The effects of landscape structure on wildlife populations have drawn more attention from ecologists and wildlife managers as landscapes have rapidly changed worldwide. The objectives of this study were to (1) conduct a statewide habitat suitability assessment for wild turkeys (Meleagris gallopavo) in Mississippi using machine learning methods; (2) determine landscape-abundance relationships of wild turkeys at 2 spatial scales; and (3) measure genetic distinction of wild turkey populations in Mississippi. I found that habitat suitability for wild turkeys was positively related to amount of forest cover. Wild turkey relative abundance peaked at an optimal hardwood forest proportion of 0.29 and increased with enhanced landscape configuration at the annual dispersal scale, supporting the landscape composition hypothesis. Using microsatellite analysis of 224 birds, I found 3 distinct genetic clusters in Mississippi; however, population genetic differentiation neither fit to the isolation by distance or isolation by resistance models but may have behavioral cues.

The California Channel Islands present an ideal system in which to study unique biogeographical patterns seen in island systems near a mainland source, where spatial barriers are likely to limit gene flow without disrupting it completely. The islands also harbor a number of endemic taxa, suggesting that isolation from the mainland may be strong for some taxa. For this study, Acmispon argophyllus, a legume species found across five of the eight islands as well as on the mainland was used to test hypotheses at three spatial scales. Northern island populations have diverged into what potentially represents a new species; populations on the younger southern islands descent from populations on the older island of San Clemente; the two taxa on San Clemente show signs of genetic structure, with limited evidence of ongoing gene flow. These results demonstrate isolation over short distances in the Channel Islands leading to evolutionary divergence and speciation.

京都大学 / 新制・課程博士 / 博士(理学) / 甲第24310号 / 理博第4880号 / 新制||理||1698(附属図書館) / 京都大学大学院理学研究科生物科学専攻 / (主査)教授 曽田 貞滋, 准教授 渡辺 勝敏, 教授 中務 真人 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM

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Understanding how wildlife utilize habitat at varying scales is important for understanding and predicting potential impacts of landscape changes (e.g., habitat loss and fragmentation, restoration efforts, climate change, etc.) and in determining effective strategies for conservation and management. This research examines fine-scale and landscape-level habitat use of black bears in Canyon de Chelly National Monument (CACH), Arizona, USA in the context of large-scale landscape change. Currently, CACH is undergoing a large-scale restoration effort to remove all of the non-native Russian olive (Elaeagnus angustifolia) and tamarisk (Tamarix ramosissima and T. chinensis) within the monument. As black bears rely on the Russian olive as a primary food source, a major goal of this research was to evaluate how bears currently use this resource and how its removal might affect bear habitat use and bear-human interactions within the monument. I developed a model of 3rd order (fine-scale) black bear habitat use in CACH using an occupancy modeling approach. Model results indicated that fine-scale habitat selection by bears in CACH is being driven by the presence of non-native Russian olive as well as native food sources. Thus availability of native foods may be sufficient to maintain the bear population in CACH, and bears may quickly adapt to the loss of the non-native food source. Similarly, results showed that bears avoid human areas and farmsteads and prefer higher elevations, suggesting that once olive is removed in the lower canyons near human areas, bear-human interactions may become less of a problem over the long term. I also developed a model of 2nd order (landscape-level) habitat use and evaluated movement patterns of black bears in CACH using location data collected from GPS collars. Model results showed that bears selected areas with higher tree canopy cover and terrain ruggedness, indicating that forest cover and escape cover are primary factors driving black bear habitat selection at the landscape scale in this region. Movement patterns revealed large mean daily movements and low average turning angles, indicating long, linear movements designed to take advantage of the mosaic of available habitats and food resources available over larger areas. I extracted DNA from hair samples collected throughout the study area to examine genetic variability and population structure of black bears in the region. Analyses revealed a relatively healthy, panmictic population across the wider landscape. No substantial genetic structuring was observed in multiple analyses, though I did find evidence of a slight isolation-by-distance pattern within the population. Measures of both current (Nb = 24) and long-term (Ne = 579) effective population size indicated a relatively high number of breeders in the current population and a sufficient amount of gene flow within the larger "superpopulation" to maintain long-term genetic viability. I focused the final portion of my dissertation research on understanding the factors that influence stakeholder acceptance capacity for black bears, which plays a central role in contemporary wildlife management issues, including human-wildlife conflict. I used data from telephone interviews of 1,546 residents in Virginia to develop conceptual models of black bear acceptance capacity at both county and state levels. Model results suggested that more deep-seated and less easily influenced factors (e.g., values and risk perceptions) are at the heart of stakeholder attitudes and perceptions of wildlife, making influencing these perceptions more difficult. Agencies can indirectly affect these attitudes and perceptions, however, by targeting more potentially pliable factors related to wildlife acceptance capacity such as knowledge, personal experience with wildlife, and trust in management agencies. / Ph. D.

The United States Fish and Wildlife Service (USFWS) expressed the need to develop appropriate management strategies for apparently high-density, growing black bear populations in the Roanoke-Neuse-Tar-Cape Fear ecosystem in coastal North Carolina and Virginia. In order to provide the scientific information necessary to develop these strategies, I investigated population densities and genetic structure of black bears at 3 national wildlife refuges [Great Dismal Swamp (GDSNWR), Pocosin Lakes (PLNWR), and Alligator River (ARNWR)]. Density estimates were derived from DNA samples collected noninvasively at each of the 3 refuges for 2 consecutive summers. Hair samples were analyzed for individual identification using 6-7 microsatellite markers. Estimated densities were some of the highest reported in the literature and ranged from 0.56-0.63 bears/km2 at GDSNWR to 0.65-1.12 bears/km2 at ARNWR to 1.23-1.66 bears/km2 at PLNWR. Sex ratios were male-biased in all areas of all refuges. Genetic variability and structure of bears at these refuges was assessed using 16 microsatellite markers for 40 bears from each refuge. Genetic variability of the 3 refuge populations was substantially high compared to other bear populations in North America, with observed heterozygosities ranging from 0.6729 at GDSNWR to 0.7219 at ARNWR. FST and DS values were relatively low (0.0257-0.0895 and 0.0971-0.3640, respectively), indicating movement of bears and gene flow across the landscape is adequate to prevent high levels of genetic differentiation and structure among the refuge bears. Genetic statistics at GDSNWR indicate that this population is isolated to some degree by geography (i.e., the Albemarle Sound) and encroaching urban development (i.e., the towns of Suffolk and Chesapeake). ARNWR has the potential to become isolated in the future if movement corridors to the south of the refuge are not maintained. Harvest of bears is likely warranted at PLNWR and ARNWR, though extreme caution must be taken the first few seasons as hunter success will be extremely high. Further research is needed to determine population growth rates, reproductive parameters, and survival rates at all 3 refuges, particularly if a hunting season will be established and maintained in these areas. Methods for regularly monitoring bear populations at these refuges also should be incorporated into biological programs, as bears comprise a significant component of the ecosystem at these refuges and cannot be ignored when outlining management goals. / Master of Science

O tucumã-do-Amazonas (Astrocaryum aculeatum), da família Arecaceae, é uma espécie com ocorrência na Amazônia Ocidental e Central brasileira. Seu fruto é muito apreciado na região amazônica que consome a polpa na forma fresca. Sua produção é feita pelos agricultores extrativistas. Não existem informações dos parâmetros de diversidade e estrutura genética das populações naturais desta espécie, fundamental para o estabelecimento de estratégias adequadas no uso deste recurso genético, e para aumentar a eficiência da domesticação e seleção para um programa de melhoramento genético. Não é conhecido também como este extrativismo pode estar influenciando a diversidade entre estas populações ao nível dos genitores e progênies, o fluxo gênico e a estrutura genética espacial. Assim, o objetivo desta pesquisa foi caracterizar a estrutura e a diversidade genética de populações de A. aculeatum no Estado do Amazonas, utilizando marcadores microssatélites. Como objetivos específicos o estudo visou desenvolver iniciadores de microssatélites para A. aculeatum; avaliar a diversidade e a estrutura genética; determinar o fluxo gênico, bem como o grau de parentesco, a estrutura genética espacial (EGE) e o coeficiente de coancestria numa população. Os iniciadores de microssatélites foram isolados a partir de uma biblioteca genômica enriquecida e caracterizados usando 40 amostras provenientes de duas populações selvagens. Foram identificados 14 iniciadores de microssatélites, mostrando um alto polimorfismo nas populações avaliadas. Para estimar a diversidade e estrutura genética foram utilizadas amostras de material vegetal de 218 plantas distribuídas em 15 populações, localizadas em 14 municípios do estado de Amazonas. Foram identificados 101 alelos nos iniciadores, com média de 10,1 alelos. As médias das heterozigosidades observadas (HO) foram superiores às esperadas (HE) ao nível de população (HO=0,639, HE=0,557) e locos (HO=0,639; HE=0,594). Os baixos valores de FST (0,07) mostraram uma moderada estrutura populacional e a análise Bayesiana indicou um agrupamento mais adequado de k=4, o que foi confirmado pelas análises de PCoA. Para realizar o fluxo gênico, EGE e coeficiente de coancestria foram utilizadas 244 amostras de material vegetal, distribuídas entre 112 possíveis genitores, 12 matrizes e 120 progênies numa população. Foi detectada EGE significativa para os adultos até a distância de 50 m, indicando dispersão de sementes a curtas distâncias. A análise de paternidade detectou 9,2% de imigração de pólen. Não foram detectadas autofecundações e a distância média de polinização dentro da população foi de 81 m. Os índices de diversidade genética confirmaram a estratégia reprodutiva por alogamia da espécie, com níveis elevados de heterozigotos nas populações, e a estrutura genética sugere que a espécie teria iniciado o processo de formação das subpopulações há pouco tempo, tendo sido influenciada antes e após o início do desmatamento. O fluxo gênico detectado indica que a entrada de alelos na população através da imigração de pólen está contribuindo para manutenção da diversidade genética da população. Com relação à conservação da espécie, esta deve ser realizada ao nível das bacias hidrográficas, direcionando políticas de manejo para as bacias hidrográficas da Amazônia. Entretanto, dentro da população é importante a renovação com novas progênies selecionadas a partir de um espaçamento mínimo de 50 m entre plantas matrizes para diminuir as probabilidades de coletar sementes de plantas parentes. / The tucum palm (Astrocaryum aculeatum), family Arecaceae, is a species occurring in Western and Central Brazilian Amazon. Its fruit is widely appreciated in the Amazon region that consumes the pulp in fresh form. Its production is made by extractive farmers. There is no information on the genetic diversity and structure of natural populations of this species, fundamental to establishing adequate strategies in the use of this genetic resource, increase the efficiency of domestication and selection for a breeding program. It is also unknown the way this extrativism may be influencing to diversity of these populations at the level of the parents and offspring, as well as gene flow and spatial genetic structure. Therefore, the objective of this research was to characterize the structure and genetic diversity of populations of A. aculeatum in Amazonas State, using microsatellite markers. As specific objectives, the study aimed to develop microsatellite primers for A. aculeatum; evaluate the genetic diversity and structure; determine the gene flow, the degree of relationship or kinship, the spatial genetic structure (SGS) and the coefficient of coancestry in one population. The loci were isolated from a microsatellite-enriched genomic library and were characterized using 40 samples coming from two wild populations. Fourteen microsatellite primers were identified, showing a high polymorphism in the populations evaluated. To estimate the genetic diversity and structure we used samples of plant material from 218 plants distributed in 15 populations located in 14 municipalities of the state of Amazonas. A total of 101 alleles were identified in the primers, with an average of 10.1 alleles. The averages of the observed heterozygosities (HO) were higher than the expected heterozygosities (HE) at the population (HO=0.639; HE=0.557) and loci (HO=0.639; HE=0.594) levels. The low values of FST (0.07) showed a moderate population structure and the Bayesian analysis indicated as the most suitable a cluster of k=4, confirmed by the groups formed in the PCoA. To conduct gene flow, SGS and the coefficient of coancestry, 244 samples of plant material were used, distributed among 112 possible progenitors, 12 matrices and 120 progenies in a population. A significant SGS was detected for adult trees up to the distance of 50 m, indicating seed dispersal over short distances. Paternity analysis indicated 9.2% of pollen immigration. Selfing was not detected and the average distance of pollination within the population was 81 m. The genetic diversity indices confirmed the outcrossing reproductive strategy of the species with high levels of heterozygotes in the populations, and the genetic structure suggests that the species would have started the process of formation of subpopulations a short time ago, being influenced before and after the start of deforestation. The gene flow detected indicates that the entry of alleles in the population through pollen immigration is contributing to the maintenance of genetic diversity of the population. With respect to the conservation of the species, it should be performed at the level of the river basins, directing management policies for the river basins of the Amazon. However, within the population it is important to renew with new progenies selected from a minimum spacing of 50 m between plant matrices to decrease the probability of collecting seeds from plant relatives.