanisms and progeny sex allocation of females foraging alone, and of females foraging under direct or indirect, intra- or interspecific competition. Trichogramma pintoi females favoured a general strategy entirely based on the perceived quality of the patch, whereas T. minutum females favoured a strategy that was adapted to the type of competition (direct or indirect) and to the nature of the competitors (intra- or interspecific) they were subjected to, with no regards for the quality of the patch. The distinction between these two strategies brings forth interesting research opportunities regarding the effects of competition at the landscape level, and should be of interest for biological control practitioners wishing to increase the efficacy of biological control programs and of commercial mass rearings.
67

"O avunculado na Antropologia Evolutiva: uma abordagem intercultural" / "The avunculate in the evolutionary anthropology: a cross cultural survey"

Maia, Antonio Carlos do Amaral 28 February 2007 (has links)
O presente trabalho se propõe a compreender a variabilidade cultural humana em relação à organização da família por meio das teorias darwinianas da seleção natural e da seleção sexual, e se encontra baseado em evidências vindas da comparação de dados etnográficos. Pretende-se demonstrar que existe uma alteração marcante no comportamento de todos os envolvidos nas relações familiares quando mudam as regras de herança. Essas alterações assim ocorrem porque as regras de herança direcionam o Investimento Parental Masculino (MPI), ora ao sobrinho, ora ao filho. A hipótese apresentada é a de que a variação do MPI modifica de maneira compreensível e previsível as relações familiares em organizações matrilineares e patrilineares. A prova da hipótese será feita por meio da aplicação do método intercultural com pesquisa etnográfica nos bancos de dados do HRAF, e utilizando-se da amostra PSF. Os resultados do presente trabalho indicarão que em sociedades em que o tio tem uma relação afetuosa com seu sobrinho, o marido espanca a mulher; e quando o pai se relaciona de maneira indulgente e amigável com seu filho, irmãos e irmãs se evitam, alinhando esses fatos de maneira que possam ser coerentemente entendidos com a teoria sociobiológica. A riqueza cultural, o sem número de costumes, as tradições, os tabus, as normas explícitas ou ocultas, os aparatos de coerção de toda sorte, as regras sobre herança, casamento, dote, preço da noiva, divisão de trabalho, enfim, todas as regras observadas em todos os agrupamentos humanos podem ser explicadas à luz das seguintes teorias: a) da “seleção de consangüíneos" (Hamilton, 1963), b) do “altruísmo recíproco" (Trivers, 1971), c) do “investimento parental e seleção sexual" (Trivers, 1972), e d) do “conflito entre prole e parentais" (Trivers, 1974). / The present work proposes to account for cultural variability in connection to human family organization, through Darwin’s theories of natural selection and sexual selection. It is also founded on evidence based on the comparison of ethnographic data of diverse human societies. It intends to demonstrate that there is a significant alteration in the behavior of family members when the rules of inheritance of wealth change. These alterations are triggered because the rules of inheritance dictate the MPI – Male Parental Investment – sometimes in the nephew and sometimes in the son. The hypothesis is that this variation in MPI (male investment in either the nephew or the son) modifies family relations in matrilineal and patrilineal organizations in a predictable manner. The role played by MPI in determining family tensions will be shown by applying cross cultural analysis to the data obtained from HRAF (Human Relations Area Files), using PSF (Probability Sample Files). The results of the present work show that societies in which the uncle’s relation with his nephew is affectionate, the husband beats the wife; on the other hand, when the father’s relation with his son is indulgent and friendly, brother and sister avoid each other. This variability of behavior can be coherently explained by sociobiological theory. Cultural wealth: the innumerable customs, the traditions, the taboos, the manifest and hidden norms, the apparatus of coercion, the rules of inheritance, marriage, dowry, bride price, the division of labor, in short, all the rules observed in all human groups can be explained in the light of the following theories: a) ‘kinship selection’ (Hamilton, 1963); b) ‘reciprocal altruism’ (Trivers, 1971; Axelrod, 1981); c) ‘parental investment and sexual selection’ (Trivers, 1972); and d) ‘parentoffspring conflict’ (Trivers, 1974).
68

Mountains as crossroads : temporal and spatial patterns of high elevation activity in the Greater Yellowstone ecosystem, USA

Reckin, Rachel Jean January 2018 (has links)
In the archaeological literature, mountains are often portrayed as the boundaries between inhabited spaces. Yet occupying high elevations may have been an adaptive choice for ancient peoples, as rapidly changing elevations also offer variation in climate and resources over a relatively small area. So what happens, instead, if we put mountain landscapes at the center of our analyses of prehistoric seasonal rounds and ecological adaptation? This Ph.D. argues that, in order to understand any landscape that includes mountains, from the Alps to the Andes, one must include the ecology and archaeology of the highest elevations. Specifically, I base my findings on new fieldwork and lithic collections from the Absaroka and Beartooth Mountains in the Greater Yellowstone Ecosystem (GYE) of the Rocky Mountains, which was a vital crossroads of prehistoric cultures for more than 11,000 years. I include five interlocking analyses. First, I consider the impacts of anthropogenic climate change on high elevation cultural resources, focusing on the diminishing resiliency of ancient high elevation ice patches and the loss of the organic artifacts and paleobiological materials they contain. Second, I create a dichotomous key for chronologically typing projectile points, suggesting a methodological improvement for typological dating in the GYE and for surface archaeology more broadly. Third, I use obsidian source data to consider whether mountain people were a single, unified group or were represented by a variety of peoples with different zones of land tenure. Fourth, I consider high elevation occupation in both mountain ranges as part of the seasonal round, using indices of diversity in tool types and raw material to study how the duration of those occupations changed through time. And, finally, I test the common contention that ancient people primarily used mountains as refugia from extreme climatic pressure at lower elevations. Ultimately, I find that, in both mountain ranges, increased high elevation activity is most highly correlated with increased population, not with hot, dry climatic conditions. In other words, the mountains were more than simply refugia for plains or basin people to occupy when pressured by climatic hardship. In addition, between the Absarokas and the Beartooths the evidence suggests two different patterns of occupation, not a monolithic pan-mountain adaptation. These results demonstrate the potential contributions of surface archaeology to our understanding of prehistory, and have important implications for the way we think about mountain landscapes as peopled spaces in relation to adjacent lower-elevation areas.
69

Compétition intra- et interspécifique chez deux parasitoïdes sympatriques : résolution des conflits et conséquences sur les stratégies d'exploitation des hôtes / Intra- and interspecific competition in two sympatric parasitoids : resolution of conflicts and consequences on the strategies of hosts exploitation

Dib, Rihab 22 October 2012 (has links)
Quand deux espèces exploitent la même niche écologique, elles entrent en compétition. Cette compétition interspécifique peut conduire à l’exclusion de l’une d’entre elles. Toutefois, il est possible qu’un équilibre s’installe et que les deux espèces coexistent en sympatrie. Eupelmus vuilleti et Dinarmus basalis sont deux espèces de parasitoïdes solitaires, exploitant la même niche écologique, les larves et les nymphes de Callosobruchus maculatus un coléoptère séminivore. En situation de compétition par exploitation, E. vuilleti présente les caractéristiques d’une espèce dominante, potentiellement capable d’exclure D. basalis. Aussi, nous nous sommes demandés comment D. basalis peut se maintenir dans la même niche écologique qu’E. vuilleti, comme cela est observé dans certaines zones africaines ? Nos résultats montrent qu’en présence de compétitrices (compétition par interférence), les femelles des deux espèces expriment des comportements agonistiques et la résolution des conflits est principalement influencée par la valeur que les femelles placent dans la ressource. Nous montrons finalement que dans les conditions de compétition interspécifique directe, les femelles de D. basalis sont plus agressives et font du self-suparparasitisme pour augmenter leur gain en fitness. Au contraire, les femelles d’E. vuilleti s’éloignent et attendent pour finalement revenir multiparasiter après le départ de cette dernière. En conséquence, la coexistence de ces deux espèces est le résultat d’un équilibre entre les stratégies adoptées par les femelles dans ces deux situations de compétition. / When two species exploit the same ecological niche, interspecific competition may lead to the exclusion of one of them. For the two species to co-exist, resource exploitation strategies developed by both species must somehow counter-balance each other. Eupelmus vuilleti and Dinarmus basalis are two solitary parasitoid species exploiting the same hosts, larvae and pupae of Callosobruchus maculatus. When confronted to already parasitized hosts (i.e. exploitative competition), Eupelmus vuilleti seems to be dominant and potentially able to exclude D. basalis. Here, we aim at understanding how E. vuilleti and D. basalis can coexist when in sympatry. More particularly, we investigate the behavioral strategies adopted by females of both species when exploiting the resource (i.e. host) in presence of a competitor female (conspecific or interspecific) (i.e. interference competition). Our study reveals that in presence of a competitor female, E. vuilleti and D. basalis females display agonistic behaviors and the contest resolution is mainly influenced by the value that contestants place on the resource. Finally, under interspecific direct competition, D. basalis females tend to outcompete E. vuilleti females: they are more aggressive. In contrast, E. vuilleti females adopt a waiting strategy, waiting for the opponent female’s departure to multiparasitize hosts after committing an ovicide. Thus, both species seem to show counterbalancing strategies which could promote their coexistence in nature and granaries.
70

História natural e ecologia da aranha Aglaoctenus lagotis (Araneae, Lycosidae)

Moreira, Vanessa Stefani Sul 26 February 2010 (has links)
CHAPTER I: The present study has the objective to describe the life history of Aglaotenus lagotis since the youngest birth until adulthood, analysing the number of eggs in each cocoon, the birth rate, the instar number, sexual ratio and development time until adulthood, quantifying the size cephalothoraxes during all the stages of the development. The results indicate that the species is able to produce two egg sacs during the reproductive period with twelve instars after the outbreak. The youngest, during the development had the greatest a mortality rate on the three first instars, what characterizes a type III survival curve. During the adulthood the sexual ratio was turned to the female, and there is no significant differentiation between the cephalothoraxes width between males and females in laboratory environment, what makes it possible to, be considered a monomorphic species. The sexual dimorfism was observed on the coloration. Males show a light brown coloration and the female show a dark one. This study provides an opportunity to evaluate all the phases of life cycle of Lycosidae A. lagotis, what can help on the initial construction of studies about the post-embryonic development of the species, offering comparative parameters with other species from this family. CHAPTER II: The present study shows the description of the sexual behavior and the maternal care of the spider A. lagotis (Lycosidae), testing by experiments the hypothesis that the male of A. lagotis is attracted by chemical cues in the sheet web built by the female. A maternal care behavior is described, testing the hypothesis that youngest from the studied species that had maternal care have a greater fitness than youngest without the maternal care. The study made it clear that males are able to observe, note, identify realize chemical cues in the web, telling virgin females from females that were fertilized. It was possible to quantify e categorize the sexual behavior of the males into three different categories: court, pre-mate and mate. After the mate, the females built an cocoon that was transported adhered in the spinnerets and hold by the last pair of legs. After the outbreak of the eggs, the youngest migrated to a dorsal region of the mother s body for five days. It was observed during the maternal care that the mother eliminates a yellowish drop from its cheliceraes which is collected by the youngest. During the development of the youngest until the adulthood, the youngest that have the presence of their mother in the first stages of life have a greater survival, if compared with the ones that do not have the presence of their mother. So, for the A. lagotis species, by its abundance and wide distribution represent an interesting model of study for the hypothesis test in behavioral ecology, which makes possible new comparative analyses with other species of Lycosidae. CHAPTER III: The present study shows the ecological aspects of A. lagotis from two distinct populations, in a semi-deciduous dry forest in Araguari municipality, Minas Gerais. the study was developed in four distinct periods october 2008, january, april and july 2099, in two different sites. the results show that A. lagotis is a seasonal species, with an aggregated distribution and with a strong parental similarity component between the individuals from the same region. The life history of A. lagotis seems to be characterized by seasonal aspects, seen that some components of its life cycle show a well defined period of ocorrence. As long as they grow, both the area and the height of the web get bigger with the individual size, what suggests that webs progressively bigger and taller are necessary for the capture of prey enough for the maintenance of the individual biomass. Despite of happening little variation in the number of spider tenant individuals associated to the vertical interception web between the studied areas (except for April), a positive correlation was characterized between these variables in all the samples. It means that, the greater the volume of the vertical web, the greater the number of parasite spiders. So, the variations in the densities of spiders between the study sites and through time in each site, observed in this study, can be the result of the interaction between several factors, as the availability of food, climate factors and other parameters that must be investigated in future studies. / CAPÍTULO I: O presente estudo teve como objetivo de descrever a história de vida de Aglaoctenus lagotis desde o nascimento dos filhotes até a fase adulta, analisando o número de ovos em cada ovissaco, a taxa de nascimento, o número de instares, razão sexual e o tempo de desenvolvimento até a fase adulta, quantificando o tamanho do cefalotórax durante todas as etapas de desenvolvimento. Os resultados apresentados indicaram que a espécie estudada é capaz de produzir dois sacos de ovos durante o período reprodutivo e que após a eclosão o número de instares registrados foi de 12. Os filhotes, durante o desenvolvimento, tiveram uma taxa de mortalidade maior nos três primeiros instares, caracterizando uma curva de sobrevivência do tipo III. Na fase adulta a razão sexual foi voltada para a fêmea e não existindo diferenciação significativa entre a largura do cefalotórax entre macho e fêmeas em ambiente de laboratório, podendo, portanto ser considerada uma espécie monomórfica. O dimorfismo sexual encontrado foi na coloração da cutícula, machos apresentaram uma coloração marrom clara e a fêmea uma coloração marrom escura. Este estudo proporcionou uma oportunidade de avaliar todas as fases de vida do Lycosidae A. lagotis, podendo auxiliar na formação inicial de estudos sobre desenvolvimento pós-embrionário da espécie oferecendo parâmetros comparativos com outras espécies desta família. CAPÍTULO II: O presente estudo apresenta a descrição do comportamento sexual e do cuidado maternal da aranha Aglaoctenus lagotis (Lycosidae), testando experimentalmente a hipótese de que o macho é atraído por odores deixados na teia de lençol construída pela fêmea. Foi descrito o comportamento de cuidado maternal, testando a hipótese que filhotes da espécie estudada que tiveram cuidado maternal possuem o fitness maior do que filhotes sem o cuidado maternal. O estudo evidenciou que machos são capazes de perceber o odor presente na teia, diferenciando fêmeas virgens receptivas de fêmeas já fecundadas. Foi possível quantificar e categorizar o comportamento sexual dos machos em três categorias distintas: corte, pré-cópula e cópula. Depois da cópula as fêmeas construíram uma ooteca que foi transportada aderida nas fiandeiras e segurada pelo último par de pernas. Após a eclosão dos ovos os filhotes migraram para a região dorsal do corpo da mãe e permaneceram durante cinco dias. Foi observado durante o cuidado maternal a mãe eliminando uma gota amarelada de suas quelíceras,a qual é coletada pelos filhotes. Durante o desenvolvimento dos jovens até a fase adulta, os filhotes que tiveram a presença da mãe nos primeiros estágios de vida obtiveram uma sobrevivência maior, se comparado com os que não tiveram a presença da mãe. Portanto, devido à sua abundância e ampla distribuição a espécie Aglaoctenus lagotis representa um interessante modelo de estudo para teste de hipóteses em ecologia comportamental, possibilitando análises comparativas com outras espécies de Lycosidae. CAPÍTULO III: O presente estudo apresenta aspectos da ecologia da Aglaoctenus lagotis a partir de duas populações distintas, em floresta semi-decidual seca no Município de Araguari, Minas Gerais. O estudo foi desenvolvido em quatro períodos distintos - outubro de 2008, janeiro, abril e julho de 2009, em dois locais diferentes. Os resultados indicaram que A. lagotis é uma espécie sazonal, com distribuição agregada e com um forte componente de similaridade parental entre os indivíduos de uma mesma região. A história de vida de A. lagotis parece ser marcada por aspectos sazonais, sendo que alguns componentes de seu ciclo de vida apresentam um período bem definido de ocorrência. À medida que crescem, tanto a área da teia como a altura da teia aumentam com o tamanho do indivíduo, o que sugere que teias progressivamente maiores e mais altas são necessárias para a captura de presas suficientes para a manutenção da biomassa individual. Apesar de ocorrer pouca variação no número de indivíduos de aranhas inquilinas associadas à teia de interceptação vertical entre as áreas estudas (com exceção de abril) foi caracterizada uma correlação positiva entre estas variáveis em todas as amostras. Ou seja, quanto maior o volume da teia vertical maior número de aranhas parasitas. Portanto, as variações nas densidades de aranhas entre os locais de estudo e ao longo do tempo em cada local, observados neste estudo, podem ser resultado da interação entre diversos fatores, como disponibilidade de alimento, fatores climáticos e outros parâmetros que devem ser investigados em estudos posteriores. / Doutor em Ecologia e Conservação de Recursos Naturais

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