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Consequences Of The Megafauna Extinction: Changes In Food Web Networks On The Edwards Plateau Across The Pleistocene-Holocene Transition, Quentin A. Smith Jr.

School of Biological Sciences: Dissertations, Theses, and Student Research

We are experiencing biodiversity loss due to climate change and human impacts, which is not only harmful to the environment but can also alter the composition of communities and interactions among species. The late Pleistocene experienced a loss of large-bodied mammals which resulted in significant changes in community structure due to changes in body size, diet, and species associations. The impact of these changes on species interactions and community structure across the Pleistocene-Holocene transition remains poorly understood. Using a robust data set of species composition, stable isotopes, body size, and climate variables, we constructed and compared ecological networks of mammal …

Trophic Ecology Of Black Swallowers (Scombriformes: Chiasmodontidae: Chiasmodon) In The Deep-Pelagic Gulf Of Mexico, Travis J. Kirk

All HCAS Student Capstones, Theses, and Dissertations

The ecology of deep-pelagic predatory fishes remains poorly understood despite their importance as ecosystem regulators and energy transfer vectors. This study investigated the trophic ecology of three species of the predatory fish genus Chiasmodon (“black swallowers”) in the Gulf of Mexico, a region that serves as an analog for the global low-latitude deep pelagial, the world’s largest cumulative ecosystem. Foraging habits (e.g., selectivity, chronology, daily ration) of an “advanced” evolutionary fish in a system that is otherwise dominated by basal fish taxa, were quantitatively estimated via high-resolution stomach content analysis. A quantitative dataset of both predator and prey abundance, the …

Spatial Mapping Of The Benthic Community And How It Is Used To Research Effects Of Dredging In Louisiana's Lake Borgne., Meghan Johnson

LSU Master's Theses

Benthic communities are vitally important for healthy aquatic ecosystems across Louisiana’s coast. Specifically in Lake Borgne, ecologically important species of fish like the Gulf Sturgeon (Acipenser oxyrinchus desotoi) rely on benthic macrofauna as their main food source. The purpose of this study was to determine the spatial landscape of biodiversity and abundance of the benthic macrofauna community in Lake Borgne. Environmental conditions played a key role in community structure during the study period (fall 2021 through summer 2023) with a major drought occurring in 2023. In 2023, the decline in the abundance of most benthic invertebrates and in …

Comparison Of Ketamine-Xylazine, Butorphanol-Azaperone-Medetomidine, And Nalbuphine-Medetomidine-Azaperone For Raccoon (Procyon Lotor) Immobilization, Shylo R. Johnson, Christine K. Ellis, Chad Wickham, Molly R. Selleck, Amy T. Gilbert

USDA Wildlife Services: Staff Publications

Raccoons (Procyon lotor) are frequently handled using chemical immobilization in North America for management and research. In a controlled environment, we compared three drug combinations: ketamine-xylazine (KX), butorphanol-azaperone-medetomidine (BAM), and nalbuphinemedetomidine- azaperone (NalMed-A) for raccoon immobilization. In crossover comparisons, raccoons received a mean of the following: 8.66 mg/kg ketamine and 1.74 mg/kg xylazine (0.104 mL/kg KX); 0.464 mg/kg butorphanol, 0.155 mg/kg azaperone, and 0.185 mg/kg medetomidine (0.017 mL/kg BAM); and 0.800 mg/kg nalbuphine, 0.200 mg/kg azaperone, and 0.200 mg/kg medetomidine (0.020 mL/kg NalMed-A). Induction time was shortest with KX (mean6SE, 10.060.7 min) and longest with NalMed-A (13.061.3 min). …

Estimation Of Probability Of Habitat Use Of Roosevelt Elk On The Olympic Peninsula, Vincent Michael Gugliotti

Undergraduate Theses, Professional Papers, and Capstone Artifacts

Estimating the probability of habitat use for a particular species is crucial to the direct management and conservation of that species. Without knowledge of habitat preferences, managers cannot effectively focus efforts on vital resources or landscape types. However, modelling probability of habitat use can be done in several ways which leaves room for variation and uncertainty in the estimates produced by each method. This study is an examination of the variation between two estimates of probability of habitat use while focusing on a particular subspecies of elk that inhabits a unique ecosystem relative to other elk subspecies. I modeled elk …

Modeling The Long-Distance Effects Of Predation, Henry Ogu

Annual Symposium on Biomathematics and Ecology Education and Research

No abstract provided.

Water Quality Of Madari Khal Tributary Of The Halda River, Chattogram, Bangladesh, Md. Shafiqul Islam, M.A. Azadi

Journal of Bioresource Management

Tidal canal Madari-Khal is one of the important tributaries of the river Halda, through which nearby hill stream water, agricultural washings, and effluents (treated or untreated) of Chattogram Asian paper Mill are drained to the Halda River. In this paper water quality and pollution level of Madari Khal are presented. A one-year study was conducted to ascertain the water quality and pollution level by using different physicochemical parameters i.e. Air temperature, Water temperature, Transparency, EC (Electrical Conductivity), TDS (Total Dissolved Solids), pH, DO (Dissolved Oxygen), freeCO₂, Ca⁺⁺ (Calcium), TH (Total Hardness), TA (Total Alkalinity), and Biological Oxygen …

Landscape Ecology And Conservation Of Freshwater Turtles Across The Eastern United States, H. Patrick Roberts

Doctoral Dissertations

Space use and movement patterns are integral to population dynamics and are often indicative of vulnerability to anthropogenic threats. Spatial ecology research can be fundamental to conservation strategies but is largely biased toward short-term intra- and interannual patterns. Without an understanding of space use over temporal scales commensurate with lifespan and the processes that may influence movement, conservation tools derived from short-term (2–4 yrs) movement patterns may be misguided or ineffective, particularly for long-lived species. The goal of Chapter 1 was to characterize the long-term (multi-decadal) spatial ecology of three long-lived (80–110 yrs) turtle species. We revisited six areas where …

Detecting Native Freshwater Mussels In Pennsylvania Waterways: Comparison & Validation Of Environmental Dna Methods, Meredith Bennett

Electronic Theses and Dissertations

North America is home to approximately one third of the world's freshwater mussel species. They are highly imperiled organisms due to habitat destruction and invasive species. Traditional surveys rely on visual identification of mussels, but individuals tend to be rare and difficult to identify. An alternative method is to extract environmental DNA (eDNA) from water samples, which has advantages over traditional sampling, including less sampling effort and fewer hazards to researchers and organisms. We conducted a review of the two main eDNA approaches: single-species detection and metabarcoding. We also developed and validated metabarcoding primers for the detection of native mussels. …

Hibernating Tricolored Bats At A Southeastern Recreation Site: Microsite Use And Public Perceptions, Rebecca Brown

All Theses

High bat mortality from white-nose syndrome (WNS) has increased the need to manage hibernation sites. Management decisions should be based on science, and when sites are accessible to the public, also need to consider human dimensions. We used Stumphouse Tunnel, a recreation site and tricolored bat (Perimyotis subflavus) hibernaculum in northwestern South Carolina, as a case study to understand potential conflicts between conservation and recreation. The population declined by 90% after the arrival of white-nose syndrome (WNS), followed by stabilization and slight increases. Because the increase was associated with more bats roosting in the publicly accessible section, a potential …

Factors That Affect Home Range Of Timber Rattlesnakes (Crotalus Horridus) In Northwest Arkansas, Bannon Gallaher

Graduate Theses and Dissertations

Conservation of animal populations requires knowledge of their habitat and spatial needs. Quantifying spatial requirements involves the analysis of home range. We examined the effects of sex, body size (SVL), body condition (log mass/log SVL), and year on home range in Timber Rattlesnakes (Crotalus horridus) in Northwest Arkansas. Individual locality data from an ongoing, 22+ year radio-telemetry study in Madison Co., Arkansas were analyzed using both minimum convex polygon (MCP) and Kernel Density Estimates (KDE). Plots of the number of sequential observations versus home range (MCP and KDE) determined that a minimum of 25 locations per individual per active season …

Ecological Impacts Of Invasive Crayfish In A Naïve Riparian System, Gregor L. Hamilton

Biology ETDs

Aquatic and riparian food webs are inextricably linked. In deserts, they provide critical energy subsidies to surrounding terrestrial food webs, but these vital subsidies are not guaranteed; streams in arid lands are especially sensitive to perturbations. In this dissertation, I investigated the role of an oft-cited threat to stream communities in the lower Colorado River basin: non-native crayfish. I contributed to methodologies in passive integrated transponder use and length-weight relationships in crayfish to aid future research. I leveraged stable isotope analysis of δ¹⁵N, δ¹³C, and δ²H to understand crayfish role in the food webs. …

Evaluation Of Acoustic Telemetry Array Performance And Fine- Scale And Broad-Scale Spatial Movement Patterns For Coral Reef Species In Culebra, Puerto Rico, Roxann Cormier

Masters Theses

Acoustic telemetry is an important tool when studying the spatial ecology of marine animals. First, it is important to identify the challenges of using this tool in shallow tropical marine environments before tracking marine animals. One significant issue that can influence the effectiveness of acoustic telemetry is the efficiency or detectability of acoustic signals by receivers. Understanding factors influencing detection efficiency of acoustic tags is especially important for fine-scale positioning systems (such as the VEMCO positioning system, VPS) that use detections in an overlapping receiver network to calculate geographic positions of tagged fish. I modelled the efficiency of an acoustic …

Lichens Of Ultramafic Rocks: A Multidisciplinary Approach To Understanding The Ecology Of An Understudied Organism In A Well-Studied System, Michael Mulroy

Master's Theses

Lichens are among the most prominent and successful life forms of metal-rich habitats, including ultramafic rocks and soils; however, research on lichens of ultramafic habitats is limited, especially on the North American continent. A review of the published literature on lichens of ultramafic substrates in North America yielded a total of 437 lichen species reported from ultramafic rocks and soils. Lichen assemblages of ultramafic substrates vary in composition and are dominated by acidophytic (low pH preferring) taxa with a minor, but consistent, basiphytic (high pH preferring) component. Species lists from ultramafic habitats in different geographic regions varied widely, suggesting that …

Fairy Shrimp (Anostraca) In The Vernal Pools Of Eastern Washington, Megan Garvey

EWU Masters Thesis Collection

Vernal pools are ephemeral wetlands that retain water annually from winter and spring precipitation and snowmelt but are dry the rest of the year. Though important habitats and sources of freshwater biodiversity, they are little accounted for in wetland conservation and restoration practices. Like much of the world’s wetlands, they have seen a significant decline from anthropogenic impacts and conversion for alternative land use. Pools are also at significant risk due to the impacts of climate change and invasive species. These small temporary water bodies perform vital ecosystem services and are host to rare and endemic species. Anostraca, or fairy …

Integrating Robotics Into Wildlife Conservation: Testing Improvements To Predator Deterrents Through Movement, Stewart W. Breck, Jeffrey T. Schultz, David Prause, Cameron Krebs, Anthony J. Giordano, Byron Boots

USDA Wildlife Services: Staff Publications

Background Agricultural and pastoral landscapes can provide important habitat for wildlife conservation, but sharing these landscapes with wildlife can create conflict that is costly and requires managing. Livestock predation is a good example of the challenges involving coexistence with wildlife across shared landscapes. Integrating new technology into agricultural practices could help minimize human-wildlife conflict. In this study, we used concepts from the fields of robotics (i.e., automated movement and adaptiveness) and agricultural practices (i.e., managing livestock risk to predation) to explore how integration of these concepts could aid the development of more effective predator deterrents.

Methods …

Population Density Of The Small Indian Mongoose (Urva Auropunctata) Across Multiple Habitat Types And Seasons In Puerto Rico, Are R. Berentsen, Caroline C. Sauvé, Mel J. Rivera-Rodriguez, Fabiola B. Torres-Toledo, Richard B. Chipman, Amy T. Gilbert

USDA Wildlife Services: Staff Publications

The small Indian mongoose (Urva auropunctata) is a rabies reservoir on several Caribbean Islands including Puerto Rico. In the continental United States, oral rabies vaccination (ORV) has been used to control and locally eliminate rabies viruses targeting meso-carnivores including raccoons (Procyon lotor), grey foxes (Urocyon cinereoargenteus), and coyotes (Canis latrans), and has more recently been proposed to mitigate and control mongoose rabies in Puerto Rico. A fundamental understanding of the population density of the target species is an important factor in planning bait application rates prior to ORV operations. In Puerto Rico, …

Comparison Of Daily Activity Patterns Across Seasons Using Gps Telemetry And Camera Trap Data For A Widespread Mammal, David W. Wolfson, Peter E. Schlichting, Raoul K. Boughton, Ryan S. Miller, Kurt C. Vercauteren, Jesse S. Lewis

USDA Wildlife Services: Staff Publications

Daily activity patterns of animals can be dynamic across seasons in response to changing environmental conditions. Daily activity, though, has rarely been evaluated in relation to multiple factors (for example, seasons, demographics, and data collection methods), which could be important for understanding what drives activity patterns. Here, we evaluated the daily activity patterns of a widespread invasive species, wild pigs (Sus scrofa), across two ecologically different study areas at Buck Island Ranch, Florida, and Tejon Ranch, California (United States), from 2015 to 2018. Using GPS telemetry data (62 individuals in Florida, 21 individuals in California) and detections from …

Investigating The Effects Of Disturbance And Competition On Establishment, Growth, And Reproduction Of The Endangered Ripariosida Hermaphrodita, Daniel Engelking

Theses and Dissertations (Comprehensive)

Ripariosida hermaphrodita (Virginia Mallow) is a perennial riparian plant with broad, maple-like leaves. It grows up to three meters high and is often found in large clonal patches, but sexually reproduces readily. While this plant may seem like a redoubtable competitor when growing in large colonies, it is declining across its range in North America. The only known occurrences in Canada are in southern Ontario. Prior to this study, no new populations had been recorded even though one of the known populations produces copious amounts of viable seed with potential to disperse. There are many hypotheses for its rarity, but …

Effects Of Agricultural Chemicals On Native Plants Of The Northern Great Plains, Gabrielle Bolwerk

Electronic Theses and Dissertations

Agricultural chemicals are ubiquitous on the Northern Great Plains landscape and have negative impacts on non-target plant communities, even at small doses. Northern Great Plains grassland plant communities may experience herbicide drift from agricultural fields or be subject to livestock pharmaceuticals in grazing lands. My research objective was to evaluate if and how native plants are affected by agricultural chemical presence at different concentrations. In Chapter 2, I studied the effect of different concentrations of three common agricultural herbicides (2,4-D, atrazine, and trifluralin) on the germination, emergence, and growth of native plant species of the Northern Great Plains. I performed …

Carnivore And Ungulate Occurrence In A Fire-Prone Region, Sara J. Moriarty-Graves

Cal Poly Humboldt theses and projects

Increasing fire size and severity in the western United States causes changes to ecosystems, species’ habitat use, and interspecific interactions. Wide-ranging carnivore and ungulate mammalian species and their interactions may be influenced by an increase in fire activity in northern California. Depending on the fire characteristics, ungulates may benefit from burned habitat due to an increase in forage availability, while carnivore species may be differentially impacted, but ultimately driven by bottom-up processes from a shift in prey availability. I used a three-step approach to estimate the single-species occupancy of four large mammal species: mountain lion (Puma concolor), coyote …

Patterns, Mechanisms, And Characterization Of Carbon Cycling Stability Following Partial Forest Disturbance, Kayla C. Mathes

Theses and Dissertations

Among the most essential questions in the era of climate change is how the forest carbon (C) cycle will respond to an increase in the extent of biotic disturbances from insects and pathogens. While research has focused on stand-replacing disturbance regimes, less is known about C cycling stability following partial disturbances that produce gradients of disturbance severity. Belowground C cycling responses to disturbance are especially poorly understood, even though temperate forest soils contain up to 50% of total ecosystem C and soil respiration (R_s) accounts for more than half of temperate forest C loss. Interpreting trends and mechanisms …

Activity Patterns Of The Critically Endangered Central American River Turtle (Dermatemys Mawii), Cora Dyslin

MSU Graduate Theses

The Central American River Turtle (Dermatemys mawii) is native to southern Mexico, eastern Guatemala, and Belize and is primarily restricted to watersheds that drain into the Gulf of Mexico and Caribbean Sea. Hunting, both for personal consumption and market meat, has been the primary driver of declines, and the species is now classified as critically endangered. Results from past studies that have used netting and visual surveys to detect D. mawii suggest that the species is chiefly nocturnal. However, it is unclear to what extent the perception of nocturnality has been biased by the timing of survey efforts …

Phytoplankton Community Of Boalia Khal Tributary Of The Halda River, Chattogram, Bangladesh, Md. Shafiqul Islam, M.A. Azadi, Munira Nasiruddin

Journal of Bioresource Management

Boalia Khal is one of the important tributaries of the River Halda. The productivity of the Boalia Khal tributary of the Halda River mainly depends on the phytoplankton diversity. A study was conducted for two years period from January 2017 to December 2018 to identify the phytoplankton community of the Boalia Khal tributary. A total of 61 species of phytoplankton under 37 genera belonging to 8 classes were recorded. The dominant group of phytoplankton was 25 species of Diatoms (40.98 %) followed by 18 species of Green Algae (29.5 %), 9 species of Euglenophytes (14.75 %), 7 species of Blue …

Combining Isotopic And Genetic Analyses To Quantify Microbial Facilitation Of Recalcitrant Resource Use By Terrestrial And Aquatic Consumers, Alexi Christina Besser

Biology ETDs

Quantifying the flow of energy and nutrients through food webs is foundational to understanding the structure and function of ecosystems. Here, I utilize the stable carbon and nitrogen isotope analysis of individual amino acids to trace the movement of essential amino acids through terrestrial and freshwater food webs in New Mexico, USA. I first explore isotopic patterns among co-occurring terrestrial plants and aquatic algae. I then combine this molecular isotopic approach with 16S and 18S rRNA sequencing to demonstrate the importance of gut microbiota as sources of essential amino acids to wild mammalian hosts. Next, I explore the roles of …

Filamentous Green Algae (Cladophora Glomerata) In Near Shore Lake Ontario: An Investigation Of Tissue And Water Nutrient Dynamics Through A Period Of Growth And Decomposition., James L. Wagner Jr

Biology Theses

Cladophora glomerata, a filamentous green alga abundant in the Laurentian Great Lakes, has long been considered a nuisance throughout the region. Previous phosphorus (P) abatement practices and legislation successfully reduced the abundance of the algae, but with the introduction of dreissenid mussels, a resurgence has been observed. Though there is substantial literature and modeling of the growth cycle of Cladophora, relatively little research has been dedicated to the decomposition stage of the algae, a period which may contribute to a substantial influx of nutrients to near-shore environmental regions. By first examining a period of in-situ growth within Lake …

Afforestation And Biodiversity: Bryophyte Richness Changes Between Icelandic Forest Types, Kian Mcdonough

Independent Study Project (ISP) Collection

Forest-dwelling bryophytes (mosses, liverworts, hornworts) greatly contribute to biodiversity and ecosystem function but are largely under-studied in comparison to vascular plants. With Iceland’s large-scale afforestation efforts there is a need to understand how different afforestation species are affecting biodiversity, including bryophyte diversity. This study looked at differences in ground-floor bryophyte richness across Sitka spruce, lodgepole pine, and downy birch forests and found that bryophyte richness was highest in the Sitka spruce forests and lowest in downy birch forests. While this suggests a negative correlation between bryophyte richness and light availability, since the conifer species have the densest copy cover, other …

Montezuma Quail In The Edwards Plateau Of Texas: Detection, Occurrence, And Habitat, Zachary J. Pearson, Eric D. Grahmann, Fidel Hernández, Robert Perez, Leonard A. Brennan, Humberto L. Perotto-Baldivieso

National Quail Symposium Proceedings

Montezuma quail (Cyrtonyx montezumae) were historically found throughout nearly every county in the Edwards Plateau region of Texas, USA. Over the last century, shifting land use, reduction of fire on the landscape, and the subsequent encroachment of woody vegetation have constricted the distribution of Montezuma quail to a few counties in the southern portion of the Edwards Plateau. A renewed interest in management for Montezuma quail over the last decade has been met with a lack of information regarding their habitat requirements in this region. This lack of general information and increased sightings of this elusive species in …

Effect Of Food Distribution On Northern Bobwhite Resource Selection, Rachel R. Gardner, John Maerz, Theron M. Terhune Ii, Ira B. Parnell, James A. Martin

National Quail Symposium Proceedings

Supplemental feeding is a common management tactic used to increase survival and reproduction of northern bobwhite (Colinus virginianus; hereafter, bobwhite). Different supplemental feeding methods alter the distribution of resources across a landscape in unique ways and may influence the space use and resource selection of target species differently. Predators may concentrate their movements near fed sites, and different distributions of supplemental feed may encourage bobwhite to concentrate their movements closer to feed than other areas, thereby altering the potential for predator-prey interactions near feed. We used radio-tracked locations and movements in areas with stationary feeders (“feeder fed”) and …

3d Computer Modeling Offers New Insights Into Diatom Ecology, Joseph Mohan

Electronic Theses and Dissertations

Algae supply over half of the Earth’s global primary production and form the base of almost all aquatic food networks. Thus, changes in algal productivity or composition will induce profound shifts in many ecosystems. This research is guided by two questions. Herein I ask if 3D models of algae can be created accurately enough to use for research applications? If they can be accurately created, then how can these models be used to advance our understanding of functional trait evolution and paleoecology? Herein, I develop 3D computer models for estimating the volume of individual algae and their parts. I also …