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Environmental Sciences

Invasive species

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From Pixels To Plants: Remote Sensing Of California Invasive Plants, Kenneth Rangel May 2024

From Pixels To Plants: Remote Sensing Of California Invasive Plants, Kenneth Rangel

Master's Projects and Capstones

Invasive plants cause significant impacts to ecosystems, the economy, and human health. California has experienced significant plant invasions and is well suited to future invasion because of its Mediterranean climate and human disturbance. Eradication or control of invasive plant species requires a detailed understanding of their spatial distribution, which typically involves on the ground surveys that can be expensive or inconsistent. Remote sensing offers a potential alternative or supplement to in-person invasive plant mapping. This study performed a comparative analysis of 41 remote sensing studies that mapped the distribution of California invasive plants. I found that while high spectral resolution …


Informing Control Efforts For A Prolific Invasive Species: Characterizing Common Carp Spatio-Temporal Distribution And Evaluating The Impacts Of Gear Selectivity In Utah Lake, Rae Fadlovich May 2024

Informing Control Efforts For A Prolific Invasive Species: Characterizing Common Carp Spatio-Temporal Distribution And Evaluating The Impacts Of Gear Selectivity In Utah Lake, Rae Fadlovich

All Graduate Theses and Dissertations, Fall 2023 to Present

Management programs that aim to reduce the consequences of invasive species are often challenged by populations that can rapidly recover from removal efforts. Selectivity, the relative impact of harvest on different size classes, can contribute to population recovery when younger fish are not effectively targeted. In Utah Lake, the location of one of the world’s largest freshwater fish control programs, managers have been attempting to control the common carp (Cyprinus carpio, hereafter “carp”) population since 2009 but efforts have been hindered by the use of selective fishing gears. I conducted a lake-wide field study to gain insights into …


Distribution And Prevalence Of Antibodies To Trichinella Spp. And Toxoplasma Gondii In Wild Pigs (Sus Scrofa) In The United States, Christopher A. Cleveland, Ellen Haynes, Katherine C. Callaghan, Alinde Fojtik, Sarah Coker, Emily Doub, Vienna R. Brown, Ania A. Majewska, Michael J. Yabsley Jan 2024

Distribution And Prevalence Of Antibodies To Trichinella Spp. And Toxoplasma Gondii In Wild Pigs (Sus Scrofa) In The United States, Christopher A. Cleveland, Ellen Haynes, Katherine C. Callaghan, Alinde Fojtik, Sarah Coker, Emily Doub, Vienna R. Brown, Ania A. Majewska, Michael J. Yabsley

USDA Wildlife Services: Staff Publications

Invasive wild pigs (Sus scrofa) are a reservoir for over 100 viral, bacterial, and parasitic pathogens that are transmissible to humans, livestock, domestic animals, and wildlife in North America. Numerous historical local surveys and results from a nation-wide survey (2006–2010) indicated that wild pigs in the United States act as reservoirs for Trichinella spp. and Toxoplasma gondii, two zoonotic pathogens of importance for human and animal health. Since that time, wild pig populations have expanded and increased in density in many areas. Population expansion of wild pigs creates opportunities for the introduction of pathogens to new areas …


What Are The Impacts Of Deer Browsing And Japanese Stiltgrass (Microstegium Vinenium) On Native Sapling Growth In A Residential Wetland In Southeastern Georgia?, Josie Richards May 2023

What Are The Impacts Of Deer Browsing And Japanese Stiltgrass (Microstegium Vinenium) On Native Sapling Growth In A Residential Wetland In Southeastern Georgia?, Josie Richards

Honors College Theses

Wetlands promote biodiversity, act as climate stabilizers, and regulate water flow, yet are vulnerable to invaders. An invasive species can affect the biodiversity, abiotic conditions, and increase vulnerability of an ecosystem over time and deer browsing can actively affect new growth by removing the apical buds of young woody vegetation. Japanese stiltgrass (Microstegium vimineum), a wetland specific invader, has been shown to compete against native species for limited resources and actively crowd them out. Growth of native saplings can be further complicated by the presence of white tailed deer (Odocoileus virginianus), which browse woody vegetation and limit recruitment of trees. …


Optimal R&D Investment In The Management Of Invasive Species, William Haden Chomphosy, Dale T. Manning, Stephanie A. Shwiff, Stephan Weiler May 2023

Optimal R&D Investment In The Management Of Invasive Species, William Haden Chomphosy, Dale T. Manning, Stephanie A. Shwiff, Stephan Weiler

USDA Wildlife Services: Staff Publications

Invasive alien species (IAS) threaten world biodiversity, ecosystem services, and economic welfare. While existing literature has characterized the optimal control of an established IAS, it has not considered how research and development (R&D) into new removal methods or technologies can affect management decisions and costs over time. R&D can lower the costs of control in a management plan and creates an intertemporal trade-off between quick but costly control and gradual but cheaper removal over time. In this paper, we develop and solve a continuous time dynamic optimization model to study how investment in R&D influences the optimal control of an …


Using Music And Storytelling As Strategies For Conservation Education, Frances Hincks Mar 2023

Using Music And Storytelling As Strategies For Conservation Education, Frances Hincks

Honors College Theses

Given the frequently negative effects each person imposes on their environment (e.g., resource consumption, use of private and public land, and waste production), the public needs to be included in conservation messaging to sustain a healthy, functioning planet. People are generally not informed about conservation topics, which creates difficulties in creating a conservation mindset. Moreover, there is a disconnect between conservation research and presenting conservation related topics to the public in a coherent, accessible format. Thus, conservation education messaging strategies need to be evaluated to determine which are most effective. The objective of this research was to determine the effectiveness …


Burmese Pythons In Florida: A Synthesis Of Biology, Impacts, And Management Tools, Jacquelyn C. Guzy, Bryan G. Falk, Brian J. Smith, Johnd David Willson, Robert N. Reed, Nicholas G. Aumen, Michael L. Avery, Ian A. Bartoszek, Earl Campbell, Michael S. Cherkiss, Natalie M. Claunch, Andrea F. Currylow, Tylan Dean, Jeremy Dixon, Richard Engeman, Sarah Funck, Rebekah Gibble, Kodiak C. Hengstebeck, John S. Humphrey, Margaret E. Hunter, Jillian M. Josimovich, Jennifer Ketterlin, Michael Kirkland, Frank J. Mazzotti, Robert Mccleery, Melissa A. Miller, Matthew Mccollister, M. Rockwell Parker, Shannon E. Pittman, Michael Rochford, Christina Romagosa, Art Roybal, Ray W. Snow, Mckayla M. Spencer, J. Hardin Waddle, Any A. Yackel Adams, Kristen M. Hart Jan 2023

Burmese Pythons In Florida: A Synthesis Of Biology, Impacts, And Management Tools, Jacquelyn C. Guzy, Bryan G. Falk, Brian J. Smith, Johnd David Willson, Robert N. Reed, Nicholas G. Aumen, Michael L. Avery, Ian A. Bartoszek, Earl Campbell, Michael S. Cherkiss, Natalie M. Claunch, Andrea F. Currylow, Tylan Dean, Jeremy Dixon, Richard Engeman, Sarah Funck, Rebekah Gibble, Kodiak C. Hengstebeck, John S. Humphrey, Margaret E. Hunter, Jillian M. Josimovich, Jennifer Ketterlin, Michael Kirkland, Frank J. Mazzotti, Robert Mccleery, Melissa A. Miller, Matthew Mccollister, M. Rockwell Parker, Shannon E. Pittman, Michael Rochford, Christina Romagosa, Art Roybal, Ray W. Snow, Mckayla M. Spencer, J. Hardin Waddle, Any A. Yackel Adams, Kristen M. Hart

USDA Wildlife Services: Staff Publications

Burmese pythons (Python molurus bivittatus) are native to southeastern Asia, however, there is an established invasive population inhabiting much of southern Florida throughout the Greater Everglades Ecosystem. Pythons have severely impacted native species and ecosystems in Florida and represent one of the most intractable invasive-species management issues across the globe. The difficulty stems from a unique combination of inaccessible habitat and the cryptic and resilient nature of pythons that thrive in the subtropical environment of southern Florida, rendering them extremely challenging to detect. Here we provide a comprehensive review and synthesis of the science relevant to managing invasive …


Validation Of A Nutria (Myocastor Coypus) Environmental Dna Assay Highlights Considerations For Sampling Methodology, Anna M. Mangan, John A. Kronenberger, Ian H. Plummer Jan 2023

Validation Of A Nutria (Myocastor Coypus) Environmental Dna Assay Highlights Considerations For Sampling Methodology, Anna M. Mangan, John A. Kronenberger, Ian H. Plummer

USDA Wildlife Services: Staff Publications

Nutria (Myocastor coypus) is a semiaquatic rodent species that is invasive across multiple regions within the United States. Here, we evaluated a qPCR assay previously described for use in Japan for application across invasive populations in the United States. We also compared two environmental DNA sampling methodologies for this assay: field filtration of large volumes of water passed through filters versus direct sampling of small volumes of water. We validated assay specificity, generality, and sensitivity, compared assay performance between two independent laboratories, and successfully tested the assay in situ on a known wild population. The filtration method required …


Differences In Feeder Visitation By Invasive Rose-Ringed Parakeets (Psittacula Krameri) Between Hawaiian Islands, Steven C. Hess, Jane Anderson, Eric A. Tillman, William P. Bukoski, Aaron B. Shiels, Page Klug, Shane R. Siers, Bryan M. Kluever Jan 2023

Differences In Feeder Visitation By Invasive Rose-Ringed Parakeets (Psittacula Krameri) Between Hawaiian Islands, Steven C. Hess, Jane Anderson, Eric A. Tillman, William P. Bukoski, Aaron B. Shiels, Page Klug, Shane R. Siers, Bryan M. Kluever

USDA Wildlife Services: Staff Publications

Rose-ringed parakeets (Psittacula krameri; parakeets) are among the most invasive bird species worldwide. In their introduced range, populations of this species have caused negative effects on native species, natural environments, economies, and human safety. Lethal population management has been complicated by the intelligence of the birds, as they quickly alter behavior to avoid risks. Further, lethal control programs have been halted due to public opposition, as parakeets are considered to be charismatic by animal welfare advocates. The contraceptive DiazaCon has been demonstrated to effectively reduce fertility in captive parakeets. In field applications, any chemical control agents (e.g., toxicants or contraceptives) …


Development And Evaluation Of Prototype Toxicant-Delivery Bait Stations For The Control Of The Small Indian Mongoose, Carmen C. Antaky, Robert T. Sugihara, Israel L. Leinbach, Shane R. Siers, Emily W. Ruell, Steven C. Hess Jan 2023

Development And Evaluation Of Prototype Toxicant-Delivery Bait Stations For The Control Of The Small Indian Mongoose, Carmen C. Antaky, Robert T. Sugihara, Israel L. Leinbach, Shane R. Siers, Emily W. Ruell, Steven C. Hess

USDA Wildlife Services: Staff Publications

We conducted research to develop a safe and effective toxic bait to control the small Indian mongoose (Urva auropunctata), an invasive vertebrate predator impacting the survival of native species in Hawai‘i (United States) and in other parts of the world. A preserved fish-based bait product was found to be highly palatable to mongooses in cage trials and subsequent formulations with diphacinone (0.005%) showed promise as an efficacious toxic bait for mongooses. This product is intended for future use to control mongooses in conservation and urban areas, and as a biosecurity tool at ports of entry to address accidental …


Shifting Hotspots: Climate Change Projected To Drive Contractions And Expansions Of Invasive Plant Abundance Habitats, Bethany A. Bradley, Et. Al. Jan 2023

Shifting Hotspots: Climate Change Projected To Drive Contractions And Expansions Of Invasive Plant Abundance Habitats, Bethany A. Bradley, Et. Al.

Environmental Conservation Faculty Publication Series

No abstract provided.


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 Jan 2023

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 …


The Path To U.S. National Registration Of A Toxic Bait For The Control Of The Small Indian Mongoose, Carmen C. Antaky, Steven C. Hess, Emily W. Ruell, Israel L. Leinbach, Shane R. Siers, Robert T. Sugihara Jan 2023

The Path To U.S. National Registration Of A Toxic Bait For The Control Of The Small Indian Mongoose, Carmen C. Antaky, Steven C. Hess, Emily W. Ruell, Israel L. Leinbach, Shane R. Siers, Robert T. Sugihara

Human–Wildlife Interactions

The small Indian mongoose (Urva auropunctata [syn. Herpestes auropunctatus]; mongoose) is a highly invasive species in its introduced range that negatively impacts ecosystems. Mongooses depredate native species, serve as a vector of disease posing a risk to human health, and cause sanitation issues in food processing facilities and public areas. Introduced for biocontrol in the late 1800s in Hawaiʻi and the Caribbean, mongooses currently have well-established populations across multiple islands in both island archipelagos and have invaded numerous other locations throughout the world. The concern of accidental introduction to mongoose-free islands, the difficulty in species detection, and the …


The Influence Of Income And Loss On Hunters' Attitudes Towards Wild Pigs And Their Management, Samantha Leivers, Keith M. Carlisle, Rachel L. Connally, Maureen G. Frank, John M. Tomeček Jan 2023

The Influence Of Income And Loss On Hunters' Attitudes Towards Wild Pigs And Their Management, Samantha Leivers, Keith M. Carlisle, Rachel L. Connally, Maureen G. Frank, John M. Tomeček

USDA Wildlife Services: Staff Publications

Wild pigs (Sus scrofa) are one of the most pervasive invasive species in North America. Wild pigs pose a threat to crops, livestock, and the environment, but also provide recreational hunting opportunities. There are avenues for some stakeholder groups to generate income from wild pigs, however, stakeholders vary in attitudes towards wild pigs and their management. We investigated whether financial loss and income resulting from wild pigs influenced hunter stakeholder attitudes towards their management in Texas. We examined how land use influenced hunting landowner attitudes towards wild pigs. We analyzed 22,176 responses (8,707 landowners, 13,469 nonlandowners) fromTexas hunters …


Assessing The Host Range Of Anastatus Orientalis, An Egg Parasitoid Of Spotted Lanternfly (Lycorma Delicatula) Using Eastern U.S. Non-Target Species, Joseph S. Elkinton, Danielle B. Pitt, Shannon C. Davis, Et. Al. Jan 2023

Assessing The Host Range Of Anastatus Orientalis, An Egg Parasitoid Of Spotted Lanternfly (Lycorma Delicatula) Using Eastern U.S. Non-Target Species, Joseph S. Elkinton, Danielle B. Pitt, Shannon C. Davis, Et. Al.

Environmental Conservation Faculty Publication Series

The spotted lanternfly, Lycorma delicatula (Hemiptera: Fulgoridae), an invasive planthopper discovered in Pennsylvania, U.S. in 2014, has spread to many surrounding states despite quarantines and control efforts, and further spread is anticipated. A classical (importation) biological control program would contribute to the long-term management of L. delicatula in the eastern U.S. In its native range of China, Anastatus orientalis (Hymenoptera: Eupelmidae), an egg parasitoid, causes significant mortality. Anastatus orientalis consists of multiple haplotypes that differ in important biological parameters. To delineate the physiological host range of A. orientalis Haplotype C, we completed no-choice and choice testing. No-choice testing of non-target …


Using Unmanned Aircraft Systems To Investigate The Detectability Of Burmese Pythons In South Florida, Joseph Cerreta Ph.D., William Austin Ed.D., David Thirtyacre Ph.D., Scott S. Burgess Ph.D., Peter Miller Jan 2023

Using Unmanned Aircraft Systems To Investigate The Detectability Of Burmese Pythons In South Florida, Joseph Cerreta Ph.D., William Austin Ed.D., David Thirtyacre Ph.D., Scott S. Burgess Ph.D., Peter Miller

Journal of Aviation/Aerospace Education & Research

Burmese pythons are an invasive, non-native species of snake to southern Florida and attempts at eradicating the snakes had yielded mixed results. The current rate of detection had been reported as 0.05%. The purpose of this research project was to determine if a UAS equipped with a near-infrared (NIR) camera could be used to detect pythons at a higher rate when compared to a RGB camera. The approach involved collecting 55 images from RGB and NIR cameras, over carcass pythons at flying heights of 3, 6, 9, 12, and 15 meters. A likelihood ratio consisting of a true positive rate …


Efficacy Of A Preemergence Herbicide Following Postemergence Control To Reduce Sericea Lespedeza In Old Fields Managed For Northern Bobwhite, Mark A. Turner, Bonner L. Powell, Craig A. Harper Sep 2022

Efficacy Of A Preemergence Herbicide Following Postemergence Control To Reduce Sericea Lespedeza In Old Fields Managed For Northern Bobwhite, Mark A. Turner, Bonner L. Powell, Craig A. Harper

National Quail Symposium Proceedings

Sericea lespedeza (Lespedeza cuneata; hereafter, sericea) is a nonnative forb that commonly invades sites managed for northern bobwhite (Colinus virginianus; hereafter, bobwhite). Sericea can reduce habitat quality for bobwhite as it outcompetes native plants that provide forage and cover. Bobwhite eat sericea seed, but seed are relatively indigestible and may limit nutrition intake and reduce the fecundity rate. Postemergence herbicides, including glyphosate, triclopyr, and fluroxypyr+triclopyr, control standing sericea, but do not provide preemergence control, which would increase long-term control because sericea annually produces large amounts of hard seed with high dormancy rates. Imazapic is labeled to …


Life And Death In A Dynamic Environment: Invasive Trout, Floods, And Intraspecific Drivers Of Translocated Populations, Brian D. Healy, Phaedra Budy, Mary M. Conner, Emily C. Omana Smith Apr 2022

Life And Death In A Dynamic Environment: Invasive Trout, Floods, And Intraspecific Drivers Of Translocated Populations, Brian D. Healy, Phaedra Budy, Mary M. Conner, Emily C. Omana Smith

Wildland Resources Faculty Publications

Understanding the relative strengths of intrinsic and extrinsic factors regulating populations is a long-standing focus of ecology and critical to advancing conservation programs for imperiled species. Conservation could benefit from an increased understanding of factors influencing vital rates (somatic growth, recruitment, survival) in small, translocated populations, which is lacking owing to difficulties in long-term monitoring of rare species. Translocations, here defined as the transfer of wild-captured individuals from source populations to new habitats, are widely used for species conservation, but outcomes are often minimally monitored, and translocations that are monitored often fail. To improve our understanding of how translocated populations …


European Starling Use Of Nest Boxes Relative To Human Disturbance, Bradley Blackwell, Bruce N. Buckingham, Morgan B. Pfeiffer Apr 2022

European Starling Use Of Nest Boxes Relative To Human Disturbance, Bradley Blackwell, Bruce N. Buckingham, Morgan B. Pfeiffer

USDA Wildlife Services: Staff Publications

gars and to engine and flight surfaces of moored aircraft. We questioned whether consistent removal of nest material would negatively affect use of a nest site, measured by a reduction in material accumulation. We conducted our study on a 2,200-ha site in Erie County, Ohio, USA (41° 22’ N, 82° 41’ W), from April 15 through June 2, 2020. We used 120 wooden nest boxes on utility poles, protected by an aluminum predator guard below the box. Our treatments included (1) twice weekly, repeated nest material removal (RMR; n = 40 nest boxes); (2) complete nest removal, but only after …


Using Fine-Scale Aquatic Habitat Data To Construct Dreissenid Sdms In The Laurentian Great Lakes, Grace C. Henderson Mar 2022

Using Fine-Scale Aquatic Habitat Data To Construct Dreissenid Sdms In The Laurentian Great Lakes, Grace C. Henderson

USF Tampa Graduate Theses and Dissertations

The invasion of the Laurentian Great Lakes by aquatic invasive species (AIS) has been the subject of investigation for decades, due to their dramatic alterations to the ecosystem and high economic costs. Two AIS with the largest impacts are dreissenid zebra and quagga mussels, and though these species have been studied extensively, questions remain about what factors control their distributions, and whether lake warming will alter these distributions. Species distribution models (SDMs) offer a powerful tool to examine the relationship between species presences and environmental variables, which are typically bioclimactic data. The creation of the Aquatic Habitat (AqHab) dataset containing …


Optimizing Management Of Invasions In An Uncertain World Using Dynamic Spatial Models, Kim M. Pepin, Amy J. Davis, Rebecca S. Epanchin-Niell, Andrew M. Gormley, Joslin L. Moore, Timothy J. Smyser, H. Bradley Shaffer, William L. Kendall, Katriona Shea, Michael C. Runge, Sophie Mckee Feb 2022

Optimizing Management Of Invasions In An Uncertain World Using Dynamic Spatial Models, Kim M. Pepin, Amy J. Davis, Rebecca S. Epanchin-Niell, Andrew M. Gormley, Joslin L. Moore, Timothy J. Smyser, H. Bradley Shaffer, William L. Kendall, Katriona Shea, Michael C. Runge, Sophie Mckee

USDA Wildlife Services: Staff Publications

Dispersal drives invasion dynamics of nonnative species and pathogens. Applying knowledge of dispersal to optimize the management of invasions can mean the difference between a failed and a successful control program and dramatically improve the return on investment of control efforts. A common approach to identifying optimal management solutions for invasions is to optimize dynamic spatial models that incorporate dispersal. Optimizing these spatial models can be very challenging because the interaction of time, space, and uncertainty rapidly amplifies the number of dimensions being considered. Addressing such problems requires advances in and the integration of techniques from multiple fields, including ecology, …


Development Of A Novel Vertebrate Pesticide For The Invasive Small Indian Mongoose, Carmen Antaky, Steven C. Hess, Israel Leinbach, Robert T. T. Sugihara, Emily W. Ruell, Shane Siers Jan 2022

Development Of A Novel Vertebrate Pesticide For The Invasive Small Indian Mongoose, Carmen Antaky, Steven C. Hess, Israel Leinbach, Robert T. T. Sugihara, Emily W. Ruell, Shane Siers

USDA Wildlife Services: Staff Publications

Small Indian mongooses are detrimental introduced predators in the United States, where they depredate native species, serve as vector of disease, and threaten public safety. Due to the risk of accidental introduction to mongoose-free islands, high cost and limitations to trapping, and no national (Section 3) Environmental Protection Agency (EPA)-registered toxicants for mongoose control, there is a need for an efficacious toxic bait for mongooses for use in conservation areas and at points of entry in the United States. Over the last five years, the National Wildlife Research Center (NWRC) worked to develop a toxic bait for mongooses for registration …


Economic Damages Of Wild Pigs In Non-Traditional Areas: From The Fairway To The After Life, Sophie Mckee, Julie Elser, Maryfrances Miller, Lirong Liu, Ryan Miller, Steven S. Shwiff, Stephanie A. Shwiff Jan 2022

Economic Damages Of Wild Pigs In Non-Traditional Areas: From The Fairway To The After Life, Sophie Mckee, Julie Elser, Maryfrances Miller, Lirong Liu, Ryan Miller, Steven S. Shwiff, Stephanie A. Shwiff

USDA Wildlife Services: Staff Publications

Invasive wild pigs are widely known to cause damage to agricultural properties and commodities, but less has been reported about damages to other types of property. A survey was distributed to golf courses and cemeteries across Texas to explore the extent of damage these properties experience. While both property types reported significant damages, golf courses were found to experience more damage than cemeteries. Using average reported costs and predicted county-level damage, total costs for all golf courses and cemeteries across the state were estimated to exceed $1.6 million USD per year.


Comparing Molecular Methods To Estimate Fish Stomach Contents And Gastric Evacuation Rates: Implications For Measuring The Impacts Of Predation On Central Valley Chinook Salmon, Cory M. Dick Jan 2022

Comparing Molecular Methods To Estimate Fish Stomach Contents And Gastric Evacuation Rates: Implications For Measuring The Impacts Of Predation On Central Valley Chinook Salmon, Cory M. Dick

Cal Poly Humboldt theses and projects

Juvenile Chinook Salmon (Oncorhynchus tshawytscha) migrating through the Sacramento – San Joaquin Delta (the Delta) in central California have higher mortality rates than salmonids migrating through other west coast estuaries. Some hypotheses for high mortality rates include entrainment into water export facilities, physical alterations of the river system, and predation. Of these factors, predation is considered the least understood but may have the largest impact. Predation from large populations of non-native piscivorous fishes in the Delta is believed to effect abundances of Central Valley Chinook salmon, however sufficient data supporting this hypothesis is scarce. In this study, I …


Developing Novel Molecular Detection Techniques For Hemlock Woolly Adelgid (Adelges Tsugae), Meg Sanders Dec 2021

Developing Novel Molecular Detection Techniques For Hemlock Woolly Adelgid (Adelges Tsugae), Meg Sanders

Masters Theses

Hemlock forests in eastern North America face a deadly threat: the invasive insect, hemlock woolly adelgid (HWA), Adelges tsugae. Early detection of this pest remains a key focus for management groups to ensure rapid response to control and stop the spread of HWA. In Chapter II, our goals were to develop an affordable, easy-to-use trap that is compatible with airborne eDNA sampling techniques and assess its efficiency as a monitoring tool for HWA. We tested three potential trap designs (i.e., passive trap, funnel trap, and motorized trap) against a standard sticky trap. Our passive, funnel, and motorized traps estimated …


American Burying Beetle, Plant Richness, And Soil Property Responses To Collapse Of Juniperus Virginiana Woodlands With Fire, Alison Ludwig Dec 2021

American Burying Beetle, Plant Richness, And Soil Property Responses To Collapse Of Juniperus Virginiana Woodlands With Fire, Alison Ludwig

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Grasslands are declining in the Great Plains due to land use changes, woody plant encroachment, and loss of historic fire cycles. Prescribed burn associations have utilized prescribed fire to collapse invading woodlands and allow the restoration of grasslands. This fire is considered “extreme” because it is capable of changing the structure and function of an ecosystem. Our study site is the Loess Canyons Experimental Landscape, a long-term, ecoregion-scale experiment to apply prescribed fire across the region to restore grasslands. The Nebraska Natural Legacy Project established the Loess Canyons ecoregion as a Biologically-Unique Landscape in 2005 with the state’s wildlife action …


Rooting Out Genetic Structure Of Invasive Wild Pigs In Texas, Anna M. Mangan, Antoinette J. Piaggio, Michael J. Bodenchuk, Courtney F. Pierce, Timothy J. Smyser Nov 2021

Rooting Out Genetic Structure Of Invasive Wild Pigs In Texas, Anna M. Mangan, Antoinette J. Piaggio, Michael J. Bodenchuk, Courtney F. Pierce, Timothy J. Smyser

USDA Wildlife Services: Staff Publications

Invasive wild pigs (Sus scrofa), also called feral swine or wild hogs, are recognized as among the most destructive invasive species in the world. Throughout the United States, invasive wild pigs have expanded rapidly over the past 40 years with populations now established in 38 states. Of the estimated 6.9 million wild pigs distributed throughout the United States, Texas supports approximately 40% of the population and similarly bears disproportionate ecological and economic costs. Genetic analyses are an effective tool for understanding invasion pathways and tracking dispersal of invasive species such as wild pigs and have been used recently …


Invader Removal Triggers Competitive Release In A Threatened Avian Predator, J. David Wiens, Katie M. Dugger, J. Mark Higley, Damon B. Lesmeister, Alan B. Franklin, Keith A. Hamm, Gary C. White, Krista E. Dilione, David C. Simon, Robin R. Bown, Peter C. Carlson, Charles B. Yackulic, James D. Nichols, James E. Hines, Raymond J. Davis, David W. Lamphear, Christopher Mccafferty, Trent L. Mcdonald, Stan G. Sovern Aug 2021

Invader Removal Triggers Competitive Release In A Threatened Avian Predator, J. David Wiens, Katie M. Dugger, J. Mark Higley, Damon B. Lesmeister, Alan B. Franklin, Keith A. Hamm, Gary C. White, Krista E. Dilione, David C. Simon, Robin R. Bown, Peter C. Carlson, Charles B. Yackulic, James D. Nichols, James E. Hines, Raymond J. Davis, David W. Lamphear, Christopher Mccafferty, Trent L. Mcdonald, Stan G. Sovern

USDA Wildlife Services: Staff Publications

Changes in the distribution and abundance of invasive species can have far-reaching ecological consequences. Programs to control invaders are common but gauging the effectiveness of such programs using carefully controlled, large-scale field experiments is rare, especially at higher trophic levels. Experimental manipulations coupled with long-term demographic monitoring can reveal the mechanistic underpinnings of interspecific competition among apex predators and suggest mitigation options for invasive species. We used a large-scale before-after control-impact removal experiment to investigate the effects of an invasive competitor, the barred owl (Strix varia), on the population dynamics of an iconic old-forest native species, the northern spotted owl …


Invasives In Our National Parks: How Tourists Can Help Stop The Spread Of Invasive Species, Alexandria Elivira Marci Aug 2021

Invasives In Our National Parks: How Tourists Can Help Stop The Spread Of Invasive Species, Alexandria Elivira Marci

Masters Theses

Invasive species are a major issue around the world and more specifically in our U.S. National Parks. Ranging from plants to insects to animals, invasive species are a greater threat than many may imagine. The impact that invasive species have on an ecosystem encompasses more than taking over a native species’ environment; it includes competing for food, water, and other resources, as well as having an adverse effect on our economy and threatening us with deadly diseases. Many factors lead to the cause of spread of invasive species, but all point back to human interference, from purposely spreading invasive species …


Weedy Relations: Narratives Of Invasion And Intimacy With Tamarisk In The Chihuahuan Desert, Shannon S. Pepper Jul 2021

Weedy Relations: Narratives Of Invasion And Intimacy With Tamarisk In The Chihuahuan Desert, Shannon S. Pepper

Geography ETDs

Tamarix spp., also known as salt cedar or tamarisk, is a shrub that has garnered a notorious reputation in North America as an invasive plant, with widespread policy and research advocating for its eradication in the Southwest U.S. and Northern Mexico. This study examines both governmental conservation documents and news articles to investigate narrative trends on tamarisk in the Southwestern U.S. and Northern Mexico as a contiguous region (the Chihuahuan Desert), expanding on current research to include transborder effects on the perception and management of introduced species. This paper asks: In the last 25 years, how has the movement, …