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Bat Resource Utilization Along the Potomac River Corridor in MarylandLitterer, Amber Starr 15 April 2024 (has links)
In 2021, 17-year periodical cicadas (Magicicada spp.) in Brood X emerged throughout much of the eastern United States. Due to their abundance and lack of predator avoidance during their short six-week period on the above-ground landscape, many species of animals consume cicadas and in turn have short-term habitat use and population responses. The response of bats to periodical cicadas is largely unknown. Using a before-after-control-impact study design, we deployed ultrasonic acoustic detectors during the summers of 2020–2022 within and just outside the range of the cicada emergence along the Potomac River corridor of Maryland and Virginia. For total bat activity, there was significantly more acoustic activity within the range of the cicada emergence the year during and the year following emergence than where emergence did not occur. Additionally, for all individual species and phonic groups, bat activity increased the year during and year after the emergence within the range of periodical cicadas compared to the year prior to emergence. Our study demonstrates that periodical cicadas may serve as a resource pulse that can cause an increase in bat activity and suggests at least a short-term local to regional population increase from immigration the year during and from recruitment the year following.
Bats of the mid-Atlantic have been negatively affected by numerous stressors including white-nose syndrome, wind turbine development, and land use change. One species suffering widespread population decline over the last decade in the mid-Atlantic has been the little brown bat (Myotis lucifugus). Understanding the space use and resource selection of remaining populations is critical for management and species recovery. Nevertheless, there are difficulties with studying the movement of insectivorous bats due to their small size and high vagility. Traditional foraging studies of Myotis spp. have used fixed station telemetry and associated multi-azimuthal observations to estimate the location of individuals. However, single azimuth observations are often unable to be included in these studies leading to more potential location estimates missing from movement models. During the summer of 2022, I radio-tagged little brown bats from a maternity colony along the Potomac River in Maryland and collected bearings on nine individuals using fixed station telemetry from sunset until bats returned to the maternity roost. Location estimates were obtained from both single and multi-azimuthal observations. I fit movement models for each individual and used auto-correlated kernel density estimation (AKDE) to estimate space use. I also assessed second and third order habitat selection of individual bats. The average 95% AKDE for males was 889 ha ± 424.6 and 699.3 ha ± 129 for adult females. I found bats had higher predicted use of habitat that was closer in distance to water and wetlands and further from open habitat at the second order and closer to water and open habitat at the third order of resource selection. Habitat associations were similar to previous little brown bat resource selection studies. However, estimates of space use were larger than those using other movement models. This study was novel in that it incorporated single azimuth observations and periodicity into models of space use, thereby increasing sample size and offering a new framework for future telemetry studies. These estimates of space use can be used by land managers to protect the habitat of this imperiled species. / Master of Science / In 2021, 17-year periodical cicadas (Magicicada spp.) in Brood X emerged throughout much of the eastern United States in high abundance. As an abundant food resource, many animals consume periodical cicadas while they are above ground during the summers. This has allowed for short-term population increases and changes in reproduction in some species. However, the response of bats to periodical cicadas is largely unknown. To study this, I deployed ultrasonic acoustic detectors that recorded six species/species groups of bats during the summers of 2020–2022 within and just outside the range of the cicada emergence along the Potomac River Corridor, Maryland, and Virginia. I observed significantly more total bat acoustic activity within the range of the cicada during the emergence year and the year following than where emergence did not occur. Also, for all individual species and species groups, bat activity increased in the year during and after the emergence within the range of periodical cicadas compared to the year before emergence. My study demonstrates that periodical cicadas cause an increase in bat activity and may suggest a population increase in the areas where the emergence has occurred.
Bats of the mid-Atlantic have experienced population declines due to numerous stressors including white-nose syndrome caused by the fungus Pseudogymnoascus destructans, wind turbine development, and habitat fragmentation. One species that has been heavily affected by white-nose syndrome is the little brown bat (Myotis lucifugus). To help conserve the species, understanding their home range and their resource needs is critical. However, little brown bats are small and agile fliers which poses difficulties for tracking them. Traditional foraging studies of species in this genus have used telemetry to obtain triangulations and location estimates of individuals but often leave out data collected from a single bearing as it is difficult to calculate the true location of the animal. During the summer of 2022, I radio-tagged little brown bats from a maternity colony along the Potomac River in Maryland and collected bearings on nine individuals using fixed station telemetry from sunset until bats returned to the maternity roost. We estimated locations from both triangulations and single bearings. I calculated movement models for each individual and fit them to an auto-correlated kernel density estimator (AKDE) of space use. The average 95% auto-correlated kernel density estimates of space use (AKDE) for males was 889 ha ± 424.6 and 699.3 ha ± 129 for adult females. I also assessed the habitat selection of individuals within their home range and across the nearby landscape. I found that bats preferred to use areas closer to water and wetlands and preferred to use areas closer to open habitat within their home range but preferred to use areas further from open habitat across the landscape. Habitat associations were similar to previous little brown bat resource selection studies. However, estimates of space use were larger than those using other movement models. My study was novel in that it incorporated single azimuth observations and periodicity into models of space use, thereby increasing sample size and offering a new framework for future telemetry studies. These estimates of space use can be used by land managers to protect the habitat of this imperiled species.
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Habitat use by largemouth bass (Micropterus salmoides), bluegill (Lepomis macrochirus), and redear sunfish (Lepomis microlophus) in two Central Florida lakesLundy, Ronald Earl 01 April 2003 (has links)
No description available.
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Habitat selection by small mammals: seasonality of responses to conditions created by fire and topography in tallgrass prairieGurtz, Sharon Peterson. January 1985 (has links)
Call number: LD2668 .T4 1985 G87 / Master of Science
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Les effets directs et indirects de la structure du paysage sur l'utilisation d'îlots forestiers par le Colibri à gorge rubis (Archilochus colubris) / Direct and indirect effects of landscape structure on the use of forest patches by ruby-throated hummingbirds (Archilochus colubris)Desroches, Claudie January 2011 (has links)
Abstract :The main goal of this stud y was to quantify the effect s of landscape structure on the abundance of Ruby-throate d Hummingbird s (Archilochus colubris) in forest patches and this, while accounting for its indirect effects on open flower community an d the occurrence of Yellow-bellied Sapsucker s (Sphympicus varius), a potential commensal of hummingbirds. We sampled 40 forest patches (0. 5 to >10 0 ha ) where we had installed 2 nectar feeders (forest edge and 40 m within forest ) during 2 breeding season s (2006 and 2007) . We visited forest patches weekly and recorded the number of hummingbirds detected within 10 m of feeders during 10 min. Mean daily artificial nectar consumption by hummingbirds, as well as their relative total abundance an d the respective relative abundance of adult males and females, were all affected by forest cover. Except for the relative total abundance, this effect of forest cover depended upon the size of forest patches. Nectar consumption and abundance generally peaked in forest patches of intermediate size found in landscapes characterized by intermediate forest cover. Mea n daily artificial nectar consumption and the relative total abundance, a s well as that of males, were higher at feeders located on the forest edge compared to 40 m inside forest patches. Regarding indirect landscape effects, landscape structure influenced the structure of open flower communities surrounding feeders, which in turn, affected the relative total abundance of hummingbirds, a s well as that of adult males. On the other hand, we failed to find strong evidence that landscape structure affected the occurrence of Yellow-bellied Sapsuckers or that the latter influenced Ruby-throated Hummingbird abundance patterns. These results support the idea that landscape structure may affect the abundance pattern of a species directly as well as through mechanisms which are themselves dependent upon the composition and configuration of landscapes //Résumé : La structure des paysages peut influencer l'écologie d'une espèce directement, en contraignant ses mouvements, par exemple, de même qu'indirectement en affectant, entre autres, l'abondance de ses proies ou prédateurs. Quoique plusieurs études aient tenté de quantifier l'influence de la structure du paysage sur les patrons d'abondance, rares sont celles qui ont mesuré simultanément les effets directs et indirects du paysage. L'objectif de ce mémoire consiste à modéliser simultanément les effets directs de la structure du paysage sur l'abondance relative du Colibri à gorge rubis ( Archilochus colubris ) et sa consommation de nectar artificiel ainsi que les effets indirects par lesquels le paysage peut aussi agir tels la disponibilité en ressources alimentaires (communautés floristiques) et la relation interspécifique de commensalisme avec le Pic maculé ( Sphyrapicus varius ). Pour ce faire, j'ai échantillonné 40 îlots forestiers (0,5 à >100 ha) dans la région de l'Estrie (Québec, Canada). À chacun d'eux, j'ai installé deux abreuvoirs (en bordure et 40 m à l'intérieur) durant les étés 2006 et 2007 et ont été visités de façon hebdomadaire. J'ai détecté une relation quadratique du couvert forestier dans le paysage avec l'abondance totale relative, celle des mâles et des femelles ainsi que pour la consommation quotidienne moyenne. Ces effets varient en fonction de la taille d'îlot sauf pour l'abondance relative totale. Les valeurs maximales se situent à des niveaux intermédiaires de couvert forestier et de taille d'îlots. Certaines caractéristiques mesurées étaient à l'échelle locale comme la position de l'abreuvoir dans l'îlot forestier ou la structure de la végétation. J'ai détecté un effet de bordure pour toutes les variables sauf l'abondance des femelles. L'indice de structure de végétation n'avait d'influence que sur l'abondance des mâles. Concernant les effets indirects, l'ensemble des variables du paysage explique 69,61% de l'indice de communauté floristique et ce dernier a un effet significatif sur l'abondance totale et l'abondance des colibris mâles. Pour la relation avec le pic, les variables du paysage mesurées n'ont pas permis de détecter un effet. De plus, bien qu'étant une variable non significative, les modèles incluant la présence du Pic maculé étaient généralement parmi les plus performants. L'ensemble de ces résultats soutient l'importance de combiner l'écologie du paysage et l'écologie comportementale dans les mêmes modèles afin de tenir compte non seulement des effets directs mais aussi des effets indirects du paysage //
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Stopover Ecology of Mallards : Where, when and how to do what?Bengtsson, Daniel January 2016 (has links)
The mallard (Anas platyrhynchos) is the most numerous and widespread duck in the northern hemisphere and a model species in ecology and harvest management. Migration is a crucial life stage for many birds and understanding the drivers of migration has important implications for conservation biology and assessment of animal population responses to global changes. Furthermore, mallard migration is a fundamental determinant of the epidemiology of many diseases of major relevance for both animal and human health. For example, it is the reservoir host for influenza A viruses (IAV), a widespread zoonosis causing mortality and economic damage. Improved knowledge of mallard behaviour during migration and the impacts of infection in mallards is needed to determine the role of wild birds in global IAV dynamics. This thesis focuses on mallard stopover ecology, an explicitly important part of the annual life cycle that is not well understood. The study area was southern Öland, SE Sweden, where mallard stopover behaviour was scrutinized by a combination of telemetry and ringing data analyses. Specifically, habitat preferences, movements, and emigration decisions were studied in-depth. Potential effects of low pathogenic avian influenza (LPAIV) infection on movement parameters were also investigated. Radio-tracking revealed that stopover mallards adhered to a strict diel pattern, in which they spent the days resting along the coast, visited crop fields at dawn and dusk, and foraged on inland water bodies during the darkest night hours. Notably, the importance of residual maize, as well as small ephemeral wetlands on the unique alvar steppe habitat that predominates on Öland, was previously unknown. LPAIV infection status did not affect movement behaviour, highlighting the possible risk of spread of IAV from wild mallards to poultry along the migratory flyway. Through capture-mark-recapture modelling, it was confirmed that weather, particularly wind direction, was the most important determinant of departure from the stopover site. In contrast, the body condition of departing mallards was less crucial. Taken together, the research presented in this thesis contributes to improved knowledge about mallard stopover ecology and its role in LPAIV disease dynamics.
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Ecologia e comportamento do ouriço-preto (Chaetomys subspinosus, Olfers 1818) em fragmentos de Mata Atlântica do município de Ilhéus, sul da Bahia / The ecology and behavior of thin-spined porcupine (Chaetomys subspinosus, Olfers 1818) in fragments of the Atlantic forest, Ilheus, southern BahiaFernandez Giné, Gastón Andres 22 May 2009 (has links)
O ouriço-preto (Chaetomys subspinosus, Olfers 1818), roedor endêmico da Mata Atlântica ameaçado de extinção, foi estudado na região cacaueira do sul da Bahia. O conhecimento acerca de aspectos básicos de sua história natural ainda é insipiente. Neste contexto, foi estudada a ecologia comportamental do ouriço-preto quanto à ecologia alimentar, organização temporal do comportamento, uso do espaço e seleção do habitat, a fim de conhecer suas estratégias adaptativas, seus requerimentos de habitat e embasar ações de conservação. Foram rádio-monitorados quatro indivíduos em vida-livre, por 11 a 13 meses cada, durante 24 dias completos (24h) e 146 noites parciais, totalizando 1.520 horas de observação, entre abril de 2005 a setembro de 2006. Dados sobre o comportamento, localização e uso de recursos foram registrados a cada 10 minutos por visualização direta dos animais. Simultaneamente, foram coletados dados sobre: clima, disponibilidade de alimento, fase da lua, tipo de vegetação na paisagem, estrutura horizontal e vertical da vegetação, abundância de recursos, e composição nutricional de espécies da dieta. Os dados foram analisados através de três abordagens. Os resultados do primeiro enfoque revelam que os ouriços-preto estudados foram estritamente folívoros e especialistas, e não apresentaram mudanças na composição da dieta ao longo do ano. Preferiram folhas jovens, espécies pioneiras, principalmente Fabaceas com capacidade de fixação biológica de nitrogêncio. Os resultados do segundo enfoque indicaram que os ouriços estudados são estritamente noturnos, solitários, possuem baixos níveis de atividade entre outras estratégias voltadas para a conservação de energia. Eles apresentaram ritmo circadiano de atividade e padrão bimodal de atividade que parecem associados a aspectos que permeiam o processo digestivo e de forrageamento. Não mostraram expressivas mudanças comportamentais ao longo do ano, mas em noites chuvosas sua atividade foi reduzida. Os resultados da terceira abordagem indicam que eles possuem áreas de vida pequena, são estritamente arborícolas, e preferem locais com alta complexidade vertical da vegetação e infestação de cipós em todas as escalas de seleção de habitat avaliadas. Dessa forma, as florestas e as áreas de borda foram preferidas pelos ouriçospreto, e raramente foram usadas as capoeiras e sistemas agroflorestais. Este estudo comprova que os ouriços-preto são estritamente folívoros, arborícolas e especialistas. Eles adotam estratégias comportamentais voltadas à conservação de energia, similares a outros mamíferos folívoros, e são altamente seletivos no uso de recursos do habitat. Estes recursos são comuns em áreas florestais sobre perturbação do efeito de borda. Enquanto, por um lado os ouriços-preto mostram ser especializados em bordas de floresta, por outro, evitam áreas forestais estruturalmente simplificadas. A tolerância ao efeito de borda e a evitação dos sistemas agroflorestais pelos ouriços-preto são discutidas no âmbito de sua conservação. / The behavioral ecology of thin-spined porcupine (Chaetomys subspinosus, Olfers 1818), threatened rodent endemic from Atlantic forest, was researched in the cacao-growing region of southern Bahia. The knowledge about basic aspects of specie natural history is still incipient. The aim of the present research was to study feeding ecology, behavior temporal organization, use of space, and habitat selection, to know the adaptation strategies, their habitat requirements and to support conservation actions. In this way, four individuals in situ were followed using radiotelemetry along 11 to 13 months each, during 146 half-nights and 24 complete days (24h), totaling 1520 hours of observation, from April 2005 to September 2006. Data about behavior, localization and use of resources were registered by instantaneous sampling performed each 10 minutes by direct visualization of animals. Simultaneously, data about climatic variables, food availability, moon phase, vegetation types in landscape, horizontal and vertical vegetation structure, resource abundance, and nutritional composition of diets species were collected. Data was analyzed following three different approaches. The results of the first part revealed that the thin-spined porcupines are strictly folivorous and specialist, eating a lot of few species, any change on foraging patterns and diet composition were observed along the year. The preference was for young leaves, pioneer species, mainly Fabaceas with capability of biological nitrogen fixation. The results of the second part indicated that the studied thin-spined porcupines are strictly nocturnal and solitary presenting low level of activity among other strategies for energy conservation. Also, presented circadian rhythm and activity bimodal pattern related to aspects that permeate their foraging and digestive process. They did not change their activities or dislocations due to seasonal but in raining nights their activity was reduced. The results of the third approach revealed that they exhibit small home range, were strictly arboreal and preferred locals with high complexity vertical vegetation and lianas abundance in all the habitat-scales selection evaluated. Thus the forest and the edged areas were preferred by the porcupine, and rarely went to early-growth forest and agro-forest systems. This study confirmed that thin-spined porcupine is strictly folivore, arboreal and specialist. They adopt conservative-energy strategies similar to others arboreal folivorous mammals, and denotes that are highly selective in use habitat resources. Those resources are common in forest areas with edge effect disturbance. While demonstrated to be specialist in edges forest, in other side, they avoid simplified structurally areas. The thin-spined porcupine tolerance to edge effect and their avoidance to agroforest systems are discussed under the focus of conservation.
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Área de vida, uso e seleção de habitat pela corujinha-do-mato Megascops choliba (Strigiformes: Strigidae) em uma área de cerrado na região central do Estado de São Paulo / Home range, habitat use and selection by the Tropical Screech-Owl Megascops choliba(Strigiformes: Strigidae) in a cerrado area in central Estate of São PauloBarros, Fábio Monteiro de 28 November 2011 (has links)
Informações sobre o tamanho da área de vida, o uso e seleção de habitat contribuem para o entendimento da ecologia das espécies e por isso acabam servindo como importantes referências para o manejo e conservação. Apesar de no Hemisfério Norte muitos estudos abordarem área de vida e uso de habitat em Strigiformes, na região Neotropical, informações dessa natureza ainda são escassas na literatura. No presente estudo, quatro indivíduos machos da corujinha-do-mato (Megascops choliba) foram monitorados por radiotelemetria durante cerca de seis meses em uma área de cerrado (lato sensu) no interior do Estado de São Paulo. Apesar das diferenças dos habitats utilizados, o tamanho médio da área de vida de M. choliba segundo o mínimo polígono convexo (51,2 ± 26,9 ha) foi semelhante à de espécies do mesmo gênero na América do Norte. A grande variação individual encontrada no tamanho das áreas de vida pode ser explicada pelos tipos de habitats utilizados e também pelo status social dos indivíduos. No período noturno, a corujinha-do-mato preferiu fisionomias de cerrado semi-abertas e fechadas e, além disso evitou fisionomias abertas. No período diurno, habitats com vegetação mais densa e fechada como matas de galeria e manchas de Pinus invasor foram preferencialmente utilizados para uso como abrigo. O uso desses locais durante o dia, provavelmente está ligado à maior cobertura vegetal dessas áreas que podem fornecer proteção contra predadores e também microclimas adequados. / Information on home ranges and habitat use and selection is useful to understand species ecology and therefore may help to establish species management and conservation plans. Despite the large numbers of Northern Hemisphere studies addressing Strigiformes home range and habitat use, the same is not applied to Neotropical owl species, what makes such information still scarce. In this study, four males of Tropical Screech-Owls (Megascops choliba) were radio-tracked for about six months in a cerrado (lato sensu) region in state of São Paulo, southeastern Brazil. Despite the differences in used habitats between species from the two hemispheres, the mean home range size of Tropical Screech-Owls (51.2 ± 26.9 ha) appears to be similar to North American Megascops species. The considerable individual variation in home range sizes may be related to types of habitats and individual social status. At night, the Tropical Screech-Owls preferred semi-open and closed savannas and, moreover, avoided open savannas. Habitats with dense vegetation, such as gallery forests and invasive pine forests were preferentially used for daytime roost. Use of these sites during the day is probably associated to higher vegetation cover which can provide protection against predators and suitable microclimates
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Área de vida, movimentação e seleção de habitat do cágado Hydromedusa maximiliani (Testudines: Chelidae) no parque estadual Carlos Botelho, SP / Home range, movements and habitat selection of the freshwater turtle Hydromedusa maximiliani (Testudines: Chelidae) at the Parque Estadual Carlos Botelho, São Paulo state, BrazilCosta, Shirley Famelli da 27 June 2013 (has links)
Um fator-chave para a conservação da biodiversidade é a adequada estruturação de áreas protegidas. Para quelônios, no entanto, a determinação do tamanho e da configuração dessas áreas requer a execução de estudos de longa duração capazes de integrar as diversas informações que garantam o sucesso reprodutivo, o recrutamento de novos indivíduos e o entendimento de todos os aspectos necessários para o extenso ciclo de vida, assegurando, portanto, diversidade genética que proporcione a persistência das populações desses animais ao longo do tempo. Um total de dezenove cágados adultos (10 machos e nove fêmeas) foram equipados com rádio-transmissores e outros 18 animais (11 fêmeas e sete machos) foram monitorados com bobinas de rastreamento com a finalidade de determinar a área de vida, os padrões de movimentação e o uso e seleção de habitat de Hydromedusa maximiliani, uma espécie de cágado Vulnerável e endêmica de áreas de Mata Atlântica, um dos ecossistemas mais ameaçados do planeta. Por meio de diferentes estimadores (Polígono Convexo Mínimo ou MCP \"Minimum Convex Polygon\", Kernel e Cluster para os dados de telemetria) foi possível observar que H. maximiliani apresenta área de vida que varia entre 0,2 e 1,5 ha ao longo de um período anual, com média de 0,4 ha, independentemente da estação do ano. Apesar da diferença de tempo empregado no monitoramento pelos dois métodos (72 horas para o bobinas de rastreamento e 15 meses para a telemetria), observou-se que o tamanho da área de vida não foi diferente quando comparadas as estimativas obtidas. Esse resultado, bem como o baixo deslocamento apresentado pela espécie (3 a 138 m/dia) e o intenso uso de refúgios pelos indivíduos monitorados, pode ser explicado pelo comportamento sedentário e intensa fidelidade ao ambiente aquático. Contudo, esse aspecto não descarta a sua relação com o ambiente terrestre, o que, entretando, necessita de melhor e mais prolongada investigação, uma vez que a seleção de locais para a postura dos ovos é um comportamento maternal sujeito à seleção natural e que contribui para a sobrevivência e a variação fenotípica da prole. / A key factor in conservation biology is a suitable design of protected areas. Long-term study is required when determining the size, structure, shape of these areas for freshwater turtles, thereby integrating essential information to guarantee the reproductive success, recruitment of new individuals into the population and persistence of the population over the years. Nineteen adult animals (10 males and 9 females) were fitted with radio-transmitters in order to analyze the home range, movement patterns, habitat use and selection of the vulnerable freshwater Hydromedusa maximiliani, an endemic and vulnerable freshwater turtle from Atlantic Rainforest in Brazil, one of the world\'s most threatened ecosystems. Another eighteen adult animals (11 females and 7 males) were also monitored with the technique of thread-bobbins. Three different methods such as MCP \"Minimum Convex Polygon\", Kernel and Cluster were applied to measure home range size which varied between 0.2 to 1.5 ha throughout a year period of monitoring, with mean size of 0.4 ha either for the wet or the dry season. No difference was found when the home range measured using different methods were compared even with the time difference between them (72 hours for thread-bobbins and 1 year for telemetry). This result associated with the low movements showed by Hydromedusa maximiliani (3 to 138 m/day) and the intense use of burrows can be explained by the sedentary behavior and intense site fidelity of the turtles with the river. Nevertheless, the importance of the terrestrial habitat for freshwater turtles is already known though longterm monitoring is necessary to study this aspect which would contribute to future conservation strategies including nests sites and also habitat use and selection of young turtles.
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Levantamento, área de vida, uso e seleção de hábitat de Falconiformes na região central do estado de São Paulo / Survey, home range, habitat use and selection of the Falconiformes in the central region of the state of São PauloGranzinolli, Marco Antonio Monteiro 07 May 2009 (has links)
As aves de rapina, assim como os outros grupos animais, não estão distribuídas de maneira uniforme nos diferentes hábitats que compõem a paisagem terrestre. Conhecer e entender os fatores (e as implicações) que levam as espécies a escolher um determinado hábitat é questão essencial nos estudos de ecologia. Esse tema ganha ainda mais importância não só pela escassez de informações sobre a ecologia e história natural das aves de rapina na região Neotropical, mas também, pelo atual cenário de alteração dos hábitats. Estes são modificados rapidamente sem que haja um conhecimento básico da relação espécie/hábitat e dos efeitos provocadas por tais alterações. Dessa maneira, a presente tese teve como objetivo principal verificar o uso e a seleção de hábitat por aves de rapina diurnas em uma paisagem heterogênea (151. 866 ha) na região central do Estado de São Paulo (22° 15′ S; 47° 49′ W), onde a Estação Ecológica de Itirapina (EEI) foi considerada como área núcleo. Ainda, foi também alvo desse estudo estimar a área de vida de três espécies de rapineiros (Falco femoralis, Rupornis magnirostris e Heterospizias meridionalis) por meio de rádio-telemetria; verificar a eficiência de captura das aves de rapina frente a dois tipos de armadilhas, bal-chatri e goshawk; e elaborar um mapa de uso/ocupação do solo da área em questão, bem como analisar a paisagem no entorno da EEI. Entre setembro de 2005 e fevereiro de 2007 foram registradas 19 espécies de Falconiformes (Pandionidae n =1, Falconidae n = 5, Accipitridae n = 13) em uma paisagem essencialmente ocupada por monoculturas (cana-de-açúcar 22 %, laranja 14 %, eucalipto 13 %) e pastagens (21%). A riqueza média dos Falconiformes em áreas de monoculturas foi de 4,6 espécies e nas áreas naturais 10,3. A composição de espécies da taxocenose se mostrou mais relacionada às outras de área abertas sob influência do Cerrado. Um total de 48 indivíduos, pertencentes a cinco espécies, foram capturados pelos dois tipos de armadilhas. O sucesso de captura geral foi de 15,3 % (n = 33) para a armadilha bal-chatri e de 1 captura a cada 11,8 dias (8,5 %) para goshawk trap (n = 15). Implicações e limitações referentes à captura das aves de rapinas em áreas abertas foram também discutidas. A média da área de vida pelo método Kernel adaptativo (KA) 95 % foi de 1.329 ± 780 ha para F. femoralis, 129 ± 140 ha para R. magnirostris e de 1.883 ha para o indivíduo de H. meridionalis. A média da área de vida de F. femoralis foi 2,8 maior em áreas alteradas quando comparada a áreas naturais. De maneira geral, a qualidade do hábitat parece ter influenciado nos diferentes valores de requerimento de área apresentado pelos indivíduos e, também, na seleção/rejeição dos diferentes hábitats. Na maioria dos casos, as monoculturas foram rejeitadas, enquanto as áreas naturais foram selecionadas pelas aves de rapina. Cana-de-açúcar foi rejeitada por todas as aves de rapina. O único ambiente alterado utilizado em maior proporção que o esperado foi pastagem, selecionada por quatro das 10 espécies analisadas. Em contrapartida, três espécies evitaram este hábitat. Este é o primeiro estudo a avaliar a seleção de hábitat por Falconiformes no Brasil e demonstra que o intensivo incremento de áreas para agricultura pode afetar negativamente até mesmo as espécies mais abundantes e generalistas, contrário a algumas generalizações da literatura. A interação entre estrutura do hábitat, disponibilidade de presas, morfologia e comportamento de caça parece explicar tanto o tamanho da área de vida requerida quanto a utilização diferenciada dos diferentes tipos de hábitats. / Raptors, similarly to other animal groups, are not randomly distributed in the different habitats in the terrestrial landscape. Knowing and understanding the factors (and implications) influencing these species to chose a certain habitat are essential in ecological studies. This subject has become even more important not only because of the lack of information on the ecology and natural history of raptors of the Neotropics, but also because of current scenario of habitat changes. Areas are being rapidly modified without a basic knowledge of the species/habitat relationship and the effects it may cause. Thus, the main goal of this thesis was to examine habitat use and selection by diurnal birds of prey in a heterogeneous landscape (151. 866 ha) in the central region of state of São Paulo (22° 15′ S; 47° 49′ W), where the Estação Ecológica de Itirapina (EEI) was considered the central area. Also, this study aimed at estimating the home range size of three raptor species (Falco femoralis, Rupornis magnirostris and Heterospizias meridionalis) through radio-telemetry; examining the efficiency of capture of birds of prey using two types of traps, bal-chatri and goshawk; and mapping land use/occupation of the study area and making the landscape analysis around the EEI. Between September 2005 and February 2007, 19 species of Falconiformes (Pandionidae n = 1, Falconidae n = 5, Accipitridae n = 13) were observed in a landscape basically occupied by monocultures (sugar cane 22 %, orange 14 %, eucalyptus 13 %) and pastures (2 1%). The average richness of Falconiformes in areas occupied by a monoculture was 4,6 species and 10,3 in natural areas. The species composition of the assemblage was more similar to those of other open areas influenced by Cerrado. Forty-eight individuals from five species were captured in the two types of traps. The general capture success was 15.3 % (n = 33) for the bal-chatri trap and 1 capture every 11,8 days (8,5 %) for the goshawk trap (n = 15). Implications and limitations of the capture of birds of preys in the areas were also discussed. The average home range obtained with the 95 % adaptive Kernel method (AK 95%) was 1.329 ± 780 ha for F. femoralis, 129 ± 140 ha for R. magnirostris and 1.883 ha for the individual of H. meridionalis. The average home range of F. femoralis was 2.8 higher in altered areas when compared to natural ones. In general, habitat quality seems to have influenced the different values of home range requirement of individuals, and also, in the selection/rejection of the different habitats. In most cases, monocultures were rejected, while natural areas were selected by raptors. Sugar cane plantations were rejected by all raptors. The only altered habitat used more than expected was pastures, selected by four of ten species analyzed. However, three species avoided this habitat. This is the first study to evaluate habitat selection by Falconiformes in Brazil and demonstrate that the increase of areas for agriculture may negatively affect even the most abundant and generalist species, contrary to some generalizations described in the literature. The interaction among the habitat structure, prey availability, morphology and hunting behavior seems to explain home range size requirements as well as the differential use of the various types of habitats.
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Uso do espaço e seleção de hábitat pelo Mico-Leão-da-Cara-Preta (Leontopithecus caissara) / Space use and habitat selection by the Black-faced Lion Tamarin (Leontopithecus caissara)Nascimento, Alexandre Túlio Amaral 20 June 2008 (has links)
Comprometida com a compreensão da relação entre hábitat e uso do espaço pelo mico-leão-da-cara-preta (Leontopithecus caissara), esta dissertação se norteia por três perguntas: Diferenças de hábitat entre ilha e continente influenciam o tamanho da área de vida? Há predileção da espécie por alguma classe de vegetação dentro da área de uso? Qual a capacidade suporte em sua área de ocorrência continental, bem como nas áreas potenciais para seu manejo conservacionista? Na tentativa de elucidar essas questões esta dissertação se divide em três capítulos. O primeiro contextualiza o trabalho e a apresenta o estado atual de conhecimento de L. caissara. Os capítulos segundo e terceiro concernem às questões centrais do trabalho - uso e seleção do hábitat pelo mico-leão-da-cara-preta. No capítulo dois apresentamos o uso do espaço pela espécie em sua região continental de ocorrência e comparamos os resultados obtidos com as informações disponíveis para a Ilha do Superagui. No capítulo três tratamos da seleção do hábitat por grupos insulares e continentais de L. caissara e estimamos a capacidade suporte para a espécie considerando seus limites de ocorrência e as áreas passíveis de receber animais em situação de manejo. Ao final desses capítulos apresentamos algumas considerações e recomendações para pesquisa e conservação do mico-leão-da-cara-preta. A preocupação com uma postura crítica e construtiva acerca das metodologias de estudos e análises sobre uso do espaço por espécies animais é transversal aos assuntos tratados ao longo de todo o trabalho. Os resultados apresentados confirmam as grandes áreas de vida de L. caissara, as quais parecem ser compensadas energeticamente pela incorporação de novas áreas e abandono de outras ao longo do tempo. Os tipos de hábitats mais intensamente utilizadas pelos mico-leão-da-cara-preta intercalaram áreas de floresta madura e em clímax edáfico com áreas antropizadas em sucessão, ambos hábitats sobre pouco desnível altimétrico. A capacidade suporte estimada é aparentemente incapaz de sustentar uma população viável e ressalta a urgência de pesquisas genéticas que colaborem para a compreensão do histórico ecológico/evolutivo de L. caissara. Potenciais translocações com vistas ao aumento populacional devem considerar as amplas áreas de diva, a espacialidade dinâmica, a relação uso/disponibilidade do hábitat e as diferenças entre ilha e continente. / This dissertation focuses on the interaction between habitat and space use by the black-faced lion tamarin (Leontopithecus caissara). We seek to answer three questions: 1) Do differences in vegetation between insular and continental habitats influence how the species use the space? 2) Does the species prefer a specific type of vegetation within its home-range? 3) What is the carrying capacity of the continental distribution and which are areas for potential conservation management? The first chapter of this dissertation relates the subjects discussed and introduces what is known about L. caissara. The second and third chapters develop the central questions of the research: the use and selection of habitat by the black-faced lion tamarin. In Chapter Two, we introduce space use by the species in its continental distribution and compare the results with data from Superagui Island. In Chapter Three, we address habitat selection by insular and continental groups of L. caissara and estimate the carrying capacity for the species given its distribution and areas potentially able to receive animals in a management context. The conclusion of each chapter presents considerations and recommendations for research and conservation. The study methods and analyses of space use aim to be critical and constructive and are relevant to the topics addressed throughout the text. The results presented confirm that the large home-ranges of L. caissara undergo dynamic turnovers, with some areas being abandoned and others incorporated throughout the year. The habitat types most intensively used by tamarins include areas of mature and forest mixed with areas of anthropic succession, both occurring at low altitudes. The estimated carrying capacity is apparently insufficient to maintain a viable population and highlights the importance of genetic studies that incorporate the ecological/evolutionary history of the species. Potential translocations meant to increase population size should consider the large home-ranges, dynamic spatial structure, relation of habitat use/availability and the differences between island and continent.
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