Download or read book Survival of Snowshoe Hares at a Geographic Range Boundary written by Paul Raymond Sievert and published by . This book was released on 1984 with total page 118 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Ecology Habitat Use and Winter Thermal Dynamics of Snowshoe Hares in Pennsylvania written by Laura Gigliotti and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Differences in biotic and abiotic characteristics can lead to geographic variation in the ecology of species and populations. Investigating intraspecific variation over large geographic extents can provide insights into the ecological drivers of population dynamics, which is especially important for predicting how future climatic conditions will affect ecological processes. The snowshoe hare (Lepus americanus) is an excellent species to investigate geographic variation in ecological dynamics because it has a geographic range that encompasses a wide range of climates and habitat types. Although the population dynamics of snowshoe hares in the northern portion of their range are well-studied, information on southern populations is limited. I investigated the ecology, habitat use, and winter thermal dynamics of snowshoe hares in Pennsylvania and compared these data to previous research on other hare populations. From January 2014 -- June 2015 I trapped and monitored snowshoe hares to estimate body condition, survival rates, home range size, and home range overlap. I found that hares in Pennsylvania had greater body mass in relation to their structural size, higher annual survival, and larger home ranges than populations from higher latitudes. Home range overlap occurred frequently and I did not find that hares temporally partitioned their home ranges to minimize interaction with nearby hares. Also I trapped three snowshoe hares that exhibited uncharacteristic brown winter coat coloration, indicating potential differences in the winter molt patterns or color morphs. Using locations collected from GPS collars I examined snowshoe hare seasonal habitat use at the stand-level and at fine-scale microhabitats. I determined that during both summer and winter hares preferred areas of mature scrub oak or conifers and avoided open habitats. At the population level, hares preferred areas with dense understory vegetation and high canopy coverage, although I found substantial individual variability in habitat preferences. My research highlights the importance of incorporating multiple scales of analysis into habitat use studies, as well as accounting for individual variation in habitat preferences. Finally, I investigated geographic differences in snowshoe hares' responses to winter temperatures by comparing winter pelage characteristics and heat production between hares in Pennsylvania and the Yukon, as well as investigated the influence of temperature on resting spot selection and movement rates. I found that hares from Pennsylvania had shorter and less dense winter coats than hares from the Yukon and that the Pennsylvania population had less visible white in their winter coats. Hares in the Pennsylvania population also produced less heat than the Yukon population, indicating a lower metabolic rate. Snowshoe hares did not select for resting spots that offered them thermal advantages, but selected locations providing visual obstruction from predators. Movement rates were associated with ambient temperature, with the lowest hourly movements occurs at the extreme high (>4 oC) and low (

Download or read book Influences of Environmental Factors on Survival of Sympatric Snowshoe Hares and Cottontail Rabbits Near Geographic Range Limits written by Eric W. Cox and published by . This book was released on 1996 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Wildfire and Furbearers in the Boreal Forest with Emphasis on Marten Lynx and Their Prey written by Audrey Jean Magoun and published by . This book was released on 1991 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book General Technical Report RM written by and published by . This book was released on 1992 with total page 600 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Theory of Island Biogeography Revisited written by Jonathan B. Losos and published by Princeton University Press. This book was released on 2009-10-19 with total page 988 pages. Available in PDF, EPUB and Kindle. Book excerpt: Robert H. MacArthur and Edward O. Wilson's The Theory of Island Biogeography, first published by Princeton in 1967, is one of the most influential books on ecology and evolution to appear in the past half century. By developing a general mathematical theory to explain a crucial ecological problem--the regulation of species diversity in island populations--the book transformed the science of biogeography and ecology as a whole. In The Theory of Island Biogeography Revisited, some of today's most prominent biologists assess the continuing impact of MacArthur and Wilson's book four decades after its publication. Following an opening chapter in which Wilson reflects on island biogeography in the 1960s, fifteen chapters evaluate and demonstrate how the field has extended and confirmed--as well as challenged and modified--MacArthur and Wilson's original ideas. Providing a broad picture of the fundamental ways in which the science of island biogeography has been shaped by MacArthur and Wilson's landmark work, The Theory of Island Biogeography Revisited also points the way toward exciting future research.

Download or read book Lagomorph Biology written by Paulo C. Alves and published by Springer Science & Business Media. This book was released on 2007-12-29 with total page 405 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the first book to cover all aspects of Lagomorph biology. Lagomorphs are a mammalian order which includes rabbits, hares and pikas. They are distributed throughout the world and are of both scientific and public interest as they are classified between endangered and pest species. In addition, some have a high economic value as important game species. In the last few decades, a huge amount of information has been made available to the scientific community that has resulted in remarkable advances on all aspects of Lagomorph biology.

Download or read book Cestode Zoonoses Echinococcosis and Cysticercosis written by Philip Craig and published by IOS Press. This book was released on 2002 with total page 418 pages. Available in PDF, EPUB and Kindle. Book excerpt: Parasitic zoonoses or parasitic infections transmitted from animals to humans are likely to become increasingly important in the spectrum of emergent and re-emergent diseases for both developed and developing countries. Tapeworm zoonoses form an important group of such pathogens and are being recognized more and more as a public health problem in Europe, Central Asia, the Middle East, sub-Saharan Africa, Latin America and the USA.

Download or read book The Scientific Basis for Conserving Forest Carnivores written by Leonard F. Ruggiero and published by . This book was released on 1994 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt: This cooperative effort by USDA Forest Service Research and the National Forest System assesses the state of knowledge related to the conservation status of four forest carnivores in the western United States: American marten, fisher, lynx, and wolverine. The conservation assessment reviews the biology and ecology of these species. It also discusses management considerations stemming from what is known and identifies information needed. Overall, we found huge knowledge gaps that make it difficult to evaluate the species' conservation status.

Download or read book Population Cycles written by Alan Andrew Berryman and published by Oxford University Press, USA. This book was released on 2002 with total page 207 pages. Available in PDF, EPUB and Kindle. Book excerpt: For over sixty years, understanding the causes of multiannual cycles in animal populations has been a central issue in ecology. This book brings together ten of the leaders in this field to examine the major hypotheses and recent evidence in the field, and to establish that trophic interactions are an important factor in driving at least some of the major regular oscillations in animal populations that have long puzzled ecologists.

Download or read book A Manual for Wildlife Radio Tagging written by Robert Kenward and published by Gulf Professional Publishing. This book was released on 2001 with total page 325 pages. Available in PDF, EPUB and Kindle. Book excerpt: Previous ed.: published as Wildlife radio tagging, 1987.

Download or read book Density Demography and Seasonal Movements of Snowshoe Hares in Central Colorado written by Jacob Scott Ivan and published by . This book was released on 2011 with total page 141 pages. Available in PDF, EPUB and Kindle. Book excerpt: Snowshoe hares (Lepus americanus), their famous 10-year population cycle, and close association with Canada lynx (Lynx canadensis) have been well-studied in boreal Canada for decades. Snowshoe hare range, however, extends south into the Sierra Nevada, Southern Rockies, upper Lake States, and Appalachian Mountains. Ecology of snowshoe hares in these more southerly regions is not as well understood, though hare research in the U.S. Rocky Mountains has accelerated over the past decade. Through this recent work, biologists have identified stands of young, densely-stocked conifers and those of mature, uneven-aged conifers as primary hare habitat in the region. Both stand types are characterized by dense understory vegetation that provides both browse and protection from elements and predators. From 1999 to 2006, Canada lynx were reintroduced into Colorado in an effort to restore a viable population to the southern portion of their former range. Snow tracking of released individuals and their progeny indicated that the majority of lynx winter diet in Colorado was comprised of snowshoe hares. Thus, long-term success of the lynx reintroduction effort hinges, at least partly, on maintaining adequate and widespread populations of snowshoe hares in the state. To improve our understanding of snowshoe hare ecology in the southern portion of their range, and enhance the ability of agency personnel to manage subalpine landscapes for snowshoe hares and lynx in Colorado, I conducted an observational study to evaluate purported primary hare habitat in the state. Specifically, I estimated snowshoe hare density, survival, recruitment, and movement indices in mature, uneven-aged spruce/fir (Picea engelmannii/Abies lasiocarpa) and 2 classes of young, even-aged lodgepole pine: 1) "small" lodgepole pine (Pinus contorta) stands, which were clear cut 20-25 years prior to this study and had regenerated into densely stocked stands with trees 2.54-12.69 cm in diameter, and 2) "medium" lodgepole pine stands (tree diameter = 12.70-22.85 cm) which were clear cut 40-60 years prior to this study and pre-commercially thinned ~20 years prior. I used a combination of mark-recapture and radio telemetry to estimate parameters. I sampled during both summer and winter to cover the range of annual variation in parameters. Animal density is one of the most common and fundamental parameters in wildlife ecology and was the first metric I used to evaluate the stand types. However, density can be difficult to estimate from mark-recapture data because animals move on and off of a trapping grid during a sampling session (i.e., lack of geographic closure). In Chapter 1, I developed a density estimator that uses ancillary radio telemetry locations, in addition to mark-recapture information, to account for lack of geographic closure resulting in relatively unbiased estimates of density. I derived the variance for this estimator, showed how individual covariates can be used to improve its performance, and provided an example using a subset of my snowshoe hare data. In Chapter 2, I completed a series of simulations to test the performance of this "telemetry" estimator over a range of sampling parameters (i.e., capture probabilities, sampling occasions, densities, and home range configurations) likely to be encountered in the field. I also compared the percent relative bias of the telemetry estimator to two other commonly used, contemporary estimators: spatially explicit capture-recapture (SECR), and mean maximum distance moved (MMDM). The telemetry estimator performed best over most combinations of sampling parameters tested, but was inferior to SECR at low capture probabilities. The telemetry estimator was unaffected by home range configuration, whereas performance of SECR and MMDM was dependent on home range shape. Density is an important metric of habitat quality, but it can be misleading as some habitats with high animal density may function as population sinks. A complete assessment of habitat quality requires estimation of habitat-specific demographic rates in addition to density. In Chapter 3, I used the telemetry estimator to estimate snowshoe hare densities in each stand type during summer and winter, 2006-2009. I then combined mark-recapture and telemetry data to estimate survival via the Barker robust design model as implemented in Program MARK. Finally, I used age- and habitat-specific density and survival estimates to estimate recruitment in each stand type. During summer, hare densities were highest in small lodgepole (0.20 ± 0.01 (SE) to 0.66 ± 0.07 hares/ha), lowest in medium lodgepole pine (0.01 ± 0.04 to 0.03 ± 0.03 hares/ha), and intermediate in spruce/fir (0.01 ± 0.002 to 0.26 ± 0.08 hares/ha). During winter, densities became more similar among the 3 stand types. Annual survival was highest in spruce/fir (0.14 ± 0.05 (SE) to 0.20 ± 0.07) and similar among the 2 lodgepole stands types (0.10 ±0.03 to 0.16 ± 0.06). Across stands, summer-winter survival was nearly twice as high as winter-summer survival. Recruitment of juvenile hares occurred during all 3 summers in small lodgepole stands, 2 of 3 summers in spruce/fir stands, and in only 1 of 3 summers in medium lodgepole. Stand attributes indicative of dense cover were positively correlated with density estimates and explain relatively more process variance in hare densities than other attributes. These same attributes were not positively correlated with hare survival. In addition to density and demography, movement is an informative aspect of animal ecology. Timing, extent, and frequency of movements can reflect predation pressure, food scarcity/abundance, availability of mates, or seasonal changes in any of these parameters. In Chapter 4, I used telemetry data to assess movement patterns of snowshoe hares at 2 scales (within-season, between-season) in all 3 stand types. Within-season movements of hares were larger during winter than during summer and tended to be larger in small lodgepole stands. Within-season movements of males tended to be larger than females during summer, possibly as a means of maximizing mating opportunities. Movements were similar between the sexes during winter. Hares in both small and medium lodgepole stands tended to make larger movements between seasons than hares in spruce/fir stands, possibly reflecting the variable value of these stands as mediated by snow depth. In summary, snowshoe hare density, survival, and recruitment were relatively low in thinned, medium lodgepole stands compared to spruce/fir or small lodgepole. Thus, while hares occur in these stands, they do not appear to be capable of supporting self-sustaining hare populations, and this stand type is probably less important than mature spruce/fir and small lodgepole stand types. Management for snowshoe hares (and lynx) in central Colorado should focus on maintaining the latter. Given the more persistent nature of spruce/fir compared to small lodgepole, and the fact that such stands cover considerably more area, mature spruce/fir may be the most valuable stand type for snowshoe hares in the state.

Download or read book Medicine Bow Routt National Forests N F Bark Beetle Analysis written by and published by . This book was released on 2002 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Mechanisms of Community Disassembly Along a Southern Range Boundary written by Evan Costello Wilson and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Climate change is altering and disassembling historical vertebrate communities globally. The resultant novel, no-analogue communities are operating in new and often unexpected ways. Some species are especially impacted by changing abiotic conditions, while others are more resilient yet are vulnerable to altered biotic interactions. Due to the velocity of changing climatic conditions, it can be difficult to identify the mechanisms that result in population declines for affected species retrospectively. Experimental manipulations in the field can help elucidate both proximate and ultimate drivers of population and community dynamics, as well as help to predict how climate change will alter these dynamics both directly and indirectly. My dissertation centers on an experimental translocation that repatriated a population of snowshoe hares (Lepus americanus) to a formerly occupied, but recently functionally extirpated, site in central Wisconsin. To understand the mechanisms driving snowshoe hares' range contraction and how the loss of snowshoe hares and associated community interactions have affected the remaining community members, we monitored vital rates and habitat associations of snowshoe hares and linked community members as hare densities increased and subsequently declined following repatriation. Chapter 1 examines the proximate and ultimate mechanisms that resulted in the functional extirpation of snowshoe hares along their southern range boundary. To do so, I analyzed survival and spatial data from translocated hares, and found that while hares suffer high predation during periods of camouflage mismatch, availability of large patches of high-quality habitat, specifically young aspen forest, buffers this mortality. Chapter 2 examines the effects of habitat composition, snow cover and landscape configuration on persistence and colonization of snowshoe hares using multi-season occupancy models. I show that colonization is driven by patch size of young aspen habitat and proximity to existing populations, and that these contemporary patterns are consistent with areas relictual hares occupied during historical extirpation. Finally, I provide a framework for managing timber harvest to maximize young forests and maintain hare habitat on landscapes. Chapter 3 examines the demographic consequences of hare extirpation and loss of associated biotic interactions on persisting alternative prey species sharing the same predator guild with hares by monitoring survival and recruitment in porcupines (Erethizon dorsatum) and ruffed grouse (Bonasa umbellus) with and without hares present. I show that grouse are only loosely connected to this community module, but that porcupines are linked to hares via an enemy-mediated indirect interaction. Porcupines show both direct positive effects from climate change due to declining snow cover and warmer early spring temperatures, and indirect negative effects due to increased predation on neonates driven by loss of snowshoe hares. Overall, this work shows that climate change is having varied effects on species, both direct and indirect, that will likely drive range contraction of multiple northern-adapted species along their shared southern range boundary. While habitat manipulation can be a potential stop-gap method for maintaining hares and associated biotic interactions on the landscape, long-term planning and mitigation of climate change will be necessary for conserving these communities along southern range boundaries.

Download or read book Lynx Wolverine and Fisher in the Western United States written by John Weaver and published by . This book was released on 1993 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Ecological Principles of Nature Conservation written by I. Hansson and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 454 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume is the first in a series entitled Conservation Ecology: Principles, Practices and Management, a theme which Elsevier's pioneer ing journal Biological Conservation has promoted since its foundation thirty-three years ago. The science of conservation ecology is now widely acknowledged as an essential component in the planning and develop ment of activities which change or modify our natural environment. Nevertheless in spite of much research and publicity, there is still a wide gap between theory and practice. Today it is especially important to try to bridge this gap by interpreting the results of ecological research so that they are understandable and relevant to a wide range of land managers, agriculturalists, foresters, and those working in the many categories of protected areas. The volumes in this series are designed to fulfil this purpose, and also to play an important educational role for students of the environmental sciences in schools, universities and other institutions.

Download or read book Forest Fragmentation written by James Arthur Rochelle and published by BRILL. This book was released on 1999-01-01 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book contains 15 chapters and provides an overview and synthesis of forest fragmentation and its influences on key ecological processes and vertebrate productivity. Land use practices and their effects on vertebrate populations and productivity are discussed and examples of several planning approaches to address landscape-level management effects are described.