Kleine blattfressende Primaten sind selten, da die Verarbeitung von Blättern oft umfangreiche Anpassungen des Verdauungsapparates und lange Retentionszeiten für die Fermentierung der Blattfasern erfordert. Dennoch basiert die Nahrung von Lepilemur leucopus (Weißfuß-Wieselmaki) auf Blättern trotz kleinem Körpergewichts (<1 kg). Um unser Verständnis darüber voranzutreiben wie kleine Blattfresser ihre Verhaltensstrategien anpassen um ihre Nahrungsbedürfnisse zu stillen, beabsichtigte ich zu untersuchen wie extrinsische (i.e. Nahrungsquantität und -qualität) und intrinsische Faktoren (i.e. Fortpflanzungsstatus) Strategien der Nahrungssuche, Nahrungswahl und soziale Interaktionen beeinflussen. Ich sammelte Daten bezüglich Aktivitätsmuster, Fressverhalten, sozialer Interaktionen und Streifverhalten in einer Population von L. leucopus in Berenty Reserve (Madagaskar) über einen kompletten Jahreszyklus. Ich erhob Daten zur Habitatstruktur und Phänologie des Dornenwaldes und sammelte Blattproben für die chemische Analyse des Nährstoffgehaltes. Es gab keine eindeutigen Anhaltspunkte, dass die saisonale Abnahme in der Nahrungsverfügbarkeit einen beträchtlichen Einfluss auf Fressverhalten oder soziale Interaktionen in L. leucopus hatte, vermutlich aufgrund der geringen Nahrungsselektivität und der Nutzung der am häufigsten im Wald vorkommenden Pflanzenarten, und Nahrungsstress stand wahrscheinlich eher mit Nahrungsqualität als -quantität in Verbindung. Nahrungsprotein scheint nur begrenzt zur Verfügung gestanden zu haben, da L. leucopus Protein- gegenüber nicht-Protein-Aufnahme über Jahreszeiten und Reproduktionsstadien hinweg priorisierte. Da Veränderungen hinsichtlich Aktivitätsmuster und sozialer Interaktionen nicht im Zusammenhang mit Nahrungsknappheit standen, scheinen Bottom-Up-Prozesse weniger wichtig als Top-Down-Prozesse für die Formgebung des sozialen Systems von L. leucopus zu sein. Die Ergebnisse unterstützen außerdem die Idee, dass quantitative Nahrungsknappheit während der Trockenzeit eine untergeordnet Rolle gegenüber Blattqualität als Selektionsdruck für blattfressende Primatenpopulationen spielt.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-12-26T20:08:57Z No. of bitstreams: 1 EugeniaCorderoSchmidt_DISSERT.pdf: 37502107 bytes, checksum: 8ea90c3282a2c39d9600a891b990f41e (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-12-26T20:17:54Z (GMT) No. of bitstreams: 1 EugeniaCorderoSchmidt_DISSERT.pdf: 37502107 bytes, checksum: 8ea90c3282a2c39d9600a891b990f41e (MD5) / Made available in DSpace on 2016-12-26T20:17:54Z (GMT). No. of bitstreams: 1 EugeniaCorderoSchmidt_DISSERT.pdf: 37502107 bytes, checksum: 8ea90c3282a2c39d9600a891b990f41e (MD5) Previous issue date: 2016-02-19 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq) / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / A Caatinga ? uma forma??o florestal escler?fila, dec?dua e espinhosa. Situase em uma regi?o semi-?rida, com cerca de 730 000 km2, exclusiva do territ?rio brasileiro. Este ambiente apresenta grande varia??o de tipos de vegeta??o que foram atribu?das ? varia??es em larga escala no clima, padr?es de geomorfologia e diferen?as de pequena escala em relevo e solos. A precipita??o escassa e flutuante das regi?es ?ridas e semi-?ridas, exercem um forte controle sobre: hist?rias de vida, caracter?sticas fisiol?gicas e composi??o de esp?cies de sua biota. Pelo menos 77 esp?cies de morcegos das 178 esp?cies presentes no Brasil s?o encontrados na Caatinga, dos quais 13 s?o frug?voros e cinco nectarivorous incluindo o end?mica Xeronycteris vieirai. Os morcegos s?o conhecidos por desempenharem pap?is importantes no controle de pragas, poliniza??o e dispers?o de sementes. No entanto, pouca informa??o foi gerada sobre o papel ecol?gico dessas esp?cies em um ambiente como Caatinga. Em geral, esse habitat ? o ecossistema brasileiro mais negligenciado em termos de pesquisa e conserva??o da sua biodiversidade. Especificamente no caso dos morcegos, o Rio Grande do Norte possui uma das maiores lacunas de conhecimento no Brasil. Os dados aqui apresentados, representam uma das primeiras pesquisas formais com morcegos na Caatinga do Rio Grande do Norte. Foram geradas informa??es sobre a estrutura aninhada e assim?trica da rede mutual?stica entre morcegos nectar?voros e esp?cieschave de plantas para a manuten??o da comunidade de morcegos nectar?voros nesta regi?o. Al?m disso, a primeira evid?ncia de folivoria de pelo menos 16 esp?cies de plantas pelo morcego frug?voro Artibeus planirostris foi documentada. Isto representa o primeiro registro para um ambiente semi-?rido e o primeiro registro para a esp?cie. Finalmente, o primeiro ?insight? para aspectos biol?gicos do morcego end?mico X. vieirai, incluindo dieta, poleiros e dados de reprodu??o, assim como a extens?o de sua distribui??o a n?vel nacional. / Caatinga is a deciduous thorny woodland and sclerophyllous vegetation, encountered in a semi-arid region of around 730 000 km2 entirely within the Brazilian territory . This environment presents high variation of vegetation types that have been attributed to large-scale variations in the climate, geomorphology patterns, and smallscale differences in topography and soils. The sparse and fluctuation precipitation of arid and semiarid regions is believed to exert strong control over life histories, physiological characteristics, and species composition of their biotas. At least 77 bat species of the 178 species present in Brazil are found in Caatinga, of which 13 are frugivorous and five nectarivorous including the endemic Xeronycteris vieirai. Bats are known play important roles in pest control, pollination and seed dispersal, nonetheless little information has been generated regarding the ecological role these species play in an environment like Caatinga. In general, this habitat is the most neglected Brazilian ecosystem in terms of investigation and conservation of its biodiversity. Specifically in the case of bats, Rio Grande do Norte is one of the biggest knowledge gaps in Brazil. The data presented here represent one of the first formal investigations with bats in the Caatinga in Rio Grande do Norte. Information on the nested and asymmetric structure of the mutualistc network between nectarivorous bats and plants was generated, with data on key plant species for the maintenance of the community of nectar-feeding bats in this region. Also, the first evidence of folivory of at least 16 plant species by the fruit-eating bat Artibeus planirostris was documented, representing the first record for a semi arid enviroment and the first record for the bat species. Finally, the first insight to biological aspects of the endemic X. vieirai including diet, roosts and reproduction data were registered as well the extention of its range distribution at a national level.

<p>Tolerance to herbivory is the ability of plants to maintain fitness in spite of damage. The goal of this thesis is to investigate the genetic variation and expression of tolerance within species, determine whether and in what conditions tolerance has negative side-effects, and how tolerance is affected by different ecological factors. Tolerance is investigated with special focus on the effects of different damage types, competitive regimes, history of herbivory, and polyploidization in plants. Studies are conducted as a literature review and three experiments on two cruciferous species Raphanus raphanistrum and Cardamine pratensis.</p><p>In the tolerance experiments, plants are subjected to artificial damage solely, or in a combination with natural damage. A literature review was conducted in order to investigate the effects of damage method. We found that traits related to tolerance, such as growth and fitness were not as sensitive in regard to damage method as measures of induced chemical traits, or measures of secondary herbivory.</p><p>Genetic variation of tolerance was demonstrated within populations of R. raphanistrum and between subspecies of C. pratensis. In R. raphanistrum, traits involved in floral display and male fitness were positively associated with plant tolerance to herbivore damage. A potential cost of tolerance was demonstrated as a negative correlation between levels of tolerance in high and low competitive regimes. I found no evidence of other proposed costs of tolerance in terms of highly tolerant plants suffering of reduced fitness in the absence of herbivores or trade-offs in terms of a negative association between tolerance to apical and leaf damage, or between tolerance and competitive ability. In C. pratensis, higher ploidy level in plants involved higher levels of tolerance measured as clonal reproduction. Furthermore, populations exposed to higher levels of herbivory had better tolerance than populations exposed to lower levels of herbivory. In this thesis, I demonstrate evidence of different components for the evolution of tolerance in plants: genotypic variation, selective factors in terms of costs and ploidization, and selective agents in terms of changing environment or herbivore pressure.</p>

Tolerance to herbivory is the ability of plants to maintain fitness in spite of damage. The goal of this thesis is to investigate the genetic variation and expression of tolerance within species, determine whether and in what conditions tolerance has negative side-effects, and how tolerance is affected by different ecological factors. Tolerance is investigated with special focus on the effects of different damage types, competitive regimes, history of herbivory, and polyploidization in plants. Studies are conducted as a literature review and three experiments on two cruciferous species Raphanus raphanistrum and Cardamine pratensis. In the tolerance experiments, plants are subjected to artificial damage solely, or in a combination with natural damage. A literature review was conducted in order to investigate the effects of damage method. We found that traits related to tolerance, such as growth and fitness were not as sensitive in regard to damage method as measures of induced chemical traits, or measures of secondary herbivory. Genetic variation of tolerance was demonstrated within populations of R. raphanistrum and between subspecies of C. pratensis. In R. raphanistrum, traits involved in floral display and male fitness were positively associated with plant tolerance to herbivore damage. A potential cost of tolerance was demonstrated as a negative correlation between levels of tolerance in high and low competitive regimes. I found no evidence of other proposed costs of tolerance in terms of highly tolerant plants suffering of reduced fitness in the absence of herbivores or trade-offs in terms of a negative association between tolerance to apical and leaf damage, or between tolerance and competitive ability. In C. pratensis, higher ploidy level in plants involved higher levels of tolerance measured as clonal reproduction. Furthermore, populations exposed to higher levels of herbivory had better tolerance than populations exposed to lower levels of herbivory. In this thesis, I demonstrate evidence of different components for the evolution of tolerance in plants: genotypic variation, selective factors in terms of costs and ploidization, and selective agents in terms of changing environment or herbivore pressure.

The landscapes of the Great Basin and Mojave Deserts are changing due to plant invasion. Highly flammable invasive grasses increase the size and frequency of fire causing a cascade of effects through the plant and animal communities. One of the most influential animal groups in desert systems is small mammals. We sought to learn how small mammals are impacted by fire and how their influence on the plant community differs between burned and unburned habitat. Small mammals did not have higher rates of mortality as a direct result of a controlled burn. In the Great Basin, there were short-term reductions in abundance, richness, and diversity of the small mammal community in burned plots. In the Mojave, species richness and diversity increased in burned plots shortly after fire and no abundance differences were detected. These results correspond with our prediction based on the dominant small mammal species at each site. Small mammals are primarily granivores; however, they also have strong impacts on the plant community via folivory. We tested for small mammal impacts on seedling survival in burned and unburned habitat. Small mammal access, burned vs. unburned habitat, and plant species were all important determinants of survival. Small mammals greatly reduced survival at both sites in burned and unburned habitat and often had a stronger impact in unburned than burned plots. Accounting for small mammal folivory may be a crucial step in successful post-fire rehabilitation. Finally, we used seed trays to test how small mammals influence the persistence of seed on the landscape. Small mammals reduced persistence of an invasive and native plant species in the Great Basin in 2012, yet a year later when small mammal abundance was reduced, no small mammal effect was observed. In the Mojave, persistence was reduced for the majority of species both years of the study. Small mammals did not appear to avoid seed of invasive plant species as we had predicted and may be important consumers reducing the reproductive potential of these invaders. If small mammals do prefer non-native seedlings over natives and are also consuming non-native seed, they may be greatly reducing the presence of non-natives both on the unburned landscape as well as after fire. Non-native consumption by small mammals could aid in the biotic resistance of these desert ecosystems. This research further enforces the important role that small mammals play as consumers, dispersers, and regulators of the plant community.