Digital Commons Network^™

Hiding In The Lianas Of The Tree Of Life: Molecular Phylogenetics And Species Delimitation Reveal Considerable Cryptic Diversity Of New World Vine Snakes, Robert C. Jadin, Christopher Blair, Michael J. Jowers, Anthony Carmona, John C. Murphy

Publications and Research

The Brown Vine Snake, Oxybelis aeneus, is considered a single species despite the fact its distribution covers an estimated 10% of the Earth’s land surface, inhabiting a variety of ecosystems throughout North, Central, and South America and is distributed across numerous biogeographic barriers. Here we assemble a multilocus molecular dataset (i.e. cyt b, ND4, cmos, PRLR) derived from Middle American populations to examine for the first time the evolutionary history of Oxybelis and test for evidence of cryptic lineages using Bayesian and maximum likelihood criteria. Our divergence time estimates suggest that Oxybelis diverged from its sister genus, Leptophis …

Cognitive Models Of Defense Behaviors In Hosts Of Brood Parasites, Thomas J. Manna

Dissertations, Theses, and Capstone Projects

Social parasites exploit the behavioral repertoire of their hosts for their own benefit, thereby reducing host reproductive success. Whether and how hosts respond to prevent, reduce, or eliminate the costs of parasitism requires the characterization of host cognitive algorithms in response to parasites. In this dissertation, I review the suite of the defense behaviors and decision rules of hosts targeted by avian and insect brood parasites, and present new experimental data on the detection of parasitism through the visual system of focal host species. In Chapter 1, I review extensive data already accumulated to isolate the cognitive mechanisms used by …

Insect Populations Across An Urban-To-Suburban Land Use Gradient., Jacob T. Lawson

College of Arts & Sciences Senior Theses

Insect populations, especially those of pollinators, have been steadily declining across the globe in recent decades, a trend that is intensified in cities. Since the conservation of pollinators is crucial for maintaining ecosystems and ecological processes, new approaches are being promoted beyond those of conserving large natural areas. Urban native plant gardens could potentially offset some of these losses locally. This research attempts to set a local baseline for the insect diversity in urban gardens in Louisville and determine whether differences exist in garden insects in cities versus suburbs in Jefferson County, Kentucky. To address the land-use question we established …

A Biotelemetric Study Comparing Diving Behavior And Brumation Sites Of Translocated And Resident Northern Map Turtles (Graptemys Geographica) And Their Response To Replica Model Turtles On Artificial Basking/Nesting Platforms In The Upper Niagara River, Jesse M. Karcher

Biology Theses

Anthropogenic shoreline development leading to a lack of access to terrestrial nesting sites is one of the causes for northern map turtle decline in the upper Niagara River. Translocation of adult map turtles and the development of floating basking/nesting platforms were proposed as possible remedies for this population decline. Biotelemetry along with aerial and underwater drones were used to assess habitat preferences between resident and translocated turtles. It was expected that the platforms would be used for basking and nesting and that a platform located in a natural location would be more successful than one in a developed area, due …

Age-Related Tick Infestation Patterns In Springtime Migratory Passerines, Matthew Dunning

Honors Theses

To test the hypothesis that younger migrants are more prone to arrive at stopover sites on the northern coast of the Gulf of Mexico with ticks than adult migrants, 2177 migratory passerines were screened for ticks at Gulf Coast sites in Texas and Louisiana. Fifty eight (2.7%) were infested with ticks with 28 (1.3%) being young birds and 30 (1.4%) being adult birds. The body condition of the birds was assessed to determine if tick infestation had negative consequences and if the severity of consequences varied between ages. I found no relationship of age with the prevalence of a tick …

Phylogenomics And Geometric Morphometrics Define Species Flocks Of Snowtrout (Teleostei: Schizothorax) In The Central Himalayas, Binod Regmi

Graduate Theses and Dissertations

Schizothorax (Snowtrout) is a genus of medium-sized minnows (Cypriniformes) inhabiting glacier-fed streams, rivers, and lakes in the Himalayas. There are more than 30 species of Schizothorax across the region. The speciation and diversity of the Snowtrout in the vast hinterlands of the Himalayan Region has not been fully explored. Three species in Lake Rara, Western Nepal are considered a species flock, comprising endemic ecotypes that are morphologically differentiated and reproductively isolated.

My dissertation research examined the diversity of Schizothorax in the Central Himalayan region and evolutionary relationships among species distributed in the Tibet, Central and Southeast Asia. Chapter I describes …

Amphibian And Reptile Community Responses To Forest And Riparian Disturbance, Jacquelyn Christine Guzy

Graduate Theses and Dissertations

Riparian zones are transitional, semi-terrestrial areas regularly influenced by freshwater. These areas serve as dispersal corridors for many animal and plant species and ultimately function as important reservoirs of biodiversity in altered landscapes. While much of the riparian habitat in the United States has been affected by anthropogenic activities, management actions may mitigate potentially negative influences of these activities. For example, Streamside Management Zones (i.e., riparian buffers; SMZs) are commonly implemented within managed forests to protect water quality, but may also provide habitat for riparian-associated wildlife. Yet, little research has rigorously addressed the value of SMZs for wildlife, particularly cryptic …

Cool And Warm Season Climate Signals In Tree Rings From North America, Max Carl Arne Torbenson

Graduate Theses and Dissertations

Earlywood (EW) and latewood (LW) ring-width chronologies have become an increasingly important proxy in paleoclimate reconstructions. These subannual variables can provide estimates of past hydroclimate variability for seasonal windows that total ring-widths cannot resolve. The strength of the relationship between EW and LW series may influence what type of paleoclimate information is embedded within the tree-ring series. High correlations (> 0.70) between EW and LW are recorded for much of the continent but the magnitude of correlation varies greatly across space and species boundaries. Using four LW chronologies from shortleaf pine, the North American conifer species displaying the lowest EW-LW …

Do Enallagma Exsulans From Streams And Lakes Show Patterns Of Divergence?, Savannah Rae Graham

Graduate Theses and Dissertations

Divergent selection across heterogenous environments could lead to adaptive divergence in populations resulting in potential local adaption. These populations have phenotypic differences that are fitness related and make native individuals more fit than non-native individuals. My research focuses on a species of damselfly, Enallagma exsulans, to explore local adaptation and morphological differences as a result of divergent selection or plasticity. My first study explored potential local adaptation of wild caught stream and lake E. exsulans using a reciprocal transplant design, a classic approach for this objective. The stream and lake sites chosen were on a small spatial scale allowing for …

Implementing The North American Bat Monitoring Program In Nebraska: An Assessment Of Nebraska Bats With An Emphasis On Citizen Science, Baxter Seguin

School of Natural Resources: Dissertations, Theses, and Student Research

Over the past decade bat species in North America have been under immense stress due to anthropogenic activities throughout the continent along with severe declines from foreign invaders. Though many specific anthropogenic related activities such as deforestation, land-use alteration, and hibernacula disturbance/modification were the primary culprits of negative impacts on bat species in the past, they pale in comparison to the threats bats face today. White nose syndrome a disease caused by the fungus Pseudogymnoascus destructans and wind energy development have caused declines and disruptions to the bat populations of North America at an unprecedented rate.

Due to the significant …

Effects Of Ecological Restoration Techniques In Glen Canyon National Recreation Area, Simone Ka-Voka Jackson

UNLV Theses, Dissertations, Professional Papers, and Capstones

A better understanding of key ecological restoration techniques can inform land management in the Southwest on restoration options for areas infested by invasive grasses that can pose threats to ecosystems, from changes in nutrient cycling to altered fire regimes. In the semi-arid desert of Glen Canyon National Recreation Area (GLCA), several exotic grasses pose risks to local ecosystems: Saccharum ravennae, a relatively new invasive perennial grass, and Bromus rubens and Bromus tectorum, widespread annual grasses. In this study, multiple ecological restoration techniques were implemented to assess their effects on native and nonnative vegetation on sites invaded by the non-native grasses …

Assessing Minimal-Input Restoration Strategies For Desert Soil And Vegetation Restoration, Audrey Jean Rader

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Mojave and Sonoran Deserts have been negatively impacted by anthropogenic disturbances. Considering that these ecosystems may recover on millennial timescales, research has shown that restoration techniques can be fairly successful in initiating long-term recovery processes in these sensitive environments. However, uncertainty remains as to which techniques are effective in different circumstances, such as in different climates or across different soil properties, and which techniques may best avoid unintended consequences, such as facilitating non-native plants. To reduce fugitive dust as a human health hazard, increase soil stability, and enhance wildlife habitat, further work is necessary to develop restoration techniques for …

Ecosystem Services Provided By Soundscapes Link People And Wildlife, Mitchell Jerome Levenhagen

Boise State University Theses and Dissertations

Protected natural areas are not free from noise exposure, both external to and within park boundaries. Natural soundscapes are important in animal life histories, provide positive visitor experiences, and may increase motivation to protect natural areas. To examine the potential coupling of natural and human systems via the soundscape and the use of signs as an effective anthropogenic noise mitigation strategy, we experimentally introduced educational and enforcement signage along a trail and road system in an alternating, weeklong block design within Muir Woods National Monument, CA and Grand Teton National Park, WY, respectively. In Grand Teton National Park, speed limits …

Dispersal And Distributions In The Era Of Global Change: Patterns And Mechanisms Of Individual Dispersal And Distributional Shifts In North American Birds, Hanna Marie Mccaslin

Boise State University Theses and Dissertations

Dispersal is a critical process influencing population dynamics, and patterns of dispersal movement impact species distribution and abundance and have important evolutionary and ecological consequences. In particular, long-distance dispersal (LDD) can be especially important for gene flow and adaptability, although little is known about the mechanisms of LDD because of the challenges of studying large-scale animal movement. Global change is driving selection for new movement patterns in animals by stressing physiological tolerances and affecting the dynamics of biotic interactions. This is resulting in shifts in species distributions that are widespread across taxa. The distributions of migratory bird species are shifting …

Comparative Thermal Ecology Of Coastal And Inland Pacific Rattlesnakes (Crotalus Oreganus), Hayley Layne Crowell

Master's Theses

Global biodiversity is declining as a direct result of anthropogenic climate change. Ectothermic species have become focal organisms for studying the ecological effects of altered climates due to the clear relationship between environmental temperatures and ectotherms’ basic physiological functions. Historically, examinations of these effects have focused heavily on heliothermic lizards, and most others have tended to focus on single populations or sympatric species within a single community. Addressing the longterm energetic implications of environmental temperature variation will provide valuable insight into the cascading physiological effects that certain populations or species may experience as a result of altered climates.

In this …

The Functional Morphology Of Ingestion In The Platyrrhine Sclerocarpic Harvesters (Platyrrhini, Primates), Zachary Stoffel Klukkert

Dissertations, Theses, and Capstone Projects

The identification of anatomical correlates of diet and feeding behavior in nonhuman primates is an important area of research in biological anthropology. The morphology of the jaws and teeth reflects the phylogeny and adaptations that distinguish taxa and their different ecological niches. Studying the form-function relationships of jaws and teeth in modern species provides a framework for interpreting the diets of extinct species and for inferring the ecological pressures that may have contributed to the evolutionary diversification of primate craniodental morphology. Previous work on modeling primate jaw mechanics has focused largely on the functional context of a closed jaw. Little …

Conservation Of Threatened Canada-Usa Trans-Border Grizzly Bears Linked To Comprehensive Conflict Reduction, Michael F. Proctor, Wayne F. Kasworm, Kimberly M. Annis, A. Grant Machutchon, Justin E. Teisberg, Thomas G. Radandt, Chris Servheen

Human–Wildlife Interactions

Erratum to "Conservation of Threatened Canada-USA Trans-border Grizzly Bears Linked to Comprehensive Conflict Reduction". https://doi.org/10.26077/yjy6-0m57

Seasonal Changes In Black-Capped Chickadee (Poecile Atricapillus) Social Structure And Gargle Vocalizations, James Vanorman

All NMU Master's Theses

Many organisms form social groups for many different reasons. Individuals within a group gain benefits from having a way of effectively communicating with their group, especially in organisms that maintain their social affiliations for long periods of time. In birds, vocalizations are the main means of communicating among individuals. When there are multiple groups of birds in an area, each group could share vocalizations. This sharing can then create local dialects. Black-capped chickadees (Poecile atricapillus) are small songbirds of temperate habitats of North America that group together in larger flocks every winter. Dialects of the gargle vocalization have …

Reassessment Of The Extinction Risk Of The Neotropical Freshwater Crabs Of The Family Pseudothelphusidae, Ada Acevedo Alonso

All NMU Master's Theses

The Neotropical region is one of the world’s biodiversity hotspots, and its freshwater crabs are notably diverse, and are represented by two families, Pseudothelphusidae and Trichodactylidae. This study focuses on this region’s highly diverse Pseudothelphusidae which includes 48 genera and 289 species. The 2008 IUCN global conservation assessment found 15.5% of the Pseudothelphusidae to be threatened with extinction and projected that in the worst-case scenario (if all of the Data Deficient species turned out to be threatened), the number of threatened species would be significantly higher. In the last decade several new species of pseudothelphusids have been described, and more …

Long-Term Monitoring Of Rare Gypsum Communities In The Eastern Mojave Desert: A Study In Science And Art, Tiffany Jane-Marie Pereira

UNLV Theses, Dissertations, Professional Papers, and Capstones

For land managers, reliable estimates of soil seed banks, and more specifically, change in seed banks over time, provide insight into the restoration and regeneration potential of the landscape, site history and disturbance mapping, and, invasive and rare plant management. To understand the intricacies of desert soil seed banks in relation to aboveground vegetation change, my research evaluated long-term change in soil seed banks, fertile islands, and plant communities of conservation-priority gypsum rare plant habitat of the eastern Mojave Desert. Research found significant spatial and temporal differences in seed bank composition and density over an 11-year period; however, the gypsum …

Beyond Genetics: Addressing Activity In Microbial Ecology, Scott Christopher Thomas

UNLV Theses, Dissertations, Professional Papers, and Capstones

The field of microbial ecology is on the cusp of another revolution, one that uses synergy to address the limitations of previous studies. My dissertation is representative of the new era of research to come, through combining the latest technological advances with established classical methods to provide a more complete understanding of microbial ecosystems. In my first study, I evaluate the conservation of central carbon metabolic pathways and activity along a temperature and diversity gradient (60-95 ℃) through the use of 16S rRNA gene amplicon data, metagenome sequencing, and position-specific 13C-labeled metabolite probing. In my second study, I provide the …

Effects Of Disturbance And Restoration Treatment On Fertile Islands In Lake Mead National Recreation Area, Camille Traylor

UNLV Theses, Dissertations, Professional Papers, and Capstones

Disturbances by humans are one of the main drivers of change in contemporary desert ecosystems. Restoration treatments such as topsoil application and outplanting can be implemented in response to disturbances in order to maintain soil stability and a diverse plant community. Fertile islands - nutrient enriched areas beneath perennial shrubs - are fundamental features of deserts that can facilitate annual plant growth. A major uncertainty in desert ecology is how much time is required for fertile islands and nurse plant effects (the facilitation of one plant by another) to develop below maturing perennial plants. By studying naturally recruited perennial plants …

Bottlenose Dolphin (Tursiops Truncatus) Vocal Responses To Sonar And Spectrally Pink Background Noise, Maria Zapetis

Dissertations

As human populations rise, the level of man-made noise increases globally. Naval sonar and boat traffic are underwater sound sources of particular concern to marine mammal welfare. To better understand the impact of these noise increases on cetaceans, studies can explore animals’ behavioral changes in response to noise. Studies have investigated the ‘dose-response’ relationship between the received sound pressure level of sonar signals and the behavior of cetaceans in the wild, but exposure studies in controlled environments are limited. The studies in this dissertation examined bottlenose dolphin vocal modifications during various experimental noise treatments. Acoustic recordings previously obtained for bottlenose …

Contributions Of Historical Ecology To Ecological Services Assessments In The Lower Rio Grande Valley Texas, Julianna Katherine Schaefer Kurpis

Theses and Dissertations

Historic and current anthropogenic land-use activities affect ecological functions and ecosystem services quality. The clearing of native Tamaulipan thorn forest and riparian forests for agricultural use and expansion followed by rapid urbanization and population growth resulted in profound ecological impacts to the Lower Rio Grande Valley (LRGV), Texas. The goals of this study are 1) document trends in land use change and vegetation health in the LRGV 2) evaluate and demonstrate the application of the Ecosystem Services Identification & Inventory Tool (ESII Tool) for collecting ecological data and measuring percent ecological performance and 3) use historical ecology indicators to compare …

Ecometric Estimation Of Present And Past Climate Of North America Using Crown Heights Of Rodents And Lagomorphs: With Application To The Middle Miocene Climatic Optimum, Julia Schap

Electronic Theses and Dissertations

Continental scale studies on ungulate crown heights in relation to climate and habitat changes have revealed a correlation between increasing hypsodonty and a shift to more arid environments. Small mammals have been shown to adapt to changing habitats millions of years earlier than larger mammals. In this study I examined fossil localities throughout the last 37 Ma across North America. Diversity of rodents and lagomorphs were analyzed through this time period, with examination of community structure characterized by relative percentages of taxa with different crown heights. Overall, a decrease in precipitation and temperature was found across North America from 37 …

Differentiating Black Bears (Ursus Americanus) And Brown Bears (U. Arctos) Using Linear Tooth Measurements And Identification Of Ursids From Oregon Caves National Monument, Emily Bogner

Electronic Theses and Dissertations

North American black bears and brown bears can be difficult to distinguish in the fossil record due to similar dental and skeletal morphologies. Challenges identifying ursid material from Oregon Caves National Monument (ORCA) called for an accurate tool to distinguish the species. This study utilized a large database of lower tooth lengths and ratios in an attempt to differentiate black and brown bears in North America. Further, this project examined how these linear measurements differ geographically. Analysis of variance (ANOVA) found significant differences between black and brown bears from across North America for every variable studied. Stepwise discriminant analyses (DA) …

Investigating Diel Periodicity In Export Flux In The Gulf Of Mexico Using A Particulate Imaging System, Justin Edward Blancher

Master's Theses

To estimate the diurnal periodicity in the biological pump, a floating array with a marine snow camera system at 150 m depth was used, and particles were imaged at a 40 second interval for a 24 to 30 hour period at five sites in the Gulf of Mexico in June 2017. Each image was processed to identify and size all the particles within the frame, which was then processed to determine diameter, an estimated volume, and settling speed for each particle. Using these parameters, particle mass was estimated using algebraically rearranged calculations for settling speed. Each hour during the deployment …

Effects Of Experimental Forest Management On Avian Communities In The Missouri Ozarks, David R. Hollie

Electronic Theses & Dissertations

In recent decades, concern for migratory birds has stimulated research assessing the relationships between forest management and bird populations. The Missouri Ozark Forest Ecosystem Project (MOFEP) is a long-term, landscape-scale experiment designed to examine the effects of even-aged (i.e. clearcutting), uneven-aged (i.e. selection cutting), and no harvest forest management on ecosystem level processes. The management systems were randomly assigned to three sites each (mean area = 400 ha) under a 100-year rotation with a 15-year re-entry period.

In the first chapter, we used non-metric multidimensional scaling and generalized linear mixed models to investigate the effects of silvicultural treatment and year-since-harvest …

Antipredator Mechanisms Of Post-Metamorphic Anurans: A Global Database And Classification System, Rodrigo B. Ferreira, Ricardo Lourenço-De-Moraes, Cássio Zocca, Charles Duca, Karen H. Beard, Edmund D. Brodie Jr.

Ecology Center Publications

A crucial step in any ethological study is to distinguish and classify the observed behavior into categories. The literature on anuran antipredator mechanisms is largely scattered and descriptive due to the opportunistic nature of the observations and the lack of a simple, widely accepted classification scheme. We propose an explanatory classification system of antipredator mechanisms for post-metamorphic anurans (i.e., juveniles and adults) based on a thorough review of the literature and observations made during fieldwork and in the laboratory since 1970. In addition, we provide a freely available global database on antipredator mechanisms of post-metamorphic anurans. The classification system is …

The Role Of Gene Expression Noise In Mammalian Cell Survival, Kevin Farquhar

Dissertations and Theses (Open Access)

Drug resistance and metastasis remain obstacles to effective cancer treatment. A major challenge contributing to this problem is cellular heterogeneity. Even in the same environment, cells with identical genomes can display cell-to-cell differences in gene expression, also known as gene expression noise. Gene expression noise can vary in magnitude in a population or in fluctuation time scales, which is influenced by gene regulatory networks.

Currently, it is unclear how gene expression noise from gene regulatory networks contributes to drug survival outcomes in mammalian cells. An isogenic cell line with a noise-modulating genetic system tuned to the same mean is required. …