<p> Size-at-age of Pacific Halibut (<i>Hippoglossus stenolepis</i>) has declined significantly since the 1980s. For instance, the average weight of a 20-year-old female declined from 55 kg in 1988 to 20 kg in 2014. The decline in size-at-age corresponds to a period of declining Pacific Halibut recruitment, spawning biomass, and reductions in catch limits for the directed commercial Pacific Halibut longline fishery. The causes of changes in Pacific Halibut size-at-age are poorly understood. Our project investigates several hypotheses related to declines in size-at-age, including the effects of environmental and ecological variability on growth, and the cumulative effects of harvest and size-selective fishing. Specific potential environmental covariates include the Pacific Decadal Oscillation, which is an index of basin-wide sea surface temperatures, and summer sea surface temperatures along the continental shelf of the Gulf of Alaska. Specific ecological variables include annual biomass estimates of Arrowtooth Flounder (<i>Atheresthes stomias</i>) and Pacific Halibut to investigate the potential role of inter- and intraspecific competition, respectively. We used a population modeling approach to simulate the effects of fishing on size-at-age. We found that the large increase in Arrowtooth Flounder biomass since the 1970s corresponds to declines in Pacific Halibut size-at-age. Our results also suggest that periods of high Pacific Halibut biomass relates to poor growth and low size-at-age. Finally, we found that harvest and size-selective fishing explains between 30 and 65% of observed declines since the 1980s in the Gulf of Alaska, and up to 100% of the declines in Southeast Alaska and British Columbia where harvest rates were high in the 1990s and 2000s. Our findings have implications for fisheries management, including balancing tradeoffs associated with size limits, and understanding how changes in environmental and ecological conditions can shift management reference points such as maximum sustainable yield.</p>

<p> I studied current educational efforts about urban wildlife in Tucson, Arizona using three main approaches: a) interviews with key informants, b) analysis of the dissemination of and reaction to informative booklets about urban wildlife, and c) a review of regionally-relevant news articles published online from 2013 to 2015. These triangulated research efforts provide a general snapshot of the relative effectiveness of urban wildlife education practices and result in suggestions for improvement with future efforts. Key informants provided insight into successful human-wildlife conflict resolution and avoidance techniques and successful education practices. An analysis of the dissemination of information on living with urban wildlife, revealed that 53% of the small participating businesses valued the effort and requested additional booklets for their clients. All 45 of the recipients of the educational booklet found them useful and 65% cited them as their only such source of information about wildlife. Thus, I recommend additional concerted dissemination of such materials towards improved education of the public about urban wildlife interactions. Analysis of online news articles revealed that 51% focused on human-wildlife conflicts and, of these, 30% contained information about conflict avoidance. By contrast, 35% of all articles reviewed were strictly educational and yet, of these, 74% addressed conflict avoidance. Thus, I recommend that future media efforts continue this focus on human-wildlife conflict avoidance and resolution strategies. The culmination of this work demonstrates that much work is being conducted towards urban wildlife education and revealed education projects and strategies that may be applied in the future to help facilitate an informed coexistence with urban wildlife.</p>

Management of deer populations is directed toward multiple objectives. Deer populations on public and private lands belong to the public and thus management is a political process. Four components for an effective management system for deer populations are identified. These are the set of objectives relating to the resource, the set of regulations which will achieve the objectives, knowledge of the expected population response to alternative management strategies, and a means of monitoring these responses to determine whether or not the objectives are being achieved. Deer provide benefits mainly through the associated recreational opportunities and cause costs by interacting with land based economic activities such as agricultural crop production and reforestation. At certain times of the year deer may also compete with domestic livestock for forage. Deer also cause significant costs through collisions with automobiles on the highways. The extent of these benefits and costs, and others, is related to the biosystem through parameters such as the size and composition of the population, the extent of the hunting kill, and so on. In this thesis a computer simulation model of the Mendocino County, California, deer population is presented. The population is modeled as a density dependent birth and death process. Hunting strategies are potentially the most flexible management tool. Thus the model is structured to permit detailed examination of the response over time of the population to alternative hunting strategies. In California, a bucks-only hunting strategy has been followed since about the turn of the century. This study demonstrates that the bucks-only strategy neither effectively controls the size of the deer population, nor does it provide for the greatest recreational opportunities. The extent of the costs referred to above are directly related to the size of the population and the consumptive recreational benefits, that is those due to hunting, are directly related to the size of the hunting kill. Experiments with the model show that population control can be achieved and the hunting kill can be increased by a mixed buck and antlerless deer hunting strategy. Other results show that the computer simulation model can provide information about the biosystem which is not otherwise available. Simulation methods permit considerable insights into the operation and control of complex biosystems where the status of the systems is time dependent and the systems are influenced by uncontrollable elements so that at best the outcomes resulting from particular management actions are uncertain. The simulation model used in this study is applicable to other deer populations and other wildlife species. / Graduation date: 1972

Thesis (PHD)--University of Montana, 2009. / Contents viewed on December 22, 2009. Title from author supplied metadata. Includes bibliographical references.

Thesis (Ph. D.)--Lehigh University, 2001. / Includes vita. Includes bibliographical references (leaves 402-422).

Thesis (Ph. D.)--University of Texas at Austin, 2000. / Vita. Includes bibliographical references (leaves 497-523). Available also in a digital version from Dissertation Abstracts.

Thesis (Ph. D.)--University of Texas at Austin, 2002. / Vita. Includes bibliographical references. Available also from UMI Company.

<p> Identifying species occurrence in ecosystems of high conservation concern is especially important in the context of modern landscapes. This study investigated how stand-scale and landscape-scale factors affect priority birds associated with longleaf pine (<i>Pinus palutris</i>) ecosystems. Herein, I compared priority bird occupancy among 12 stand types throughout the historic range of longleaf pine. I found open pine stands positively influenced red-cockaded woodpecker (<i>Picoides borealis</i>) and Bachman&rsquo;s sparrow (<i>Peucaea aestivalis</i>) occupancy, but were not significantly linked to northern bobwhite (<i>Colinus virginianus</i>) and brown-headed nuthatch (<i>Sitta pusilla</i>) occurrence. Landscape- and stand-scale factors affected red-cockaded woodpecker, Bachman&rsquo;s sparrow, and brown-headed nuthatch occupancy. Northern bobwhite occupancy was influenced solely by landscape-scale factors. Red-cockaded woodpecker and Bachman&rsquo;s sparrow were positively influenced by metrics associated with longleaf pine ecosystems suggesting they are effective indicator species. My analysis indicates that using this multi-scale approach is valuable to identifying areas on the landscape of conservation and restoration priority.</p>

<p> Wildlife management and conservation frequently rely on understanding mechanisms that influence distribution and abundance of animals. I quantified space use for a population of inland riverine adult male alligators in Mississippi. Results indicated habitat selection is a scale-dependent process and aquatic vegetation, water depth, and water temperature may be important factors influencing alligator foraging and thermoregulation. Apparent habitat suitability and low alligator density did not manifest in an observed body size-based dominance hierarchy. I also analyzed long-term Mississippi alligator spotlight survey data for trends and effects of environmental covariates on counts. Model results indicated alligator counts have increased over time. This response likely reflects benefits accrued from decades of protection and wetland conservation. Distance sampling does not appear to be a feasible monitoring technique for riverine alligator populations. Nevertheless, it is important that survey protocols and monitoring programs account for imperfect detection and model important covariates.</p>

<p> The bog turtle (<i>Glyptemys muhlenbergii</i>) is listed as threatened under the U.S. Endangered Species Act primarily because of the loss and degradation of its specialized wetland habitat. Adequate nesting habitat may be a limiting factor for bog turtle recovery, and nesting habitat creation or expansion may be an effective conservation tool but only if managers understand nesting behaviors, habitat requirements, and threats to nest success. The objective of this study was to understand the nesting ecology of the bog turtle and to use this information to suggest improvements to bog turtle management. I used radio telemetry to locate nesting females. I then used nest location and maternal genetic microsatellite data to investigate nest-site fidelity and natal homing. I collected microhabitat data at each nest and random points in both spring and fall at three spatial scales to understand nest-site selection. I also studied nest success with and without predator excluder cages to determine if predator excluders reduced predation or altered nest conditions. I found evidence that females display nest-site fidelity to nest-site areas but no evidence for natal homing. Bog turtles nested in relatively small patches of habitat in close proximity to water or saturated soil with low densities of woody stems and low percent cover of woody vegetation, forbs, and ferns. Predator excluders reduced predation by &sim;40% while having no effect on nest temperatures, incubation periods, or underlying (disregarding predation) nest success. Given the results of this research, I conclude that the creation of new nesting areas could be a viable conservation tool, as females do not always return to the same nest-site area. Managers should create or maintain small patches of open-canopy habitat with reduced woody vegetation in areas that have consistent moisture from spring to fall. Increasing the availability of nesting areas may eventually lead to increases in recruitment, but if predation pressures are high, managers should also deploy predator excluders. This is the first study to examine the behavioral drivers of bog turtle nest-site selection and the efficacy of predator excluders on bog turtle nests.</p>