Download or read book Landscape Level Approaches to Desert Bighorn Sheep Ovis Canadensis Nelsoni Conservation in a Changing Environment written by Tyler Graydon Creech and published by . This book was released on 2016 with total page 225 pages. Available in PDF, EPUB and Kindle. Book excerpt: Landscape characteristics can strongly influence demographic and genetic processes in wildlife populations. Climate change and human land use are causing many landscapes to change rapidly, and the effects on wildlife populations must be understood to properly manage these threats and design effective conservation strategies. In this dissertation, I explored the implications of landscape heterogeneity for desert bighorn sheep (Ovis canadensis nelsoni), an ecologically and culturally important ungulate species in the southwestern United States, and demonstrated new approaches that can be applied to landscape-level conservation of many wildlife species in changing landscapes. This research focused on populations within and surrounding U.S. national parks, comprising a large portion of the desert bighorn sheep's geographic range, and utilized a genetic dataset including > 1,600 individuals that was developed during this and previous projects. Landscape resistance models have been used extensively to predict potential linkages among fragmented wildlife populations, including desert bighorn sheep, but have rarely been used to guide systematic decision-making such as prioritizing conservation actions to maximize regional connectivity. In Chapter 1, I combined network theory and landscape resistance modeling to prioritize management for connectivity, including protection and restoration of dispersal corridors and habitat patches, in a desert bighorn sheep metapopulation in the Mojave Desert. I constructed network models of genetic connectivity (potential for gene flow) and demographicconnectivity (potential for colonization of empty habitat patches). I found that the type of connectivity and the network metric used to quantify had substantial effects on prioritization results; however, I was able to identify high-priority habitat patches and corridors that were highly ranked across all combinations of the above factors. Potential diet quality varies across landscapes and through time for desert bighorn sheep and other ungulates, but is difficult to measure at fine spatial and temporal resolution using traditional field-based methods. The remotely sensed vegetation index NDVI can potentially overcome these limitations, but its relationship to diet quality has never been empirically validated for desert herbivores. In Chapter 2, I examined how strongly NDVI was associated with diet quality of desert bighorn sheep in the Mojave Desert using fecal nitrogen data from multiple years and populations, and considered the effects of temporal resolution, geographic variability, and NDVI spatial summary statistic. I found that NDVI was more reliably associated with diet quality over the entire growing season than with instantaneous diet quality for a population, and was positively associated with population genetic diversity (a proxy for long-term diet quality). Although NDVI was a useful diet quality indicator for Mojave Desert bighorn sheep, my analysis suggested that it may be unreliable if satellite data are too spatially coarse to detect microhabitats providing high-quality forage, or if diet is strongly influenced by forage items that are weakly correlated with landscape greenness. Landscape genetic studies typically rely on neutral genetic markers to explore gene flow and genetic variation, but the potential for species to adapt to changing landscapes depends on how natural selection influences adaptive genetic variation. In Chapter 3, I optimized landscape resistance models for desert bighorn sheep in three regions with different landscape characteristics, and then used genetic simulations incorporating natural selection to determine how the spread of adaptive variation is influenced by differences among landscapes. Optimized landscape resistance models differed between regions but slope, presence of water barriers, and major roads had the greatest impacts on gene flow. Differences among landscapes strongly influenced the spread of adaptive genetic variation, with faster spread in landscapes with more continuously distributed habitat and when a pre-existing allele (i.e., standing genetic variation) rather than a novel allele (i.e., mutation) served as the source of adaptive genetic variation. Climate change presents a substantial threat to desert bighorn sheep and wildlife worldwide, and adaptation may be required to persist in novel environmental conditions. Knowledge of how adaptive capacity - the potential to cope with climate change by persisting in situ or moving to more suitable ranges or microhabitats - varies across populations is needed to establish conservation priorities for minimizing climate change impacts to individual species. In Chapter 4, I explored variation in the evolutionary component of adaptive capacity for 62 desert bighorn sheep populations on and near U.S. national parks. I measured adaptive capacity of populations as a function of two factors that are strongly associated with the potential for evolutionary adaptation, genetic diversity and connectivity (estimated using a landscape resistance model from Chapter 3). Genetic diversity and connectivity were highly variable across regions and populations. I identified populations with high adaptive capacity that could serve as genetic refugia from climate change impacts (e.g., those in Death Valley and Grand Canyon National Parks), but also populations with low adaptive capacity that may require conservation actions to improve their potential for adaptation (e.g., those in eastern Utah and the southern Mojave Desert). Genetic structure analyses suggested that populations in eastern Utah were genetically distinct from the rest of the study area, likely resulting from restricted gene flow following regional population extinctions. This dissertation highlighted the effects of landscape heterogeneity on genetic and demographic processes in desert bighorn sheep populations. Collectively, the information in these chapters should help guide management of desert bighorn sheep in the face of climate change and human land use. The landscape-level approaches demonstrated here may be useful for managing many other wildlife species.
Download or read book And Then There Were None written by Paul R. Krausman and published by University of New Mexico Press. This book was released on 2017-04-01 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt: Once plentiful in the mountains of southern Arizona, by the 1990s desert bighorn sheep were wiped out in the Pusch Ridge Wilderness of the Santa Catalina Mountains as a result of habitat loss and alteration. This book uses their history and population decline as a case study in human alteration of wildlife habitat. When human encroachment had driven the herd to extinction, wildlife managers launched a major and controversial effort to reestablish this population. For more than forty years Paul R. Krausman directed studies of the Pusch Wilderness population of these iconic animals, located in the mountainous outskirts of Tucson. The story he tells here reveals the complex relationships between politics and biology in wildlife conservation. His account of the evolution of wildlife conservation practices includes discussions of techniques and of human attitudes toward predators, fire, and their management.
Download or read book Recovery Plan for Bighorn Sheep in the Peninsular Ranges California written by Esther Rubin and published by . This book was released on 2000 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Bighorn Sheep Conservation Within Mine influenced Landscapes written by Dayan J. Anderson and published by . This book was released on 2018 with total page 177 pages. Available in PDF, EPUB and Kindle. Book excerpt: I examined biodiversity management issues, implications and opportunities in a working industrial landscape of the San Bernardino Mountains, California, USA, where historic and active mining operations overlap habitat occupied by threatened, endangered or protected plant and animal tax. To elucidate patterns of habitat use by ungulates in a mini-influenced landscape, I evaluated resource selection by the Cushenbury population of desert bighorn sheep (Ovis Canadensis nelsoni). Modeling of a resource selection function (RSF) for that population identified proximity to active mine areas, water sources, and revegetation sites as important determinants of habitat selection. Next, I reviewed two collaborative dialogues between the public, private and civil sectors resulting in workable solutions achieving biodiversity conservation goals simultaneous with economic development: a habitat management strategy for threatened and endangered plants and a research collaborative focused on the long-term viability of an isolated bighorn sheep population. Finally, I integrated results of RSF modeling with principles adopted by those two initiatives into a conceptual framework to aid the development of an adaptive management plan for the Cushenbury bighorn sheep population. A formulation of conservation value is presented using results of RSF analysis and mitigation credits reflecting the degree to which degraded habitat is enhanced to benefit wild sheep. The proposed Bighorn Habitat Assessment Tool (BHAT) seeks to a) establish a habitat reserve providing maximum benefit to the unique requirements of bighorn sheep, b) incentivize voluntary actions by industry to ensure mining activities are compatible with bighorn sheep conservation, and c) allow for the objective evaluation of multiple mine planning and resource management alternatives.
Download or read book Desert Bighorn Sheep and Water written by Paul R. Krausman and published by . This book was released on 1996 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Desert Bighorn Sheep written by Norman S. Smith and published by . This book was released on 1988 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: This guide summarizes pertinent literature on four topics of desert bighorn sheep ecology and management: (1) their water requirements and adaptations are compared with those of other desert-dwelling ungulates; (2) the effects of human activities such as mining, poaching, hunting, ranching, hiking, and urban encroachment are discussed; (3) diseases and disease control, specifically scabies and desert bighorn sinusitis, are reviewed; and (4) the relation of bighorn sheep to other resident wildlife is addressed.
Download or read book Desert Bighorn Sheep written by Norman S. Smith and published by . This book was released on 1988 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Population Processes in a Changing Climate written by Clinton Wakefield Epps and published by . This book was released on 2004 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Rangewide Plan for Managing Habitat of Desert Bighorn Sheep on Public Lands written by United States. Bureau of Land Management and published by . This book was released on 1989 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Conservation and Spatial Use Analyses for the Recovery of Bighorn Sheep in the Peninsular Ranges written by Stacey D. Ostermann and published by . This book was released on 2001 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt: The status of wild sheep in North America typifies the plight of many wildlife species in modern times: wild sheep have declined to 10-40% of their numbers during pristine times and on a global scale approximately 31% of Caprine are considered threatened or critical. As human populations and the number of threatened and endangered wildlife species increase, research into the causes of wildlife population declines and tools to aid recovery are urgently needed. We conducted two studies of endangered desert bighorn sheep (Ovis canadensis nelsoni) in the Peninsular Ranges of Southern California with the primary goal of furthering recovery efforts for this species. First, in order to evaluate a captive breeding program for Peninsular bighorn, we developed the following criteria to provide a standard means of evaluating ongoing captive breeding and reintroduction programs: (1) survival and recruitment rates in the captive population, (2) survival of released animals, (3) recruitment of released animals, (4) growth rate of the reintroduced or augmented population, and (5) establishment of a viable wild population. In assessing the Peninsular bighorn sheep program, we found that while reintroduction did not result in population growth or establishment of a viable population, it helped prevent extirpation of the reinforced deme, preserved metapopulation linkage, and aided habitat preservation. Chronic low recruitment and low adult survivorship precluded achievement of criteria 3-5. Environmental conditions in the release area also appeared to hinder program success. We suggest that periodic evaluations are useful for improving the success of individual captive breeding and reintroduction programs, as well as for meta-analyses needed to refine reintroduction science as a recovery tool for threatened or endangered populations. Wildlife habituated to the presence of humans have been recognized as a new dilemma facing wildlife managers. Our second study involved examining the habitat use, home range size, and nutritional levels of Peninsular desert bighorn sheep along an urbanwildland interface during two time periods (1981-82 and 1995-98). We found that bighorn sheep monitored during 1995-98 used habitat within (P
Download or read book American Desert Bighorn Sheep in Colorado written by and published by . This book was released on 1990 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book American Desert Bighorn Sheep in Utah written by and published by . This book was released on 1990 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book American Desert Bighorn Sheep in Arizona written by and published by . This book was released on 1990 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book American Desert Bighorn Sheep in California written by and published by . This book was released on 1990 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Neutral and Adaptive Genetic Variation in Desert Bighorn Sheep Ovis Canadensis microform Implications for Conservation written by Gustavo A. Gutiérrez-Espeleta and published by Ann Arbor, Mich. : University Microfilms International. This book was released on 2000 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Advances in Ungulate Ecology written by R. Terry Bowyer and published by Frontiers Media SA. This book was released on 2021-06-28 with total page 308 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mountain Sheep Ecosystem Management Strategy in the 11 Western States and Alaska written by and published by . This book was released on 1994 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt:
