Download or read book An Integrative Population and Landscape Genomic Approach to Conservation of a Threatened California Amphibian at Multiple Spatial Scales written by Kevin M. Neal and published by . This book was released on 2019 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt: Amphibians are threatened world-wide, and due to the elusive, seasonal, and often nocturnal habits of adults, biological assessments of amphibian species are often best conducted via genetic analysis of easily-sampled pond-dwelling larvae. Genetic analysis of amphibian species can benefit their conservation in several ways, including identification of evolutionary lineages and subpopulations as fundamental units of conservation, genetic assessment of demography and diversity, and inference of patterns of gene flow among populations and how patterns are affected by environmental variation. In this dissertation I elucidated the evolutionary relationships and population genetic status of a threatened California amphibian (Spea hammondii) at multiple spatial scales using a combination of genetic, genomic, and environmental data. Chapter one utilized limited genetic data to determine phylogenetic relationships of Spea species and used environmental niche modeling to examine ecological differentiation between two allopatric lineages identified within S. hammondii. Chapter two took advantage of a newer genomic-scale dataset of thousands of SNP markers to look at fine-scale patterns of genetic variation among natural and artificial S. hammondii ponds in a highly urbanized region of Southern California. Chapter three also made use of thousands of markers to validate species-level relationships in Spea and used the added genomic resolution to examine relationships within and among genetic clusters and quantified the potential impacts of urbanization on functional genetic connectivity. Broadly, I found that the nominal taxon S. hammondii likely comprises two species. Populations within each species were highly differentiated from one another and had exceptionally low effective population sizes, such that each species lacks sufficient adaptive potential to thrive without intervention. Overall, this dissertation applied a suite of phylogenetic, population genomic, and landscape genomic tools to analyze patterns of genetic variation in S. hammondii to guide ongoing and future conservation efforts.

Download or read book Landscape and Conservation Genetics of Amphibians and Reptiles in California written by Erin Maurine Toffelmier and published by . This book was released on 2019 with total page 147 pages. Available in PDF, EPUB and Kindle. Book excerpt: Examining patterns of diversity at fine and global spatial scales is an important component of to inferring underlying evolutionary mechanisms, understanding species distributional patterns, and informing conservation. Globally, amphibians and reptiles are among the fastest declining taxonomic groups, and now more than ever, it is necessary to quantify diversity and its spatial drivers in order to most effectively conserve species. In this dissertation, I examine the population, landscape, and conservation genomics of several species along a continuum of endangerment, from highly endangered and on the brink of extinction to widespread and abundant. Throughout, I use large-scale molecular data sets coupled with spatial analyses to examine spatial genetic diversity in these varied species. My goals were to contribute to our understanding of how genetic diversity is distributed across a multitude of landscapes and to provide genetic context for the conservation of these species. In Chapters 1 and 2, I examined how genetic diversity is spread across the limited ranges of two ecologically disparate species, California tiger salamanders, Ambystoma californiense, in Santa Barbara County, and the Panamint alligator lizard, Elgaria panamintina, found only in the isolated desert mountain ranges of eastern California, and found surprising parallels. In both, I found populations with exceedingly low levels of genetic diversity and genetic effective population sizes. For tiger salamanders, genetic diversity and divergence is strongly correlated with the number of suitable breeding habitats in regional neighborhoods and presence of natural vernal pools, while divergence across the range of E. panamintina is primarily mediated by geographic distance. In both cases, our findings have important implications for how management and mitigation efforts may more effectively assist the recovery and/or protection of these groups. In Chapter 3, I examined the drivers of spatial genetic structure in the widespread southern alligator lizard, Elgaria multicarinata. I found that patterns of genetic isolation are driven primarily by geographic distances, but that regional ecological niches have also diverged. Collectively, my work demonstrates the utility of integrating genetic and spatial analyses across spatial scales to help elucidate how genetic diversity is distributed across variable landscapes.

Download or read book Genomic Approaches to Confront Disease caused Amphibian Declines written by Thomas Poorten and published by . This book was released on 2015 with total page 85 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recently emerged diseases in natural populations present novel problems for biodiversity conservation. Integrated approaches are needed to better understand disease-related threats, to mitigate these threats, and to assist population recovery. My dissertation research confronts the global amphibian biodiversity crisis. The recently emerged infectious disease chytridiomycosis, caused by the chytrid fungal pathogen Batrachochytrium dendrobatidis (Bd), infects hundreds of species around the world and is a major contributor to amphibian population declines. I use a multi-faceted approach to address critical issues of disease-caused amphibian declines. In this dissertation, I implement a novel methodology to gain insights on variability of host response to Bd (Chapter 2). Next, I analyze the spatial genetic structure of post-decline populations to aid conservation (Chapter 3). Finally, I examine the genetic underpinnings of pathogen attenuation - loss of virulence - using genomic sequencing (Chapter 4). First, I examine differential disease progression and host response in two related species (Chapter 2). Determining how different hosts respond to infection by a widespread pathogen is essential for understanding - and ultimately limiting - the devastating effects of emerging infectious diseases. Previous work demonstrated that susceptibility to chytridiomycosis is variable among species, but the mechanism(s) that underlie the difference between winners and losers remains a mystery. I used an integrative approach to analyze host response to infection in two related toad species that are thought to differ in susceptibility: the invasive Cane Toad (Bufo marinus) and the threatened Boreal Toad (Bufo boreas). With my results, I characterize the nature of differential susceptibility and compare host response using genome-wide gene expression analysis. The susceptible B. boreas exhibited high pathogen loads, loss in body weight, severe changes in the epidermis, and dramatic transcriptomic changes without a robust immune response. Conversely, the resistant B. marinus exhibited low pathogen loads, stable body weight, only mild disruption of the epidermis and relatively few changes in transcriptomic profile. Together our results show intrinsic differences in host response between related species, which are likely to be an important factor in explaining variation in response to a deadly emerging pathogen in wild populations. Second, I conducted a conservation genetics study of an endangered amphibian species in Yosemite National Park (Chapter 3). The most striking example of chytrid-associated population declines in North America is the mountain yellow-legged frog (Rana muscosa and Rana sierrae), including populations in Yosemite National Park. A clear picture of genetic structure and demography of remaining R. sierrae populations is critical to short-term management and conservation. I conducted a study to describe phylogeographic patterns of R. sierrae in Yosemite NP in collaboration with ecologists and park biologists. I utilized a recently developed method for multilocus amplicon sequencing that allows sequence data collection from a vast collection of swabs that contain low quantities of input DNA. My analysis of population genetic structure suggests that three genetic clusters occur in Yosemite NP with a significant signature of isolation by distance. This analysis of population genetic structure adds a critical component to the population recovery plan and will assist management strategies such as translocations, reintroductions, and monitoring. Third, I investigated the genomic changes associated with virulence attenuation in a lab-evolved Bd strain (Chapter 4). Despite recent efforts to characterize the diversity of Bd lineages, there are many questions that remain about the genetic underpinnings of pathogenicity. In a collaborative study, I take advantage of an accidental case of virulence reduction in a Bd strain that was lab passaged over many generations. I analyzed the genomic changes in strain samples cryo-archived before and after virulence attenuation. I found multiple patterns that may be linked to attenuation including decreases in chromosome copy number and mutations in putative virulence genes. These results contribute to the growing body of knowledge of how changes in pathogen genomes occur within a relatively short period of time, which has major implications for host-pathogen dynamics in natural systems. In conclusion, my dissertation provides important new contributions to the study of host-pathogen interactions with specific relevance to the fields of disease biology, conservation genetics, and pathogen evolution. Integrating genomic tools into a variety of experimental methods enabled not only valuable novel insights, but also opened up many new opportunities for further exploration of disease-caused amphibian declines using the generated genomic and computational resources.

Download or read book Amphibian Ecology and Conservation written by C. Kenneth Dodd and published by Oxford University Press. This book was released on 2010 with total page 585 pages. Available in PDF, EPUB and Kindle. Book excerpt: Describes the latest methodologies used to study the ecology of amphibians throughout the world. Each of the 27 chapters explains a research approach or technique, with emphasis on careful planning and the potential biases of techniques. Statistical modelling, landscape ecology, and disease are covered for the first time in a techniques handbook.

Download or read book California Amphibian and Reptile Species of Special Concern written by Robert C. Thomson and published by Univ of California Press. This book was released on 2016-06-21 with total page 407 pages. Available in PDF, EPUB and Kindle. Book excerpt: One of the most important hotspots of herpetological biodiversity in the United States, California is home to many endemic amphibians and reptiles found nowhere else on earth. Many of these taxa have unique ecological and morphological specializations, and their management is an important conservation challenge. Increasing climate change impacts, human development, and extreme drought mean many of these species face an ever-greater risk of extinction. California Amphibian and Reptile Species of Special Concern provides an up-to-date synthesis of the current state of knowledge regarding the biology and conservation risks faced by 45 of California’s most sensitive amphibian and reptile species. With the goal of enhancing management based on the best available science, the authors developed a novel set of risk metrics to identify special concern species and the threats they face, including population declines, range size and restrictions, and ecological specializations and niche restrictions. In addition to detailed species accounts, this book provides a quantitative analysis of the conservation status and pressing management issues facing individual species and the state’s amphibian and reptile fauna as a whole. The volume focuses on identifying threats, concrete recommendations for management and recovery, and future research needs. The text is complemented by detailed distribution maps, color photos, and graphs. Written in nontechnical language, California Amphibian and Reptile Species of Special Concern will be a valuable resource to a broad range of users from resource managers, field biologists, and academic herpetologists to students and recreational naturalists. Published in association with the California Department of Fish and Wildlife.

Download or read book Rewilding Agricultural Landscapes written by H. Scott Butterfield and published by Island Press. This book was released on 2021-04-08 with total page 290 pages. Available in PDF, EPUB and Kindle. Book excerpt: As the world population grows, so does the demand for food, putting unprecedented pressure on agricultural lands. In many desert dryland regions, however, intensive cultivation is causing their productivity to decline precipitously. "Rewilding" the least productive of these landscapes offers a sensible way to reverse the damage, recover natural diversity, and ensure long-term sustainability of remaining farms and the communities they support. This accessibly written, groundbreaking contributed volume is the first to examine in detail what it would take to retire eligible farmland and restore functioning natural ecosystems. The lessons in Rewilding Agricultural Landscapes will be useful to conservation leaders, policymakers, groundwater agencies, and water managers looking for inspiration and practical advice for solving the complicated issues of agricultural sustainability and water management.

Download or read book A Framework for Amphibian Habitat Conservation Across Spatial Scales Using Community Occupancy Models written by Vishnupriya Sankararaman and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Agricultural intensification and loss of native forest habitats have presented the most ubiquitous threats to faunal communities across the world. These land use modifications have caused loss of species richness, genetic diversity, biotic homogenization, and increased dominance structure from local, regional to global scales. Amphibians are amongst the most endangered vertebrate groups with high susceptibility to habitat modification. Their biphasic life history, poor mobility and low tolerance to chemical pollutants make it difficult for most species to adapt to intensively managed land uses. To combat pressures from habitat loss, commodity agroforests are recommended as suitable secondary habitats for many threatened faunal communities. However, there is little applied research on how individual land management strategies at various spatial scales can help design more wildlife-friendly landscapes. The research presented in this dissertation, uses community ecology theory to examine: (1) how land use gradients shape amphibian species and communities across local and regional spatial extents, (2) how individually evolved life history strategies influence adaptations to different habitats and land uses, (3) how conservation objectives and decisions can shape land use design in terrestrial and aquatic environments to maximize conservation potential of agroforests. In the first chapter, I studied patterns in alpha and beta diversity across areca, coffee and rubber agroforests across Karnataka's Western Ghats. A total of 106 agroforests across a 30,000 km2 landscape were surveyed for amphibians, and a multispecies occupancy model approach was used to analyze and estimate community-level and species-specific parameters. The broad-scale influence of elevation and latitude and fine-scale influences of microhabitat availability were examined on species occurrences. The availability and heterogeneity of microhabitats were also used to predict species occurrences. Overall, a heterogenous land use such as shade-grown coffee hosted much higher species richness than the more intensively managed areca and rubber agroforests. Our results indicate that site-specific diversity can be enhanced with careful management. The preservation of aquatic and terrestrial microhabitats can increase amphibian species richness by up to 75% in each agroforest. The second chapter focuses on examining the influence of life history traits on species occupancy and community structure across terrestrial and stream habitats in different land uses. I surveyed 223 transects for amphibians across tea, coffee and forest fragments in the Anamalai Hills of the Western Ghats. A joint-species distribution model was used to estimate species occupancies and cooccurrence patterns. Species richness was highest in forest fragments followed by coffee and lowest in tea agroforests. Life-history traits clearly defined habitat use, with fast-water breeding amphibians preferring forested streams first, followed by streams in coffee and the lowest occupancy was observed in tea streams. Slow-water breeding amphibians showed a reverse trend with higher preference for tea over coffee and forest stream sites. The study also revealed important patterns in species distributions across elevational ranges and the influence of annual climate patterns on amphibian populations. The results from this chapter highlight the importance of focusing conservation attention on amphibians with torrential habitat associations as they are the most vulnerable to land use intensification. In chapter three, I advance the understanding of amphibian community structure at broader spatial scales. Using results from chapter two, I estimate pairwise species dissimilarity across sites and examine the role of geographic distances, environmental distances, watershed aspects and land use on beta diversity. The mean beta diversity was lowest for within forest sites and highest for comparisons between coffee and forests. Also, terrestrial habitats displayed greater heterogeneity in species compositions than stream habitats. Rather than geographic distances, the difference in elevation was one of the strongest predictors of beta diversity patterns at the regional scale. The combined influences of the different predictors indicate that prioritizing conservation management across different land uses, elevation gradients and watersheds will be most effective in maintaining the regional diversity and heterogeneity of amphibian communities in the Anamalai Hills. Finally, in the fourth chapter, I use results from all three previous research findings with additional information about ecosystem services to identify where riparian forest restoration can have optimal conservation outcomes. Prioritization was based on predicted increase in alpha diversity, and topographic wetness index (TWI), along with elevational attributes. Five alternate scenarios were set up based on these criteria. The results were tested on ten coffee sites, ten tea sites and a combination of five coffee and tea sites. Species richness was revealed to be a poor criterion for prioritization as it resulted in the most spatially aggregated portfolio of sites and with lowest predicted gamma diversity. Incorporating TWI in land use prioritization yielded much higher gamma diversity and ecosystem function benefits. I also discuss the socioeconomic implications of restoring riparian buffers for private land owners in the region and propose mechanisms by which the restoration costs can be managed. Conservation management has to be scale dependent and rely on local and regional studies to provide empirical evidence for how decisions influence outcomes. I used a combination of theories in community ecology with applied conservation science to provide greater understanding of fine-scale and broad-scale factors influencing agrobiodiversity. This research also expands the use of hierarchical community occupancy models to examine different aspects of spatial variations in multispecies assemblages, particularly in poorly-studied and hyper-diverse tropical regions.

Download or read book Field Guide to Amphibians and Reptiles of California written by Robert C. Stebbins and published by Univ of California Press. This book was released on 2012-09-04 with total page 552 pages. Available in PDF, EPUB and Kindle. Book excerpt: “Since his first book on western amphibians in 1951, Stebbins has been recognized as the authoritative voice on this subject. This new book, written with McGinnis, continues that high standard of accuracy and usefulness. It is filled with entertaining anecdotes and user-friendly information. I recommend this to anyone getting their first introduction to the rich and diverse world of Californian herpetofauna.” -David Wake, Curator, Museum of Vertebrate Zoology, UC Berkeley “Dr. Robert Stebbins is the elder herpetological master of the American West, and this book has long been one of the finest state field guides to amphibians and reptiles. Now partnering to create a new, expanded edition with accomplished biologist Dr. Samuel McGinnis, a classic publication has become even better. Both the professional herpetologist and the weekend amateur naturalist will find this top-notch guide to be invaluable when exploring California's diverse landscapes.” -Alan St. John, author of Reptiles of the Northwest

Download or read book Understanding Amphibian Vulnerability to Extinction written by Sarah J. Corey and published by . This book was released on 2009 with total page 187 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: In the global extinction crisis currently underway, threats to biodiversity are not simply limited to species with particular risks in particular cases. Biodiversity will be increasingly affected by the wholesale decline of entire clades. In the face of this crisis, with amphibians ranking at the top of all vertebrates in the rate of extinctions, there is a great need for macroecological studies addressing three key areas of species declines. The processes that put species at great risk for extinction may be associated with 1) environmental factors, 2) spatially structured, or geographic effects, and 3) evolutionary predispositions to those processes (phylogenetic structure in vulnerability). I present a collection of work to address primarily the phylogenetic and geographic components of species vulnerability. First, I construct a theoretical foundation for using phylogenetic comparative methods for conservation assessments, emphasizing the importance of evolutionarily specific parameters and trees. I prescribe a greater conservation focus on understanding the severity of clade-level threats and potential data deficient species vulnerability, and identify evolutionary scenarios with the greatest return on resource investments. Second, I identify autocorrelated threats in the amphibian tree of life representing potential evolutionary predispositions to enigmatic rapid declines and Redlist threatened status in the superfamily Hyloidea. Third, I focus in on a family in Hyloidea, Hylidae, and use multiple phylogenetic comparative methods to identify phylogenetic signal in processes that selectively threaten lineages in the tree. I find phylogenetic signal (a predisposition to vulnerability) in pollution, habitat loss, species with multiple threatening processes, Redlist threatened status, and enigmatic rapid declines, concentrated in the clade Hylini. Among the comparative methods employed is a new application for conservation of a more flexible measure of phylogenetic signal accounting for selection using an Ornstein-Uhlenbeck model. Fourth, I use a landscape perspective to discover what spatial and environmental factors predict threats to amphibians in Venezuela. I find that traditional measures of human impact (population density and ecological footprint) effectively predict higher numbers of threatened amphibians, but indigenous peoples population density does not predict threats. Accounting for spatial dependence in the landscape reveals that cultural stewardship, i.e., parks on indigenous versus nonindigenous land, cannot predict threatened species distributions, failing to validate typical conservation concerns over indigenous population impacts to parks and biodiversity. Using a local spatial autocorrelation metric, I also find that the northwest region of Venezuela is a hotspot of geographic irreplaceability, for spatially autocorrelated threatened species, endemics and data deficient species. Overall, my collection of work addresses key themes in the amphibian extinction crisis using a macro-analytic approach: evolutionary predisposition to threats, anthropogenic threatening processes and spatial autocorrelation (or clumping) of threatened species. My work supports the emerging consensus that the extinction crisis is widespread, in terms of impact to phylogenetic diversity and geographic regions, but my findings also point to advantages for conservation policy and management gained by prioritizing vulnerable clades and geographic regions that stand to lose the most diversity and hold the greatest potential management payoffs.

Download or read book Landscape Genetics of Habitat Alteration Across Multiple Spatial and Temporal Scales in the Anuran Genus Ascaphus written by Stephen Frank Spear and published by . This book was released on 2009 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book California Amphibians and Reptiles written by Robert Hansen and published by Princeton University Press. This book was released on 2025-01-14 with total page 528 pages. Available in PDF, EPUB and Kindle. Book excerpt: A spectacularly illustrated field guide to the amphibians and reptiles of California California is home to more than 200 species of reptiles and amphibians that can be found in an extraordinary array of habitats, from coastal temperate rainforests with giant redwoods to southeastern deserts offering dazzling wildflower displays each spring. California Amphibians and Reptiles covers every species and subspecies in this biodiverse region of the United States, with outstanding color photography and in-depth species accounts that draw on the latest findings on taxonomy and distribution. Setting a new standard for regional field guides, this state-of-the-art guide will serve as the definitive reference for California’s amphibian and reptile fauna for many years to come. Covers all 209 species of amphibians and reptiles found in California Features hundreds of stunning photos that illustrate geographic and within-species variation as well as differences among males, females, and young Includes first-ever color images and species accounts for newly discovered species Shows every species and subspecies in full color on a white background Depicts all amphibian larvae in breathtaking color Detailed species accounts describe key identification features, similar species, habitat, range and elevation, activity and behavior, diet, reproduction, and conservation Provides updated status of all threatened, endangered, nonnative, and special concern species Accurate range maps reflect contemporary and, where applicable, historical distributions in light of significant habitat loss across the state An invaluable resource for amateur naturalists, resource managers, and professional herpetologists

Download or read book Quantifying Monitoring and Managing Biodiversity Across Multiple Spatial Scales written by Alexander D. Wright and published by . This book was released on 2021 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation aims to investigate how science can effectively inform management and policy decisions, leading to positive conservation outcomes for vulnerable wildlife communities. Successful conservation requires the incorporation of ecological uncertainty and socio-ecological complexity into the decision-making process. To navigate the uncertainty and complexity pertinent to landscape conservation, I demonstrate a multi-scaled approach to quantify, monitor, and manage amphibians in a case study of a regional network of national parks. In Chapter 1, I quantify biodiversity across multiple spatial scales by fitting a multi-region community occupancy model to regional amphibian monitoring data to elucidate the drivers and threats(s) to biodiversity and the relevant scale(s) to target management. In Chapter 2, I explore the efficacy of different monitoring programs and identify strategies to monitor biodiversity across multiple spatial scales to minimize uncertainty in system dynamics. In Chapter 3, I predict the impacts of, and then spatially prioritize, management to increase biodiversity across multiple spatial scales by incorporating governance complexity in the decision-making process. In Chapter 4, I synthesize findings from previously published studies to determine the extent, and conditions under which, decision support frameworks can lead to positive conservation outcomes. The chapters of this dissertation provide critical guidance on how to scale up conservation science to match the scope and scale of the ecological systems and governance structures it is meant to inform. The application of this knowledge can help conservation scientists, managers, and policy makers address the complex and multi-scaled biodiversity crisis.

Download or read book Influence of Forest Management on Headwater Stream Amphibians at Multiple Spatial Scales written by Margo A. Stoddard and published by . This book was released on 2004 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Linkages in the Landscape written by Andrew F. Bennett and published by IUCN. This book was released on 2003 with total page 261 pages. Available in PDF, EPUB and Kindle. Book excerpt: The loss and fragmentation of natural habitats is one of the major issues in wildlife management and conservation. Habitat "corridors" are sometimes proposed as an important element within a conservation strategy. Examples are given of corridors both as pathways and as habitats in their own right. Includes detailed reviews of principles relevant to the design and management of corridors, their place in regional approaches to conservation planning, and recommendations for research and management.

Download or read book Amphibian Declines written by Michael Lannoo and published by Univ of California Press. This book was released on 2005-06-15 with total page 1117 pages. Available in PDF, EPUB and Kindle. Book excerpt: This benchmark volume documents in comprehensive detail a major environmental crisis: rapidly declining amphibian populations and the disturbing developmental problems that are increasingly prevalent within many amphibian species. Horror stories on this topic have been featured in the scientific and popular press over the past fifteen years, invariably asking what amphibian declines are telling us about the state of the environment. Are declines harbingers of devastated ecosystems or simply weird reflections of a peculiar amphibian world? This compendium—presenting new data, reviews of current literature, and comprehensive species accounts—reinforces what scientists have begun to suspect, that amphibians are a lens through which the state of the environment can be viewed more clearly. And, that the view is alarming and presages serious concerns for all life, including that of our own species. The first part of this work consists of more than fifty essays covering topics from the causes of declines to conservation, surveys and monitoring, and education. The second part consists of species accounts describing the life history and natural history of every known amphibian species in the United States.

Download or read book Analyzing Landscape Connectivity in Coastal Southern California Using an Indicator Species Lynx Rufus written by and published by . This book was released on 2019 with total page 57 pages. Available in PDF, EPUB and Kindle. Book excerpt: In California, urbanization is a leading cause of habitat fragmentation. Although the consequences of a loss of landscape connectivity are typically described at a local extent, regional analyses, particularly for wide-ranging species, can be used to identify management priorities. We monitored trends in the abundance and density of bobcats through motionsensor cameras to measure potential effects of landscape fragmentation at the local scale and performed a landscape level bobcat genetic analysis across southern California, including two outgroups from northern California for comparison. Spatial capture-recapture (SCR) models are widely used to estimate population abundance and density from pictures taken at camera traps. We paired SCR with spatial partial identity models (SPIM) to estimate density of bobcats from camera traps located in three study areas in San Diego County (SD) across an urbanization gradient. We found that locally in SD, the area with the highest level of urbanization had lower bobcat density than the more natural study area, and that these densities were lower than estimates from published studies with comparable methodological approaches. With an inter-lab validation methodology, we performed a comprehensive analysis using 19 microsatellite loci for 118 individuals and 11 loci for 422 individuals. We then conducted hierarchical analyses of population genetic structure and examined how pairwise genetic distance of all population clusters aligned with geographic distance using the 19 loci dataset. Lastly, we employed a landscape genetic analysis based on resistance to determine which features of the landscape likely play a role in determining the patterns of genetic structure we observed among bobcats in southern California. Regionally in southern California, we found that some populations were constrained by major freeways and development, while populations with no clear major anthropogenic barriers to movement between them were genetically similar. Through our landscape genetic analysis, we found permeability to be the strongest predictor of the observed patterns of genetic variation across southern California bobcats. Our results highlight the importance of analyzing population parameters and genetic patterns at multiple scales, and underscore how the differences between local and regional patterns may require site-specific conservation and management actions in increasingly developed areas.

Download or read book Spatial Ecology of the Cascades Frog written by Justin Matthew Garwood and published by . This book was released on 2009 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt: