Digital Commons Network^™

The Influence Of Pollinator Behavior On Patterns Of Pollen Dispersal And Its Implications For Floral Evolution, Alex Lascher

Theses

Despite a storied history of pollination research, little information exists on how the unique characteristics of individual pollinators effect patterns of pollen dispersal. As these patterns of pollen dispersal inform our understanding of floral evolution, filling in this knowledge gap is imperative. I attempted to do so by analyzing two different outcomes of pollen dispersal: 1) pollen carryover, and 2) geitonogamy (i.e., intra-plant movements). For the pollen carryover, I analyzed the results of an experimental study in which bats in flight cages removed pollen from the male flower of a Burmeistera glabrata plant, and then visited 10 female flowers of …

Enhancing Existing Isolated Underpasses With Fencing Reduces Wildlife Crashes And Connects Habitat, Bridget M. Donaldson, Kaitlyn E. M. Elliott

Human–Wildlife Interactions

The impact of wildlife–vehicle collisions on drivers and wildlife populations has been gaining attention in the United States. Given the established success of wildlife crossings with fencing in reducing wildlife crashes and connecting habitat, information is needed on cost-effective means of implementation for departments of transportation. When wildlife crossings are constructed, they are often built into new road projects as a series of 2 or more underpasses and/or overpass structures connected by exclusionary fencing. Given limited transportation budgets and the prevalence of maintenance activities more so than new construction in many states, enhancing existing underpasses on previously constructed roads has …

Temporal Trends And Drivers Of Mountain Lion Depredation In California, Usa, Justin A. Dellinger, Daniel K. Macon, Jaime L. Rudd, Deana L. Clifford, Steven G. Torres

Human–Wildlife Interactions

Increasing human populations and expanding development across the globe necessitate continual progress in understanding and mitigating human–wildlife conflict. California, USA has the largest human population and at least half of the state is suitable mountain lion (Puma concolor) habitat. The juxtaposition of high human abundance within and adjacent to mountain lion habitat make California relevant for understanding human–large carnivore conflict. We compiled 7,719 confirmed incidents of mountain lions depredating domestic animals over a 48-year period (1972–2019) to examine temporal trends in mountain lion depredations as well as factors influencing annual depredation rates at the county level. Linear regressions …

Leveraging Multiple Data Sources: How Catch Data, Metadata, And Genetic Samples Can Aid The Recovery Of Endangered Smalltooth Sawfish (Pristis Pectinata), Kelcee Smith

LSU Doctoral Dissertations

The small population sizes characteristic of many imperiled species means that they are vulnerable to both demographic and genetic extinction threats. Responses to these threats (e.g., population trends, genetic diversity estimates) are often difficult to obtain, but critical for conservation. Thus, researchers studying imperiled species may have to consult multiple data sources, collaborate with a wide variety of stakeholders, or ask new questions about previously collected data. I used this approach to understand more about the United States (U.S.) population of Pristis pectinata, an endangered elasmobranch that has declined up to 95% due to habitat loss and bycatch in …

Zygomorphic Flowers May Reduce Extinction Rates By Allowing Angiosperms To Occur In Low Abundances, Maria Belen Alvestegui

Theses

The high species richness that angiosperm show has been extensively correlated with key floral innovations. Key floral traits contribute to species boundaries and the origin of new species. However, how these relate to extinction remains largely untested. Among the multiple theories that attribute diversification to floral innovations, the reduced extinction model predicts that floral specialization allows the persistence of small populations and avoids their loss. Bilateral symmetry (zygomorphy) is a trait that has evolved recurrently in angiosperms. It is a form of floral specialization that restricts pollination to fewer visitors and precisely places pollen to ensure more effective transmission of …

Availability And Structure Of Coarse Woody Debris In Hemiboreal Mature To Old-Growth Aspen Stands And Its Implications For Forest Carbon Pool, Silva Šēnhofa, Guntars Šnepsts, Kārlis Bičkovskis, Ieva Jaunslaviete, Līga Liepa, Inga Straupe, Āris Jansons

Aspen Bibliography

European aspen deadwood is extensively studied as a habitat for saproxylic species, while less is known of its dynamics and role in carbon sequestration. We studied unmanaged mature (41–60 years), moderately overmature (61–80 years), overmature (81–100 years), and old-growth (101–140 years) and managed mature and moderately overmature aspen stands on fertile mineral soils. In unmanaged stands, marginal mean CWD volume was from 67.3 ± 12.1 m³ ha⁻¹ in moderately overmature to 92.4 ± 5.1 m³ ha⁻¹ in old-growth stands, with corresponding marginal mean CWD carbon pool 8.2 ± 1.6 t ha⁻¹ and 12.5 ± 0.7 …

The Effects Of Climate And Demographic History In Shaping Genomic Variation Across Populations Of The Desert Horned Lizard (Phrynosoma Platyrhinos), Keaka Farleigh, Sarah A. Vladimirova, Christopher Blair, Jason T. Bracken, Nazila Koochekian, Drew R. Schield, Daren C. Card, Nicholas Finger, Jonathan Henault, Adam D. Leaché, Todd A. Castoe, Tereza Jezkova

Publications and Research

Species often experience spatial environmental heterogeneity across their range, and populations may exhibit signatures of adaptation to local environmental characteristics. Other population genetic processes, such as migration and genetic drift, can impede the effects of local adaptation. Genetic drift in particular can have a pronounced effect on population genetic structure during large-scale geographic expansions, where a series of founder effects leads to decreases in genetic variation in the direction of the expansion. Here, we explore the genetic diversity of a desert lizard that occupies a wide range of environmental conditions and that has experienced post-glacial expansion northwards along two colonization …

Coarse Woody Debris Decomposition Assessment Tool: Model Validation And Application, Zhaohua Dai, Carl C. Trettin, Andrew J. Burton, Martin F. Jurgensen, Deborah S. Page-Dumroese, Brian T. Forschler, Jonathan S. Schilling, Daniel L. Lindner

Aspen Bibliography

Coarse woody debris (CWD) is a significant component of the forest biomass pool; hence a model is warranted to predict CWD decomposition and its role in forest carbon (C) and nutrient cycling under varying management and climatic conditions. A process-based model, CWDDAT (Coarse Woody Debris Decomposition Assessment Tool) was calibrated and validated using data from the FACE (Free Air Carbon Dioxide Enrichment) Wood Decomposition Experiment utilizing pine (Pinus taeda), aspen (Populous tremuloides) and birch (Betula papyrifera) on nine Experimental Forests (EF) covering a range of climate, hydrology, and soil conditions across the continental USA. …

Fisheries Food Webs: Quantifying Habitat-Use, Trophic Structure, And Energetic Pathways In Coastal Tanzania, Mario Fernando Hernandez

LSU Doctoral Dissertations

Commercial and recreational fisheries are a valuable resource to millions of people around the world. Developing countries are particularly dependent on the revenue provided by locally harvested fish with total exports from these nations valued at $80 billion USD. For Tanzania, fisheries provide not only a source of revenue but an important source of protein with an estimated 25 to 30kg of fish consumed per person every year. There is no doubt that high fisheries production is critical to the well-being of millions of livelihoods along the Tanzanian coast. An important but poorly understood driver of fisheries production is the …

Distilling Professional Opinion To Gauge Vulnerability Of Guam Avifauna To Brown Treesnake Predation, Robert M. Mcelderry, Eben H. Paxton, Andre V. Nguyen, Shane R. Siers

United States Department of Agriculture Wildlife Services: Staff Publications

The avifauna of Guam was devastated by the introduction of the Brown Treesnake, and the restoration of native birds would need to address the problem with eradication or suppression of BTS. With eradication of the snake unlikely in the near term, and suppression capabilities limited to specific finite areas, key information for reintroductions is how low BTS abundance will likely need to be for each bird species to be re-established based on their vulnerability to BTS predation. Here, we estimate vulnerability, which can no longer be measured directly, so biologists who are familiar with one or more of seven Guam …

Effects Of Salinity On Eastern Oysters: Locating Lower-Salinity Tolerant Populations And Defining Resource Zones Suitable To Restoration, Fisheries, And Aquaculture., Lauren Swam

LSU Master's Theses

Eastern oysters (Crassostrea virginica) provide valuable ecosystem services and support a productive commercial industry in the northern Gulf of Mexico. Declining abundance from water quality changes and other factors drives development of management and restoration strategies focused on a comprehensive, metapopulation approach. Identifying oyster resource zones based on water quality combined with selective breeding of oysters adapted to specific conditions provides strategies to support aquaculture development and ensure resilient oyster populations and high production. Using 2015-2019 satellite-derived continuous salinity and temperature data for coastal Louisiana, this work created maps defining oyster resource zones supportive of (1) broodstock sanctuary …

Macroinvertebrates, Watershed Imperviousness, And A Water Quality Index: A Confluence Of Georgia Adopt-A-Stream’S Volunteer Data, Christopher H. Kodani

Georgia Journal of Science

The relationship between a stream’s macroinvertebrate community as quantified by Georgia Adopt-A-Stream’s Water Quality Index and the impervious surface of an adopted stream’s watershed was weak. Although the average WQI decreased with increasing watershed imperviousness, the R² was only 8.3%--an admittedly poor fit. To further investigate, a more comprehensive analysis was performed using forward stepwise regression. This model, which included both imperviousness and the abundance of just 15 out of the 20 kinds of macroinvertebrates, achieved an R² of 59.4%. Imperviousness alone may not be a good predictor of WQI, but a combination of selected macroinvertebrate data and …

Habitat Use And Morphology Of Birds In "Intact" Amazonia Under Changing Climate, Vitek Jirinec

LSU Doctoral Dissertations

Neotropical forests contain the core of global avian diversity. Of these, the Amazon rainforest is the largest, but ~20% has already been lost to deforestation, inspiring research into the effects of clearing and fragmentation on forest birds. These studies have consistently shown that insectivorous birds that forage on or near the ground are the most sensitive species to forest disturbance. As a preamble to our study, we synthesized bird capture data collected over 40 years within continuous forest far from human disturbance. Remarkably, we found that terrestrial and near-ground insectivores have shown substantial abundance declines even within primary forest. The …

Center For Grassland Studies, July 2021

Center for Grassland Studies: Newsletters

Contents

21st Nebraska Grazing Conference on the Horizon by Daren Redfearn

Center for Grassland Studies Policy Advisory Committee

Director's Column by Walt Schacht (Interim Director)

21st Annual Nebraska Grazing Conference Schedule, August 9-11, 2021

Club Officers Elected for FY 21-22 by Jessica Windh

2021 Fall Seminar Series Schedule

CGS Scholarships and Fellowship Awarded for FY 21-22

Congratulations May 2021 Graduates

Diversity And Host Specificity Of Nycteribiid Bat Flies (Diptera: Nycteribiidae) In Kenya, Taylor Verrett

Masters Theses & Specialist Projects

Bat flies (Diptera: Nycteribiidae and Streblidae) are hematophagous ectoparasites of bats distributed globally. Members of Nycteribiidae are morphologically constrained relative to streblids, and are united by their lack of wings, dorso-ventrally compressed bodies, and a primary distribution across the Eastern hemisphere. Bats are principal reservoirs of infectious diseases, including viral zoonoses of important consideration to human health, but the overall high host specificity of bat flies has largely been thought to curb their potential as inter-specific vectors of bat-borne pathogens. However, nycteribiid diversity and host associations remain critically understudied in some geographic regions, and rare examples of nycteribiid bat flies …

Nebraska Wildlife Club, Jacob Spooner

Honors Program: Expanded Learning Clubs

The goal of this club was for students to expand their knowledge on wildlife that exists both in and outside of Nebraska and for them to get a better idea the types of wildlife they might be able to find within the state. In addition, an objective of this club was to spark curiosity so that the kids might try to further explore aspects of wildlife on their own.

Afterschool Sustainability Club, Ethan Halman Gonzalez

Honors Program: Expanded Learning Clubs

In-depth lesson plans used at Riley Elementary to educate students about the environment around them and how to preserve it.

Establishment Of Pollinator Habitat Within A Livestock Pasture Ecosystem, Roshani Sharma Acharya

Graduate Theses and Dissertations

Pollinators are important for fertilization, setting fruits, and seed development of more than 78% of the flowering plants that provide food for human beings and other species. Use of pollinators to maximize crop production is a proven agricultural practice; however, it has been less explored in livestock forage production systems. This study investigated pollinator abundance and diversity in pastures using different sampling methods and determined the impact of different pasture management practices on insect pollinators in a livestock pasture ecosystem. In Chapter 2, utility of four different colors of pan trap (blue, green, yellow, and purple) for sampling bees in …

Notes On Eastern North American Butterflies, David J. Hoag, Harry Pavulaan, Brian Taber, Kenneth Lorenzen, Richard D. Ullrich

The Taxonomic Report of the International Lepidoptera Survey

Editor’s Note (Harry Pavulaan). New natural history elements and distribution records of several eastern North American butterflies are reported. While diversity and distribution of butterflies in the eastern United States are commonly believed to be fully known, the findings presented here show that much is yet to be learned of our butterfly fauna.

Includes:

1. Pages 1-3

Lethe eurydice and L. appalachia Larvae (Nymphalidae: Satyrinae) Eat Their Shed Cuticle (Exuvia) Soon after Molting in Vermont, USA by David J. Hoag

Abstract

Larvae of Lethe eurydice and L. appalachia were observed eating their newly shed cuticle (exuvia). Further studies are needed …

Predictive Distributional Modeling Of Rare And Uncommon Stoneflies (Insecta: Plecoptera) Of The Central Appalachian Mountains Using Maximum Entropy, Phillip Nathaniel Hogan

Masters Theses & Specialist Projects

Predicting where rare species may be found is important in addressing and directing conservation efforts. Knowledge of the distribution for many of these taxa is often lacking or unknown altogether. The use of species distributional modeling fills gaps in this knowledge by predicting where a species may be present by taking a correlative approach between presence/pseudoabsences and environmental data. The aim of this study was to describe the distribution of several rare and uncommon aquatic insects using Maximum Entropy (MaxEnt) modeling as human influences within the central Appalachian Mountains are increasing and isolating pockets of biodiversity. Species distribution modeling of …

Beaver Reintroduction And Its Potential As An Ecological Conservation Measure For At-Risk Amphibian Species In The Pacific Northwest, Danielle Schwantes

University Honors Theses

Amphibian decline is a major concern in the Pacific Northwest (PNW), with many amphibian species listed as sensitive, threatened or endangered throughout the region. Some of the predicted main causes of amphibian decline are climate change and loss of habitat. The reintroduction of beavers into ecoregions of the PNW could be an important step in the conservation of this region’s amphibians, due to the beaver’s ability to engineer and structurally manipulate forest ecosystems. Beavers are able to restore wetland quality, productivity and biodiversity, creating vital amphibian habitat. This work explored the linkage between beaver presence and wetland hydrology, geomorphology, landscape …

Physiological And Molecular Responses Of Eurythermal And Stenothermal Populations Of Zostera Marina L (Eelgrass) To Climate Change, Carmen C. Zayas-Santiago

OES Theses and Dissertations

As CO₂ levels in Earth’s atmosphere and oceans steadily rise, varying organismal responses may produce ecological losers and winners. Increased ocean CO₂ can enhance seagrass productivity and thermal tolerance, providing some compensation for climate warming. However, the consistency of this CO₂ effect across populations of cosmopolitan species such as Zostera marina L. (eelgrass) remains largely unknown. This study analyzed whole-plant performance metabolic profiles and gene expression patterns of distinct eelgrass populations in response to CO₂ enrichment. Populations were transplanted from Nisqually Landing and Dumas Bay, two cold water environments in Puget Sound, WA (USA) that rarely …

Rainfall-Runoff Mechanisms And Flood Mitigation In A Coastal Watershed With Numerous Wetlands And Ponds, Homa Jalaeian Taghadomi

Civil & Environmental Engineering Theses & Dissertations

This study analyzed mechanisms of flooding in Blackwater River Watershed, located in coastal Virginia and hydraulically connected with mid-Atlantic Ocean. The analysis was based on the examination and simulation of the rainfall-runoff relationship, and such an analysis is very important for conventional water resource management and dealing with hydrologic extremes (e.g., floods and droughts, as well as ecological and pollution discharges). The rainfall-runoff relationship is a quantitative description of the hydrologic cycle, a dynamic process that can be interactively influenced by various factors, namely climate, topography, soils, land use and land cover, and land management practice.

In the past 60 …

Range-Wide Declines Of Northern Spotted Owl Populations In The Pacific Northwest: A Meta-Analysis, Alan B. Franklin, Katie M. Dugger, Damon B. Lesmeister, Raymond J. Davis, J. David Wiens, Gary C. White, James D. Nichols, James E. Hines, Charles B. Yackulic, Carl J. Schwarz, Steven H. Ackers, L. Steven Andrews, Larissa L. Bailey, Robin Bown, Jesse Burgher, Kenneth P. Burnham, Peter C. Carlson, Tara Chestnut, Mary M. Conner, Krista E. Dilione, Eric D. Forsman, Elizabeth M. Glenn, Scott A. Gremel, Keith A. Hamm, Dale R. Herter, J. Mark Higley, Rob B. Horn, Julianna M. Jenkins, William L. Kendall, David W. Lamphear, Christopher Mccafferty, Trent L. Mcdonald, Janice A. Reid, Jeremy T. Rockweit, David C. Simon, Stan G. Sovern, James K. Swingle, Heather Wise

United States Department of Agriculture Wildlife Services: Staff Publications

The northern spotted owl (Strix occidentalis caurina) inhabits older coniferous forests in the Pacific Northwest and has been at the center of forest management issues in this region. The immediate threats to this federally listed species include habitat loss and competition with barred owls (Strix varia), which invaded from eastern North America. We conducted a prospective meta-analysis to assess population trends and factors affecting those trends in northern spotted owls using 26 years of survey and capture-recapture data from 11 study areas across the owls' geographic range to analyze demographic traits, rates of population change, and occupancy parameters for spotted …

Determination Of Freedom-From-Rabies For Small Indian Mongoose Populations In The United States Virgin Islands, 2019–2020, A. Springer Browne, Hannah M. Cranford, Clint N. Morgan, James A. Ellison, Are Berentsen, Nicholas Wiese, Alexandra Medley, John Rossow, Leanne Jankelunas, Alan S. Mckinley, Claudia D. Lombard, Nicole F. Angeli, Thomas Kelley, Jennifer Valiulus, Bethany Bradford, Valicia J. Burke-France, Cosme J. Harrison, Irene Guendel, Marissa Taylor, Gerard L. Blanchard, Jeffrey B. Doty, David J. Worthington, David Horner, Keith R. Garcia, Joseph Roth, Brett R. Ellis, Kristine M. Bisgard, Ryan Wallace, Esther M. Ellis

United States Department of Agriculture Wildlife Services: Staff Publications

Mongooses, a nonnative species, are a known reservoir of rabies virus in the Caribbean region. A cross-sectional study of mongooses at 41 field sites on the US Virgin Islands of St. Croix, St. John, and St. Thomas captured 312 mongooses (32% capture rate). We determined the absence of rabies virus by antigen testing and rabies virus exposure by antibody testing in mongoose populations on all three islands. USVI is the first Caribbean state to determine freedom-from-rabies for its mongoose populations with a scientifically-led robust cross-sectional study. Ongoing surveillance activities will determine if other domestic and wildlife populations in USVI are …

Testing A Bite-Shortened Hook To Minimize Fish Handling In A Recreational Fishery, Holden E. Harris, Brian K. Whalen, Andrew G. Gude, Michael S. Allen

United States Department of Agriculture Wildlife Services: Staff Publications

Discard mortality can make fishing unsustainable, even in catch-and-release or highly regulated fisheries. However, fishing practices and gears that minimize hook injury, handling, and air exposure can considerably improve fitness and survival in released fish. This study tested whether modified hooks could allow anglers to successfully land and then release fish in the water and without handling. Standard, barbless, and bite-shortened hooks were used to catch Spotted Seatrout Cynoscion nebulosus (n > 75 per hook type), and logistic models were used to assess the differences in landing success and hook self-release success by hook type and categorical fish size. Average landing …

Landscape Of Stress: Tree Mortality Influences Physiological Stress And Survival In A Native Mesocarnivore, Jennifer R. Kordosky, Eric M. Gese, Craig M. Thompson, Patricia A. Terletzky, Lorin A. Neuman-Lee, Jon D. Schneiderman, Kathryn L. Purcell, Susannah S. French

United States Department of Agriculture Wildlife Services: Staff Publications

Climate change and anthropogenic modifications to the landscape can have both positive and negative effects on an animal. Linking landscape change to physiological stress and fitness of an animal is a fundamental tenet to be examined in applied ecology. Cortisol is a glucocorticoid hormone that can be used to indicate an animal’s physiological stress response. In the Sierra Nevada Mountains of California, fishers (Pekania pennanti) are a threatened mesocarnivore that have been subjected to rapid landscape changes due to anthropogenic modifications and tree mortality related to a 4-year drought. We measured cortisol concentrations in the hair of 64 …

Risks Of Introduction And Economic Consequences Associated With African Swine Fever, Classical Swine Fever And Foot-And-Mouth Disease: A Review Of The Literature, Vienna Brown, Ryan S. Miller, Sophie C. Mckee, Karina H. Ernst, Nicole M. Didero, Rachel M. Maison, Meredith J. Grady, Stephanie A. Shwiff

United States Department of Agriculture Wildlife Services: Staff Publications

African swine fever (ASF), classical swine fever (CSF) and foot-and-mouth disease (FMD) are considered to be three of the most detrimental animal diseases and are currently foreign to the U.S. Emerging and re-emerging pathogens can have tremendous impacts in terms of livestock morbidity and mortality events, production losses, forced trade restrictions, and costs associated with treatment and control. The United States is the world's top producer of beef for domestic and export use and the world's third-largest producer and consumer of pork and pork products; it has also recently been either the world's largest or second largest exporter of pork …

Economic Losses Of Catfish To Avian Predation: A Case Report, Ganesh Kumar, Shraddha Hegde, David Wise, Charles Mischke, Brian Dorr

United States Department of Agriculture Wildlife Services: Staff Publications

Avian predation in catfish aquaculture has been a persistent issue throughout the history of the industry, and as production has expanded predation from piscivorous birds has intensified. Catfish ponds in the Mississippi River delta (in the Mississippi migratory flyway) provide a constant and readily accessible supply of forage for birds. Intensive foraging by fish-eating birds has led to a specific regulatory policy and numerous on-farm and regional management efforts. However, in 2016, legal challenges lead to recision of some federal policies and uncertainty as to allowable management, resulting in limitations on bird depredation. Estimating the extent of fish losses to …

Analysis Of The Slo Bay Microbiome From A Network Perspective, Lien Viet Nguyen

Master's Theses

Microorganisms are key players in the ecosystem functioning. In this thesis, we developed a framework to preprocess raw microbiome data, build a correlation network, and analyze co-occurrence patterns between microbes. We then applied this framework to a marine microbiome dataset. The dataset used in this study comes from a year-long time-series to characterize the microbial communities in our coastal waters off the Cal Poly Pier. In analyzing this dataset, we were able to observe and confirm previously discovered patterns of interactions and generate hypotheses about new patterns. The analysis of co-occurrences between prokaryotic and eukaryotic taxa is relatively novel and …