Download or read book Enhancing Line transect Distance Sampling to Increase Detectability of Gopher Tortoises gopherus Polyphemus in Population Surveys written by Heather Elizabeth Gaya and published by . This book was released on 2019 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gopher tortoise (Gopherus polyphemus) populations are declining range-wide and accurate abundance and demographic estimates are needed for proper management of the species. I developed a series of Bayesian hierarchical models to estimate the density and size demography of gopher tortoise populations while accounting for size bias against smaller individuals. In conjunction with the estimation models, I designed a survey to incorporate randomly located double-sampling blocks and systematic vegetation measurements into the standard distance sampling methodology to better account for sources of variability known to affect detection of all tortoises. My results suggest that my hierarchical models and double-sampling survey method may increase the accuracy and precision of both density point estimates and the underlying burrow size distribution estimates of gopher tortoise populations.
Download or read book Advanced Distance Sampling written by S. T. Buckland and published by OUP Oxford. This book was released on 2004-08-19 with total page 434 pages. Available in PDF, EPUB and Kindle. Book excerpt: This advanced text focuses on the uses of distance sampling to estimate the density and abundance of biological populations. It addresses new methodologies, new technologies and recent developments in statistical theory and is the follow up companion to Introduction to Distance Sampling (OUP, 2001). In this text, a general theoretical basis is established for methods of estimating animal abundance from sightings surveys, and a wide range of approaches to analysis of sightings data is explored. These approaches include: modelling animal detectability as a function of covariates, where the effects of habitat, observer, weather, etc. on detectability can be assessed; estimating animal density as a function of location, allowing for example animal density to be related to habitat and other locational covariates; estimating change over time in populations, a necessary aspect of any monitoring programme; estimation when detection of animals on the line or at the point is uncertain, as often occurs for marine populations, or when the survey region has dense cover; survey design and automated design algorithms, allowing rapid generation of sound survey designs using geographic information systems; adaptive distance sampling methods, which concentrate survey effort in areas of high animal density; passive distance sampling methods, which extend the application of distance sampling to species that cannot be readily detected in sightings surveys, but can be trapped; and testing of methods by simulation, so that performance of the approach in varying circumstances can be assessed.
Download or read book Analysis of Gopher Tortoise Population Estimation Techniques written by Raymond R. Carthy and published by . This book was released on 2005 with total page 35 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Distance Sampling Methods and Applications written by S. T. Buckland and published by Springer. This book was released on 2015-08-08 with total page 285 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this book, the authors cover the basic methods and advances within distance sampling that are most valuable to practitioners and in ecology more broadly. This is the fourth book dedicated to distance sampling. In the decade since the last book published, there have been a number of new developments. The intervening years have also shown which advances are of most use. This self-contained book covers topics from the previous publications, while also including recent developments in method, software and application. Distance sampling refers to a suite of methods, including line and point transect sampling, in which animal density or abundance is estimated from a sample of distances to detected individuals. The book illustrates these methods through case studies; data sets and computer code are supplied to readers through the book’s accompanying website. Some of the case studies use the software Distance, while others use R code. The book is in three parts. The first part addresses basic methods, the design of surveys, distance sampling experiments, field methods and data issues. The second part develops a range of modelling approaches for distance sampling data. The third part describes variations in the basic method; discusses special issues that arise when sampling different taxa (songbirds, seabirds, cetaceans, primates, ungulates, butterflies, and plants); considers advances to deal with failures of the key assumptions; and provides a check-list for those conducting surveys.
Download or read book Distance Sampling written by Stephen T. Buckland and published by . This book was released on 1993 with total page 472 pages. Available in PDF, EPUB and Kindle. Book excerpt: Introductory concepts. Introduction. Range of applications. Types of data. Known constants and parameters. Assumptions. Fundamental concept. Detection. History of methods. Program DISTANCE. Assumptions and modelling philosophy. Assumptions. Fundamental models. Philosophy and strategy. Robust models. Some analysis guidelines. Statistical theory. General formula. Hazard-rate modelling of the detection process. The key function formulation for distance data. Maximum likelihood methods. Choice of model. Estimation for clustered populations. Density, variance and interval estimation. Stratification and covariates. Line transects. Introduction. Example data. Truncation. Extensions and related work. Other models. Modelling variation in encounter rate and cluster size. Estimation of the probability of detection on the line or pint. On the concept of detection search effort. Fixed versus random sample size. Efficient simulation of distance data. Thoughts about a full likelihood approach. Distance sampling in three dimensions. ...
Download or read book Distance Sampling written by Rosemary K. Barraclough and published by . This book was released on 2000-08-01 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Reptile Biodiversity written by Roy W. McDiarmid and published by Univ of California Press. This book was released on 2012-01-10 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt: “Authoritative and comprehensive—provides an up-to-date description of the tool box of methods for inventorying and monitoring the diverse spectrum of reptiles. All biodiversity scientists will want to have it during project planning and as study progresses. A must for field biologists, conservation planners, and biodiversity managers.”—Jay M. Savage, San Diego State University “Kudos to the editors and contributors to this book. From the perspective of a non-ecologist such as myself, who only occasionally needs to intensively sample a particular site or habitat, the quality and clarity of this book has been well worth the wait.”—Jack W. Sites, Jr.
Download or read book Distance Sampling Surveys written by Joshua Harold Schmidt and published by . This book was released on 2022 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wildlife population estimators often require formal adjustment for imperfect detection of individuals during surveys. Conventional distance sampling (CDS) and its extensions (mark-recapture distance sampling [MRDS], temporary emigration distance sampling [TEDS]) are popular approaches for producing unbiased estimators of wildlife abundance. However, despite extensive discussion and development of distance sampling theory in the literature, deciding which of these alternatives is most appropriate for a particular scenario can be confusing. Some of this confusion may stem from an incomplete understanding of how each approach addresses the components of the detection process. Here we describe the proper application of CDS, MRDS, and TEDS approaches and use applied examples to help clarify their differing assumptions with respect to the components of the detection process. To further aid the practitioner, we summarize the differences in a decision tree that can be used to identify cases where a more complex alternative (e.g., MRDS or TEDS) may be appropriate for a given survey application. Although the more complex approaches can account for additional sources of bias, in practical applications one also must consider estimator precision. Therefore, we also review the concept of total estimator error in the context of comparing competing methods for a given application to aid in the selection of the most appropriate distance sampling approach. Finally, we detail how the use of more advanced techniques (i.e., informed priors, open-population distance sampling models, and integrated modeling approaches) can further reduce total estimator error by leveraging information from existing and ongoing data collection. By synthesizing the existing literature on CDS, MRDS, TEDS and their extensions, in conjunction with the concepts of total estimator error and the components of the detection process, we provide a comprehensive guide that can be used by the practitioner to more efficiently, effectively, and appropriately apply distance sampling in a variety of settings.
Download or read book Gopher Tortoise Nest Detection at Camp Shelby Mississippi written by Hollis H. Bennett and published by . This book was released on 2005 with total page 47 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Demographic Survey of Gopherus Polyphemus Gopher Tortoise at the Abacoa Greenway written by Tokio Sano and published by . This book was released on 2014 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Desert Tortoise Mojave Population Recovery Plan written by and published by . This book was released on 1994 with total page 406 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Geospatial Analysis for Management of an Urban Population of the Gopher Tortoise Gopherus Polyphemus in North Florida written by Laura Christina Becht and published by . This book was released on 2001 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Introduction to Distance Sampling written by Stephen T. Buckland and published by . This book was released on 2001 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book introduces the suite of techniques known as 'distance sampling', so-called because the common theme is the sampling of distances of objects from a line or point. The objects are usually animals or groups of animals ('clusters'), and the primary aim is to estimate their density or abundance in a survey area. In line transect sampling, the sampled distances are the shortest or perpendicular distance from a detected object to the line. It is the most widely used method for assessing the abundance of a wide range of terrestrial and marine animals. In point transect sampling, distances of detected objects from the sampled points are recorded. This book provides a comprehensive introduction to both techniques, and also describes several related techniques. "Introduction to Distance Sampling" updates the 1993 book "Distance Sampling," which was the first, and until now, only book devoted to the topic. The book is aimed at quantitative biologists and wildlife managers, and statisticians involved in wildlife monitoring programmes. Of particular significance in this update is the chapter on study design and field methods, which has been extensively rewritten and extended.; New technologies such as laser range finders, theodolites and the Geographical Positioning System (GPS) are discussed, and advice is given on a wide range of survey methods. Analysis methods have also been generalized, through the use of various types of multiplier. Many exercises have been introduced, to make the book more useful to graduate students in wildlife and conservation management.
Download or read book The Sonoran Desert Tortoise written by Thomas R. Van Devender and published by University of Arizona Press. This book was released on 2019-04-15 with total page 401 pages. Available in PDF, EPUB and Kindle. Book excerpt: One of the most recognizable animals of the Southwest, the desert tortoise (Gopherus agassizii) makes its home in both the Sonoran and Mohave Deserts, as well as in tropical areas to the south in Mexico. Called by Tohono O'odham people "komik'c-ed," or "shell with living thing inside," it is one of the few desert creatures kept as a domestic pet—as well as one of the most studied reptiles in the world. Most of our knowledge of desert tortoises comes from studies of Mohave Desert populations in California and Nevada. However, the ecology, physiology, and behavior of these northern populations are quite different from those of their southern, Sonoran Desert, and tropical cousins, which have been studied much less. Differences in climate and habitat have shaped the evolution of three races of desert tortoises as they have adapted to changes in heat, rainfall, and sources of food and shelter as the deserts developed in the last ten million years. This book presents the first comprehensive summary of the natural history, biology, and conservation of the Sonoran and Sinaloan desert tortoises, reviewing the current state of knowledge of these creatures with appropriate comparisons to Mohave tortoises. It condenses a vast amount of information on population ecology, activity, and behavior based on decades of studying tortoise populations in Arizona and Sonora, Mexico, and also includes important material on the care and protection of tortoises. Thirty-two contributors address such topics as tortoise fossil records, DNA analysis, and the mystery of secretive hatchlings and juveniles. Tortoise health is discussed in chapters on the care of captives, and original data are presented on the diets of wild and captive tortoises, the nutrient content of plant foods, and blood parameters of healthy tortoises. Coverage of conservation issues includes husbandry methods for captive tortoises, an overview of protective measures, and an evaluation of threats to tortoises from introduced grass and wildfires. A final chapter on cultural knowledge presents stories and songs from indigenous peoples and explores their understanding of tortoises. As the only comprehensive book on the desert tortoise, this volume gathers a vast amount of information for scientists, veterinarians, and resource managers while also remaining useful to general readers who keep desert tortoises as backyard pets. It will stand as an enduring reference on this endearing creature for years to come.
Download or read book Simulating Population Variation and Movement Within Fragmented Landscapes written by and published by . This book was released on 2009 with total page 878 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Distance Sampling written by S. T. Buckland and published by Springer. This book was released on 1993-05-27 with total page 446 pages. Available in PDF, EPUB and Kindle. Book excerpt: one can choose a point instead and measure the radial distances of the animals detected. It is very appropriate that the leading exponents in this field have come together to produce an authoritative description on 'how to do it'. They bring with them many years of experience in this research area. This book is a must for all those involved in estimating animal abundance as the methods can be used for such a wide variety of animal species including birds and marine mammals. The methods also apply to clusters of animals such as schools of dolphins and to animal signs. The beauty of such methods lies in the fact that not every animal has to be seen when a population is investigated. At the heart of the methodology is a 'detectability' function which is estimated in some robust fashion from the distances to the animals actually seen. Many species are not always visible and may be detected by the sounds they make or by being flushed out into the open. Clearly animals can have widely different behaviour patterns so that different models will be needed for different situations. This book provides a tool box of such methods with a computer package which helps the researcher to select the right tool for each occasion. The authors have a reputation for being very thorough and, typically, they endeavour to cover every conceivable situation that might be encountered in the field.
Download or read book Advanced Distance Sampling written by Stephen T. Buckland and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Addressing new methodologies and technologies, this text focuses on the use of distance sampling to estimate the density and abundance of biological populations.
