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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Spatial Response of Bobcats and Coyotes to Resources and Human Modification in Illinois

Gorman, Nicole 01 December 2022 (has links) (PDF)
Mesocarnivores, including bobcats (Lynx rufus) and coyotes (Canis latrans), fill a unique ecological role throughout much of North America, where they were once influenced by larger predators, but are now the top predators where large carnivores have been extirpated. Their adaptability, generalist traits, and ability to coexist with humans to a greater extent than many species makes them an important subject for current predator research. In addition, their recent population recovery in the case of bobcats and historical range expansion in the case of coyotes make their study timely given a potential increase in their influence on their prey and environments. I investigated how bobcats and coyotes in southern and central Illinois respond in their spatial behavior to factors in their environment like human modification and resources, including a local pulsed resource, white-tailed deer (Odocoileus virginianus) fawns. These spatial behaviors include home-ranging behaviors, habitat selection, and movement, which can be extremely informative in estimating how mesocarnivores respond to landscape heterogeneity. I found that individual variation, which is understudied in much of current spatial research, played a powerful role in all of these behaviors. Bobcats and coyotes used different strategies to respond to human modification in their home ranges, with bobcats broadly expanding their home range with increases in human modification, and clearly selecting for or avoiding these features on the landscape. Meanwhile, coyotes did not expand their home ranges with human modification, but instead displayed temporal and spatial complexity in their functional responses to human modification. These differences in response revealed a gradient in spatial behaviors animals can use to exist in anthropogenic environments, influenced by a species’ behavioral plasticity. I also found that while bobcat and coyote targeting of fawns during fawns’ most vulnerable period was weakly supported at the population-level, there was a substantial amount of individual variation in fawn exploitation. These results provided evidence that there were some specialist individuals that may contribute much more to fawn predation than others, which was somewhat influenced by habitat type. Overall, I found important interspecies and interindividual variation in mesocarnivore spatial behaviors. My study demonstrates how mesocarnivores respond to habitat and prey resources and risks associated with human development. Using this information, I present a framework for predicting how species may respond to changes in their environments, as well as provide further insight into how mesocarnivores may affect ungulate recruitment.
12

Lynxrufus wilsoni n.g., n.sp. (Nematoda: metastrongylidae) from the lungs of the bobcat, Lynx rufus rufus (Shreber)

Stough, Betty Delores 28 July 2008 (has links)
Of sixty-four bobcats, Lynx rufus rufus, collected in Virginia end North Carolina, twenty-five percent were found to be infected with an unidentified lungworm. As the literature showed no record of lungworm parasites from Lynx rufus rufus, a study was made of the lungworms of the cat family, Felidae. A new metastrongylid genus and species is here described, named and classified. The name is designated as Lynxrufus wilsoni. Lynxrufus wilsoni is placed tentatively in the subfamily Skrjabingylinae due to the similarity of its male reproductive organs to the male reproductive organs of the other members of that subfamily. / Ph. D.
13

Urban Bobcat (Lynx rufus) Ecology in the Dallas-Fort Worth, Texas Metroplex

Golla, Julie M. 01 December 2017 (has links)
Urban landscapes are quickly replacing native habitat around the world. As wildlife and people increasingly overlap in their shared space and resources, so does the potential for human-wildlife conflict, especially with predators. Bobcats (Lynx rufus) are a top predator in several urban areas across the United States and a potential contributor to human-carnivore conflicts. This study evaluated the movements and habitat use of bobcats in the Dallas-Fort Worth (DFW), Texas metroplex. Spatial data were collected from 10 bobcats via Global Positioning Satellite (GPS) for approximately one year. Average home range size was 4.60 km2 (n=9, SE=0.99 km2) for all resident bobcats, 3.48 km2 (n=5, SE=1.13 km2) for resident females, and 6.00 km2 (n=4, SE=1.61 km2) for resident males. Resource selection function (RSF) models show that bobcats avoid areas close to and far from grasslands and low-medium development, while selecting for these areas at intermediate distances. Bobcats also selected areas closer to developed open space, agricultural areas, and railroads. In addition, camera trap data analyzed with spatially explicit capture-recapture (SECR) models informed by the RSF results estimated a population density of 0.64 bobcats/km2 (SE = 0.22). Bobcats in DFW have significantly smaller home ranges and occur at higher densities compared to rural bobcat populations. Home ranges were also slightly smaller and densities higher than the most closely similar peri-urban bobcat studies. These differences likely arise due to the abundant urban prey species the DFW landscape provides despite limited space and habitat for bobcats. The dense urban development surrounding this population of bobcats may also discourage dispersing from the area, and contributing to higher densities. These results provide information to facilitate management of urban bobcats by providing new insight into how bobcats live amidst people in urban areas.
14

Occupancy modeling of forest carnivores in Missouri

Hackett, Harvey Mundy, January 2008 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 2008. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on June 8, 2009) Vita. Includes bibliographical references.
15

Bobcat Abundance and Habitat Selection on the Utah Test and Training Range

Muncey, Kyle David 01 December 2018 (has links)
Remote cameras have become a popular tool for monitoring wildlife. We used remote cameras to estimate bobcat (Lynx rufus) population abundance on the Utah Test and Training Range during two sample periods between 2015 and 2017. We used two statistical methods, closed capture mark-recapture (CMR) and mark-resight Poisson log-normal (PNE), to estimate bobcat abundance within the study area. We used the maximum mean distance moved method (MMDM) to calculate the effective sample area for estimating density. Additionally, we captured bobcats and estimated home range using minimum convex polygon (MCP) and kernel density estimation (KDE) methods. Bobcat abundance on the UTTR was 35-48 in 2017 and density was 11.95 bobcats/100 km2 using CMR and 16.69 bobcats/100 km2 using PNE. The North Range of the study area experienced a decline of 36-44 percent in density between sample periods. Density declines could be explained by natural predator prey cycles, by habituation to attractants or by an increase in home range area. We recommend that bobcat abundance and density be estimated regularly to establish population trends.To improve the management of bobcats on the Utah Test and Training Range (UTTR), we investigated bobcat (Lynx rufus) habitat use. We determined habitat use points by capturing bobcats in remote camera images. Use and random points were intersected with remotely sensed data in a geographic information system. Habitat variables were evaluated at the capture point scale and home range scale. Home range size was calculated using the mean maximum distance moved method. Scales and habitat variables were compared within generalized linear mixed-effects models. Our top model (AICc weight = 1) included a measure of terrain ruggedness, mean aspect, and land cover variables related to prey availability and human avoidance.
16

Relatedness Assessment and Analysis of Road Mortality Effects on <i>Lynx rufus</i> in Ohio

Heffern, William J. 10 September 2021 (has links)
No description available.
17

Identifying and Understanding the Spatial Distribution of Bobcat and Coyote Behavior

Wilson, Ryan Radford 01 May 2010 (has links)
A common observation in animal space use studies is that animals do not use space uniformly, but rather use some areas of their home ranges and territories with much higher intensity than others. Numerous methods have been developed to estimate these "core areas"; however, all of the current methods available are based on arbitrary rules. Additionally, most studies do not attempt to understand what behavioral processes lead to the observed patterns of non-uniform space use. This study has four main objectives: 1) to develop an objective and more precise method for estimating core areas, 2) to understand the processes leading to unequal coyote capture probabilities across territories, 3) to understand the biological mechanisms that influence the location of bobcat core areas, and 4) to determine how differences in territory size affect coyote movement patterns. The core area estimation method I developed consistently performed better than methods using arbitrary values to define core areas. Using this method to estimate coyote core areas, I determined that coyote capture locations were not actually biased towards low use areas because of low familiarity with those areas, but rather because of a higher probability of encountering traps there. Intensity of coyote use did, however, influence the location of bobcat core areas. When prey abundance was high, bobcat core areas were located in areas of low coyote use but occurred in areas of high coyote use when prey abundance was low, indicating bobcat core areas are the result of at least two processes: foraging conditions and avoidance of intraguild predation. Lastly, coyote movement behavior changed significantly as territory size increased, leading to faster and straighter movement patterns. However, even though coyotes in larger territories moved twice as fast as those in small territories, they took significantly longer to traverse their territories compared to those in small territories. This might be the result of coyotes occupying large territories being less constrained by defense due to lower conspecific density compared to coyotes occupying small territories. Overall, my research reveals the importance of using more precise methods to delineate animal space use patterns, and the greater information researchers can obtain when they attempt to understand the processes underlying space use patterns.
18

Factors Influencing White-Tailed Deer Mortality Risk within a Multi-Predator System in Michigan, USA

Kautz, Todd M 14 December 2018 (has links)
I monitored cause-specific mortality and factors influencing mortality risk for white-tailed deer in the Upper Peninsula of Michigan, USA, during two high mortality risk periods: adult female deer during Feb–May, and fawns from birth to 6 months. I observed high rates of predation and starvation for adult female deer during Apr–May, suggesting that late winter represents a survival bottleneck due to nutritional declines. A strong negative relationship existed between snow free days during late winter and mortality risk. Predation was the dominant mortality source for fawns but predation risk decreased with larger birth mass. Black bears and coyotes accounted for most fawn kills at the population level, but wolves and bobcats had greatest per-individual fawn kill rates. My results suggest predation was the dominant mortality source for fawns and adult female deer, but multiple predator species were important and nutritional condition of deer influenced their vulnerability to predation.
19

Modeling the Distribution of Bobcats and Areas of Reintroduction for Fisher in the Southern Washington Cascades

Halsey, Shiloh Michael 16 August 2013 (has links)
The fisher (Martes pennanti) is a medium sized member of the mustelid family that once roamed the forests of Washington and whose historic range in the western United States once spread throughout the northern Rocky Mountains, the Cascade and Coast Ranges, and the Sierra Nevada (Carroll, Zielinski, and Noss 1999; Powell 1993, Spencer et al. 2011). Due to pressures from trapping and habitat fragmentation, the abundance of the species in the western United States has decreased dramatically and is thought to be limited to several small, isolated populations. In 2008, fishers were reintroduced to the Olympic Peninsula; however, bobcat (Lynx rufus) predation in the first years is thought to have killed off a significant portion of the released fisher hindering their ability to establish a self-sustaining population (Lewis et al. 2011). Other studies in the western United States have shown that bobcats can be a dramatic force on small or isolated fisher populations. The coniferous forest of the southern Washington Cascades is the possible site of a release of currently extirpated fishers. My research examines the distribution of bobcats in the region and explores the implication this and the habitat variables of the area have for a future reintroduction of fisher. The workflow of the research was a stepwise process of: 1) surveying forested areas in the southern Washington Cascades for the presence and absence of bobcat and acquiring previously completed survey data 2) using a classification tree to model the correlation of bobcat presence or absence with forest variables and 3) applying these relationships to spatial analysis the creation of maps showing areas of high ranking fisher habitat. The classification tree modeled the correlation between the forest variables and the results of the surveys, which included 145 bobcat absence observations and 39 presence observations. The model highlighted a 95% probability of absence above 1,303 m in elevation, 73% probability of absence in areas under 1,303 m in elevation and with a tree diameter value under 43.45 cm, 57% probability of absence in areas between 1,070 m and 1,303 m in elevation and with a tree diameter value above 43.45 cm, and an 89% probability of bobcat presence in areas under 1,070 m in elevation with a tree diameter value above 43.45 cm. I applied an upper elevation limit of 1,676 meters as a threshold for suitable habitat and only considered habitat suitable in cells with a tree diameter above 29 cm. The three locations highlighted as the most suitable areas for reintroduction due to a large amount of the highest ranking habitat and the largest aggregations of suitable habitat cells were around the William O. Douglas Wilderness that straddles the border of the Gifford Pinchot National Forest (GPNF) and the Wenatchee National Forest, another location in the Norse Peak Wilderness northeast of Mount Rainier, and a third location in Indian Heaven Wilderness in the southern portion of the GPNF.
20

The Impacts of Three Common Mesopredators on the Reintroduced Population of Eastern Wild Turkeys in Texas

Melville, Haemish 1972- 14 March 2013 (has links)
Early in the 20th century wild turkeys (Meleagris gallopavo) in North America were on the brink of extinction. Conservation and reintroduction efforts ensured that this species recovered throughout most of its historic range. Efforts to reintroduce eastern wild turkeys (Meleagris gallopavo sylvestris) to the Pineywoods of east Texas have achieved limited success. Previous research suggested that predation may have confounded this reintroduction. My aim was to quantify the influence of mesopredators on the wild turkey population in the Pineywoods. Raccoons (Procyon lotor), bobcats (Lynx rufus) and coyotes (Canis latrans) occur sympatrically in east Texas and are thought to prey on wild turkeys, their nests and poults. I fitted bobcats, coyotes and raccoons with both GPS and VHF collars and used location data and GIS applications to estimate home ranges, home range overlap and habitat selection for these mesopredators. I used scat analysis to determine diet of mesopredators and to establish whether they preyed on wild turkeys. I used capture mark recapture (CMR) techniques to investigate small mammal population dynamics at annual and seasonal bases. I used spotlight counts and track plates to assess seasonal relative abundance of eastern cottontail rabbits (Sylvilagus floridana). I used artificial nests to identify likely nest predators of wild turkey nests. I found that mesopredators in the Pineywoods had larger home ranges than elsewhere in the Southeast. Bobcat and coyote home ranges varied seasonally, being largest in fall. Raccoon home ranges did not vary seasonally. Bobcats and coyotes shared space more than did raccoons with bobcats or coyotes. There was differential habitat selection between species, but mature pine and young pine were important to the mesopredators and as nesting habitat for eastern wild turkeys. I found no evidence of wild turkey remains in scat samples. White tailed deer (Odocoileus virginianus), lagomorphs and small mammals occurred in the diets of all three mesopredators. Small mammal numbers varied seasonally, declining from spring to summer, in synchrony with mesopredator diet diversification, and wild turkey nesting and brood rearing. Lagomorph abundance did not vary seasonally. Bobcats were predominantly carnivorous while coyotes and raccoons were omnivorous, consuming seasonal fruit and insects. American crows (Corvus brachyrhynchos) and raccoons were the primary artificial nest predators. Crows depredated most artificial nests, except in summer, when raccoons depredated the most nests. I concluded that the impact of mesopredators on wild turkeys was not as severe as suggested by previous research. I suggest a combination of video monitoring live wild turkey nests to identify nest predators, improvement of nesting habitat to reduce mesopredator / wild turkey nest encounters, and a program of conditioned taste aversion to reduce any nest predation by mesopredators and crows.

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