• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 35
  • 11
  • Tagged with
  • 70
  • 57
  • 15
  • 15
  • 14
  • 14
  • 14
  • 13
  • 13
  • 12
  • 10
  • 9
  • 7
  • 6
  • 6
  • 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.
51

Using Remote Sensing Data to Predict Habitat Occupancy of Pine Savanna Bird Species

Allred, Cory Rae 01 September 2023 (has links)
A combination of factors including land use change and fire suppression has resulted in the loss of pine savanna habitats across the southeastern U.S., affecting many avian species dependent on these habitats. However, due to the ephemeral nature of the habitat requirements of many pine savanna species (e.g., habitat is only present for a couple of years after a fire), targeted management of such habitats can be challenging. Moreover, the growing numbers of imperiled pine savanna species can make prioritizing management difficult. One potential tool to better inform management of pine savanna species is satellite imagery. Sentinel-2 satellite imagery data provides an instantaneous snapshot of habitat quality at a high resolution and across a large geographic area, which may make it more efficient than traditional, ground-based vegetation surveying. Thus, the objectives of my research were to 1) evaluate the use of remote sensing technology to predict habitat occupancy for pine savanna species, and 2) use satellite imagery-based models to inform multispecies management in a pine savanna habitat. To meet my objectives, I conducted point count surveys and built predictive models for three pine savanna bird species: Bachman's Sparrow (BACS; Peuacea aestivalis), Northern Bobwhite (NOBO; Colinus virginianus), and Red-Cockaded Woodpecker (RCW; Dryobates borealis) across Georgia. I assessed the performance of satellite imagery in predicting habitat occupancy of these pine savanna species and its potential for multispecies management. I found that models created using satellite imagery habitat metric data performed well at predicting the occupancy of all three species as measured by the Area Under the Receiver Operating Characteristic Curve: BACS=0.84, NOBO=0.87, RCW=0.76 (with values between 0.7-1 defined as acceptable or good predictive capacity). For BACS and NOBO, I was able to compare these satellite imagery models to field-based models, and satellite models performed better than those using traditional vegetation survey data (BACS=0.80, NOBO=0.79). Moreover, I found that satellite imagery data provided useful insights into the potential for multispecies management within the pine savanna habitats of Georgia. Finally, I found differences in the habitat selected by BACS, NOBO, and RCW, and that BACS may exhibit spatial variations in habitat use. The results of this study have significant implications for the conservation of pine savanna species, demonstrating that satellite imagery can allow users to build reliable occupancy models and inform multispecies management without intensive vegetation surveying. / Master of Science / Land-use changes have resulted in the disruption of natural disturbances such as fires, resulting in the loss of pine savanna habitats throughout the southeastern U.S. Although many of the species that occupy these habitats are experiencing rapid population declines, habitat for pine savanna species can be challenging to manage. Without reoccurring fire, pine savanna habitat can become unsuitable for obligate species within short periods of time, forcing these species to disperse to newly disturbed habitats. The transient nature of the preferred habitat of pine savanna species makes targeting management for these species difficult, as it can be challenging to locate exactly where occupied habitats exist. Furthermore, as the number of pine savanna species that are declining is large, prioritizing management of these species can be difficult especially given limited conservation funding. One potential tool to better inform the management of pine savanna species is satellite imagery. Satellite imagery can capture habitat information across broad areas, at fine resolutions, and at frequent intervals, potentially making satellite imagery more efficient than conducting field vegetation surveys on the ground for gaining information on habitat suitability. Thus, the objectives of my research were to 1) determine if satellite imagery can effectively predict the habitats occupied by pine savanna species (habitat occupancy), and 2) use satellite imagery-based models to inform the simultaneous management of multiple species (multispecies management) in a pine savanna habitat. To meet these objectives, I conducted surveys and built predictive models for three pine savanna bird species: Bachman's sparrow (BACS; Peuacea aestivalis), Northern Bobwhite (NOBO; Colinus virginianus), and Red-Cockaded Woodpecker (RCW; Dryobates borealis) in Georgia. I found models informed by satellite imagery performed well at predicting habitats occupied for all three species. Furthermore, models developed using satellite imagery performed better at predicting the habitats occupied by pine savanna species than models developed using on the ground vegetation surveys. I also found that satellite imagery data provided useful insights into strategies to manage pine savanna species simultaneously. I found evidence that BACS, NOBO, and RCW may have contrasting habitat needs and that BACS may use habitat differently between sites in Georgia. The results of this study demonstrate that satellite imagery can be used to predict the habitats occupied by pine savanna species and inform multispecies management without surveying vegetation on the ground, which is a more efficient use of time and funding.
52

Economic Tradeoffs of Managing Pine Plantations for Timber Production or Wildlife Habitat

Davis, Phillip B 11 December 2015 (has links)
Little information is available to nonindustrial-private forest (NIPF) owners regarding economic tradeoffs between managing pine plantations for timber production or wildlife habitat. Loblolly (Pinus taeda) and longleaf (Pinus palustris) pine plantations were modeled to quantify economic tradeoffs for competing management scenarios utilizing densities aimed at wildlife habitat or timber production in Mississippi. Models contained a range of site indices, planting densities, and rotation lengths for timber maximization and white-tailed deer (Odocoileus virginianus) or northern bobwhite (Colinus virginianus) habitat production. All management scenarios in loblolly plantations produced positive Land Expectation Values (LEVs), while one fifth of the management scenarios in longleaf plantations produced positive LEVs. Comparison to the regional hunting lease rate the compensatory lease rates from the study could be realized, making wildlife management as valuable as timber management. The results of this study will help landowners be more informed about economic tradeoffs when making management decisions on their property.
53

Landscape Level Evaluation of Northern Bobwhite Habitats in Eastern Virginia Using Landsat TM Imagery

Schairer, Garrett L. 22 May 1999 (has links)
Northern bobwhite (<I>Colinus virginianus</I>) are important game birds associated with early successional habitats across the southeastern United States. In the past 30+ years there has been an almost universal decline in bobwhite population numbers despite a long history of management. The Virginia Bobwhite Quail Management Plan was implemented in 1996 to slow and stop the current population declines in Virginia. Virginia Department of Game and Inland Fisheries (VDGIF) personnel identified a lack of knowledge about the broad-scale, landscape level habitats in eastern Virginia. A large scale land cover map along with a detailed understanding of the spatial arrangements of bobwhite habitats will not only aid Virginia's management plan, but also allow focused efforts by our wildlife managers. I explored the possibilities of using remote sensing to map various habitats important to bobwhite. I compared several classification algorithms applied to Landsat TM imagery prior to selecting the classification method that best delineated early successional habitats. After method selection, a classified land cover map for the Coastal Plain and Piedmont of Virginia was generated. Using the classified images available from the first part of the study and 4 years of bobwhite call count data, I studied the landscape level habitat associations of bobwhite. A number of landscape metrics were calculated for the landscapes surrounding bobwhite call count routes and were used in two modeling exercises to differentiate between high and low bobwhite populations. Both pattern recognition (PATREC) and logistic regression models predicted levels of bobwhite abundance satisfactorily for the modeled (84.0% and 96.0% respectively) and independent (64.3% and 57.1%, respectively) data sets. The models were applied to remotely-sensed habitat maps to develop prediction maps expressing the quality of a landscape for supporting a high population of bobwhite based on existing land cover. Finally, I explored the possibility of eliminating the time consuming and very costly step of classifying a remotely-sensed image prior to examining its quality for a particular species. Using raw Landsat TM imagery and bobwhite call count data, I developed predictive logistic regression models expressing the quality of a landscape surrounding a pixel. The first model predicted the probability of the landscape supporting a high bobwhite population. Due to a number of stops with an average of zero, I was also able to generate a model that expressed the probability of the landscape supporting any number of bobwhite. This method also satisfactorily predicted high/low population and presence/absence for the modeled data (65.7% and 83.1%, respectively) and independent data (65.3% and 83.7%, respectively). The method described will allow for rapid assessment of our wildlife resources without having to classify remotely-sensed images into habitat classes prior to analyses. / Master of Science
54

Habitat relationships of bobwhite quail and cottontail rabbits on agricultural lands in Halifax County, Virginia

Cline, Gerald A. 22 June 2010 (has links)
I examined the relationships of quail and rabbits to agricultural land uses in the Virginia Piedmont during 1986-1987. Bobwhites and cottontails were censused and the associated habitat components quantified at 2 scales: macro-scale at 121 road transect stations, and a micro-scale at 87-foot transect stations. Additionally, the quail's immediate habitat was measured using variables found in the HSI model for northern bobwhite. The paucity of rabbit sightings prevented an analysis of habitat relationships for this species. Relative quail densities decreased from 1986 to 1987 along both road and foot transects (P < 0.05). A model (R² = 0.374) relating relative density of quail at stations to adjacent habitat found positive (P < 0.10) relationships for crop/crop, road/pasture, road/fallow, and "other" edges and negative (P < 0.10) relationships for road/tall grass yard edge and 3 variables describing dense overstory canopies. The presence/absence of quail at foot transect stations was related to habitat characteristics using logistic regression. Wooded fallow fields, the length (m) of pasture/fallow and forest/forest edges, and the total number of all edges present were positively related to quail presence (P < 0.001). Analysis of quail-centered plots indicated quail preferred areas with more woody cover, less grass composing the herbaceous canopy, more bare ground or light litter ( < 2 cm deep), and more honeysuckle canopy than was randomly available (P < 0.05). Management recommendations are to emphasize maximizing the number of different edges present, especially the combinations highlighted by this analysis. Efforts should be made to maximize the number of fallow fields in early successional stages. Cultivation of field borders and corners, waterways, and other idle areas should be discouraged. / Master of Science
55

Effects of altered prenatal auditory experience on postnatal auditory preferences in bobwhite quail chicks

Stoumbos, Julia A. 07 April 2009 (has links)
Part I of the present study analyzed the acoustic features of bobwhite quail embryonic vocalizations emitted during the final 36 hours prior to hatching. Using software for sound spectrographic analyses, information was collected on the average fundamental frequency, frequency modulation and range, repetition rate, and duration in seconds of notes emitted by the embryos. Based on frequency distributions plotted separately for three of these acoustic features, the vocalizations emitted spontaneously by bobwhite quail embryos were characterized. Although there were not two dichotomous note types to justify adopting the "distress/contentment" terminology utilized by previous researchers of avian vocalizations, there was a distinctive note type with medium note duration and fast repetition rate, as well as a second common note type with short note duration and fast repetition rate. Evidence from precocial neonates of several species indicates that altering the usual prenatal sound environment alters later perceptual performance. Part II of the present study examined the influence of altered prenatal auditory stimulation (in the form of embryonic vocalizations altered in repetition rate) on postnatal auditory preferences in precocial bobwhite quail chicks. Results indicate that when embryos are exposed to altered prenatal auditory stimulation in the period immediately prior to hatching, their postnatal auditory preference behavior is altered. Specifically, when exposed to a repetition rate that is (only slightly) faster than the species-typical rate for embryos, quail hatchlings did not show a strong preference for the maternal call typically seen at 24 hr post-hatch. Chicks that were exposed prenatally to either unaltered auditory stimulation or auditory stimulation with a slower-than-normal repetition rate did demonstrate the species-typical naive auditory preference. These findings illustrate the importance of understanding the subtle experiential links between the prenatal sensory environment and early postnatal perceptually-directed behavior. / Master of Science
56

Assessing northern bobwhite habitat use and short-term response to prescribed fire in an intensively managed longleaf pine ecosystem

Grayum, Jeffrey Martin 10 May 2024 (has links) (PDF)
Effective conservation requires reliable knowledge of habitat selection and data describing the target species’ response to prominent management techniques. Herein, I describe northern bobwhite breeding season resource selection in an intensively managed longleaf pine ecosystem and investigate the influence of post-fire succession and days-since-fire on bobwhite use of recently burned areas. I recorded bobwhite locations three times per week and surveyed recently burned areas twice daily. I found that bobwhite prefer natural pine woodlands burned the current year and pine plantations, hardwood pine forest, and shrub/scrub communities burned 1-2 years ago. Bobwhite avoided natural pine woodlands burned 1-2 years ago, recently burned (<1 year) shrub/scrub and hardwood-pine communities, urban/mowed areas, and hardwood forests. Few bobwhite used burned areas immediately following fire, but use of burned areas increased as post-fire green-up progressed. Days-since-fire was the best competing model to explain bobwhite use of recently burned areas.
57

The role of stimulus matching in the development of intersensory perception in bobwhite quail

McBride, Thomas 06 June 2008 (has links)
The present study examined the role of the relationship between the type and amount of prenatal and postnatal stimulus cues in directing the perceptual preferences of bobwhite quail chicks. Results reveal that chicks prefer postnatal stimulus cues that matched the particular type of prenatal stimulation they received as embryos over stimulus cues that match the amount of prenatal stimulus cues they received. Specifically, when chicks were tested with novel stimuli, or when the preference for matching types of stimulus cues was controlled for, chicks exposed to prenatal auditory/visual cues showed a preference for combined auditory/visual cues over auditory cues presented alone. These findings suggest that exposure to enhanced prenatal auditory/visual stimulation can accelerate chicks perceptual responsiveness. However, this effect can be masked depending upon the relationship between the specific type of auditory stimulus cues used during prenatal exposure and subsequent postnatal testing. Further results indicate that preference for familiar type of stimuli can account for why exposure to enhanced prenatal stimulation does not always appear to accelerate responsiveness to combined auditory/visual cues. Therefore, studies examining the effects of prenatal sensory manipulations on postnatal perceptual responsiveness must take into account the specific nature of the relationship between the type and amount of prenatal and postnatal stimulus cues employed in the experiment. In a more general sense, these results suggest that the study of early perceptual development requires the incorporation of complex, dynamic, and hierarchically based notions about the mechanisms associated with behavioral development. / Ph. D.
58

Effects of five different intensities of stand establishment on wildlife habitat quality and tree growth in loblolly pine (Pinus taeda) plantations in southern Mississippi

Jones, Phillip Daniel, January 2008 (has links)
Thesis (Ph.D.)--Mississippi State University. Department of Wildlife and Fisheries. / Title from title screen. Includes bibliographical references.
59

Usable Space and Microhabitat Characteristics for Bobwhites on Private Lands in Southwestern Ohio

Wiley, Mark Joseph 31 August 2012 (has links)
No description available.
60

Spatial Analyses of Northern Bobwhite Occupancy and White-tailed Deer Hunter Distribution and Success in Ohio

Sforza, Stephanie A. 22 July 2022 (has links)
No description available.

Page generated in 0.023 seconds