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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.
261

A Habitat Suitability Model for Ricord’s Iguana in the Dominican Republic

Dine, James 23 June 2009 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / The West Indian iguanas of the genus Cyclura are the most endangered group of lizards in the world (Burton & Bloxam, 2002). The Ricord’s iguana, Cyclura ricordii, is listed as critically endangered by the International Union for Conservation of Nature (IUCN) (Ramer, 2004). This species is endemic to the island of Hispaniola (Figure 1), and can only be found in limited geographic areas (Burton & Bloxam, 2002). The range of this species is estimated to be only 60% of historical levels, with most areas being affected by some level of disturbance (Ottenwalder, 1996). The most recent population estimation is between 2,000 and 4,000 individuals (Burton & Bloxam, 2002). Information on potentially suitable habitat can help the conservation efforts for Ricord’s iguana. However, intensive ground surveys are not always feasible or cost effective, and cannot easily provide continuous coverage over a large area. This paper presents results from a pilot study that evaluated variables extracted from satellite imagery and digitally mapped data layers to map the probability of suitable Ricord’s iguana habitat. Bayesian methods were used to determine the probability that each pixel in the study areas is suitable habitat for Ricord’s iguanas by evaluating relevant environmental attributes. This model predicts the probability that an area is suitable habitat based on the values of the environmental attributes including landscape biophysical characteristics, terrain data, and bioclimatic variables.
262

Genetic Structure and Demographic Analysis of Key deer (Odocoileus virginianus clavium)

Villanova, Vicki 01 January 2015 (has links)
Recent improvements in genetic analyses have paved the way in using molecular data to answer questions regarding evolutionary history, genetic structure, and demography. Key deer are a federally endangered subspecies assumed to be genetically unique (based on one allozyme study), homogeneous, and have a female-biased population of approximately 900 deer. I used 985bp of the mitochondrial cytochrome b gene and 12 microsatellite loci to test two hypotheses: 1) if the Moser Channel is a barrier to gene flow, I should expect that Key deer are differentiated and have reduced diversity compared to mainland deer and (2) if isolation on islands leads to a higher probability of extinction, I should expect that Key deer exhibit a small population size and a high risk of extinction. My results indicate that Key deer are genetically isolated from mainland white-tailed deer and that there is a lack of genetic substructure between islands. While Key deer exhibit reduced levels of genetic diversity compared to their mainland counterparts, they contain enough diversity of which to uniquely identify individual deer. Based on genetic identification, I estimated a census size of around 1,000 individuals with a heavily skewed female-biased adult sex ratio. Furthermore, I combined genetic and contemporary demographic data to generate a species persistence model of the Key deer. Sensitivity tests within the population viability analysis brought to light the importance of fetal sex ratio and female survival as the primary factors at risk of driving the subspecies to extinction.
263

Red-Tailed Hawk Home Range, Habitat Use, and Activity Patterns in North-Central Puerto Rico

Llerandi-Roman, Ivan C 13 May 2006 (has links)
I determined abundance, movement and activity patterns of the Red-tailed Hawk (Buteo jamaicensis jamaicensis, RTHA) in Río Abajo Forest, Puerto Rico and surrounding lands during 2003-2004. Captive-reared Puerto Rican Parrots (Amazona vittata, PRPA) are scheduled for release in Rio Abajo Forest in 2006. Annual density of RTHAs (0.90 RTHAs/km2) was similar to the Caribbean National Forest (CNF; 1.29 RTHAs/ km2). RTHAs annual survival was high (0.89), and birds maintained compressed territories around the Rio Abajo Forest. Home ranges were 91% smaller than estimates reported for CNF, yet similar to those in North America. Approximately 98.3% of RTHA locations occurred outside the Río Abajo Forest boundaries. RTHAs exhibited random macrohabitat use patterns in north-central Puerto Rico. However, within their home ranges, RTHAs selected fragmented habitats with high patch and edge density, and avoided large tracts of dense closed canopy forest. Encounters between RTHAs and PRPAs may increase as parrots venture beyond the boundaries of Rio Abajo Forest.
264

REPROT OF AN INTERNSHIP WITH THE BUREAU OF LAND MANAGEMENT FOR THE FALCON TO GONDER CONSTRUCTION PROJECT

Bailey, Kenneth D. 02 November 2004 (has links)
No description available.
265

INTERNSHIP WITH THE OHIO NATURAL HERITAGE PROGRAM

Arbour, Thomas Paul 02 December 2005 (has links)
No description available.
266

Using genetic tools to understand the population ecology of stream fishes

Roberts, James Henry 05 June 2012 (has links)
Stream fishes are highly diverse, yet highly imperiled by human alterations of stream environments. Many species are poorly characterized with regard to the size and structure of populations and patterns of dispersal between populations, which complicates assessment of how human activities, both harmful and beneficial, will affect persistence. I used genetic tools to further this understanding in three case-study fish species of the southeastern United States: Roanoke logperch (Percina rex) of the greater Roanoke River basin and redline (Etheostoma rufilineatum) and greenside darters (E. blennioides) of the upper Tennessee River basin. I found that endangered P. rex persists in seven isolated populations. Within populations, individuals exhibit extensive dispersal and gene flow, which maintains connectivity throughout entire watersheds. Most populations exhibit small contemporary effective population sizes and occupy few stream channels, and thereby face an elevated risk of extinction. Genetic estimates of divergence indicate that fragmentation was recent, coincident with the construction of major dams throughout the species' range. Close evolutionary relationships between most populations suggest that a translocation strategy could decrease extinction risks. I developed a framework to help guide the process of balancing small-population versus translocation risks when formulating conservation strategies. When the framework was applied to populations of P. rex, straightforward management prescriptions emerged. The framework also may prove useful for other fragmented species. Unlike P. rex, E. rufilineatum and E. blennioides are relatively abundant where they occur. However, both species were strongly affected by fragmentation due to hydroelectric dams and reservoirs. Populations in small streams flowing directly into a reservoir had lower genetic diversity than populations in larger, more fluvially connected streams. Furthermore, indices of watershed urbanization (e.g., percent impervious surface, road density) were negatively correlated with genetic diversity and with a genetic index of population stability. This suggests that darters occupying isolated streams and/or urbanizing watersheds experience smaller, more variable population sizes than darters elsewhere. Monitoring of such genetic responses could provide a useful early indicator of ecosystem stress and a useful complement to other biomonitoring techniques. / Ph. D.
267

The Emergence of the Wyoming Core Area Strategy: "The Sage Grouse Rebellion"

Trefren, Jennie Lee 05 June 2012 (has links)
This research sought to explain the emergence of the Wyoming Core Area Strategy (WCAS), a state-based Greater Sage Grouse conservation plan. It presents a theoretical framework that is based on and adds nuance to the Advocacy Coalition Framework (ACF). The hypothesis this study explored was: if a subsystem's jurisdiction is threatened by a hierarchically superior subsystem's policy outputs and this jurisdiction is necessary to meet the threatened subsystem's goals, then policy change may occur as a result of a strategy by the agents in the threatened subsystem. The data used to examine the hypothesis included expert interviews, historical documents, and interviews from media sources (secondary source interviews). The hypothesis was supported; the WCAS emerged because the Endangered Species Act listing outputs within the Species Conservation Policy Subsystem threatened the Wyoming Land Use Policy (WLUP) Subsystem's jurisdiction, which was necessary to meet the WLUP Subsystem's economic and lifestyle goals; the Governor of Wyoming drove the development and enactment of the WCAS as a strategy to retain jurisdiction. The research demonstrated that in order to fully account for the WCAS's emergence, a less mechanistic view of the framework, one that accounts for the ability of agents in a subsystem to act strategically, was needed. The research also demonstrated that the Greater Sage Grouse conservation benefited from the ESA listing process despite its warranted but precluded listing status. The time frame the research explored was 2002 through March 2012. / Master of Arts
268

Down Stream [Appalachia]

Franusich, David J. 06 May 2020 (has links)
Down Stream [Appalachia] is an immersive, interactive art installation that addresses themes of ecological preservation, conservation, and connectedness—illuminating the precarity of imperiled freshwater species in the Appalachian region. The exhibition is composed of reflective, refractive sculptures and underwater video footage, surrounded by fully-immersive spatial audio. Both the audio and visual elements react to audience presence and proximity. Species highlighted are the Candy Darter (Etheostoma osburni); the Cumberlandian Combshell (Epioblasma brevidens) and other freshwater mussels; and the Eastern Hellbender Salamander (Cryptobranchus alleganiensis alleganiensis). This paper examines the context and content of this installation, its progression and influences, and themes of ecology and the environment in the Southeast United States. / Master of Fine Arts / There are endangered species right here in the mountains of Virginia, and hardly anyone knows about them. Down Stream [Appalachia] is an immersive, interactive art installation that attempts to raise awareness and allow people to connect to these animals that otherwise go unseen. This paper examines the context, content, and themes of the installation.
269

Building a Predictive Model of Delmarva Fox Squirrel (Sciurus niger cinereus) Occurrence Using Infrared Photomonitors

Morris, Charisa Maria 28 November 2006 (has links)
Habitat modeling can assist in managing potentially widespread but poorly known biological resources such as the federally endangered Delmarva fox squirrel (DFS; Sciurus niger cinereus). The ability to predict or identify suitable habitat is a necessary component of this species' recovery. Habitat identification is also an important consideration when evaluating impacts of land development on this species distribution, which is limited to the Delmarva Peninsula. The goal of this study was to build a predictive model of DFS occurrence that can be used towards the effective management of this species. I developed 5 a'priori global models to predict DFS occurrence based on literature review, past models, and professional experience. I used infrared photomonitors to document habitat use of Delmarva fox squirrels at 27 of 86 sites in the southern Maryland portion of the Delmarva Peninsula. All data were collected on the U.S. Fish and Wildlife Service Chesapeake Marshlands National Wildlife Refuge in Dorchester County, Maryland. Preliminary analyses of 27 DFS present (P) and 59 DFS absent (A) sites suggested that DFS use in my study area was significantly (Wilcoxon Mann-Whitney, P < 0.10) correlated with tree stems > 50 cm dbh/ha (Pmean = 16 + 3.8, Amean = 8+ 2.2), tree stems > 40 cm dbh/ha (Pmean = 49 + 8.1, Amean = 33 + 5.5), understory height (Pmean = 11 m + 0.8, Amean = 9 m + 0.5), overstory canopy height (Pmean = 31 m + 0.6, Amean = 28 m + 0.6), percent overstory cover (Pmean = 82 + 3.9, Amean = 73 + 3.1), shrub stems/ha (Pmean = 8068 + 3218, Amean = 11,119 + 2189), and distance from agricultural fields (Pmean = 964 m + 10, Amean = 1308 m + 103). Chi-square analysis indicated a correlation with shrub evenness (observed on 7% of DFS present sites and 21% of DFS absent sites). Using logistic regression and the Information Theoretic approach, I developed 7 model sets (5 a priori and 2 post hoc) to predict the probability of Delmarva fox squirrel habitat use as a function of micro- and macro-habitat characteristics. Of over 200 total model arrays tested, the model that fit the statistical, biological, and pragmatic criteria postulated was a post hoc integrated model: DFS use = percent overstory cover + shrub evenness + overstory canopy height. This model was determined to be the best of its subset (wi = 0.54), had a high percent concordance (>75%), a significant likelihood ratio (P = 0.0015), and the lowest AICc value (98.3) observed. Employing this predictive model of Delmarva fox squirrel occurrence can benefit recovery and consultation processes by facilitating systematic rangewide survey efforts and simplifying site screenings. / Master of Science
270

Contextualizing and Evaluating the Klamath Basin Restoration Agreement

Wilson, Jackman 01 January 2016 (has links)
This thesis explores the background of the Klamath Basin Restoration Agreement, a 250 page water use agreement among irrigators, Indian tribes, fishermen, environmental groups, federal and state agencies in the Klamath Basin. The agreement is contextualized in terms of water rights law, Indian law and the Endangered Species Act. The specific details of the agreement are explored. Finally, this thesis evaluates the agreement's merits and suggests a path forward for the agreement to become law.

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