Download or read book Use of Stable Isotopes to Investigate Black Bear Diets and to Evaluate the Human bear Management Program at Yosemite National Park CA written by John Brooks Hopkins (III.) and published by . This book was released on 2011 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt: Yosemite has applied extraordinary effort to manage people and bears over the past century. For the past decade, human-bear management has implemented both proactive (population-level) and reactive (individual-level) management to prevent bear incidents; however, incidents continue to occur at high frequency even though the program has received $500,000 in congressional funding each year since 1999. For this study, we developed a new method to detect human food-conditioned (FC) bears throughout the Park using isotopic data and used these results and dietary estimates for these bears to evaluate the effectiveness of the human-bear management program. In the first chapter, we proposed 40 definitions for terms and concepts common to human-bear management. In the second chapter, we provide details on a stable isotope mixing model designed to accurately estimate dietary parameters in the remaining two chapters. In these last chapters, we collected tissues (bone and hair) from contemporary and historic bears with known and unknown management statuses (FC or non-food-conditioned [NFC]) and analyzed them for their stable isotopic composition. In chapter 3, we used these isotopic data to predict the management status of unknown bears using a logistic regression model. For chapters 3 and 4, we used isotopic data for FC bears and stoichiometric data for their food sources to estimate the proportional dietary contributions to bear diets through time using our mixing model. Results from chapter 3 show a small proportion (~13%) of the unknown sampled population (n = 145) is currently FC, and chapter 4 results showed the proportion of human food in food-conditioned bear diets increased before the park began implementing a rigorous proactive human-bear management strategy in 1999. Since then, the amount of human food in known FC bear diets has decreased dramatically. We conclude that proactive human-bear management was effective at reducing the amount of human food available to bears since 1999. In contrast, evidence suggests reactive human-bear management was not effective at eliminating or reducing the amount of human food in individual bear diets. We suggest the Park reevaluate the effectiveness of their reactive human-bear management strategy, reduce problem bears from the population, and continue proactive management.

Download or read book Speaking of Bears written by Rachel Mazur and published by Rowman & Littlefield. This book was released on 2015-05-01 with total page 301 pages. Available in PDF, EPUB and Kindle. Book excerpt: As majestic as they are dangerous, and as timeless as they are current, bears continue to captivate readers. Speaking of Bears is not your average collection of stories. Rather it is the history, compiled from interviews with over 100 individuals, of how Yosemite, Sequoia, and Kings Canyon National Parks, all in California’s Sierra Nevada, created a human-bear problem so bad that there were eventually over 2,000 incidents in a single year. It then describes the pivotal moments during which park employees used trial-and-error, conducted research, invented devices, collaborated with other parks, and found funding to get the crisis back under control. Speaking of Bears is for bear lovers, national park buffs, historians, wildlife managers, biologists, policy and grant-makers, and anyone who wants to know the who, what, where, when, and why of what once was a serious human-bear problem, and the path these parks took to correct it. Although these Sierran parks had some of the worst black bear problems in the country, hosted much of the research, and invented the bulk of the technological solutions, they were not the only ones. For that reason, intertwining stories from several other parks including Yellowstone, the Great Smoky Mountains, and Banff-Canada are included. For anyone seeking solutions to human-wildlife conflicts throughout the world, the lessons-learned are invaluable and widely applicable.

Download or read book Using Stable Isotopes to Assess Longitudinal Diet Patterns of Black Bears Ursus Americanus in Great Smoky Mountains National Park written by Jennapher L. Teunissen van Manen and published by . This book was released on 2011 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt: Long-term diet patterns based on stable isotope analysis may be helpful to understand changes in food selection of black bears (Ursus americanus) over time and guide management programs to reduce human-bear conflicts. An enriched stable carbon isotope signature indicates an anthropogenic food source in the diet and an enriched nitrogen signature indicates a higher tropic level for a species. I examined longitudinal feeding patterns from 117 hair samples of black bears live captured in Great Smoky Mountains National Park during 1980-2001 using stable carbon and nitrogen isotope analysis from hair samples. I developed a set of a priori models to examine if sex, age class, year, weight class, total hard mast index, white oak index (Quercus spp.), red oak index (Quercus spp.), nuisance status and hog harvest (Sus scrofa) affected stable isotope signatures. I used model averaging and an estimator of the unconditional variance was used to account for model uncertainty. The [delta]13C signatures differed by weight class with above average weight, ([Beta] = 0.76[Per-mille]; 95% CI = 0.28 to 1.23) and average weight ([Beta] = 0.42[per-mille]; CI = 0.06 to 0.78) showing enriched values compared to below average bears. Bears had enriched [delta]15N signatures in years with low white oak mast production ([beta] = -0.19, CI = -0.34 to -0.03) and depleted when white oak hard mast was abundant. Sub adult bears had enriched [delta]15N signatures compared to adult and older adult bears. Variation of nitrogen values was small during 1980-1991(x̄ =2.57, SD = 0.28) but increased substantially during 1992-2000 (x̄ = 2.29, SD = 0.71) when there was substantial variation in hard mast production. Bears in better physical condition appear more likely to access anthropogenic food sources. In years of low white oak acorn production, the larger bears and sub adult bears are more likely to turn to alternative food sources. The long term variation detected in this study is important in identifying which bears are potentially more likely to seek out the anthropogenic food sources when changes occur in availability of natural foods.

Download or read book Ecology and Management of Black Bears in Yosemite National Park written by David Murray Graber and published by . This book was released on 1982 with total page 442 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Paleozoological Stable Isotope Data for Modern Management of Historically Extirpated Missouri Black Bears Ursus Americanus written by Corinne N. Rosania and published by . This book was released on 2010 with total page 65 pages. Available in PDF, EPUB and Kindle. Book excerpt: Human population growth and intensification of resource extraction during the 19th century changed the American landscape. Deforestation, residential sprawl and hunting activities impacted the behavior and sometimes the existence of native species. By the early 1900s, North American black bears (Ursus americanus) were extirpated from Missouri. Modern efforts to restore this species to the region are guided by the assumption that extant extra-local black bear ecology accurately depicts native Missouri ursid ecology. Paleozoological data provide the only means to test this assumption. Stable carbon and nitrogen isotope analysis of skeletal remains of ten late Holocene black bears from Lawson Cave in central Missouri reveals three aspects of native black bear diet: 1) Lawson Cave black bears are isotopically distinct from herbivores and carnivores; 2) There is no clear trend in black bear diet over the past 600 years; and 3) Lawson Cave black bear diet is not significantly different from that of modern black bears. Native Missouri black bears, as reflected by the Lawson Cave ursids, are no different from extralocal modern black bears in terms of diet. Therefore, these ecological data can be applied to future management and conservation planning regarding Missouri black bears by indicating appropriate regions (which can support the resource-use habits of black bears) for relocation programs.

Download or read book Wildlife Research Report written by and published by . This book was released on 2012 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Use of Stable Isotope Ratio Analysis to Characterize the Diets of American Black Bears in Great Smoky Mountains National Park and Utah written by Amanda Kathleen Loveless and published by . This book was released on 2007 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Using Stable Isotope Analysis to Estimate Black Bear Ursus Americanus Diet in Vermont written by Eliese Antona Dykstra and published by . This book was released on 2015 with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Use of Stable Isotopes to Determine Diets of Living and Extinct Bears written by Grant Vaughan Hilderbrand and published by . This book was released on 1995 with total page 58 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Stable Isotopes in Human Nutrition written by S. A. Abrams and published by CABI. This book was released on 2003-04-25 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt: The use of stable isotopes in nutritional studies is now widespread, and the technique is becoming increasingly popular. Practical applications are numerous and include:calcium and iron absorption studiesstudies looking at the impacts of diet, physical activity, aging, and medical therapy and supplementation on nutrient metabolismthe measurement of energy cost of pregnancystudies on the causes of growth faltering in infantsinvestigations into childhood and adult obesity.This book is designed as a laboratory handbook of methods used to perform stable isotope studies in humans. It covers basic principles, dosage information, sample preparation procedures, analytical instrumentation, and necessary mathematical methods and provides the fundamentals to enable researchers to evaluate and establish stable isotope methods in their own laboratories.

Download or read book Selecting the Best Stable Isotope Mixing Model to Estimate Grizzly Bear Diets in the Greater Yellowstone Ecosystem written by John B. Hopkins (III.) and published by . This book was released on 2017 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt: Past research indicates that whitebark pine seeds are a critical food source for Threatened grizzly bears (Ursus arctos) in the Greater Yellowstone Ecosystem (GYE). In recent decades, whitebark pine forests have declined markedly due to pine beetle infestation, invasive blister rust, and landscape-level fires. To date, no study has reliably estimated the contribution of whitebark pine seeds to the diets of grizzlies through time. We used stable isotope ratios (expressed as ?13C, ?15N, and ?34S values) measured in grizzly bear hair and their major food sources to estimate the diets of grizzlies sampled in Cooke City Basin, Montana. We found that stable isotope mixing models that included different combinations of stable isotope values for bears and their foods generated similar proportional dietary contributions. Estimates generated by our top model suggest that whitebark pine seeds (35±10%) and other plant foods (56±10%) were more important than meat (9±8%) to grizzly bears sampled in the study area. Stable isotope values measured in bear hair collected elsewhere in the GYE and North America support our conclusions about plant-based foraging. We recommend that researchers consider model selection when estimating the diets of animals using stable isotope mixing models. We also urge researchers to use the new statistical framework described here to estimate the dietary responses of grizzlies to declines in whitebark pine seeds and other important food sources through time in the GYE (e.g., cutthroat trout), as such information could be useful in predicting how the population will adapt to future environmental change.

Download or read book Ecology and Management of Black Bears in Yosemite National Park written by David Murray Graber and published by . This book was released on 1981 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Black Bear Food Habits in Yosemite National Park written by D. M. Graber and published by . This book was released on 1983 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Human bear Interactions in the Back Country of Yosemite National Park written by Bruce Charles Hasting and published by . This book was released on 1982 with total page 368 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Dietary Adjustability of Grizzly Bears and American Black Bears in Yellowstone National Park written by Jennifer Kay Fortin and published by . This book was released on 2013 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: Grizzly bears (Ursus arctos) and American black bears (U. americanus) are sympatric in much of Yellowstone National Park. Three primary bear foods, cutthroat trout (Oncorhynchus clarki), whitebark pine (Pinus albicaulis) nuts, and elk (Cervus elaphus), have declined in recent years. Because park managers and the public are concerned about the impact created by reductions in these foods, we quantified bear diets to determine how bears living near Yellowstone Lake are adjusting. We estimated diets using: 1) stable isotope and mercury analyses of hair samples collected from captured bears and from hair collection sites established along cutthroat trout spawning streams and 2) visits to recent locations occupied by bears wearing Global Positioning System collars to identify signs of feeding behavior and to collect scats for macroscopic identification of residues. Approximately 45 ± 22% ([x bar] ± SD) of the assimilated nitrogen consumed by male grizzly bears, 38 ± 20% by female grizzly bears, and 23 ± 7% by male and female black bears came from animal matter. These assimilated dietary proportions for female grizzly bears were the same as 10 years earlier in the Lake area and 30 years earlier in the Greater Yellowstone Ecosystem. However, the proportion of meat in the assimilated diet of male grizzly bears decreased over both time frames. The estimated biomass of cutthroat trout consumed by grizzly bears and black bears declined 70% and 95%, respectively, in the decade between 1997?2000 and 2007?2009. Grizzly bears killed an elk calf every 4.3 ± 2.7 days and black bears every 8.0 ± 4.0 days during June. Elk accounted for 84% of all ungulates consumed by both bear species. Whitebark pine nuts continue to be a primary food source for both grizzly bears and black bears when abundant, but are replaced by false-truffles (Rhizopogon spp.) in the diets of female grizzly bears and black bears when nut crops are minimal. Thus, both grizzly bears and black bears continue to adjust to changing resources, with larger grizzly bears continuing to occupy a more carnivorous niche than the smaller, more herbivorous black bear.

Download or read book Ecology of the Black Bear in Sequoia National Park written by and published by . This book was released on 1981 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Applications of Stable Isotope Analysis to Advancing the Understanding of Brown Bear Dietary Ecology written by Matthew C. Rogers and published by . This book was released on 2021 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dietary ecology is one of the most important drivers of brown bear fitness at the individual and population levels. However, researchers do not have an in-depth understanding of the trophic niche breadth, diet composition, and seasonal diet variation for most Alaskan populations. I set out to better understand multiple facets of brown bear dietary ecology using stable isotope analysis (13C & 15N) as the primary tool to infer brown bear diet and gain insights into their trophic niche, dietary seasonality, dietary generalism and specialism, and isotopic trophic discrimination factors. I determined that using sectioned hair samples is the best practice for determining the isotopic trophic niche of brown bears. Additionally, I determined amino acid trophic discrimination factors for brown bears and explored the ability to separate salmon species in bear diets. I also used stable isotope mixing models with sectioned hair samples to infer seasonal dietary patterns of individual bears in five distinct Alaskan ecosystems. Approximately one-quarter of bears relied solely on vegetation over multiple years despite access to other sources of nutrition; these bears could be considered specialists. Other bears, approximately half, switched diets seasonally but had the same pattern of resource use year over year, a foraging class that I termed persistent seasonal generalism. Approximately one-quarter of bears did not have a persistent dietary pattern across years and could be considered true generalists. Most bears appear to have preferred dietary patterns that are persistent through time, which may be indicative of foraging inertia; maintaining foraging patterns even when faced with changing resource availability due to natural fluctuations, disturbance, or climate change. The sum of this work advances our understanding of brown bear dietary ecology from the individual seasonal level to population level degrees of generalism and specialism, and the methods developed can be applied to many species for which dietary ecology information is difficult to obtain.