abstract: Identifying the ecological role, or niche, that a species occupies within their larger community elucidates environmental adaptability and evolutionary success. This dissertation investigates the occupied niche of chimpanzees (Pan troglodytes schweinfurthii) living in an open, dry savanna-woodland environment by examining patterns of resource use and interspecific interactions. Data were collected October 2010--November 2011 at Issa, in the Ugalla region of western Tanzania, which is one of the driest, most open, and seasonal habitats inhabited by chimpanzees. Unlike most primatological studies which employ methods that include focal follows, this study focused instead on observing 'resource patches' for chimpanzees. Patch focals allow for the observation of all animals within a study area; capture resources that are not used by the study species; and are particularly well suited for unhabituated communities. In order to better understand relationships between environment and behavior, data collected at Issa are compared with published data from other chimpanzee populations. Issa chimpanzees were expected to have broader resource use than forest chimpanzees, as well as increased competition with other fauna, due to fewer available resources. However, in contrast to the assumption of food scarcity in dry habitats, dietary resources were available throughout the year. Like other populations, the diet of Issa chimpanzees consisted of mostly fruit, but unlike at other sites, the majority of plants consumed were woodland species. Additionally, although chimpanzees and other fauna shared spatial and dietary resources, there was only nominal overlap. These results point to extremely low levels of indirect competition between chimpanzees and other fauna. Despite extensive study of forest chimpanzees, little is known about their role within their faunal community in open, dry habitats, nor about how greater seasonality affects resource use. This project addresses both of these important issues and fosters novel approaches in anthropological studies, especially in reference to chimpanzee ecology and evolution. Understanding current chimpanzee behavioral relationships with their environments shapes hypotheses about their pasts, and also informs predictions about behaviors of similar taxa in paleo-environments. Lastly, examining the ecological role of chimpanzees within their larger communities will influence the formation of, as well as evaluate, conservation strategies. / Dissertation/Thesis / Ph.D. Anthropology 2013

La décomposition des litières est un processus clé du fonctionnement du sol contribuant à de nombreux services écosystémiques. En climat tempéré, les lombriciens en interaction avec les micro-organismes du sol, contribuent significativement à ce processus. Cependant, les connaissances sur les lombriciens ciblent le plus souvent les trois catégories écologiques selon lesquelles ils sont définis : les épigés, les endogés et les anéciques. Les anéciques sont très répandus dans les sols tempérés, constituent la majeur partie de la biomasse lombricienne et interviennent dans la décomposition des litières. Plusieurs études ont observé des traits comportementaux, morphologiques et physiologiques distinguant deux sous-catégories au sein des anéciques : les épi-anéciques et les anéciques stricts. Le premier objectif de ce travail de thèse était de vérifier si cette distinction avait une réalité dans le cadre du processus de décomposition des litières. En conditions contrôlées, nous avons évalué (i) le rôle des principales espèces anéciques dans le processus de décomposition, (ii) l’impact de ces espèces sur les communautés de microorganismes et (iii) les activités enzymatiques des microorganismes du sol et (vi) l’impact des interactions entre espèces anéciques sur le processus de décomposition. A partir d’observations sur le terrain, le second objectif de ce travail de thèse était de définir les règles d’assemblages des communautés lombriciennes en prairie compte-tenu de leurs rôles majeurs dans divers processus du sol. Les résultats obtenus ont confirmé la distinction entre lombriciens anéciques stricts et épi-anéciques : les épi-anéciques étant les seuls à contribuer au processus de décomposition des litières et celui-ci étant corrélé à la biomasse individuelle moyenne de chaque espèce. Cette contribution passe par une plus forte stimulation des activités enzymatiques du sol, indépendamment des espèces considérées. En revanche, contrairement aux bactéries, les communautés fongiques du sol dépendent de l’espèce épi-anécique avec laquelle ils interagissent. Ce travail met également en évidence que l’abondance, la biomasse et la diversité des communautés lombriciennes des sols prairiaux sont régulées par différents filtres environnementaux dont la diversité du paysage. Cette thèse met en évidence que les deux sous-catégories écologiques au sein des anéciques ont des rôles différents sur le processus de décomposition des litières et qu’elles contribuent donc à des services écosystémiques fournis par le sol de manière différenciée. / Litter decomposition is a key process in soil functioning that contributes to many ecosystem services. In temperate climates, earthworms interacting with soil microorganisms contribute significantly to this process. However, knowledge about earthworms most often targets the three ecological categories in which they are defined: epigeics, endogeics and anecics. Anecics are very common in temperate soils, constitute the major part of the earthworm biomass and are involved in the litter decomposition. Several studies have observed behavioral, morphological and physiological traits that distinguish two subcategories within anecics: epi-anecics and strict-anecics. The first objective of this thesis was to verify if this distinction had a reality in the context of the litter decomposition process. Under controlled conditions, we evaluated (i) the role of the main anecic earthworm species in the decomposition process, (ii) the impact of these species on microorganism communities and (iii) soil enzymatic activities and (vi) the impact of interactions between anecic species on the decomposition process. Taking into account their major roles in various soil processes, based on field observations, the second objective of this thesis was to define the assembly of earthworm communities in grassland, The results obtained confirmed the distinction between epi and strict-anecic earthworms: only epic-anecics contribute to the litter decomposition process, which is correlated to the average individual biomass of each species. This contribution involved a greater stimulation of soil enzymatic activities, regardless of the species considered. In contrast to bacteria, soil fungal communities depend on the epi-anecic earthworm species with which they interact. This work also highlights that the abundance, biomass and diversity of earthworm communities in grassland soils are regulated by different environmental filters, including landscape diversity. This thesis highlights that the two ecological subcategories within the anecic category have different roles in the litter decomposition process and therefore contribute to ecosystem services provided by the soil in a differentiated way.

Os ecossistemas aquáticos são afetados por processos que ocorrem em escalas finas (locais) e amplas (regionais). Os processos locais incluem, por exemplo, filtros ambientais e interações interespecíficas, enquanto que os regionais abrangem principalmente questões relacionadas à dispersão de indivíduos. O entendimento de como esses processos atuam sobre comunidades, populações e interações em peixes de riachos é fundamental para a conservação dos ecossistemas aquáticos, pois permite predizer as consequências de alterações antrópicas e fornece subsídios para ações de manejo e políticas de conservação. Na presente tese, eu desenvolvi cinco estudos em distintas escalas espaciais. Cada um é apresentado em capítulos distintos. Nos capítulos 1 e 2, eu abordei questões relacionadas à compreensão de como alterações antrópicas feitas em distintas escalas espaciais influenciam as diversidades alfa e beta de comunidades de peixes de riachos. No capítulo 3, eu procurei entender como processos previstos na teoria de metacomunidades influenciam mudanças temporais na composição e abundâncias de espécies em comunidades locais. No capítulo 4, eu estudei como os impactos antrópicos levam a alterações no papel trófico e no intestino de populações de uma espécie generalista e persistente. Por fim, no capítulo 5, eu usei uma abordagem de aninhamento, desenvolvida inicialmente na Ecologia de Comunidades, para avaliar a ocupação de larvas de uma espécie de quironomídeo (Diptera) sobre o corpo de seu hospedeiro (uma espécie de peixe da família Loricaridae). / Aquatic ecosystems are influenced by processes that occur at fine (local) and broad (regional) scales. Local processes include, for example, environmental filters and interspecific interactions, whereas regional processes encompass mainly questions regarding individual dispersion. Knowledge on how these processes affect communities, populations and interactions in stream fish is essential for conservation of aquatic ecosystems, as it allows predicting consequences of human-alterations and provides subsidy for management actions and conservation policies. In this dissertation, I developed five studies using distinct spatial scales. I presented each one in a separate chapter. In the 1st and 2nd chapters, I addressed questions concerned with the understanding of how human alterations at different spatial scales influence alpha and beta diversity of stream fish communities. In the 3rd chapter I looked for understanding how processes predicted in metacommunity theory influence mid- to long-term changes in composition and species abundances of local communities. In the 4th chapter, I studied how anthropic impact drives modification in the trophic role and intestine of a generalist and persistent fish species. Lastly, in the 5th chapter, I employed nestedness approach previously developed for Community Ecology to evaluate occupation of chironomid species larvae (Diptera) on the body of its host (an armored catfish species of the family Loricariidae).

Os ecossistemas aquáticos são afetados por processos que ocorrem em escalas finas (locais) e amplas (regionais). Os processos locais incluem, por exemplo, filtros ambientais e interações interespecíficas, enquanto que os regionais abrangem principalmente questões relacionadas à dispersão de indivíduos. O entendimento de como esses processos atuam sobre comunidades, populações e interações em peixes de riachos é fundamental para a conservação dos ecossistemas aquáticos, pois permite predizer as consequências de alterações antrópicas e fornece subsídios para ações de manejo e políticas de conservação. Na presente tese, eu desenvolvi cinco estudos em distintas escalas espaciais. Cada um é apresentado em capítulos distintos. Nos capítulos 1 e 2, eu abordei questões relacionadas à compreensão de como alterações antrópicas feitas em distintas escalas espaciais influenciam as diversidades alfa e beta de comunidades de peixes de riachos. No capítulo 3, eu procurei entender como processos previstos na teoria de metacomunidades influenciam mudanças temporais na composição e abundâncias de espécies em comunidades locais. No capítulo 4, eu estudei como os impactos antrópicos levam a alterações no papel trófico e no intestino de populações de uma espécie generalista e persistente. Por fim, no capítulo 5, eu usei uma abordagem de aninhamento, desenvolvida inicialmente na Ecologia de Comunidades, para avaliar a ocupação de larvas de uma espécie de quironomídeo (Diptera) sobre o corpo de seu hospedeiro (uma espécie de peixe da família Loricaridae). / Aquatic ecosystems are influenced by processes that occur at fine (local) and broad (regional) scales. Local processes include, for example, environmental filters and interspecific interactions, whereas regional processes encompass mainly questions regarding individual dispersion. Knowledge on how these processes affect communities, populations and interactions in stream fish is essential for conservation of aquatic ecosystems, as it allows predicting consequences of human-alterations and provides subsidy for management actions and conservation policies. In this dissertation, I developed five studies using distinct spatial scales. I presented each one in a separate chapter. In the 1st and 2nd chapters, I addressed questions concerned with the understanding of how human alterations at different spatial scales influence alpha and beta diversity of stream fish communities. In the 3rd chapter I looked for understanding how processes predicted in metacommunity theory influence mid- to long-term changes in composition and species abundances of local communities. In the 4th chapter, I studied how anthropic impact drives modification in the trophic role and intestine of a generalist and persistent fish species. Lastly, in the 5th chapter, I employed nestedness approach previously developed for Community Ecology to evaluate occupation of chironomid species larvae (Diptera) on the body of its host (an armored catfish species of the family Loricariidae).

Os ecossistemas aquáticos são afetados por processos que ocorrem em escalas finas (locais) e amplas (regionais). Os processos locais incluem, por exemplo, filtros ambientais e interações interespecíficas, enquanto que os regionais abrangem principalmente questões relacionadas à dispersão de indivíduos. O entendimento de como esses processos atuam sobre comunidades, populações e interações em peixes de riachos é fundamental para a conservação dos ecossistemas aquáticos, pois permite predizer as consequências de alterações antrópicas e fornece subsídios para ações de manejo e políticas de conservação. Na presente tese, eu desenvolvi cinco estudos em distintas escalas espaciais. Cada um é apresentado em capítulos distintos. Nos capítulos 1 e 2, eu abordei questões relacionadas à compreensão de como alterações antrópicas feitas em distintas escalas espaciais influenciam as diversidades alfa e beta de comunidades de peixes de riachos. No capítulo 3, eu procurei entender como processos previstos na teoria de metacomunidades influenciam mudanças temporais na composição e abundâncias de espécies em comunidades locais. No capítulo 4, eu estudei como os impactos antrópicos levam a alterações no papel trófico e no intestino de populações de uma espécie generalista e persistente. Por fim, no capítulo 5, eu usei uma abordagem de aninhamento, desenvolvida inicialmente na Ecologia de Comunidades, para avaliar a ocupação de larvas de uma espécie de quironomídeo (Diptera) sobre o corpo de seu hospedeiro (uma espécie de peixe da família Loricaridae). / Aquatic ecosystems are influenced by processes that occur at fine (local) and broad (regional) scales. Local processes include, for example, environmental filters and interspecific interactions, whereas regional processes encompass mainly questions regarding individual dispersion. Knowledge on how these processes affect communities, populations and interactions in stream fish is essential for conservation of aquatic ecosystems, as it allows predicting consequences of human-alterations and provides subsidy for management actions and conservation policies. In this dissertation, I developed five studies using distinct spatial scales. I presented each one in a separate chapter. In the 1st and 2nd chapters, I addressed questions concerned with the understanding of how human alterations at different spatial scales influence alpha and beta diversity of stream fish communities. In the 3rd chapter I looked for understanding how processes predicted in metacommunity theory influence mid- to long-term changes in composition and species abundances of local communities. In the 4th chapter, I studied how anthropic impact drives modification in the trophic role and intestine of a generalist and persistent fish species. Lastly, in the 5th chapter, I employed nestedness approach previously developed for Community Ecology to evaluate occupation of chironomid species larvae (Diptera) on the body of its host (an armored catfish species of the family Loricariidae).

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