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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.
21

Landscape Ecology of Eastern Wild Turkeys in Mississippi

Davis, Annie Moriah 12 August 2016 (has links)
The effects of landscape structure on wildlife populations have drawn more attention from ecologists and wildlife managers as landscapes have rapidly changed worldwide. The objectives of this study were to (1) conduct a statewide habitat suitability assessment for wild turkeys (Meleagris gallopavo) in Mississippi using machine learning methods; (2) determine landscape-abundance relationships of wild turkeys at 2 spatial scales; and (3) measure genetic distinction of wild turkey populations in Mississippi. I found that habitat suitability for wild turkeys was positively related to amount of forest cover. Wild turkey relative abundance peaked at an optimal hardwood forest proportion of 0.29 and increased with enhanced landscape configuration at the annual dispersal scale, supporting the landscape composition hypothesis. Using microsatellite analysis of 224 birds, I found 3 distinct genetic clusters in Mississippi; however, population genetic differentiation neither fit to the isolation by distance or isolation by resistance models but may have behavioral cues.
22

DEEP LEARNING APPROACHES FOR AUTOMATIC ACOUSTIC DETECTION OF THE BACHMAN'S SPARROW AND ITS APPLICATION TO ASSESSING ITS RESPONSE TO PRESCRIBED BURNS IN SUBTROPICAL HABITATS OF CENTRAL FLORIDA

Santiago Ruiz Guzman (16735197) 09 August 2023 (has links)
<p><b></b>Passive acoustic monitoring (PAM) is a tool with immense potential to evaluate the response of wildlife to ecosystem disturbances. PAM allows to evaluate wildlife dynamics by means of acoustic indices that estimate the diversity or complexity of sounds in a recording, as well as to study ecological aspects at the species level by training machine learning-based automatic acoustic detector. In this study, five deep learning approaches for automatic song detection were evaluated of the near-threatened Bachman's Sparrow in data scarcity scenarios, and then used this classifier to study the response of this bird to the number of days following a prescribed burn in six subtropical habitats in central Florida. At the same time, the response of avifauna acoustic activity to prescribed burning was quantified by means of three of the most used acoustic indices used in the literature (Acoustic Complexity Index, Acoustic Diversity Index and Bioacoustic Index). I found that it is possible to construct competitive birdsong detectors with small datasets using pre-trained models regardless. Furthermore, the use of data augmentation can lead to a detriment of the detector performance, especially of lower quality recordings, and that increasing the dataset does not necessarily increase the generalizability of the model. On the other hand, I found that unlike Acoustic Diversity Index, the Bioacoustic and Acoustic Complexity indices are negatively correlated with time after a burn, the same trend that Bachman's Sparrow presence showed, even though it was more influenced by habitat type than by the effect of the prescribed burns. This study shows the potential of tools including automatic song detection and acoustic indices to model at different scales the dynamics of avifauna in response to ecosystem disturbances. Their development can provide efficient tools for the study and conservation of both threatened wildlife species and the ecosystems they inhabit.</p>
23

Responses Of The Florida Mouse (podomys Floridanus) To Habitat Management

DePue, Jason 01 January 2005 (has links)
The Florida mouse (Podomys floridanus), a species restricted to the Lake Wales Ridge and the Atlantic Coastal Ridge, is recognized by the Florida Fish and Wildlife Conservation Commission as a species of special concern, highlighting its status as a species that is threatened by habitat loss statewide. Publicly owned lands offer protection for the species, but management is generally focused on protecting biodiversity in general and not a particular species. The response of the Florida mouse to land management practices such as mechanical treatment and prescribed fires is poorly documented. This research examined the population responses of Florida mice on three public lands in central Florida, namely, Bullfrog Creek Mitigation Park in Hillsborough County, Split Oak Mitigation Park in Orange County, and Chuluota Wilderness in Seminole County. Florida mice numbers increased or recovered to pre-burn levels within six months following prescribed burns in 2003 and 2004 on the Bullfrog Creek site. Florida mice dropped in numbers following a fire on the Split Oak site, but were increasing when the study ended. The steady decrease in numbers of mice at the Chuluota Wilderness site remained unaffected by habitat modification. Management of public lands that support Florida mice should continue to utilize prescribed fire to maintain upland habitats. When possible, prescribed fires should be limited to the spring and early summer months and applied to only a portion of the total available area in any year.
24

ECONOMIC IMPACT ANALYSES OF CONSUMPTIVE USES OF NATURAL RESOURCES IN INDIANA

Dhruba Burlakoti (14284862), Mo Zhou (46274), Eva Haviarova (12631618), Carson Reeling (7346774) 21 December 2022 (has links)
<p>This research combines the economic contribution analysis of hardwood industries in Indiana and the economic impact analysis of furbearer hunting and trapping in Indiana. This research employs input-output analysis using Impact Analysis for Planning (IMPLAN) software. </p>
25

To plant or not to plant? A decision support tool to minimize risk associated with water level uncertainty in reservoir habitat management.

Norris, David M 01 May 2020 (has links)
Reservoir mudflats limit development of healthy fish assemblages due to the lack of structural habitat provided by plants. Seeding mudflats with agricultural plants may mimic floodplain wetlands once inundated and provide fish habitat. However, planting success is uncertain because of unpredictable water level fluctuations that affect plant growth. Decision support tools can quantify uncertainty that influences decision outcomes, thus reducing risk in the decision-making process. I used Bayesian Decision Networks and sensitivity analyses to quantify uncertainty surrounding mudflat plantings as supplemental fish habitat in four northwest Mississippi reservoirs. When averaged across all uncertainty, planting was the optimal decision only in Enid Lake. Response profiles identified specific contours within Enid, Sardis, and Grenada reservoirs at which planting was the optimal decision. No such contours were identified in Arkabutla Lake. These results provide a quantified basis for establishing best management practices and identifying key system states that influence decision outcomes.
26

Decision Support for Natural Resource Management

Cummings, Jonathan 01 January 2014 (has links)
This research spans a variety of research topics with a common theme, providing decision support through the development and analysis of methods that assist decision making for natural resource and wildlife management. I used components of structured decision making and decision analysis to address natural resources management problems, specifically monitoring and estimating the status of harvested populations, as well as data collection decisions for landscape conservation. My results have implications for the way populations are monitored and their status is estimated. I find that the inclusion of error in data collection can have a substantial impact of the performance of abundance and growth rate estimates of harvested species and that the selection of estimation methods depends on what management objectives are most important. For example, the Sex-Age-Kill population estimation method best estimates the size of populations, while the Downing population reconstruction method better estimates trends in population growth rates. I provide a framework to support selection of the best estimation method while considering a monitoring program as a whole. Based on this framework the Vermont Fish and Wildlife Department will obtain the most benefits from a monitoring program including necropsy analysis that uses the Downing method to track population status. Finally, I demonstrated the use of value of information analysis as a tool to determine the relative expected benefits of addition spatial data collection for use in landscape mapping and conservation. This type of analysis can provide conservation agencies with a planning tool to direct budgets and mapping efforts.
27

Habitat Use By Early Successional Bird Species Along Powerline Rights Of Way: Making Connections Across Private Lands

Peterson, Christine Rose 01 January 2015 (has links)
Wildlife species that rely on early successional habitat are showing long-term region-wide declines, including songbirds such as Eastern Towhee (Pipilo erythrophthalmus), Field Sparrow (Spizella pusilla), Blue-winged Warbler (Vermivora cyanoptera), Golden-winged Warbler (Vermivora chrysoptera), Prairie Warbler (Setophaga discolor), and Brown Thrasher (Toxostoma rufum). All six species are listed as Species of Greatest Conservation Need on a majority of the New England state's Wildlife Action Plans and in 2011, the Golden-winged Warbler was placed under review for federal listing. In areas where vegetation structure is actively maintained in early successional stages, such as powerline rights-of-way (ROWs), there is an opportunity to provide habitat over long time frames. This study focused on habitat use by six early successional bird species in the Champlain Valley in Vermont along powerline ROWs. Thirty sites that included potential habitat were established. During the breeding season, trained citizen scientist volunteers spot-mapped species distribution patterns along transects. Focal habitat use by individuals was mapped during timed field observations (n=83). Vegetation species composition and structure was evaluated within 1m2 vegetation plots across each site (n=965). Logistic regression models of study species' abundance patterns and focal habitat use were compared using Akaike's information criterion (AIC). Surrounding landscape composition, vegetation species composition and vegetation structure had the greatest influence on species abundance and focal habitat use based on best-fit models. All species occurrence, except Blue-winged Warbler and Brown Thrasher, decreased with greater development and fragmentation in the surrounding landscape. While the covariates that influenced habitat use patterns by the species were similar, the effect size and direction of influence varied. These results suggest that a universal management approach for shrubland songbird habitat would not support a broad range of species. The findings from this study determined species-specific habitat preferences that can improve management practices to benefit these declining species.
28

Ecology and Management of a High Elevation Southern Range Greater Sage-Grouse Population: Vegetation Manipulation, Early Chick Survival, and Hunter Motivations

Guttery, Michael R. 01 December 2010 (has links)
My research provided new information concerning the management, ecology, and conservation of greater sage-grouse (Centrocercus urophasianus). I report the results of an experiment using strategic intensive sheep grazing to enhance the quality of greater sage-grouse brood-rearing habitat. Although forb cover, an important component of brood-rearing habitat, responded positively to the grazing treatment, the response of other habitat variables was suppressed because the plots were not protected from domestic and wild herbivores during the years following the treatments. Measurements taken in grazing exclosures confirmed that herbivory by both large and small animals had significant impacts on vegetation. However, despite the suppressed habitat response, sage-grouse preferred the treated plots over the controls. In another chapter, I modeled survival rates of sage-grouse chicks to 42-days of age. Average chick survival across my study was high (39%). Survival varied across years and was affected by demographic, behavioral, and habitat factors. The top habitat model indicated that chick survival was positively related to grass cover and was higher in areas dominated by black sagebrush (Artemisia nova) than in big sagebrush (A. tridentata). The top model with demographic/behavioral factors indicated that survival was affected by interactions between hen age and brood mixing as well as between hatch date and brood mixing. In my last chapter I report on a survey of Utah sage-grouse hunter motivations and satisfaction. In 2008 and 2009 I surveyed over 600 sage-grouse hunters in Utah to determine why they chose to apply for sage-grouse hunting permits and what factors contributed to a satisfactory hunting experience. Originally, I had hypothesized that the impending Endangered Species Act listing petition for greater sage-grouse motivated hunters to pursue the species before they lost the opportunity. This hypothesis was not supported by the data. The majority of hunters indicated that they chose to hunt sage-grouse because it was a tradition or because it provided an opportunity to spend time outdoors with family. Additionally, Utah sage-grouse hunter satisfaction was influenced by whether or not the hunter was successful in harvesting at least one bird.
29

Mallard duckling survival and habitat selection in the Canadian prairie pothole region

Bloom, Pauline Marion 10 May 2010
Like life-history theory, wildlife management decisions are typically predicated on trade-offs between benefits associated with investing resources to achieve higher reproductive or survival rates versus costs or risks of achieving those goals. On the Canadian prairies, most waterfowl conservation resources are directed to policies and programs that seek to increase duck nesting success. Limited attention has focused on post-hatching life-cycle stages, yet, despite considerable recent work on duckling survival rates, many uncertainties remain concerning how abiotic and biotic factors affect duckling survival rates. The role of upland habitat characteristics may be important but has received limited attention. I evaluated hypothesized sources of variation in duckling survival for 617 mallard (Anas platyrhynchos) broods on 27 Canadian prairie-parkland sites, with emphasis on assessing effects of managed and remnant natural upland habitats. I contrasted suites of a priori and post hoc exploratory models that incorporated effects of landscape, weather, female and brood-related variables to explain variation in duckling survival rates. Survival was lower for ducklings that used areas with high proportions of semi-permanent wetlands, as well as for broods that travelled farther overland. Exploratory analyses revealed further that survival of ducklings was negatively related to the amount of managed hayland. In contrast, duckling survival was positively associated with the amount managed grassland. There was no evidence of trade-offs between benefits of managing habitat to enhance duck nesting success versus costs in terms of lower subsequent duckling survival.<p> I also addressed unresolved questions about how birds balance costs and benefits of selecting habitats by determining the survival consequences of habitat choices made during brood-rearing. In theory, fitness should be higher in preferred habitats, but this assumption is rarely tested. Fitness consequences (i.e., duckling survival) of habitat selection patterns were determined at landscape and local scales using logistic regression and information-theoretic model selection techniques. Best-approximating landscape-level models indicated that mallard females selected brood-rearing areas with a high proportion of wetland and perennial upland habitats, but duckling survival was not related to habitat selection patterns at this scale. At finer spatial scales, females selected brood-rearing areas with high proportions of wetland habitats, but, contrary to expectation, duckling survival was lower when females raised their broods in these areas. Females avoided areas with abundant perennial cover and wetlands with little vegetative cover and, consistent with prediction, duckling survival was higher when females selected areas with low perennial cover. Thus, females did not consistently select brood-rearing habitats that conferred the highest fitness benefits. Rather, the relationship between habitat selection and duckling survival depended on spatial scale and habitats considered.
30

Mallard duckling survival and habitat selection in the Canadian prairie pothole region

Bloom, Pauline Marion 10 May 2010 (has links)
Like life-history theory, wildlife management decisions are typically predicated on trade-offs between benefits associated with investing resources to achieve higher reproductive or survival rates versus costs or risks of achieving those goals. On the Canadian prairies, most waterfowl conservation resources are directed to policies and programs that seek to increase duck nesting success. Limited attention has focused on post-hatching life-cycle stages, yet, despite considerable recent work on duckling survival rates, many uncertainties remain concerning how abiotic and biotic factors affect duckling survival rates. The role of upland habitat characteristics may be important but has received limited attention. I evaluated hypothesized sources of variation in duckling survival for 617 mallard (Anas platyrhynchos) broods on 27 Canadian prairie-parkland sites, with emphasis on assessing effects of managed and remnant natural upland habitats. I contrasted suites of a priori and post hoc exploratory models that incorporated effects of landscape, weather, female and brood-related variables to explain variation in duckling survival rates. Survival was lower for ducklings that used areas with high proportions of semi-permanent wetlands, as well as for broods that travelled farther overland. Exploratory analyses revealed further that survival of ducklings was negatively related to the amount of managed hayland. In contrast, duckling survival was positively associated with the amount managed grassland. There was no evidence of trade-offs between benefits of managing habitat to enhance duck nesting success versus costs in terms of lower subsequent duckling survival.<p> I also addressed unresolved questions about how birds balance costs and benefits of selecting habitats by determining the survival consequences of habitat choices made during brood-rearing. In theory, fitness should be higher in preferred habitats, but this assumption is rarely tested. Fitness consequences (i.e., duckling survival) of habitat selection patterns were determined at landscape and local scales using logistic regression and information-theoretic model selection techniques. Best-approximating landscape-level models indicated that mallard females selected brood-rearing areas with a high proportion of wetland and perennial upland habitats, but duckling survival was not related to habitat selection patterns at this scale. At finer spatial scales, females selected brood-rearing areas with high proportions of wetland habitats, but, contrary to expectation, duckling survival was lower when females raised their broods in these areas. Females avoided areas with abundant perennial cover and wetlands with little vegetative cover and, consistent with prediction, duckling survival was higher when females selected areas with low perennial cover. Thus, females did not consistently select brood-rearing habitats that conferred the highest fitness benefits. Rather, the relationship between habitat selection and duckling survival depended on spatial scale and habitats considered.

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