Digital Commons Network^™

Hawaii As A Microcosm: Advancing The Science And Practice Of Managing Introduced And Invasive Species, Liba Pejchar, Christopher A. Lepczyk, Jean E. Fantle-Lepczyk, Steven C. Hess, M. Tracy Johnson, Christina R. Leopold, Michael Marchetti, Katherine M. Mcclure, Aaron B. Shiels

United States Department of Agriculture Wildlife Services: Staff Publications

Invasive species are a leading driver of global change, with consequences for biodiversity and society. Because of extraordinary rates of endemism, introduction, and extinction, Hawaii offers a rich platform for exploring the cross-disciplinary challenges of managing invasive species in a dynamic world. We highlight key successes and shortcomings to share lessons learned and inspire innovation and action in and beyond the archipelago. We then discuss thematic challenges and opportunities of broad relevance to invaded ecosystems and human communities. Important research needs and possible actions include eradicating mammals from mainland island sanctuaries, assessing hidden threats from poorly known introduced species, harnessing …

Deciphering Interactions Between White-Tailed Deer And Approaching Vehicle, Morgan Pfeiffer, Raymond B. Iglay, Thomas W. Seamans, Bradley F. Blackwell, Travis L. Devault

United States Department of Agriculture Wildlife Services: Staff Publications

Deer-vehicle collisions are a major transportation hazard, but factors affecting deer escape decision-making in response to vehicle approach remain poorly characterized. We made opportunistic observations of deer response to vehicle approach during daylight hours on a restricted- access facility in Ohio, USA (vehicle speeds were ≤64 km/h). We hypothesized that animal proximity to the road, group size, vehicle approach, and ambient conditions would affect perceived risk by white-tailed deer (Odocoileus virginianus) to vehicle approach, as measured by flight-initiation distance (FID). We constructed a priori models for FID, as well as road-crossing behavior. Deer responses were variable and did not demonstrate …

Evaluating Moose Alces Alces Population Response To Infestation Level Of Winter Ticks Dermacentor Albipictus, Daniel D. Ellingwood, Peter J. Pekins, Henry Jones, Anthony R. Musante

United States Department of Agriculture Wildlife Services: Staff Publications

Many wildlife populations are experiencing a variety of environmental pressures due to the direct and indirect consequences of a changing climate. In the northeast, USA, moose Alces alces are declining in large part because of the increasing parasitism by winter tick Dermacentor albipictus, facilitated by high host density and optimal environmental conditions. To test this hypothesis, and better understand the influence of this interaction on the stability of the regional population, we constructed a population viability model using data collected through comprehensive survival and productivity studies in 2002–2005 and 2014–2018 in northern New Hampshire. Years of heavy tick infestation (epizootics) …

Spillover Of Sars-Cov-2 Into Novel Wild Hosts In North America: A Conceptual Model For Perpetuation Of The Pathogen, Alan B. Franklin, Sarah N. Bevins

United States Department of Agriculture Wildlife Services: Staff Publications

There is evidence that the current outbreak of the novel coronavirus SARS-CoV-2, which causes COVID-19, is of animal origin. As with a number of zoonotic pathogens, there is a risk of spillover into novel hosts. Here, we propose a hypothesized conceptual model that illustrates the mechanism whereby the SARS-CoV-2 could spillover from infected humans to naive wildlife hosts in North America. This proposed model is premised on transmission of SARS-CoV-2 from human feces through municipal wastewater treatment plants into the natural aquatic environment where potential wildlife hosts become infected. We use the existing literature on human coronaviruses, including SARS CoV, …

Public Perspectives And Media Reporting Of Wolf Reintroduction In Colorado, Rebecca Niemiec, Richard E.W. Berl, Mireille Gonzalez, Tara Teel, Cassiopeia Camara, Matthew Collins, Jonathan Salerno, Kevin Crooks, Courtney Schultz, Stewart Breck, Dana Hoag

United States Department of Agriculture Wildlife Services: Staff Publications

In the state of Colorado, a citizen ballot initiative to reintroduce gray wolves (Canis lupus) is eliciting polarization and conflict among multiple stakeholder and interest groups. Given this complex social landscape, we examined the social context surrounding wolf reintroduction in Colorado as of 2019. We used an online survey of 734 Coloradans representative in terms of age and gender, and we sampled from different regions across the state, to examine public beliefs and attitudes related to wolf reintroduction and various wolf management options. We also conducted a content analysis of media coverage on potential wolf reintroduction in 10 major daily …

The Impact Of Extreme Heat On Environmental Justice Communities In California: Assessing Equity In Climate Action Plans, Karishma S. Becha

Master's Projects and Capstones

Climate change projections suggest extreme heat events will be more frequent over the next few decades. Extreme heat has both negative environmental and social impacts as it affects energy security, public health by increasing the risk of heat-related illnesses and stresses food and crop supply through prolonged droughts. The impacts of extreme heat will also disproportionately affect communities of low economic status. Because of this, there is a need for better climate action plans that can adapt to and mitigate the impacts brought upon by extreme heat that does not disproportionately impact vulnerable communities. This research analyzed local government Climate …

Detection And Enumeration Of Bacterial Pathogens In The American Oyster (Crassostrea Virginica), Mohammad Maruf Billah

Theses and Dissertations

American oyster (Crassostrea virginica) is a popular seafood for its delicacy and high nutritional value. Based on increasing concern about contamination of bacterial pathogens in raw oyster, my research objectives have been focused on detection and enumeration of two important bacterial pathogens, Escherichia coli and Salmonella spp. in the American oyster in south Texas waters, local markets and controlled laboratory studies. Immunohistochemical and RT-PCR analyses showed substantial bacterial pathogen’s presence in gills and digestive glands of oysters collected from San Martin Lake and South Padre Island as well as local markets. Laboratory studies showed increasing trend of both …

Characterization Of Microbial Communities Across Disease States And Environmental Conditions In Kemp’S Ridley (Lepidochelys Kempii) And Green Sea Turtles (Chelonia Mydas), Kerry L. Mcnally

Graduate Doctoral Dissertations

All species of sea turtles are threatened or endangered, with various diseases and conditions affecting populations around the world. Understanding healthy populations as well as populations beset by disease conditions, such as fibropapillomatosis and cold-stunning, could lead to helpful tools in the conservation management and medical treatment needed to protect these species. Microbial communities, or the microbiome, at different body sites of sea turtles likely play important roles in the health of these animals, from aiding in digestion to immune system regulation. Disruption of these communities, either through disease and/or environmental factors, may play a role in disease processes and …

Impact Of Meteorological Factors On The Covid-19 Transmission: A Multicity Study In China, Jiangtao Liu, Ji Zhou, Jinxi Yao, Xiuxia Zhang, Lanyu Li, Xiaocheng Xu, Xiaotao He, Bo Wang, Shihua Fu, Tingting Niu, Jun Yan, Yanjun Shi, Xiaowei Ren, Jingping Niu, Weihao Zhu, Sheng Li, Bin Luo, Kai Zhang

Publications and Research

The purpose of the present study is to explore the associations between novel coronavirus disease 2019 (COVID- 19) case counts and meteorological factors in 30 provincial capital cities of China. We compiled a daily dataset including confirmed case counts, ambient temperature (AT), diurnal temperature range (DTR), absolute humidity (AH) and migration scale index (MSI) for each city during the period of January 20th to March 2nd, 2020. First, we explored the associations between COVID-19 confirmed case counts, meteorological factors, and MSI using non-linear regression. Then, we conducted a two-stage analysis for 17 cities with more than 50 confirmed cases. In …

Mercury And Other Trace Metal Analysis In Bat Guano, Amanda Lee Houchens

Masters Theses & Specialist Projects

Heavy metal pollution in the environment pose risks to ecosystems and the populations that reside in them. Mercury, lead, and cadmium negatively impact humans by way of neurological disorders, various cancers, and damage the reproductive organs, kidneys, and lungs. Bats have been studied as a bioindicator species to identify possibly elevated levels of these metals in the environment. Previous studies have identified correlation between metal concentrations within bat tissues and fur. Many bat species are endangered or at risk due to white-nose syndrome so collection of tissues and fur for analysis can impose stress on bat colonies. This study investigates …

Talking Trash In The Big Apple: Mitigating Bird Strikes Near The North Shore Marine Transfer Station, Stephan J. Beffre, Brian E. Washburn

United States Department of Agriculture Wildlife Services: Staff Publications

Anthropogenic activities that concentrate wildlife near airports increases the risk of wildlife–aircraft collisions. Placing waste management facilities, natural areas, golf courses, and other landscape features near airports have the potential to attract wildlife hazardous to aviation. We conducted a 3-year study (March 2013–February 2016) to determine if the implementation of a Wildlife Hazard Mitigation Program (WHMP) would influence the bird use of a waste transfer station located near LaGuardia Airport, New York City, New York, USA. We conducted wildlife surveys during 3 phases: (1) no mitigation program and no waste transfer station, (2) active mitigation and no waste transfer station, …

Collective Effect Of Landfills And Landscape Composition On Bird–Aircraft Collisions, Morgan Pfeiffer, Bradley F. Blackwell, Travis L. Devault

United States Department of Agriculture Wildlife Services: Staff Publications

Ninety-three percent of all reported bird strikes occur below 1,067 m, which based on the typical approach and departure angles of aircraft is within 8–13 km of an airport. Concomitantly, the Federal Aviation Administration and the International Civil Aviation Organization recommend that any feature that would attract hazardous wildlife to the approach and departure airspace be restricted. Thus, preventing the establishment of wildlife attractants, such as municipal solid waste landfills (MSWLFs) within 8 km or 13 km extents (U.S. and international recommendations, respectively) of airports, has been recommended to mitigate the risk of bird–aircraft collisions (strikes). However, robust evidence linking …

The Current State Of Research On The Global Amphibian Epidemic, Chytridiomycosis: A Systematic Literature Review And View Into The Future Of The Field, Emily Dealto

Independent Study Project (ISP) Collection

Recent years have shown a rapid decline in global frog populations. Among other issues, one main cause of these declines has been linked to chytridiomycosis, a disease caused by the fungus Batrachochytrium dendrobatidis, or Bd. The discovery of this fungus is relatively recent in the field of herpetology, and thus there is much still unknown about the disease such as its distribution and what causes certain areas and species to be more susceptible to it. A systematic literature review was conducted to see where the state of the research is currently, in order to gain a better view of the …

Water-Electricity-Light System: Technology Innovations, Paul M. Cabacungan, Gregory L. Tangonan, Nerissa G. Cabacungan

Environmental Science Faculty Publications

This paper presents the design of the Water-Electricity-Light System (WELS) that is an integration of technologies composed of rain catcher, mechanical filter and UV irradiation, solar panel, charge converter, LED light, inverter and car battery. We traced back its development from a bulky and expensive system that was meant to generate drinking water into a more innovative water cleaning system that integrated lighting and cellphone charging. We tracked the improvements applied to the system to make the design more efficient yet simple enough to be replicated and customized in order to address varied needs. We shared the alterations made to …

Testing A Key Assumption Of Using Drones As Frightening Devices: Do Birds Perceive Drones As Risky?, Conor C. Egan, Bradley Blackwell, Esteban Fernández-Juricic, Page E. Klug

United States Department of Agriculture Wildlife Services: Staff Publications

Wildlife managers have recently suggested the use of unmanned aircraft systems or drones as nonlethal hazing tools to deter birds from areas of human-wildlife conflict. However, it remains unclear if birds perceive common drone platforms as threatening. Based on field studies assessing behavioral and physiological responses, it is generally assumed that birds perceive less risk from drones than from predators. However, studies controlling for multiple confounding effects have not been conducted. Our goal was to establish the degree to which the perception of risk by birds would vary between common drone platforms relative to a predator model when flown at …

Antibiotic Resistance In Bacteria From Songbirds And Fitness Studies Following Environmental Stressors In Vitro, Leah R. Forsyth

LSU Master's Theses

Since their initial discovery in 1928, antibiotics have been utilized for agriculture and human health purposes. The increasing use of antibiotics by humans and the rapid evolution of antibiotic resistance might be leading to the presence of more antibiotic-resistant bacteria in the environment. Understanding potential relationships between humans, bacteria, and the environment is important in order to study the spread and progression of antibiotic resistance in bacteria. Several past studies have focused on oxidative stress, temperature stress, and antibiotic resistance in bacteria, but to my knowledge few if any have done a wide comparison between these environmental stressors and the …

Factors Affecting Bait Site Visitation: Area Of Influence Of Baits, Jacquelyn E. Mcrae, Peter E. Schlichting, Nathan P. Snow, Amy J. Davis, Kurt C. Vercautern, John C. Kilgo, David A. Keiter, James C. Beasley, Kim M. Pepin

United States Department of Agriculture Wildlife Services: Staff Publications

ABSTRACT Baiting is a fundamental strategy for the global management of wild pigs (Sus scrofa); however, little information exists on how anthropogenic bait affects wild pig movements on a landscape. We investigated factors that are important in determining the spatial area of attraction for wild pigs to bait (‘area of influence’ of a bait site) using data from Global Positioning System (GPS) collars and locations of bait sites. We monitored movements of wild pigs in 2 distinct study areas in the United States from February to September 2016 and used locational data using GPS collars to analyze the influence of …

A Rapid Population Assessment Method For Wild Pigs Using Baited Cameras At 3 Study Site, Peter E. Schlichting, James C. Beasley, Raoul K. Boughton, Amy J. Davis, Kim M. Pepin, Michael P. Glow, Ryan S. Miller, Kurt C. Vercautern, Jesse S. Lewis

United States Department of Agriculture Wildlife Services: Staff Publications

Reliable and efficient population estimates are a critical need for effective management of invasive wild pigs (Sus scrofa). We evaluated the use of 10‐day camera grids for rapid population assessment (RPA) of wild pigs at 3 study sites that varied in vegetation communities and wild pig densities. Study areas included Buck Island Ranch, Florida; Tejon Ranch, California; and the Savannah River Site, South Carolina, USA, during 2016–2018. Rapid population assessments grids were composed of baited camera traps spaced approximately 500 or 750 m apart. Two RPA grids were deployed per study site and each grid was deployed twice (4–6 months …

Relationships Between Survival And Habitat Suitability Of Semi- Aquatic Mammals, Isidro Barela, Leslie M. Burger, Jimmy Taylor, Kristine O. Evans, Ryo Ogawa, Lance Mcclintic, Guiming Wang

United States Department of Agriculture Wildlife Services: Staff Publications

Spatial distribution and habitat selection are integral to the study of animal ecology. Habitat selection may optimize the fitness of individuals. Hutchinsonian niche theory posits the fundamental niche of species would support the persistence or growth of populations. Although niche-based species distribution models (SDMs) and habitat suitability models (HSMs) such as maximum entropy (Maxent) have demonstrated fair to excellent predictive power, few studies have linked the prediction of HSMs to demographic rates. We aimed to test the prediction of Hutchinsonian niche theory that habitat suitability (i.e., likelihood of occurrence) would be positively related to survival of American beaver (Castor canadensis), …

Effects Of Inactivated Mycobacterium Bovis Vaccination On Molokai-Origin Wild Pigs Experimentally Infected With Virulent M. Bovis, Pauline Nol, Morgan Wehte, Richard A. Bowen, Suelee Robbe-Austerman, Tyler Thacker, Kristina Lantz, Jack Rhyan, Laurie A. Baeten, Ramón A. Juste, Iker A. Sevilla, Christian Gortazar, Joaquín Vicente

United States Department of Agriculture Wildlife Services: Staff Publications

The wild pig population on Molokai, Hawaii, USA is a possible reservoir for bovine tuberculosis, caused by Mycobacterium bovis, and has been implicated in decades past as the source of disease for the island’s domestic cattle. Heat-inactivated vaccines have been effective for reducing disease prevalence in wild boar in Spain and could prove useful for managing M. bovis in Molokai wild pigs. We designed an experiment to test this vaccine in wild pigs of Molokai genetics. Fifteen 3–4-month-old pigs were orally administered 10⁶–10⁷ colony forming units (cfu) of heat-inactivated M. bovis (Vaccinates; n = 8; 0.2 …

Rabies Management Implications Based On Raccoon Population Density Indexes, Dennis Slate, Brandi D. Saidy, Ashlee Simmons, Kathleen M. Nelson, Amy Davis, Timothy P. Algeo, Stacey A. Elmore, Richard B. Chipman

United States Department of Agriculture Wildlife Services: Staff Publications

An estimate or index of target species density is important in determining oral rabies vaccination (ORV) bait densities to control and eliminate specific rabies variants. From 1997–2011, we indexed raccoon (Procyon lotor) densities 253 times based on cumulative captures on 163 sites from Maine to Alabama, USA, near ORV zones created to prevent raccoon rabies from spreading to new areas. We conducted indexing under a common cage trapping protocol near the time of annual ORV to aid in bait density decisions. Unique raccoons (n = 8,415) accounted for 68.0% of captures (n = 12,367). We recaptured raccoons 2,669 times. We …

Economic Estimates Of Invasive Wild Pig Damage To Crops In 12 Us States, Sophie Mckee, Aaron Anderson, Keith Carlisle, Stephanie A. Shwiff

United States Department of Agriculture Wildlife Services: Staff Publications

We report the results of a survey on invasive wild pig (Sus scrofa L.) damage and control in 12 US states (Alabama, Arkansas, California, Florida, Georgia, Louisiana, Mississippi, Missouri, North Carolina, Oklahoma, South Carolina, and Texas). The crops chosen for this study represent the “second-tier” in terms of economic importance after the six crops that were the subject of Anderson et al. (2016). The survey was distributed by the USDA National Agricultural Statistical Service (NASS) in the summer of 2019 to a sample of producers in each of the states (except California) of the following six crops: hay, pecans (Carya …

Individual And Population Fitness Consequences Associated With Large Carnivore Use Of Residential Development, Heather Johnson, David L. Lewis, Stewart W. Breck

United States Department of Agriculture Wildlife Services: Staff Publications

Large carnivores are negotiating increasingly developed landscapes, but little is known about how such behavioral plasticity influences their demographic rates and population trends. Some investigators have suggested that the ability of carnivores to behaviorally adapt to human development will enable their persistence, and yet, others have suggested that such landscapes are likely to serve as population sinks or ecological traps. To understand how plasticity in black bear (Ursus americanus) use of residential development influences their population dynamics, we conducted a 6-yr study near Durango, Colorado, USA. Using space-use data on individual bears, we examined the influence of use of residential …

Effects Of Deepwater Horizon Oil On Feather Structure And Thermoregulation In Gulls: Does Rehabilitation Work?, Katherine Horak, Nicole L. Barrett, Jeremy W. Ellis, Emma M. Campbell, Nicholas G. Dannemiller, Susan A. Shriner

United States Department of Agriculture Wildlife Services: Staff Publications

Impacts of large-scale oil spills on avian species are far-reaching.While media attention often focuses on lethal impacts, sub-lethal effects and the impacts of rehabilitation receive less attention. The objective of our study was to characterize effects of moderate external oiling and subsequent rehabilitation on feather structure and thermoregulation in gulls. We captured 30 wild ring-billed gulls (Larus delawarensis) and randomly assigned each individual to an experimental group: 1) controls, 2) rehabilitated birds (externally oiled, rehabilitated by washing), or 3) oiled birds (externally oiled, not rehabilitated). We externally oiled birds with weathered MC252 Deepwater Horizon oil (water for controls) …

Migratory Flyways May Affect Population Structure In Double‐Crested Cormorants, Steven J.A. Kimble, Brian S. Dorr, Katie C. Hanson-Dorr, Olin E. Rhodes Jr., Travis L. Devault

United States Department of Agriculture Wildlife Services: Staff Publications

Double‐crested cormorants (Phalacrocorax auritus) recovered from a demographic bottleneck so well that they are now considered a nuisance species at breeding and wintering grounds across the United States and Canada. Management of this species could be improved by refining genetic population boundaries and assigning individuals to their natal population. Further, recent radio‐telemetry data suggest the existence of Interior and Atlantic migratory flyways, which could reduce gene flow and result in substantial genetic isolation. In this study, we used 1,784 individuals collected across the eastern United States, a large panel of microsatellite markers developed for this species, and individuals banded as …

Rainfall, Precipitation, And Drought Patterns Associated With Wintertime Transmission Of Eastern Equine Encephalitis Virus (Eeev) In Florida, Bestami Cevher

USF Tampa Graduate Theses and Dissertations

Eastern Equine encephalitis virus (EEEV) is a highly pathogenic alphavirus that causes disease in humans and horses. EEEV cases are common in the eastern North America, especially in horses in the State of Florida. EEEV cases are most common in Florida during May to August but also occur year-round, unlike most other locations. According to the Florida Department of Health, 65 EEEV horse cases were documented in the winter months between 2005 and 2018. This study investigates the meteorological activities that affect the wintertime transmission of the EEEV virus to horses. In this, we examined meteorological data up to a …

Optimal Bait Density For Delivery Of Acute Toxicants To Vertebrate Pests, Kim M. Pepin, Nathan P. Snow, Kurt C. Vercauteren

United States Department of Agriculture Wildlife Services: Staff Publications

Oral baiting is a fundamental method for delivering toxicants to pest species. Planning baiting strategies is challenging because bait-consumption rates depend on dynamic processes including space use and demographics of the target species. To determine cost-effective strategies for optimizing baiting, we developed a spatially explicit model of population dynamics using field-based measures of wild-pig (Sus scrofa) space use, bait consumption, and mortality probabilities. The most cost-effective baiting strategy depended strongly on the population reduction objective and initial density. A wide range of baiting strategies were cost-effective when the objective was 80% population reduction. In contrast, only a narrow range of …

Brodifacoum Residues In Fish Three Years After An Island-Wide Rat Eradication Attempt In The Tropical Pacific, Shane R. Siers, Aaron B. Shiels, Steven F. Volker, Kristen Rex, William C. Pitt

United States Department of Agriculture Wildlife Services: Staff Publications

Invasive rats are known to threaten natural resources and human health and safety. Island-wide rat eradication attempts have been increasing in number and scale during the past several decades, as has the frequency of eradication success. The most common method to remove all rats from an island is to broadcast anticoagulant rodenticide bait into every rat’s home range on the island. Broadcast of toxicants can put humans and other nontarget species in marine and terrestrial environments at risk of exposure. The persistence of anticoagulant residues is somewhat unknown, particularly in marine environments. Three years after ~ 18,000 kg of 25 …

Predicting Livestock Depredation Risk By African Lions (Panthera Leo) In A Multi-Use Area Of Northern Tanzania, K. Beattie, E. R. Olson, B. Kissui, A. Kirschbaum, C. Kiffner

United States National Park Service: Publications

Human-wildlife conflicts, especially those involving large carnivores, are of global conservation and livelihood concern and require effective and locally-adapted prevention measures. Risk of lion attack on livestock (i.e. depredation) may vary seasonally and may be associated with variation in wild prey abundance or landscape characteristics. To test these competing hypotheses, we used a resource selection approach, and determined whether prey catchability (indicated by geo-spatial variables), or prey availability (indicated by modeled abundance recorded via camera traps) explained spatial and seasonal variation in livestock depredation risk by African lions on Manyara Ranch Conservancy, a multi-use area in northern Tanzania. Seasonal variation …

Local Adaptation Constrains Drought Tolerance In A Tropical Foundation Tree, Kasey E. Barton, Casey Jones, Kyle F. Edwards, Aaron B. Shiels, Tiffany Knight

United States Department of Agriculture Wildlife Services: Staff Publications

1. Plant species with broad climatic ranges might be more vulnerable to climate change than previously appreciated due to intraspecific variation in climatic stress tolerance. In tropical forests, drought is increasingly frequent and severe, causing widespread declines and altering community dynamics. Yet, little is known about whether foundation tropical trees vary in drought tolerance throughout their distributions, and how intraspecific variation in drought tolerance might contribute to their vulnerability to climate changE.
2. We tested for local adaptation in seedling emergence and establishment with a full-factorial reciprocal transplant experiment including 27 populations and 109,350 seeds along a 3,500 mm precipitation gradient for …