Download or read book The Population and Habitat Ecology of Snowshoe Hares Lepus Americanus in the Southern Rocky Mountains written by Jennifer L. Zahratka and published by . This book was released on 2004 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Distribution Habitat Characterists and Population Demographics of Snowshoe Hare LEPUS AMERICANUS at the Extreme Southern Edge of Its Geographic Range written by Jason L. Malaney and published by . This book was released on 2003 with total page 248 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 Habitat Utilization of Snowshoe Hares Lepus Americanus in Interior Alaska written by Jerry Wolff and published by . This book was released on 1977 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Climate Change Gene Flow and the Legendary Synchrony of Snowshoe Hares written by Ellen Cheng and published by . This book was released on 2010 with total page 254 pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent decades, climate change has been invoked in the apparent collapse of some of the best-known examples of cyclic and synchronous population dynamics among boreal species. Simultaneously, some studies have predicted that as species' ranges shift poleward and southern habitats fragment in response to climate change, we will lose the southern glacial refugial populations that have historically harbored species' highest genetic diversity and uniqueness. I investigated how climate change and habitat fragmentation may impact genetic and population dynamic processes for the snowshoe hare (Lepus americanus), a species historically recognized as a key driver of North American boreal community dynamics. I collected>1000 genetic samples and>300 time series from 175 cooperators in 30 U.S. states and Canadian provinces and territories. Based on analyses of nuclear and mitochondrial DNA, I identified three highly divergent groups of snowshoe hares in the Boreal, Pacific Northwest, and Southern Rockies regions of North America. I found high genetic diversity in mid-range (Boreal) hare populations, and high genetic uniqueness but lower diversity in the species' southern range (Pacific Northwest and Rockies). If southern populations decline due to climate change, snowshoe hares may still retain high genetic diversity, but will lose many alleles currently unique to southern populations. In a simulation study comparing five synchrony metrics, I found the Kendall metric performed best with short, noisy time series similar to those available for snowshoe hares. I used this metric in partial Mantel tests, modified correlograms, and shifting window analyses of hare synchrony patterns. Confirming long-held but previously untested assumptions, I found northern hare populations are significantly synchronized at distances up to several thousand kilometers, while southern populations are not significantly synchronized at any of the distance classes evaluated. I found that historical patterns of synchrony still persist for snowshoe hares, in contrast to reports for some other synchronous species. Hare synchrony patterns clustered into groups defined according to genetic criteria--but not ecoregions or climatic regions--highlighting the importance of dispersal and population connectivity in snowshoe hare synchrony.
Download or read book Snowshoe Hare Population Ecology in Lynx occupied Areas of Washington written by Paul Otto Jensen and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Boreal forest ecosystems are being disrupted by climate change, resulting in alterations to species distribution and abundance. Snowshoe hares (Lepus americanus) are a keystone boreal forest herbivore that has begun to experience range contraction in the continental United States. Despite their importance, we have limited spatio-temporal knowledge of their densities along the southern edge of their range where boreal habitat is fragmented and climatic conditions are marginal. To address this limitation, we explored the accuracy of three non-invasive techniques for estimating hare density including two indices (pellet density and camera trap detection rate) and a camera-trap-based model for direct density estimation (Random Encounter Model - REM) at 13, 10.25 ha sites in northcentral Washington. We compared these values to spatially explicit capture-recapture (SECR) density estimates from live-capture efforts at the same 13 sites. SECR ranged from 0.16-1.58 hares/ha. Pellet densities had a strong linear association to SECR (R2 = 0.91) and camera trap detection rates had a strong exponential relationship with SECR (R2 = 0.81). REM densities using our camera-trap-derived animal speed (2.4 km/day) ranged from 0.16 to 1.10 hares/ha, though estimates were sensitive to animal speed. Average absolute difference between REM- and SECR-based density estimates were 0.19 hares/ha (range = 0.00-0.84, SE = 0.07), with REM-based estimates for 10 of 13 sites falling within SECR confidence intervals. Additionally, using pellet density data maintained by two external sources and remote sensed data derived to describe forest structure and topography, we developed a landscape-scale pellet density model, converted pellets to density, and related hare density to detection rates of a threatened species, Canada lynx (Lynx canadensis) that relies heavily on hare as prey. We found pellet density is best predicted by stand age, horizontal and vertical cover and lynx detection rates are significantly higher when hare density is > 0.5 hares/ha. As hare populations change along their southern range edge, non-invasive techniques will enable the collection of cost-effective large-scale data that can be used to inform management and conservation, and provide the means to better assess trophic relationships within forested communities.
Download or read book Arapaho Roosevelt Pike San Isabel Grand Mesa Uncompahgre Gunnison San Juan Rio Grande and Medicine Bow Routt National Forests N F Southern Rockies Canada Lynx Amendment written by and published by . This book was released on 2008 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Wildlife Research Report written by and published by . This book was released on 2006 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mammals of Colorado Second Edition written by David M. Armstrong and published by University Press of Colorado. This book was released on 2011-05-18 with total page 637 pages. Available in PDF, EPUB and Kindle. Book excerpt: Co-published with the Denver Museum of Nature & Science. Thoroughly revised and updated, Mammals of Colorado, Second Edition is a comprehensive reference on the nine orders and 128 species of Colorado's recent native fauna, detailing each species' description, habitat, distribution, population ecology, diet and foraging, predators and parasites, behavior, reproduction and development, and population status. An introductory chapter on Colorado's environments, a discussion of the development of the fauna over geologic time, and a brief history of human knowledge of Coloradan mammals provide ecological and evolutionary context. The most recent records of the state's diverse species, rich illustrations (including detailed maps, skull drawings, and photographs), and an extensive bibliography make this book a must-have reference. Amateur and professional naturalists, students, vertebrate biologists, and ecologists as well as those involved in conservation and wildlife management in Colorado will find value in this comprehensive volume.
Download or read book Snowshoe Hare written by I. B. Keith and published by . This book was released on 2005 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: The snowshoe hare (Lepus americanus), one of our commonest forest mammals, is found only in North America. This document presents a description of the species and provides information on habitat and habits, range, feeding, breeding, and conservation measures.
Download or read book An Analysis of a Population of Snowshoe Hares Lepus Americanus Washingtonii Baird in Western Oregon written by Hugh C. Black and published by . This book was released on 1965 with total page 570 pages. Available in PDF, EPUB and Kindle. Book excerpt: The ecology of a population of snowshoe hares, Lepus americanus washingtonii, was studied in western Oregon from 1960 to 1962. Objectives were to obtain information to control hares, which frequently cause damage to coniferous reproduction in the region, and to compare the life history of this little-studied subspecies with others. The study area was located on cut-over forest land at 2900-foot elevation in the western Cascades. The climate is characterized by heavy precipitation in winter and summer drought. Snowfall is slight. Sixty-four live-traps were located in a square grid of 8 rows of 8 traps each, at spacings of approximately 100 and 200 feet. Half the traps were located on a recently clear-cut area and half in young-growth western hemlock and Douglas-fir. Traps usually were set for three successive days at monthly intervals. Trapped hares were marked and released on the main study area, and hares from nearby areas were removed for necropsy. In all, 207 hares were caught 889 times on the trapping grid during the 18-month study. One-third of hares tagged and released were not recaught, but the remainder were recaught one or more times. Trapping success varied from 3.6 to 44.4 percent. Principle factors influencing movements of hares, trapping success, and distribution of catches were vegetative structure, weather, and differing behavior of adults. Estimates of numbers of hares were computed from live-trapping data by the recapture, and the calendar-graph methods. Both methods indicated comparable trends in the population. Estimates of hares on the area trapped ranged from 41 in March to 136 in August. Estimated density of hares was 1.6 per acre at start of trapping in October. Density was nearly doubled to about 3.0 hares per acre in late summer. Most adult females on the area studied had two or three litters a year, averaging three young per litter. First litters were born in May and last litters in August. Most juveniles approached maximum size by four months. Mean total length of adults of both sexes was greater than that of subadults. Foot and total length of adult females were greater than in adult males. Mean weight of adult males in winter was 40.6 ounces and of females, 43.4 ounces. Subadults and adults weighed slightly less in early winter than in late fall. Sex ratio of 205 adult and juvenile hares was 80 females to 100 males; ratio of 84 young juveniles tagged during the summer was 87 females to 100 males. Juveniles tagged (154) exceeded adults tagged (51) by a ratio of 3:1. Weighted mean range-size of adult hares caught three or more times as computed by the inclusive-boundary-strip, and circular-bivariant-distribution methods was 5.76 and 10.15 acres for males; 3.30 and 7.80 acres for females. Mean home range of juveniles was comparable to the range of adult females. Distribution of catches of hares repeatedly caught and tracking of toe-clipped hares showed that trap-revealed ranges are related to true ranges and that ranges of most adults are fairly stable. A tendency towards farther ranging and linearity of movements was shown by some hares in winter. Location and use of forms are described. Signs of feeding showed that hares fed on conifers and shrubs in winter and herbaceous vegetation in summer. Young juvenile hares "disappeared" from the population at a high rate. Probability of their survival from birth to the first breeding season was less than 0.18. Crude survival rate of all hares was 0.73. Neither disease nor parasitism constituted serious decimating factors, and pathology of 74 hares necropsied was normal. Predation was the most important source of mortality among hares of all ages. Symptoms of "trap sickness" were shown, mainly in winter, by 29 of 207 hares. The following parasites were found in 50 necropsied hares, and 207 hares examined for ticks and fleas: Protozoa, Eimeria stiedae; Cestoda, Mosgovoyia pectinata americana, and Taenia pisiformis; Nematoda, Trichostrongylus affinis, and Nematodirus triangularis; Acarina, Haemphysalis leporis-palustris; and Siphonaptera, Cediopsyllus simplex and Hoplopsyllus affinis.
Download or read book Survival and Activity Patterns of Snowshoe Hares Lepus Americanus in Interior Alaska written by Dashiell S. Feierabend and published by . This book was released on 2013 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt: Snowshoe hare (Lepus americanus) survival depends on the interaction of habitat characteristics with numerous biological and environmental variables. In boreal regions where considerable habitat heterogeneity exists, hares balance food availability with predation risk by moving among habitats seasonally, but it is largely unknown how often they move at shorter time scales. I investigated the seasonal effects of habitat, weather, and individual hare characteristics on survival and movement in two common but fundamentally different boreal habitats. Survival was highest in summer, for hares with higher body condition, and in black spruce rather than early successional forest. Hares moved among core use areas in different habitats twice per day on average, using more open areas at night when they were presumably feeding on preferred browse. Movement rates were lowest in mid-afternoon when hares appeared to be resting under dense cover. Behavior of individuals varied greatly with some hares repeatedly moving up to 1 km between defined patches in less than 5 hours and others remaining roughly within a 1 ha area. These findings illustrate the complexity of snowshoe hare ecology in an area where habitat variation promotes daily movement of hares among radically different habitats over a few hundred meters.
Download or read book Influence of Precommercial Thinning on Snowshoe Hares written by and published by . This book was released on 2005 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Habitat Suitability Index Models written by Raymond G. Carreker and published by . This book was released on 1985 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Wild Carnivores of New Mexico written by Jean-Luc E. Cartron and published by University of New Mexico Press. This book was released on 2024-02-15 with total page 1145 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this first-ever landmark study of New Mexico's wild carnivores, Jean-Luc E. Cartron and Jennifer K. Frey have assembled a team of leading southwestern biologists to explore the animals and the major issues that shape their continued presence in the state and region. The book includes discussions on habitat, evolving or altered ecosystems, and new discoveries about animal behavior and range, and it also provides details on the distribution, habitat associations, life history, population status, management, and conservation needs of individual carnivore species in New Mexico. Like Cartron's award-winning Raptors of New Mexico, Wild Carnivores of New Mexico shares the same emphasis on scientific rigor and thoroughness, high readability, and visual appeal. Each chapter is illustrated with numerous color photographs to help readers visualize unique morphological or life-history traits, habitat, research techniques, and management and conservation issues.
Download or read book Distribution and Population Status of the Snowshoe Hare Lepus Americanus Erxleben on Connecticut Hill Wildlife Management Area New York written by Chia-Yuan Chien and published by . This book was released on 1973 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt:
