• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 79
  • 23
  • 11
  • 4
  • 3
  • 2
  • 2
  • 2
  • Tagged with
  • 140
  • 27
  • 21
  • 20
  • 19
  • 17
  • 16
  • 13
  • 13
  • 13
  • 12
  • 12
  • 10
  • 10
  • 9
  • 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.
31

Análisis filogenético del género Mimon Gray, 1847 (Chiroptera, Phyllostomidae) con énfasis en el subgénero Anthorhina

Hurtado Miranda, Natali Edith January 2014 (has links)
Mimon es considerado actualmente un género monofilético conformado por dos subgéneros: Mimon (representado por M. bennettii y M. cozumelae), y el taxón anteriormente llamado “Anthorhina” (representado por M. crenulatum y M. koepckeae). Sin embargo, los recientes resultados de estudios filogenéticos moleculares indican que Mimon es un género parafilético dentro de Phyllostomidae. En el presente estudio se realizó una revisión de caracteres morfológicos de todas las especies de Mimon, con énfasis en las poblaciones del taxón anteriormente llamado “Anthorhina”, construyendo una matriz a partir de 91 caracteres de la morfología externa, cráneo-dental y postcraneal. Las especies Lophostoma occidentalis, Trachops cirrhosus, Tonatia saurophila, Phyllostomus discolor y Micronycteris megalotis fueron elegidas como grupo externo, de las cuales M. megalotis fue usada para el enraizamiento. Se realizó una búsqueda exhaustiva para encontrar el mejor árbol a partir de 135 caracteres no ordenados, que incluyen los caracteres descritos en este estudio y los caracteres del aparato Hioideo, lengua, tracto digestivo y reproductivo y cerebro, tomados de Wetterer et al. (2000). Se obtuvo un único árbol más parsimonioso bien soportado de 305 pasos. El soporte de la ramas fue pesado con Bremer y el remuestreo por Bootstrap y Jacknife con 10000 réplicas. El árbol más parsimonioso confirma que Mimon no es monofilético, donde Mimon s.s. y el taxón anteriormente llamado “Anthorhina” están fuertemente respaldados en nodos no relacionados ni como grupos hermanos. Con la finalidad de resolver el surgente problema taxonómico, recomendamos elevar al taxón anteriormente llamado “Anthorhina” a género. Dado que “Anthorhina” es sinónimo de Tonatia, se propone que éste taxón sea renombrado. Finalmente, brindamos las diagnosis corregidas de Mimon s.s. y del taxón anteriormente llamado “Anthorhina”, basadas en los caracteres usados en el análisis filogenético. Palabras clave: caracteres morfológicos, género nuevo, Máxima Parsimonia, polifilia. / Tesis
32

Assessing bat (Chiroptera) diversity: determinants of assemblage and ensemble structure at Kwalata Game Ranch, Gauteng South Africa

Pierce, Michael William 29 January 2013 (has links)
In this study I assessed bat (Chiroptera) diversity on Kwalata Game Ranch (KGR) in Gauteng, South Africa. I investigated the influence of habitat heterogeneity, specifically vegetation type and level of cover, on the local bat assemblage structure. I sampled bats within three vegetation types (savanna-woodland, riparian and ecotone) on KGR and estimated percentage vegetation cover at sample sites as a proxy for vegetation structural complexity. I used passive sampling with bat detectors and active trapping with mistnets, harp-traps and roost searches to ensure as thorough an inventory as possible. Sample-based rarefaction revealed that the KGR bat assemblage is relatively species-poor and bat diversity is equivalent among the different vegetation types (confirmed with Whittaker’s β diversity index). A total of only eight insectivorous species was recorded and pteropodids appear to be absent from KGR. Moreover, species richness estimators indicated sampling was exhaustive. I attributed the low bat diversity to the impacts of known land use, particularly historical grazing by cattle (during 1980’s) and land clearing by humans that have resulted in a relatively fragmented savannah-woodland . In addition to the diversity assessment I evaluated effects of the deterministic processes of interspecific competition and prey defences on the ensemble structure of insectivorous bats . I measured the parameters of size, wing morphology and echolocation call structure for each species. These are the primary traits governing the habitat in which insectivorous bats can forage and the types of prey they can handle. Competition should result in size assortment of species that minimizes their similarity while defences of insect prey should result in a narrow range of effective echolocation parameters. Taking size into account is important as size can govern the type of prey able to be handled thus differently sized sympatric bat species may have similar echolocation characteristics but do not compete for prey. I used null models to test for the effects of competition and prey defences. I compared the insectivorous bat ensemble of KGR with random ensembles constructed from regional species pools of insectivorous bats. My results suggest evidence for competition – minimum size differences were larger and more evenly distributed than expected from chance. Moreover, my results are unlikely to be reflecting the “ghost of competition past” as the majority of insectivorous bat species at KGR are generalists thus making resource overlap more likely. Prey defences, on the other hand, appear to have no influence on the KGR ensemble structure – echolocation call parameters were clumped rather than more similar than chance would expect. Evidence for competition was surprising given the species-poor nature of the ensemble. Thus alternative factors potentially contributing to assortment of size and wing morphology parameters are discussed. KGR is bordered by large peri-urban settlements with numerous street lamps and large spotlights that produce substantial light pollution. High-duty cycle bats are often the main contributors to the prey defence hypothesis as they usually echolocate outside of the hearing range of tympanate insects. However, they may actively avoid artificially lit areas as a result of the slow flight making them more susceptible to predation. Also, artificial lights can interfere with the defence mechanisms of many tympanate insects thus allowing low-duty cycle echolocating bats to take advantage of a usually unavailable resource. The lack of evidence for the influence of prey defences was thus attributed to impacts of ecological light pollution.
33

Seasonal and Reproductive Effects on Wound Healing in the Flight Membranes of Captive Big Brown Bats (Eptesicus fuscus)

Ceballos-Vasquez, Alejandra 01 December 2014 (has links)
Bats (Order Chiroptera) are the only mammals capable of power flight. The flight membranes of bats are not only essential for locomotion, but also play vital roles in homeostasis. Although understanding wound healing in the flight membranes of bats is important because injuries in the wild are common, with the recent emergence of white-nose syndrome, understanding wound healing in bat flight membranes has become even more important. In order to conduct my studies on wound healing in the flight membranes of bats, it was necessary to manually restrain bats. In this thesis I present a novel bat restrainer that I designed and that reduces stress experienced by restrained bats during experimentation and data collection. Wound healing is an energy dependent process, as such it is expected that wound healing times will vary during periods of energy constraint (i.e. hibernation) and/or at times of peak demand (i.e. lactation). However, previous studies on wound healing have only looked at healing at times when there are no energy constraints. In thesis I aimed to better understand the effects of seasonality and reproduction on wound healing. Using an 8 mm circular punch, I inflicted biopsy wounds to the chiropatagium of healthy captive big brown bats, Eptesicus fuscus. I compared wound healing times between winter and summer seasons, and between reproductive (i.e. lactating) and non-reproductive females. As expected, wound healing times were longer during the winter months when bats are conserving energy. On the other hand, reproductive status did not have an effect on wound healing times. Although most bats heal, I observed impaired wound healing. This finding is important because it is the first time that impaired wound healing is reported in healthy bats. / Thesis / Master of Science (MSc)
34

Reinforcement of the Larynx and Trachea in Echolocating and Non-Echolocating Bats

Carter, Richard T. 01 September 2020 (has links)
The synchronization of flight mechanics with respiration and echolocation call emission by bats, while economizing these behaviors, presumably puts compressive loads on the cartilaginous rings that hold open the respiratory tract. Previous work has shown that during postnatal development of Artibeus jamaicensis (Phyllostomidae), the onset of adult echolocation call emission rate coincides with calcification of the larynx, and the development of flight coincides with tracheal ring calcification. In the present study, I assessed the level of reinforcement of the respiratory system in 13 bat species representing six families that use stereotypical modes of echolocation (i.e. duty cycle % and intensity). Using computed tomography, the degree of mineralization or ossification of the tracheal rings, cricoid, thyroid and arytenoid cartilages were determined for non-echolocators, tongue clicking, low-duty cycle low-intensity, low-duty cycle high-intensity, and high-duty cycle high-intensity echolocating bats. While all bats had evidence of cervical tracheal ring mineralization, about half the species had evidence of thoracic tracheal ring calcification. Larger bats (Phyllostomus hastatus and Pterpodidae sp.) exhibited more extensive tracheal ring mineralization, suggesting an underlying cause independent of laryngeal echolocation. Within most of the laryngeally echolocating species, the degree of mineralization or ossification of the larynx was dependent on the mode of echolocation system used. Low-duty cycle low-intensity bats had extensively mineralized cricoids, and zero to very minor mineralization of the thyroids and arytenoids. Low-duty cycle high-intensity bats had extensively mineralized cricoids, and patches of thyroid and arytenoid mineralization. The high-duty cycle high-intensity rhinolophids and hipposiderid had extensively ossified cricoids, large patches of ossification on the thyroids, and heavily ossified arytenoids. The high-duty cycle high-intensity echolocator, Pteronotus parnellii, had mineralization patterns and laryngeal morphology very similar to the other low-duty cycle high-intensity mormoopid species, perhaps suggesting relatively recent evolution of high-duty cycle echolocation in P. parnellii compared with the Old World high-duty cycle echolocators (Rhinolophidae and Hipposideridae). All laryngeal echolocators exhibited mineralized or ossified lateral expansions of the cricoid for articulation with the inferior horn of the thyroid, these were most prominent in the high-duty cycle high-intensity rhinolophids and hipposiderid, and least prominent in the low-duty cycle low-intensity echolocators. The non-laryngeal echolocators had extensively ossified cricoid and thyroid cartilages, and no evidence of mineralization/ossification of the arytenoids or lateral expansions of the cricoid. While the non-echolocators had extensive ossification of the larynx, it was inconsistent with that seen in the laryngeal echolocators.
35

Influencing opinions about bats the impact of levels of interaction during educational presentations

Hynes, Samantha 01 December 2012 (has links)
This experiment was run to see whether the educational presentations done at zoos and other educational facilities are effectively changing patrons' negative misconceptions about the animals they were seeing. Participants were invited to attend one of three educational presentations, where they were exposed to either a low, intermediate or high level of interaction involving a bat. I hypothesized that regardless of the level of interaction, participants would learn the information, but that a higher level of interaction would cause the biggest perceptual change in terms of how participants felt about the bat and the highest degree of learning. Across the board, participants increased their factual knowledge, with no significant differences between the baseline, taxidermy or live bat conditions. The taxidermy group had the largest difference in attitude change, but the live bat did have a role in influencing participants' views as to whether bats were beneficial to the environment. These results imply that educational facilities can use a taxidermy bat or a live bat with their patrons and depending on how they utilize the inclusion of the interactive stimulus, it will cause perceptual and educational differences.
36

Origine et radiation des chiroptères modernes : implication des faunes paléogènes d’Afrique du Nord et d'Asie du Sud / Origin and radiation of modern chiroptera : involvement of the paleogene faunas from North Africa and South Asia

Ravel, Anthony 19 December 2012 (has links)
Dans la nature actuelle, l'ordre Chiroptera constitue l'un des groupes de mammifères placentaires les plus diversifié. La particularité des chiroptères réside dans leur capacité au vol actif et à l'écholocation, deux adaptations clés qui prédisposent ces mammifères à la migration et à la colonisation de niches écologiques exclusives. La radiation initiale, dite « explosive », des chiroptères implique un ensemble de familles primitives éocènes retrouvées sur tous les continents excepté l'Antarctique. De manière quasi synchrone, plusieurs représentants appartenant aux deux principaux groupes de chiroptères actuels (c.-à-d., Rhinolophoidea et Vespertilionoidea) sont attestés dans l'Éocène inférieur terminal – Éocène moyen basal de Tunisie (Chambi). La rareté du matériel fossile pour les chiroptères paléogènes soulève de nombreuses questions sur les modalités évolutives de la radiation et de la dispersion des premières formes modernes. Cette étude intègre des faunes inédites de chiroptères fossiles issues de plusieurs campagnes de terrain réalisées en Afrique du Nord et en Asie du Sud. Il s'agit de localités fossilifères datées de l'Éocène inférieur et moyen de Tunisie (Chambi), d'Algérie (El Kohol et Glib Zegdou), et de Chine (Shanghuang). Les différentes analyses systématiques et cladistiques réalisées sur le matériel fossile, essentiellement constitué de dents isolées, ont permis d'apporter de nombreux éclaircissements sur les modalités évolutives qui ont défini la radiation des premiers microchiroptères modernes. Ces nouvelles faunes ont révélé pas moins de sept familles modernes (Rhinolophidae, Rhinopomatidae, Hipposideridae, Necromantidae, Emballonuridae, Nycteridae, Philisidae et Vespertilionidae) ainsi qu'une forme primitive, le plus ancien chiroptère d'Afrique, provenant de l'Éocène inférieur d'Algérie (El Kohol). Une approche phylogénétique met en évidence deux axes majeures de dispersions de ces chiroptères qui ont pris place durant l'Éocène moyen : une phase Est-Ouest depuis l'Asie de l'Est jusqu'en Europe, et une phase Nord-Sud depuis l'Afrique du Nord jusqu'en Europe. L'étude de la morphologie dentaire de chacune des espèces étudiées, de leur taille estimée et de la taphonomie des sites fossilifères a permis de mieux cerner le contexte paléoécologique de ces chiroptères paléogènes. Dans des conditions paléoclimatiques tropicales ou subtropicales favorables à la prolifération d'insectes, les microchiroptères, pour la plupart insectivores, avaient à disposition une ressource abondante. Mais une telle richesse spécifique, parfois très localisée comme à Chambi, devait également entrainer une forte compétition interspécifique qui a probablement été un facteur déterminant dans les événements de radiation et de dispersion. / In nature today, the order Chiroptera is one of the most diversified placental mammalian groups. The particularity of bats is their ability to fly and to echolocate, two key adaptations which allow them to migrate over long distances and to colonize exclusive ecological niches. The initial radiation of bat, described as explosive, involves primitive Eocene families that are found in all continents except Antarctica. Almost simultaneously, several representatives of the two main modern groups of chiroptera (i.e., Rhinolophoidea and Vespertilionoidea) occur in the late Early – early Middle Eocene of Tunisia (Chambi). The scarcity of fossil material for Paleogene bats raises many questions about the early evolutionary history of modern forms. This study incorporates new bat fossil faunas from several fieldwork campaigns in North Africa and South Asia. The fossiliferous localities include those of the Early – Middle Eocene of Tunisia (Chambi), Algeria (El Kohol and Glib Zegdou), and China (Shanghuang). Different systematic and cladistic analyses, carried out on fossil material principally made up of isolated teeth, allow us to highlight the modalities of the radiation of the first modern microbats. These new faunas reveal seven modern families of bats (Rhinolophidae, Rhinopomatidae, Hipposideridae, Necromantidae, Emballonuridae, Nycteridae, Philisidae and Vespertilionidae) and also a primitive form from the Early Eocene of El Kohol that is the oldest representative of the order in Africa. A phylogenetic approach highlights two major axes of dispersion that took place during the Middle Eocene: one East-West from East Asia towards Europe, the second one North-South from North Africa to Europe. The study of dental morphology, size and taphonomy provide us with a better grasp on the paleoecological context of these modern Paleogene microbats. The tropical or subtropical paleoclimatic conditions probably favoured the proliferation of insects that constituted an abundant resource for mostly insectivorous bats. But such richness, sometimes very localized as in Chambi, would also have led to strong interspecific competition, which was probably an important factor for the events of radiation and dispersion.
37

A estrutura populacional da quiropterofauna em sub-bosque florestal: o uso da amostragem sistemática / Bats population structure in understory forest: use of systematic sampling

Lazo, Lizie Jatkoske 21 September 2011 (has links)
Os métodos de amostragem por conveniência procuram maximizar o volume das amostras e podem, neste sentido, ser bastante eficazes, porém, o esperado é que venham a comprometer a acurácia e a precisão na representação de espécies em sub-bosque floretal. Isto se deve ao fato dos pesquisadores, usualmente, alocarem as redes-neblina em locais conhecidos por atrair uma maior abundância de animais e onde estes apresentariam uma redução em sua habilidade para detectar e se esquivar à rede-neblina, como em rotas de voo, fontes alimentares e abrigos. A alocação determinística das redes pode, desta forma, resultar em um elevado viés amostral, caracterizado pela superamostragem de algumas espécies que, frequentemente, utilizam estes espaços, em detrimento daquelas que, ao contrário, estariam sendo sub-representadas por não os utilizarem na mesma proporção. Baseado nisto, este estudo teve por principal objetivo o desenvolvimento de método padronizado, que pudesse elevar a acurácia e a precisão na obtenção de dados populacionais de quirópteros em sub-bosque florestal, com foco na amostragem sistemática. Como procedimentos metodológicos, uma área amostral de 8,82 ha foi delimitada em três fragmentos florestais, no interior do estado de São Paulo, dos tipos vegetacionais cerradão (22º15\'S e 47º39\'W), floresta estacional semidecidual (22º09\'S e 47º33\'W) e eucalipto (22º11\'S e 47º39\'W), para o que um conjunto móvel de doze redes-neblina foi utilizado na captura e recaptura dos quirópteros, no período de jul/2009 a jun/2010, totalizando um esforço amostral de 155.520 h.m2. A taxa de detecção das redes-neblina foi estimada, através de observações em tempo real, e utilizada na correção das estimativas populacionais. A habilidade de detecção e esquiva à captura foi elevada, porém, não diferiu do observado nas rotas de voo, anteriormente demonstrado por estudos comportamentais. O resultado disto foi o registro de quatorze espécies e, pela correção das estimativas, Desmodus rotundus foi a dominante na região e no eucalipto, enquanto que Micronycteris microtis foi a espécie mais abundante no cerradão e, Glossophaga soricina, na floresta estacional semidecidual. A abundância da Carollia perspicillata não foi corrigida, devido a sua elevada taxa de recaptura atribuída à redução na habilidade para detectar as redes, levando a uma redução de sua importância, dentre as espécies dominantes, na região e nos fragmentos de vegetação nativa. De forma inovadora, foi possível estimar o índice de densidade e o padrão de distribuição populacionais, e, ainda, dada a padronização espacial, compreender a influência de aspectos como a altitude e a declividade do solo, a densidade da vegetação, a presença e a altura do dossel florestal, sobre as populações de quirópteros. Assim, foi concluído que a amostragem sistemática pode ser mais acurada e precisa para os estudos populacionais por reduzir os vieses amostrais dos métodos de amostragem por conveniência, aumentar nossa compreenção sobre os parâmetros populacionais e a forma com que os quirópteros interagem com o ecossistema florestal, e potencializar a comparação de dados em diferentes situações e localidades. / Bats population convenience sampling methods mostly focus on maximizing sample volumes. This method can be highly effective in delivering significant number of samples, but on the other hand can potentially compromise accuracy and precision in representation of species potentially available in understory forests. This is due to the fact that researchers tend to position mist-nets according to known places by attracting greater abundance of bats and where its might be less attentive to the presence of mist-nets, such as bats flyways, food sources and shelters. However, the deterministic approach for mist-nets placement allocation may lead to a misrepresentation of the species in specific habitats and result in oversampling of the species that usually occur in those places. Based on this, the key objective of this study was to develop an standardized protocol that enhances accuracy and precision when collecting bat samples in understory forest, with focus on the evaluation of the systematic sampling. An sample area of 8.82 ha was delimited in three forest fragments within São Paulo State. These were of the vegetation types of cerradao (22º15\'S to 47º39\'W), semideciduous florest (22º09\'S to 47º33\'W) and forestation of eucalyptus (22º11\'S to 47º39\'W). A mobile set of twelve mist-nets was used to capture and recapture of bats from the Jul/2009 to Jun/2010, totaling a sampling effort of 155,520 h.m2. The detectation rate of mist-net of bats was estimated by observations in real time and was used to obtain correct population estimates. The ability of bats to detect and evade capture was hight, but consistent with observed for the flyways, earlier demonstrated by behavioral studies. The result of this was fourteen species recorded in the understory of the different forest fragments, and through the correctness of the estimates, the Desmodus rotundus was dominant in the region and in eucalyptus, while Micronycteris microtis was the most abundant specie in the cerradao and Glossophaga soricina in the semideciduous forest. The abundance of the Carollia perspicillata has not been corrected, due to its hight rate of recapture what was possibly the result of a reduced ability to detect the mist-net, leading to a reduction in your importance amoung the dominant species in the region and fragments of native vegetation. The proposed systematic design innovated and led to enhanced accuracy and precision, beyond to enable the estimate density level and the population distribution patterns. Thus, the spatial standardization in allocation mist-nets provides far representation of the influence of all habitat conditions on the bat populations, such as altitude and slope soil, vegetation density, presence and height of the forest canopy. Therefore, the overall conclusion was that the systematic sampling can be more accurate and precise for bats population studies by reduce convenience sampling methods biases, increase the understanding bats interaction with the forest ecosystem and the potentiate data comparation in different situations and localizations.
38

Pesquisa do vírus rábico em mamíferos silvestres de uma reserva natural particular no Município de Ribeirão Grande, São Paulo / Rabies virus search in wild mammals from a private natural reserve from Ribeirão Grande, São Paulo

Iamamoto, Keila 07 April 2005 (has links)
No Brasil e em alguns países da América Latina, a incidência de raiva transmitida por animais domésticos tem diminuído enquanto tem aumentado em animais silvestres. Durante os últimos anos, no Brasil, a raiva tem sido diagnosticada em morcegos hematófagos ou não, primatas não-humanos, cachorros-do-mato, quatis, guaxinins, capivaras, cervos, gambás e outras espécies silvestres. O presente estudo foi realizado em parceria com biólogos, pesquisadores na área de monitoramento de fauna silvestre, e o objetivo foi pesquisar a presença do vírus rábico em mamíferos silvestres de vida livre, provenientes de uma reserva natural particular, localizado no município de Ribeirão Grande, São Paulo, região que já foi alvo de raiva nos últimos anos. Durante o período de 2002 a 2004, 104 amostras de cérebro de animais capturados foram enviadas para diagnóstico no Laboratório de Raiva da UNESP de Araçatuba, SP, acondicionadas em pipetas plásticas do tipo Pasteur individuais. Os animais pertenciam a três ordens, Chiroptera (47,1%), Rodentia (46,2%) e Marsupialia (6,7%), sendo de diferentes idades e sexos. As amostras foram submetidas ao teste de imunofluorescência direta e inoculação intracerebral em camundongos e todas apresentaram resultado negativo para a raiva. Segundo dados da Coordenação do Programa de Controle da Raiva do Estado de São Paulo a raiva é endêmica na região estudada e a porcentagem de positividade em morcegos nos últimos dez anos é de 1,8%. Embora dos diagnósticos tenham sido negativos neste estudo, não é possível afirmar que o vírus rábico não circula naquela propriedade / In Brazil and some Latin American countries, the incidence of rabies transmitted by domestic animals has decreased while it has been increasing in wild animals. During the last few years rabies has been diagnosed in hematophagous or nonhematophagous bats, nonhuman primates, crab-eating foxes, coatis, raccoons, capybaras, deers, skunks and some other species. The present study was carried out with biologists, researchers in wild fauna monitoring and the objective was to search the presence of the rabies virus in wildlife mammals from a private natural reserve, in Ribeirão Grande city, SP, region that was target of rabies in the last few years. During 2002 to 2004, 104 brain samples of captured animals were sent for diagnosis to UNESP Rabies Laboratory from Araçatuba, SP, conditioned in individuals Pasteur plastic pipettes. The animals belonged to three different orders, Chiroptera (47,1%), Rodentia (46,2%) and Marsupialia (6,7%), and to different ages and sex. The samples were submitted to direct fluorescent antibody test and mouse inoculation test and all samples resulted negative for rabies. According to data of the Rabies Control Program Coordination from São Paulo State, rabies is endemic in the studied region and the percentage of positive cases in bats during the last 10 years was 1,8%. Although all diagnosis were negative in this study, it is not possible to affirm that the rabies virus do not circulate in that property
39

Estudo da comunidade de morcegos na área cárstica do Alto Ribeira-São Paulo. Uma comparação com 1980 / Study of the community of bats of a cárstic area of Alto Ribeira -SP. A comparison with 1980

Arnone, Ives Simoes 06 June 2008 (has links)
A investigação sobre morcegos cavernícolas brasileiros foi iniciada por TRAJANO (1981) que entre 1978 e 1980, estudou a comunidade que utiliza cavernas na área cárstica do Alto Ribeira, Sul do Estado de São Paulo. Seguiram-se estudos no norte de São Paulo, Distrito Federal e Bahia, sendo que trabalhos recentes estão sendo realizados em novas áreas, preenchendo uma lacuna importante no país. O presente estudo teve como objetivo realizar um novo levantamento da quiropterofauna do Alto Ribeira, complementando o levantamento prévio e verificando possíveis alterações devidas a perturbações antrópicas na área. Para tal, foram amostrados 13 pontos em áreas epígeas e 12 cavidades, das quais 10 foram estudadas mensalmente. O trabalho de campo consistiu de viagens mensais ao longo de um ano, com duração de cerca de 10 dias cada, com início em fevereiro de 2006 e término em janeiro de 2007. Todos os procedimentos seguiram, na medida do possível, os métodos adotados por Trajano (1981), sendo as redes colocadas nos mesmos locais amostrados há mais de duas décadas. No presente estudo, foram realizadas 121 noites de amostragem, com um esforço total de 25.320 m2 de rede x hora. No total, foram capturados 1.493 morcegos pertencentes a 35 espécies, representando cinco famílias (Emballonuridae, Furipteridae, Natalidae, Phyllostomidae e Vespertilionidae). No conjunto das doze cavernas foram obtidas 29 espécies, algumas delas representando os primeiros registros em caverna no Brasil, como Lasiurus ega e Chiroderma doriae. Nas localidades epígeas, foram registradas 24 espécies com algumas exclusivas desse ambiente, como Artibeus glaucus, Eptesicus furinalis, Eptesicus taddeii, Histiotus velatus, Vampiressa pusilla e Phylloderma stenops. Dos 1.493 morcegos capturados, 1.091 foram marcados com anilhas no antebraço, dos quais 330 foram recapturados pelo menos uma vez, havendo recapturas múltiplas, totalizando 519 recapturas. Em uma das recapturas, um espécime de Artibeus lituratus chamou a atenção por representar o maior deslocamento já registrado no país com 113 km de distância em 443 dias. As espécies com maior número de captura foram L. aurita (N = 508), seguida de D. rotundus (N = 223) e Carollia perspicillata (N = 217) e aquelas com maior número de recapturadas foram Lonchorhina aurita (N = 189), Desmodus rotundus (N = 166) e Diphylla ecaudata (N = 98); para estas últimas foi estimado o tamanho das populações em uma área de 113 km2: L. aurita, 1.639 indivíduos, D. rotundus, 548 indivíduos e D. ecaudata, 206 indivíduos. Na comparação com o estudo de TRAJANO (1981), para o mesmo esforço de coleta, foram considerados, no presente estudo, 483 indivíduos de 21 espécies (Emballonuridae, Natalidae e Phyllostomidae), sendo Lonchorhina aurita (N = 155) a espécie mais freqüente, seguida de Desmodus rotundus (N = 89) e Diphylla ecaudata (N = 71). A partir desses dados, verificaram-se diferenças no número de capturas, abundância relativa das espécies e posições no ranking de abundância entre os dois estudos, porém não na riqueza da quiropterofauna cavernícola. Dessa forma, o turismo crescente na região pode estar provocando efeitos negativos sobre algumas espécies provavelmente mais sensíveis, como os insetívoros Furipterus horrens, Micronycteris megalotis e Myotis nigricans, porém ainda não vem causando alterações significativas na riqueza e abundância total dos morcegos cavernícolas no Alto Ribeira. / The survey on Brazilian cave bats was initiated by TRAJANO (1981) that between 1978 and 1980, studied the community that uses caves in a carstic area of Alto Ribeira, south of the State of São Paulo. Another studies had been followed in the north of São Paulo, Distrito Federal and Bahia, and recent works are being carried through in new areas, filling an important gap in the country. The present study it had as objective to carry through a new survey of quiropterofauna of the Alto Ribeira, being complemented the previous survey and verifying possible changes due the antropics disturbances in the area. For such, was sampled 13 points in epígeas areas and 12 caves, of which 10 had been studied monthly. The field work consisted of monthly trips throughout one year, with duration of about 10 days each, with beginning in February of 2006 and ending in January of 2007. All the procedures had followed, in the measure of the possible one, the methods adopted for TRAJANO (1981), being the nets placed in the same sampled places have two decades more than. In the set of the twelve caves 29 species had been gotten, some of them representing the first registers in cave in Brazil, as Lasiurus ega and Chiroderma doriae. In the epigeas localities, they had been registered 24 species with some exclusive of this environment, as Artibeus glaucus, Eptesicus furinalis, Eptesicus taddeii, Histiotus velatus, Vampiressa pusilla and Phylloderma stenops. Of the 1.493 captured bats, 1.091 had been banded with metal and plastic bands in forearm, of which 330 had been recaptured at least one time, having recapture multiple, totalizing 519 recapture. One recapture of a specimen of Artibeus lituratus called the attention for representing the biggest registered movement already in the country with 113 km of distance in 443 days. The species with larger number of capture had been L. aurita (N = 508), followed of D. rotundus (N = 223) and Carollia perspicillata (N = 217), and those with larger number of recaptured had been L. aurita (N = 189), Desmodus rotundus (N = 166) and Diphylla ecaudata (N = 98); for these last ones km2 was estimated the size of the populations in an area of 113: L. aurita, 1,639 individuals, D. rotundus, 548 individuals and D. ecaudata, 206 individuals. In the comparison with the study of TRAJANO (1981), for the same collection effort, they had been considered, in the present study, 483 individuals of 21 species (Emballonuridae, Natalidae and Phyllostomidae), being Lonchorhina aurita (N = 155) the species most frequent, followed of Desmodus rotundus (N = 89) and Diphylla ecaudata (N = 71). With these data, differences in the number of captures, relative abundance of the species and position in ranking of abundance between the two studies had been verified, however not in the richness of cave bats. Therefore, the increasing tourism in the region can be causing negative effect on some species probably more sensible, as the insectivorous Furipterus horrens, Micronycteris megalotis and Myotis nigricans, however still it does not come causing significant alterations in the richness and total abundance of the cave bats in the Alto Ribeira.
40

Diet and ecosystem services of insectivorous bats assessed with stable isotopes / Dieta e serviços ecossistêmicos dos morcegos insetívoros avaliados por isótopos estáveis

Assis, Cecília Kruszynski de 12 February 2016 (has links)
Ecosystem services are natural environmental functions and ecological process that humans benefit from. In the present study, it was highlighted one of the services provided by bats: agricultural pest control. In Brazil, studies with insectivorous bats as potential pest suppressors are still scarce, despite the country being one of the biggest agricultural producers in the world and concentrating a high diversity of those animals. The use of heterogeneous landscapes, formed by native vegetation and crop fields, optimize the investment applied in this search. For that, it was described, for the first time, the bat assemblage in heterogeneous landscape in Piracicaba, at the campus \"Luiz de Queiroz\" that comprehends urbanized and agricultural areas, which provides many food resources for bats. Further, it was tested if there is difference in isotopic values (?13C and ?15N) between bat species related to diet, spatial foraging behavior, sex or taxonomic classification and which specie is a better pest suppressor. Bats were captured by mist nets and stable isotope analysis of carbon and nitrogen (?13C e ?15N, respectively) were used to access its food source. Through the analysis of ?13C and ?15N of insects, we determined the proportion of plants with photosynthetic cycles of C3 and C4 in bats\' diet and its trophic level. It was captured 90 bats of 11 species, three families and four dietary categories, corresponding to 66% of the total local richness estimated. From those, five are insectivorous species. Molossus molossus were the most abundant specie, followed by Artibeus lituratus and Glossophaga soricina. Carbon values showed that insectivores, frugivores and nectarivores consume insects, including pests, in different proportions per specie and diet group. Besides, ?15N values showed that bat trophic level were very similar, so bats are more generalist than usually assumed. This study points a need to quantify this important ecosystem service provided by bats that can reduce diseases and crop damages / Serviços ecossistêmicos são funções dos ambientes naturais e dos processos ecológicos dos quais humanos se beneficiam. Esses benefícios podem ser acessados por uma perspectiva econômica e ecológica. No presente estudo, nós destacamos um dos serviços ambientais fornecidos por morcegos: controle de pragas agrícolas. No Brasil, os estudos com morcegos insetívoros como potenciais supressores de pragas ainda são escassos, apesar de o país ser um dos maiores produtores agrícolas do mundo e abrigar uma alta diversidade desses animais. O uso de paisagens heterogêneas, formadas por vegetação nativa e lavouras agrícolas, otimiza o investimento aplicado nessa busca. Para tanto, descrevemos, pela primeira vez, a assembleia de morcegos em um ambiente heterogêneo de Piracicaba, o campus \"Luiz de Queiroz\", que possui desde áreas urbanizadas a agrícolas, disponibilizando diversos recursos alimentares para os morcegos. Ademais, testamos se há diferenças nos valores isotópicos (?13C e ?15N) entre as espécies de morcegos em relação à dieta, comportamento espacial de forrageamento, sexo ou classificação taxonômica para identificar quais grupos são os melhores supressores de pragas agrícolas. Utilizamos redes de neblina para a captura dos morcegos e análises de isótopos estáveis de carbono e nitrogênio (?13C e ?15N, respectivamente) para acessar sua fonte de dieta. Por meio das análises, determinamos a proporção de plantas com ciclos fotossintéticos do tipo C3 e C4 na dieta dos morcegos, bem como seu nível trófico. Capturamos 90 morcegos de 11 espécies, três famílias e quatro classes de dieta, correspondendo a 66% da riqueza estimada para o local. Destas, cinco são espécies classificadas insetívoras. Molossus molossus foi a espécie mais abundante, seguida por Artibeus lituratus e Glossophaga soricina. Valores de ?13C mostraram que insetívoros, frugívoros e nectarívoros consomem insetos, inclusive pragas, em diferentes proporções por espécie e grupo de dieta. O grupo mais efetivo no controle de pragas agrícolas foi M. molossus, seguido por A. planirostris. Os valores de ?15N mostraram que o nível trófico dos diferentes grupos alimentares de morcegos foi similar, de modo que eles são mais generalistas que previsto na literatura. Nosso estudo aponta a necessidade de quantificação desse importante serviço ecossistêmico promovido por morcegos, que podem reduzir doenças e prejuízos nas lavouras, além de combater vetores de doenças

Page generated in 0.0382 seconds