A Landscape-level Approach for Monitoring River Otters in Pennsylvania PDF Download
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Author: Brett Hubbard
Publisher:
ISBN:
Category : North American river otter
Languages : en
Pages : 328
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Author: Brett Hubbard
Publisher:
ISBN:
Category : North American river otter
Languages : en
Pages : 328
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Author: Nicholas Forman
Publisher:
ISBN:
Category :
Languages : en
Pages :
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Book Description
River otter (Lontra canadensis) populations in Pennsylvania experienced a range reduction and subsequent expansion of the remnant population, as well as re-colonization of parts of the state through reintroduction efforts and expansion of neighboring populations. There are currently no estimates of population size or densities for river otter populations in Pennsylvania, and large-scale monitoring efforts are hampered by the elusive behavior of river otter. Non-invasive genetic sampling has been used to survey river otter populations, but given the river otter's unique distribution across the landscape, estimation of population size and densities has been limited to linear habitats in river systems or along coastlines. Spatial capture-recapture models incorporate spatial information from captures into the estimation process, and estimates are more explicitly linked to the area in which observations occur. I analyzed the efficacy of non-invasive genetic sampling to identify individual river otter and I used spatial capture-recapture models to estimate river otter population size and density, and in northeastern Pennsylvania.I surveyed nine counties in northeastern Pennsylvania, opportunistically collecting samples from latrine sites on public and private land. Latrines were visited on three to four occasions at 6--14 day intervals, clearing latrines after each visit, in a capture-recapture framework. I amplified DNA extracted from the samples at ten microsatellite markers, to generate a genotype for each sample. I matched genotypes using program CERVUS to identify individuals. My first analysis compared amplification success rates and error rates for samples of different type and time of environmental exposure or freshness, and compared my amplification success rates to other studies. Previous studies on river otter had lower genotyping success rates than those for other otter species, and did not follow a common sampling protocol despite laboratory studies for the river otter and recommendations from field studies on other otter species. My amplification success rates were most comparable to those from studies on otter species conducted in the winter with samples collected in a storage buffer. I observed similar patterns of success rates as other studies for different sample types and samples classified for different categories related to lengths of environmental exposure, but had higher success rates for every category. Amplification error rates for the different sample types and environmental exposure categories were not reported in the literature, but I included them in the study as another measure of sample quality and to better inform future studies. The importance of comparing success rates and error rates is to better inform future studies on the preferred sampling protocol, and give measures for the amount of effort necessary for studies looking to use non-invasive genetic sampling to identify individual river otter for population analyses.To estimate population size and density in spatial capture-recapture models, I compiled spatial encounter histories given the location and occasion of collection of each sample assigned to an individual. I also used full likelihood models in program MARK to test for differences in capture and recapture probabilities. I reported the first density estimates for a river otter population in northeastern Pennsylvania (2.1 otter/100 km2, 1.4--5.0 otter/100 km2 95% Asymptotic Wald-type CI). The estimates of capture and recapture probabilities in the MARK model with those parameters estimated separately indicated that capture and recapture probabilities were not different, but that the probability of capturing an individual did vary by occasion. I observed a difference in density estimates for my SCR and MARK models. I would recommend using SCR models because of the spatial justification for density estimates, and the ability to include landscape covariates to build more informed models, which may prove to be useful for river otter given their unique space use.Future studies conducting non-invasive genetic sampling for river otter should conduct their studies in winter and use a storage buffer for samples. Sample type and length of environmental exposure should be considered when considering the amount of sampling effort to derive a genotype for identification of individual otter. NGS and SCR can be used to generate reliable population or density estimates, but as I documented from my MARK estimates of capture probability, numerous sampling occasions are desirable because of the variation in capture probability between occasions. Spatial capture-recapture models are preferable for river otter in Pennsylvania because the area for which density is being estimated is directly tied into the model, which is ideal given the diversity of linear and non-linear habitat types in northeastern Pennsylvania.
Author: Robert P. Brooks
Publisher: Springer Science & Business Media
ISBN: 1461455960
Category : Science
Languages : en
Pages : 498
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The lands and waters of the Mid-Atlantic Region (MAR) have changed significantly since before the 16th century when the Susquehannock lived in the area. Much has changed since Captain John Smith penetrated the estuaries and rivers during the early 17th century; since the surveying of the Mason-Dixon Line to settle border disputes among Maryland, Pennsylvania, and Delaware during the middle of the 18th century; and since J. Thomas Scharf described the physiographic setting of Baltimore County in the late 19th century. As early as 1881, Scharf provides us with an assessment of the condition of the aquatic ecosystems of the region, albeit in narrative form, and already changes are taking place – the conversion of forests to fields, the founding of towns and cities, and the depletion of natural resources. We have always conducted our work with the premise that “man” is part of, and not apart from, this ecosystem and landscape. This premise, and the historical changes in our landscape, provide the foundation for our overarching research question: how do human activities impact the functioning of aquatic ecosystems and the ecosystem services that they provide, and how can we optimize this relationship?
Author: Rebecca A. Mowry
Publisher:
ISBN:
Category : Electronic dissertations
Languages : en
Pages : 80
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Extirpated from Missouri by the 1930s, river otters (Lontra canadensis) were reintroduced by the Missouri Department of Conservation (MDC) from 1982-1992. Since the reintroductions, concerns over the legitimacy of otter trapping and the predator's effects on sport fish populations have sparked controversy. The MDC responded by increasing efforts to monitor river otter populations, using latrine site counts to measure relative abundance across several rivers in Missouri. However, the actual number of otters represented by these counts was unknown. To address this question, I extracted DNA from scat samples collected along 8 rivers in the winter and spring of 2009, using 10 microsatellite markers plus sexing markers to estimate the number and sex of otters. I then developed a model to estimate population size from latrine site index variables, observing that the number of scats per latrine and the density of active latrines across the river best predicted population size. I then used the genotypes to calculate the genetic diversity of the otter populations, evaluate the distribution of genotype clusters across the landscape, and track otter movements between latrines. Unexpected genetic similarities indicated that otters translocated to different areas may have come from the same source populations. Overall, this project has demonstrated the utility of genetic methods for estimating otter abundance, provided insight into the genetic diversity of the populations, and presented a model for inexpensive monitoring of river otter populations in the future.
Author:
Publisher:
ISBN:
Category : Zoology
Languages : en
Pages : 418
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Author: Mark Elbroch
Publisher: Rowman & Littlefield
ISBN: 0811767787
Category : Nature
Languages : en
Pages : 681
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Book Description
The most comprehensive reference guide to mammal tracks and sign for North America. This new edition is more visual, with more than 1300 photos and 450 illustrations for easy comparison and identification of similar sign. Each species account includes information on tracks and trails, scat and urine, nests and lodges, as well as sign on the ground, in trees and shrubs, on fungi and on plants. Winner of the 2019 National Outdoor Book Award for Outdoor Classic Books.
Author: Andrew F. Bennett
Publisher: IUCN
ISBN: 2831707447
Category : Corridors
Languages : en
Pages : 261
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Book Description
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.
Author: Nicole Duplaix
Publisher:
ISBN: 9780692042229
Category :
Languages : en
Pages :
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Author: Shane P. Mahoney
Publisher: JHU Press
ISBN: 1421432811
Category : Science
Languages : en
Pages : 177
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Book Description
The foremost experts on the North American Model of Wildlife Conservation come together to discuss its role in the rescue, recovery, and future of our wildlife resources. At the end of the nineteenth century, North America suffered a catastrophic loss of wildlife driven by unbridled resource extraction, market hunting, and unrelenting subsistence killing. This crisis led powerful political forces in the United States and Canada to collaborate in the hopes of reversing the process, not merely halting the extinctions but returning wildlife to abundance. While there was great understanding of how to manage wildlife in Europe, where wildlife management was an old, mature profession, Continental methods depended on social values often unacceptable to North Americans. Even Canada, a loyal colony of England, abandoned wildlife management as practiced in the mother country and joined forces with like-minded Americans to develop a revolutionary system of wildlife conservation. In time, and surviving the close scrutiny and hard ongoing debate of open, democratic societies, this series of conservation practices became known as the North American Model of Wildlife Conservation. In this book, editors Shane P. Mahoney and Valerius Geist, both leading authorities on the North American Model, bring together their expert colleagues to provide a comprehensive overview of the origins, achievements, and shortcomings of this highly successful conservation approach. This volume • reviews the emergence of conservation in late nineteenth–early twentieth century North America • provides detailed explorations of the Model's institutions, principles, laws, and policies • places the Model within ecological, cultural, and socioeconomic contexts • describes the many economic, social, and cultural benefits of wildlife restoration and management • addresses the Model's challenges and limitations while pointing to emerging opportunities for increasing inclusivity and optimizing implementation Studying the North American experience offers insight into how institutionalizing policies and laws while incentivizing citizen engagement can result in a resilient framework for conservation. Written for wildlife professionals, researchers, and students, this book explores the factors that helped fashion an enduring conservation system, one that has not only rescued, recovered, and sustainably utilized wildlife for over a century, but that has also advanced a significant economic driver and a greater scientific understanding of wildlife ecology. Contributors: Leonard A. Brennan, Rosie Cooney, James L. Cummins, Kathryn Frens, Valerius Geist, James R. Heffelfinger, David G. Hewitt, Paul R. Krausman, Shane P. Mahoney, John F. Organ, James Peek, William Porter, John Sandlos, James A. Schaefer
Author: Kurt Jeffrey Jenkins
Publisher:
ISBN:
Category : Ecology
Languages : en
Pages : 178
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